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Final Report 1999/2000
SPECIES-RICH GRASSLANDS
(=BD14)
Valerie K Brown
Programme Advisor for Assessment Unit
Contents
Page
1. Executive Summary
3
2. Rationale for Assessment Unit
4
3. Scientific Objectives and Structure of the AU
4
4. Approach Adopted by the Programme Advisor
5
5. Review of Ongoing Projects
(pagination for individual projects - page 2)
5
6. Annual Meeting
34
7. General Comments and Recommendations
40
Appendix 1. Programme Advisor: Terms of Reference
42
Appendix 2. Programme for Annual Meeting
43
Appendix 3. Invitees to the Annual Meeting
44
Confidential annex: Priorities for Future Research
(Report covers the period 1:4:99 - 31:3:00, submitted to MAFF: 31 March 2000)
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Contents: Review of Ongoing Projects
Project
Number (BD)
Abbreviated Title
Page Number
Monitoring and methodology
1412
Sward based guidelines
6
1427
Effects of ELMs on butterflies
7
1429
Soils/vegetation - ESAs
9
1433
Seed characteristics (review)
10
Management/restoration/enhancement of existing grassland
1402/3
Multisite experiment
12
1408
Northern hay meadows
14
1415
FYM
16
1424
Upland ESAs
18
1425
Techniques to increase biodiversity
19
1431
Multisite extension
21
1435
Grassland birds and invertebrates
22
1436
Brown Hare
24
1440
Sustainable grazing management
26
Recreation of grassland on ex-arable land
1403/4
Multisite experiment
27
1410
Seed mixtures
28
1414
Chalk grasslands
30
1431
Multisite extension
32
1434
Chalk grassland restoration
32
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1. Executive Summary
This report details the science in the Species-Rich Grassland Assessment Unit (AU) and its
relevance to MAFF. The report is based on the second year of activity of the Programme
Advisor, Valerie Brown, in respect of Terms of Reference developed by MAFF.
The AU aims to develop practical, cost-effective guidelines on the conservation,
enhancement and restoration of species-rich grassland, by the use of monitoring and
experimental research. The results are applicable to Environmental Land Management
Schemes (ELMS), especially Environmentally Sensitive Areas (ESAs) and the Countryside
Stewardship (CS) scheme, in order to provide the effective targeting of sites and
implementation of the schemes.
There are currently 15 R&D projects in the AU, although a further 7 were completed as of
31:03:99. The projects can be broadly categorised under three themes: (i) monitoring and
methodology, (ii) management, restoration and/or enhancement of existing grassland and
(iii) re-creation of grassland on ex-arable land. Most projects focus on the vegetation
dynamics of a range of grassland types, in different parts of England and Wales. However,
during this year, more projects involving other organisms and their interactions with plants
have been initiated, thereby providing a more holistic approach to the subject. Indeed, the
multidisciplinary nature of several of the projects is refreshing and relevant. Related to this
approach is the increase in consortium-based projects, which not only provide synergism
between the scientists, but provide MAFF with excellent value for money.
The science of the AU is developing very well, with some significant new projects being
commissioned during the year. Several of these projects involve long-term experimental
work. The inclusion of such projects is a valuable step forward as, by nature, many
changes in biodiversity are slow to manifest themselves. In particular, attempts to enhance
biodiversity value often gain momentum with time. Thus, much added value and relevance
is accrued by virtue of a slightly longer experimental period. The increased emphasis in the
AU on experimental manipulation enables the mechanisms underpinning changes in
biodiversity to be addressed and thereby permits reasoned generalisations, the confident
development of predictions and/or guidelines and an increase in scientific rigour. Several of
the projects contribute to MAFF’s obligation to the UK Biodiversity Action Plan. The
inclusion of projects from the Wildlife Conservation in the Wider Countryside R&D
Programme has increased the size and scope of the AU and is a welcome rationalisation.
The report is based on field visits to experimental work, wherever feasible, and with as many
contributing scientists in attendance as possible. Although 7 projects reached their end date
just before the contract for the Programme Advisor began, 5 of these have been reviewed
and are included in the report as agreed by Mr R. Brand-Hardy. For each project, following
some general introductory comments, scientific objectives and progress, in terms of key
results and achievements against milestones, are reviewed. These items are followed by
mention of the relevance of the science to MAFF policy. By an overview of the AU, some
priority areas for future research have been forthcoming. Some general recommendations
on the scope and implementation of the AU are included.
The uptake by MAFF of new areas of research, to address specific issues of relevance to its
policy, is important. The science being undertaken is generally of a high standard and is
undertaken by a committed group of scientists. The cohesion provided by the co-ordination
of the AU has enabled free exchange of ideas and needs between MAFF and the scientific
community. The second annual meeting of the AU was again successful and very well
supported by contractors, representatives of MAFF, FRCA and other relevant organisations.
The meeting focused on arable reversion and featured a range of projects and a structured
discussion forum.
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MAFF’s acknowledgement of the importance of scientific understanding of the diversity and
function of the grassland ecosystem, within the agri-environment, is to be commended.
Further, its contribution to the broader remit of the EU should not be underestimated.
2. Rationale for Assessment Unit
The area and quality of species-rich grassland has declined as a result of intensive
agricultural practice.
Environmental Land Management Schemes (ELMS), such as
Environmentally Sensitive Areas (ESAs) and Countryside Stewardship (CS), offer options
for the re-creation, restoration and management of species-rich grasslands to enhance
biodiversity.
Research in the AU focuses on the development and refinement of
management guidelines to restore, conserve and enhance the biodiversity of such
grasslands, in a manner which is cost-effective to the farmer and the Exchequer. Such
research is timely and highly pertinent to the UK Biodiversity Action Plans for both species
and habitats.
It also provides essential scientific underpinning for improving the
effectiveness of the ESA and CS schemes and for framing future regulations and subsidy
schemes, thereby enabling MAFF to discharge its responsibilities under the Agrienvironment Regulation 2078/92.
3. Scientific Objectives and Structure of the AU
The principal scientific objective is to develop practical, cost-effective guidelines on
conservation, enhancement and restoration of species-rich grassland, which can be broadly
applied to improve the effectiveness of the ESA and CS schemes. This is achieved
through:
i) quantification of the impact of different management techniques on species diversity;
ii) assessment of management measures and procedures for enhancing botanical
diversity of grassland;
iii) assessment of management methods for re-creating species-rich grassland on arable
land and quantification of the effect of reversion on flora and fauna.
The structure of the AU reflects these goals, such that the 20 contracts included in this
report can conveniently be categorised under 3 areas of work, though some projects include
an element of (i) with (ii) or (iii):
i)
ii)
monitoring, methodology, review (BD1412, BD1427, BD1429, BD1433);
management/restoration/enhancement of existing grassland involving intervention
(BD1402, BD1403, BD1408, BD1414, BD1415, BD1424, BD1425, BD1431, BD1435,
BD1436, BD1440);
iii) re-creation of grassland on ex-arable land (BD1403, BD1404, BD1410, BD1414,
BD1431, BD1434).
Research is being undertaken in a range of grassland habitats with good geographical
coverage in England and Wales.
The number of contractors involved in the AU has increased and includes some new
organisations. More projects are involving consortia of organisations, thereby facilitating a
multidisciplinary approach and an understanding of interactions between the vegetation and
soil characteristics and dynamics, plant-animal interactions and animal-animal interactions.
Understandably, early emphasis in the AU was on vegetation dynamics, often including
some assessment of agronomic measures. This year has seen the inclusion of three
projects from the Wildlife Conservation in the Wider Countryside R&D Programme into the
AU. All three involve animals: BD1427 butterflies, BD1435 bird/invertebrate interactions and
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BD1436 the Brown Hare. Indeed, the inclusion of these projects in BD14 has done much to
balance the research programme. Projects involving different trophic levels are often
important in addressing mechanisms of change and in providing additional indicators of
biodiversity value and dynamics. For example, BD1435 provides an opportunity to explore
plant/invertebrate/bird interactions providing potential for a full appreciation of species
interactions and underpinning mechanisms. In this way, not only reasons for declining
biodiversity value are determined, but pointers to reversing this decline.
4. Approach Adopted by the Programme Advisor
With the exception of projects involving literature review (BD1433), multisite survey
(BD1429) and BD1410, meetings with contractors have taken place in association with a
visit to relevant field site(s). Where applicable, all members of research teams have been
present. This approach has lead to a fruitful exchange of scientific ideas and enabled a
rigorous assessment of the results and relevance of the research. It has been welcomed by
the contractors and has also proved invaluable in assessing comparability between sites in
multisite experiments and in the evaluation of methodology and of techniques for
enhancement/restoration. For the multi-site experiments, visits to different sites from those
visited last year have enabled a more complete appreciation of site responses and
characteristics.
Relevant follow-up to meetings, sometimes in the form of provision of information, reprints
and dialogue has taken place. Emphasis has been on scientific rigour and quality, progress
in relation to milestones, relevance to MAFF policy and the dissemination of results. In the
context of the latter, site visits and workshops have been discussed and encouraged, and
several have taken place this field season.
All contractors have been very co-operative in accommodating visits and appear to have
appreciated the informal, frank discussion and exchange of ideas/plans. Indeed, the
ongoing dialogue from 1998/1999 has been very valuable and enabled greater insight into
the project’s implementation, outcome and relevance to MAFF.
All Heads of
Stations/Institutes have been kept informed of meetings and have responded very positively.
5. Review of Ongoing Projects
Projects are discussed in ascending project code order, under the three areas of work
(defined on Page 4). For each project, some general comments are made, especially
pertaining to the stage of the project and changes in scientific leadership. Following this,
the specific objectives are cited (as given in the CSG7) and a review of scientific progress.
The latter relates to discussion at the time of the site visit/meeting. The reports are not
intended to be exhaustive, but to give insight into future developments (for new projects) or
a summary of key results for established projects. The reports are a little more
comprehensive than in the 1998/99 report, especially those for completed. As requested by
MAFF, progress against milestones is given. These have been updated wherever possible.
Monitoring and Methodology
BD1412: Development of sward based guidelines for management of grassland in
ESAs and CS (Dr Mike Burke, ADAS Wolverhampton)
General
The project aims to develop and field test guidelines for assessing vegetation in ESAs and
CS, based on characteristics of the sward. It is an ADAS led project with Dr Mike Burke the
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lead contractor (having replaced Mr Steve Peel) and with Dr Iain Diack undertaking much of
the field survey.
Objectives
Overall: To develop a new framework of guidelines for management of grazed grassland in
ESAs and CS, which enables viable livestock production systems to be continued, whilst
examining environmental benefits.
Specific:
1. Identify, by review and consultation with relevant organisations, techniques of sward
measurement and management guidelines based on them.
2. Assess the potential for use of these techniques alongside assessments of sward
structure, stocking levels and livestock performance. This will take into account the
effectiveness of the techniques in enabling objectives to be met, and their ease of use.
3. Test the most promising techniques with a range of users on key types of enclosed
grassland in different geographical locations.
4. Recommend a framework of sward-based guidelines for the management of grassland,
which can be modified to facilitate the achievement of objectives across the whole
range of ESAs and CS.
5. Undertake preliminary field-testing of framework.
Progress
Following a comparison at 10cm and 30cm drop discs and the HFRO sward stick on a range
of semi-natural grassland types, the sward stick was selected as the preferred instrument
for sward height measurement. The sward stick was found to be more sensitive to sward
heterogeneity, more portable and thought likely to give greater objectivity. Measurements
using the sward stick were taken at monthly intervals on a sample of 21 well-managed seminatural grassland sites (mostly NNRs and SSSIs), representing a range of different
grassland types on calcareous, acidic and neutral soils.
Results suggested 30 measurements within a field were usually sufficient to give a
reasonably accurate estimate of the mean sward height throughout the year. Variability was
generally found to be correlated with the mean, ie the taller the sward, the greater the
variability. Variability changed in certain sites over the year, while the mean remained
relatively consistent.
Sward height measurements continued on 10 of the 21 original sites, in addition to bare
ground, an assessment of the cover of non grasses and that of species of interest (eg
weeds, or tussock-forming species). The latter provides some indication of the species
composition, and hence nature conservation value of the sward. An inter-observer trial was
also undertaken, which compared measurements of sward height, bare ground and herb
cover on 2 contrasting sites.
Based on the results of sward measurement exercises, consultation and a literature review,
draft guidelines for management of grassland have been produced. A draft framework has
been circulated to FRCA project officers.
Milestones
Relevant milestones have been met.
Relevance to MAFF
MAFF is keen to encourage the establishment of management agreements within ESA and
CS that are more flexible and able to take into account site specific objectives. This
provides the opportunity to tailor management agreements to the needs and potential of
individual sites and thus maximise the benefits provided by the agri-environment schemes.
This project aims to establish a framework, within which grazing management guidelines are
defined in a consistent, objective and precise manner in terms of sward structure and
composition.
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A visit to one of the field sites (Aston Rowant) was made on 28 July 1999. Mike Burke
and Iain Diack were present.
-----BD1427: Developing a system for assessing the effect of agri-environment schemes
on butterfly populations (Dr Martin Warren, Butterfly Conservation)
General
This is a new project within the AU that aims to develop a system for assessing the effect of
agri-environment schemes on butterfly populations. The project utilises the extensive
dataset from a network of sites monitored by volunteers and co-ordinated by Butterfly
Conservation’s local branches.
Although categorised as a monitoring project, the creative development of methodology and
synthesis for data collation and analysis is an integral part of the project.
Objectives
1. To collate existing butterfly transect data being collected by Butterfly Conservation and
other volunteers and examine the proportion of sites subject to agri-environment
scheme management.
2. To develop appropriate analytical methods to identify population trends within agrienvironment schemes, especially priority species identified within the UK Biodiversity
Action Plan.
3. To analyse monitoring data and identify trends within and outside agri-environment
scheme agreement land.
4. To examine the effects of habitat management on butterfly populations and, if
necessary, make recommendations to improve scheme prescriptions.
5. To provide feedback on the effects of scheme management on individual sites to
project officers, recorders and agreement holders.
6 To develop the network of butterfly transects and assess their long-term potential for
monitoring butterfly populations in agri-environment schemes.
Progress
This 3.5 year project began in October 1998. It focuses on an attractive, popular, yet
declining group of insects, the butterflies. Butterflies, in many respects, make ideal indicator
species, as they respond rapidly to changes in their habitat and its management. The
project is totally dependent on the monitoring activities of volunteers, which are co-ordinated
by Butterfly Conservation. The monitoring methodology adopted at a large number of field
sites is by using walked transects and, since it is generally only able and committed
volunteers who enter the scheme, the quality of data is high. The project is ambitious in that
it involves the collation of an enormous data set, based on (at the start of the project) some
350 transects in different habitats and locations. It is developing this means of collating a
somewhat disparately held data set, and the solution of problems of data entry and
exchange, which has been the major focus of activity thus far. However, responses from
volunteers have revealed a far greater data resource than was envisaged, with some 700
transects being notified.
For example, before this study began, 14 transects in
Warwickshire were known to be recorded by volunteers, whereas the real figure is 45! Initial
collation of, mainly, county data sets is undertaken by local branch co-ordinators, though
staff involved in this project have provided data sheets and are developing computer
software to aid this process. From accurate grid references of the transects, it should be
possible to divide these into those which are within agri-environmental scheme agreements
and those outside. The aim is then to compare population trends in areas in and out of
schemes. Since many of the data sets are long-term, it may well be possible to show the
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effect of entering the scheme. Clearly, care needs to be taken at this stage, since there are
no true ‘controls’. However, this is well appreciated by the scientists involved.
One of the significant objectives of the project is to disseminate the knowledge gained,
either of general trends or of site specific ones, to enable management prescriptions to be
fine tuned. The project is already interfacing well with FRCA project officers and other land
management advisors.
Feedback at the local level has potential to enhance the
environmental quality of sites still further, even though samples may then become
unrepresentative.
Much time was spent during the meeting on prioritising those tasks likely to produce
maximum return to MAFF. Bearing in mind the status of the project, within BD14, a focus
on sythesising data from grassland habitats will be made initially. Indeed, this will highlight
gaps where future transects might be sought. Methods of analyses of population trends are
being explored with an active and ongoing dialogue with the Dutch Butterfly Monitoring
Scheme.
At present, volunteers only record butterflies within a general habitat type. To relate more
tightly to changes in management imposed by agri-environment schemes, records of
vegetation characteristics are also being made. A means of standardising these records is
important.
Milestones
There are no primary milestones for this period. Relevant secondary milestones (501/01,
501/02) have been met as far as collating data from volunteers, via Butterfly Conservation
local organisers. The assessment of those sites that are not entered into agri-environment
schemes is an ongoing process and being facilitated by FRCA. 502/01, involving dialogue
with the Dutch Butterfly Monitoring Scheme, has been met fully.
Relevance to MAFF
The project provides excellent value for money for MAFF, as it relies on data collected and,
at least partially, collated by volunteers. The results will provide an index of the effects of
agri-environment schemes on butterfly populations (and by implication those of their larval
food plants). Interaction with the user community is high in this project and will involve
FRCA officers who have access to user-friendly information, often at the site specific scale.
Once the methodology for data collation and analysis has been established, it can be used
for other taxa, at different scales and in different specific habitats. There is potential for
data to be used in the targeting of sites for inclusion in agri-environment schemes, and the
results of the project may also increase awareness/appreciation of schemes.
Visit was made to Butterfly Monitoring Centre, nr. Wareham, Dorset on 11 August
1999.
BD1429: Relationship between soil analysis and vegetation on grasslands (Dr Brian
Chambers, ADAS Gleadthorpe)
General
This project started in April 1995 as a 4-year project based on 16 English ESAs. However,
in April 1997, the contract was extended for a further 4 years to enable the inclusion of 6
Welsh ESAs (as BD0343 under the previous numbering scheme) and is scheduled to
terminate in 2001. The project is collaborative with Dr Nigel Critchley (ADAS Newcastle),
who is responsible for the analysis of the vegetation data.
Objectives
Overall: To evaluate relationships between soil nutrient status and soil pH and the botanical
composition of grasslands in ESAs in England and Wales.
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Specific:
1. To assess the nutrient status and pH of the range of grassland types in ESAs.
2. To establish relationships between soil nutrient status and soil pH, and the botanical
composition of enclosed grasslands in ESAs.
3. To provide guidelines on grassland management, including fertiliser and lime inputs, to
retain or enhance the botanical composition of grasslands in ESAs.
Progress
The project involves sampling and analysis of soils in relation to pH, extractable
phosphorus, potassium, magnesium, total nitrogen and organic matter. The botanical data
are derived as part of the ESA monitoring programme and sourced from the ESA archive.
Establishment of the archive was commissioned by MAFF to ADAS. However, some delays
in access were experienced by the project scientists. These have contributed to the delay in
submitting the Phase 1 report to MAFF. Indeed, data from the Broads ESA has not been
included in this report, due to data corruption through software problems and will be
submitted as an addendum at a later stage. A synthesis of soil nutrient status and soil pH
and vegetation of 14 English ESAs has revealed trends that are clear and interesting in their
predictability.
Seven main vegetation types (calcareous grasslands, mesotrophic
grasslands, acidic grasslands, mires, heaths and woodlands) have been recognised within
38 plant communities, using the framework of the National Vegetation Classification (NVC).
The comprehensive analysis of results has focused on lowland grassland communities, with
samples being assessed in terms of NVC community or subcommunity types. Subsequent
multivariate analysis (Canonical Correspondence) enabled the relationship between plant
communities or subcommunities and soil variables to be investigated. A novel application of
this method (involving communities instead of species) enabled ordination diagrams
(biplots) to illustrate community patterns. Plant community variables explored include
species richness, nutrient score (Nu), stress radius (to provide an assessment of
‘specialisation’ based on plant strategy theory) and niche width as a measure of tolerance of
the plant community. Plant communities reflected closely the soil properties, with pH being
particularly important.
Generally, communities of highest conservation value were
associated with the most extreme soil conditions (eg calcareous and acidic grasslands).
Understandably, there is an inequality in replication of community types, with the
mesotrophic grasslands being particularly well represented. Clear differences in soils and
vegetation were found between improved, semi improved and unimproved grassland,
providing useful evidence for targeting grasslands for enhancement.
As a result of a recommendation by the Review in 1995, an extra calibration experiment was
included in the protocol, which confirmed that relationships between soil properties and plant
species composition are unlikely to be compromised by the collection of soil samples from
outside the quadrats.
Reports for ESA Project Officers have been prepared for the English ESAs and are ongoing
for the Welsh ones, with two having been completed. Feedback from Project Officers would
be welcome and it is hoped that the planned workshop (Milestone 03/02) will provide a
forum for this. The workshop should also enable the implications for management and
recommendations to be fine-tuned.
Soil sampling and analysis for the Welsh ESAs is in progress. The final report will focus on
uplands and include data for the South West Peak ESA. Publication of the project results in
peer-reviewed journals was discussed and procedures identified.
Milestones (as of Nov. 99)
Two of the four Project Officer reports for Wales have been completed. There has
apparently been some delay in the analysis of soil samples from the Welsh ESAs (01/05,
01/06). The report on English Lowlands has been submitted and data on the Upland ESA
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will be included in the report of the Welsh ESAs. The Broads ESA will be provided as an
addendum (03/01). The planned workshop (Milestone 03/02) is an important component of
dissemination of the results of the project.
Relevance to MAFF
A project of this type, understandably, produces a data set with a high degree of inherent
variability (eg in botanical sampling methods, timing of vegetation and soil sampling, size of
samples, etc). However, it is encouraging that patterns, and therefore potential for
recommendations in respect of management and restoration, are forthcoming. These will
be made more robust by the inclusion of the Welsh ESAs. It must, however, be stressed
that the statistical analyses undertaken in this project demonstrate that soil properties only
account for a small proportion of the variation in vegetation in the ESAs.
Meeting, with detailed discussion, took place on 30 November 1999 at ADAS,
Gleadthorpe.
Brian Chambers, Nigel Critchley and John Folbert (both ADAS
Newcastle) were also present.
-----BD1433: A review of the ecological characteristics of wildflower species in relation
to the success of restoration (Dr Richard Pywell, ITE Monkswood)
Project completed 31/03/99, but an extension approved by MAFF.
General
The desirability of this review was identified as a means of increasing the cost effectiveness
and reliability of restoration efforts in species rich grasslands. It was realised that much
information (published and unpublished) existed, the collation of which could provide useful
guidelines for the choice of species in specific situations.
Objectives
1. Identify a large number of case study examples of species-rich grassland restoration
through a review of the scientific literature, and consultation with lead organisations and
practitioners.
2. Derive common measures of successful establishment, survival and dispersal for a wide
range of different wildflower species.
3. Collate ecological attributes of each species from existing autecological information.
4. Compare the relative success of restoration with both the ecological attributes of the
species, and site factors and management practices controlling the processes of
establishment, survival and dispersal.
5. Identify species attributes, site factors and management practices which are positively
and negatively correlated with successful establishment and survival.
6. Provide revised guidelines for the selection of species for the restoration of species-rich
grassland in ESAs and the Countryside Stewardship scheme. Inform policy on the
selection of sites for restoration and management prescriptions.
Progress
Thirty five case studies of species-rich grassland restoration on farmland were identified by
a review of the scientific literature, and consultation with lead organisations and
practitioners. The studies investigated a number of different restoration techniques, on both
ex-arable land and agriculturally improved grasslands, situated on a wide range of soil types
and geographic locations. A total of 132 different wildflower species were introduced into
these studies, although only 58 were sown in more than 5 experiments (13 grasses, 8
legumes and 37 other forbs). An appropriate phylogenetic analysis suggested that grasses
and forbs should be treated separately. A performance index, adjusted to take into account
the frequency of a species inclusion in restoration studies, was calculated. Because of the
short duration of most restoration studies, the temporal trend had to be restricted to 4 years.
10
Individual species showed large differences in the performance indices. Seven species
consistently established and performed well. This group included 5 grass species, Festuca
rubra, Trisetum flavescens, Cynosurus cristatus, Anthoxanthum odoratum and Phleum
pratense, and 2 forbs Leucanthemum vulgare and Achillea millefolium. Similarly, 8 species
consistently performed poorly: the forbs Silaum silaus, Succisa pratensis, Linum
catharticum, Campanula rotundifolia, Filipendula vulgaris, Campanula glomerata, Centaurea
scabiosa and Helianthemum nummularium.
Information on 43 ecological characteristics or traits for each species was derived from a
detailed review of autecological information in the literature and unpublished information.
From an analysis of over 30 of these, for the 45 commonly sown forb species, mean
percentage germination and germination season (autumn) were found to be important
determinants of success. The life-history traits of competitiveness and ruderality also
significantly enhanced establishment in the first year. Spring germination and higher stress
tolerance were significantly associated with poor establishment performance. In subsequent
years, high seed weight and seed germination, autumn germination, high seedling growth
rate and the capability to spread vegetatively were all characteristics significantly associated
with good performance of sown forbs. Competitive ability became an increasingly important
determinant of success with time. Species associated with more fertile habitats in the UK
performed better than those associated with nutrient poor habitats. Similarly, stress
tolerance was increasingly associated with poor performance. In the 13 commonly sown
grass species, ruderality was the only trait associated with a significant increase in
performance. Grass species associated with high fertility habitats showed a significant,
negative trend in performance over the 4 years. However, characteristics other than seed
traits are also important, and reflect the wide environmental variation between sites and
between different start-up years. Unfortunately, there was insufficient information on the
provenance of the introduced propagules in the case studies to allow an analysis of its
effect.
Initial land use and subsequent management both had an important influence on the
performance of sown species in restoration schemes. Establishment and early performance
of species were, on average, significantly higher on sites where the land use was ex-arable,
compared to agriculturally improved grassland. Similarly, the establishment performance of
species was significantly higher on sites managed by cutting alone compared to those
managed by cutting and grazing in combination. In subsequent years, there were no
differences in performance due to management.
The review has demonstrated that it is possible to use performance indices and ecological
trait analysis to predict the establishment success of species. However, there are dangers
associated with the over-prescriptive use of such performance indices. Their use will lead to
a uniformity of restored grassland communities across Britain, some of the poor performing
species are desirable and constant components of diverse ‘target’ vegetation communities
described by the NVC and also foodplants for specialist invertebrate species.
Milestones
I understand a final report has now been submitted.
Relevance to MAFF
Reliable and effective methods of enhancing and restoring biodiversity to the countryside
are essential to the achievement of the key policy objectives of the agri-environment
schemes and the UK Biodiversity Action Plans. Since many of these involve the introduction
of seeds, a greater understanding of the ecological characteristics of the species being
introduced and the processes influencing their germination, establishment and persistence
is invaluable in targeting those species most likely to establish successfully in particular
situations.
11
Project was fully discussed with Richard Pywell during a visit to the Multisite
experiment site on the Norfolk Broads on 19 July 1999.
Management / Restoration / Enhancement of Existing Grassland
BD1402 and BD1403: Multi-site experiments on the restoration of herb-rich meadows
- grassland enhancement (Mr Alan Hopkins, IGER North Wyke and Dr Mike Burke,
ADAS Wolverhampton)
Project completed 31/03/99.
General
This was one of two major multi-site experiments initiated in 1994 and focused on
experimental techniques to grassland diversification (the parallel experiment focuses on
arable reversion). The project was organised, such that A. Hopkins co-ordinated the project
and was responsible for ensuring standardisation of methodology, data collation, analysis
and interpretation of results. Both Contract Officers were responsible for the site
management and data recording of selected sites. The chemical analyses were undertaken
by ADAS. Dr Burke assumed responsibility for the ADAS contribution from Mr S. Peel in
mid 1998. The sites were managed by IGER and ADAS; each team was responsible for
three sites.
Objective
To identify management procedures for markedly increasing botanical diversity of existing
grassland swards in ESAs, over a time span of 3-5 years. The work builds on existing
knowledge and techniques, but explores their application and success in a range of
circumstances in different ESAs.
Progress
The project explored different methods for increasing the botanical diversity of permanent
grassland. Its novelty and strengths resided in the multi-site approach, in which identical
field experiments were established in six sites on commercial farms in ESAs. Three sites
were on calcareous soils (South Downs, South Wessex Downs and Pennine Dales) and
three on neutral/acidic soils (Somerset Levels, Blackdown Hills and Radnor Forest). The
species selected for introduction were based on appropriate NVC end points (viz. MG5 for
mesotrophic sites and CG2/3 for calcareous sites). Using a randomised block design, the 6
treatments (each replicated 4 times) were control (with no intervention), strip seeding or
oversowing: following sward disturbance by light harrowing, partial rotovation or turf
removal, or by introducing plug plants. The seed mixtures for the oversown treatments
comprised 35-40 species (18 forbs and 5 grass species common to the six sites). Twelve
species were introduced as plug plants. Species lists are given as appendices in the Final
Report to MAFF. All trials were established in 1994 and monitored for 3 years (1995-1998).
Sites were managed in accordance with local ESA guidelines (simulated hay cutting from
mid July, grazing in autumn and early spring with no inputs). The major output is in the form
of detailed records of botanical composition, assessed by the presence/absence of
individual species in three randomly positioned, 40 x 40cm quadrats (divided into 16 cells).
The changes in botanical composition have been well documented in a paper by Hopkins A,
Pywell RF, Peel S, Johnson RH and Bowling PJ (1999) "Enhancement of botanical diversity
of permanent grassland and impact on hay production in Environmentally Sensitive Areas in
the UK" Grass and Forage Science 54: 163-173. In summary, significant changes in
12
botanical composition occurred during the course of the experiment, with individual species
displaying a range of responses (establishing well and consistently between sites, failing to
establish or establishing only in particular sites or treatments). It is encouraging that a
subset of species (eg Achillea millefolium, Prunella vulgaris, Leucanthemum vulgaris,
Plantago lanceolata) has established and the species are expanding their range. The most
significant changes occurred in the deturfed treatment, especially when the nutrient status of
the site was low (eg Radnor), or when the experiment was implemented on a heavily grazed
sward. Generally, strip seeding and light harrowing were of limited success, while partial
rotovation, to give 50% bare ground, was more successful. The transplantation (in autumn)
of modular growth plug plants proved successful in terms of establishment per se, but only
gave rise to an increase in species richness in those sites with lower productivity.
The variable response of individual plant species is to be expected. More significant is the
positive message that, under the ‘right’ conditions, highly desirable species (eg Cowslip
(Primula veris), Harebell (Campanula rotundifolia) and Pimpinella saxifriaga can establish
and even expand their range, in situations of low inherent biodiversity.
Herbage production, as expected, was variable between sites. However, with the exception
of the de-turfed treatment, where productivity was significantly lower, there were no
significant differences between treatments.
Milestones
These have been met and a final report submitted.
Relevance to MAFF
Insight into various methods of enhancing botanical diversity of permanent grasslands has
been provided. Such insight is relevant to assisting MAFF in achieving the goals of ESA
and other agri-environment schemes within a more rapid time frame than through
extensification alone. Results, however, suggest that resources should be focused on small
targeted areas and with appropriate pre- and post sowing site management.
The outcome of this project will be greatly increased in value by its development under
BD1431.
An appreciation of the ecological traits and amplitude (Ξ tolerance of a range of conditions)
is important in providing prescriptions for seed mixtures/plug plants in particular situations.
Methods involving high levels of disturbance, though intuitively undesirable within the
commercial farm environment, may be valuable in providing foci for colonisation on a
broader scale. The spatial configuration of such foci is likely to be important.
Visit took place 12-13 July 1999, to the Radnor Forest site. Alan Hopkins and Peter
Bowling (IGER, Trawsgoed; who manages the site) were present.
-----BD1408: The restoration of diversity to agriculturally improved meadow grassland
(Dr Roger Smith, University of Newcastle upon Tyne)
Project completion 30/05/99
General
The project built on an experiment initiated under the JAEP Initiative. MAFF continued
funding the project for a further 3 years (1996-1999), thereby enabling an 8-year data set.
The project involves an impressive consortium of scientists, each with their individual role,
with the site management being undertaken very effectively by the EN Warden, Peter
Corkhill. The project has been well co-ordinated by Roger Smith.
13
Objectives
Overall: To investigate why there was no rapid increase in plant diversity following the
restoration of traditional management regimes to an agriculturally improved meadow at
Ingleborough in the Pennines.
Specific:
1. To assess how the biomass, activity and structure of microbial populations, and soil
nutrient status, varies with plots of the Ingleborough meadow experiment and to assess
the significance of the experimental treatments on these parameters.
2. To compare data from 1 (above) with existing data from the Upper Teesdale meadow
experiment and from other modern and traditionally managed meadows in northern
England, including the Pennine Dales ESA.
3. To assess the level of VA-mycorrhizal colonisation of the root system of selected plant
species from the Ingleborough meadow experiment and from traditionally managed
meadows in the Pennine Dales ESA.
4. To assess the rate at which plant species richness increases in the Ingleborough
meadow experiment over an 8-year period.
Progress
The experiment at Colt Park, near Ingleborough, initially involved a complex split-split-split
plot experimental design, involving grazing (spring, autumn, spring and autumn), cutting (3
dates: 14 June, 21 July, 1 September), fertilizer (25kg ha-1 N plus 12.5 kg ha-1 P2O5 and
K20) and seed of many ‘typical’ species. There were 3 replicates of each treatment, giving
108 treatment plots. Different plant communities established under the treatments, but took
time to become manifest. After 4 years, there were no treatment differences, while after 6
years differences became clear. The major treatment effects were seen as a result of
combination treatments. For example, a cut date of 21 July, grazed in autumn and spring,
with seed addition, but unfertilised, realised 23 plant species, 10 higher than in the least
successful treatment. The most successful treatments have species characteristic of MG3b
(Anthoxanthum odoratum - Geranium sylvaticum) grasslands. The management of the
experiment, by the EN warden, was very labour intensive. For this reason, at the end of the
third and final field season of the project, it was decided to cease sampling from the single
spring and autumn grazed treatments, by removing the fences, and employ a single cut date
(July 21) throughout.
One of the major contributions of this project was an attempt to explain the mechanisms
underpinning the slow response of the vegetation to the treatments and the differences
between treatments. Of the possible explanations, the project has focused on the
mycorrhizal interactions of plant species and their role, the regeneration of plant species,
the modification of competitive interactions between species as a result of the differential
uptake of N and through colonisation by the hemiparasitic plant species, Rhinanthus minor.
Comparison of experimental treatments at Colt Park with traditionally managed grassland at
the Bowberhead-Piperhole SSSI, Ravenstonedale, demonstrated clear differences in the
level of mycorrhizal colonisation. Generally, mycorrhizal colonisation was impaired in the
experimental treatments compared to the traditionally managed meadow, and in fertilised
compared with unfertilised experimental treatments. An experiment, using Geranium
sylvaticum under FYM, and inorganic fertiliser (at various levels) has demonstrated the
advantage of traditional management for this very typical MG3 species.
Although the original seed input into experimental plots was not recorded, or the resident
seed back at the start of the experiment, it became clear that regeneration phenomena were
driving some of the differences between treatments. Assessment of the seed bank in
1998/9 has produced some insight into the success of various species. Additions of 3
species, typical of the target MG3 community but so far unsuccessful in terms of
colonisation, are planned for 1999, but will fall beyond the scope of current funding.
14
Rhinanthus minor, introduced as seed, spread to most plots and by 1996 was abundant in
all treatment combinations that included autumn grazing, no mineral fertiliser and a July
haycut. High density of the species was correlated with the lowest yields of hay, though
reduced competition by the grasses permitted successful establishment of desirable forbs.
This project has an excellent record of publications in peer reviewed scientific journals, even
though some built on the pre-MAFF funding of the project. Major findings are to be
prepared for TREE (Trends in Ecology and Evolution). A demonstration field visit for
farmers, ESA and Peak District National Park Staff was successfully held in 1998. Further
general publications (eg EN Newsletter and ENACT) are planned, to disseminate the major
findings of the research to a wider audience.
Milestones
All practical milestones have been met. Detailed reports of each milestone have been
produced. Milestone 3 was subject to some modification, in terms of number of species
investigated, and was reported to MAFF in May 1999.
Relevance to MAFF
The upland hay meadows of the Pennine Dales ESA are an important component of
traditionally farmed landscapes, and thus their conservation and restoration are of
importance. Evaluation of the management required to restore the diversity of agriculturally
improved mesotrophic grassland to that associated with traditionally managed grassland is
relevant and necessary. Conservation management of agriculturally improved mesotrophic
grassland requires joint implementation of appropriate cut date and grazing regimes, to
provide regeneration niches. Seed of appropriate species is required to fill these niches.
Low levels of mineral fertiliser have a measurable effect, but are of lesser importance. In
particular, guidelines as to the time needed for restoration, and its likely trajectory, are
useful.
Visit to the consortium took place 15-16 July 1999 at Colt Park, Ingleborough (site of
field experiment). Roger Smith, Juliet Franklund, Simon Peacock, Richard Bardgett,
Jan Poskitt and Peter Corkhill were present.
BD1414: Chalk grassland: enhancement of plant and invertebrate diversity through
Environmental Land Management Schemes (Dr Simon Mortimer and Prof Valerie
Brown, CABI Bioscience: Environment)
Presented under next section.
-----BD1415: The impact of organic fertilizers on semi-natural grasslands (Mr Jerry
Tallowin, IGER, North Wyke)
General
This is a new project in the AU and, indeed, the largest in terms of cost to MAFF, though
small financial and in kind contributions, from DANI, CCW and EN, are involved. The
project involves 2 joint contractors (Dr Francis Kirkham, ADAS Wolverhampton and Dr
James McAdam, Department of Agriculture for Northern Ireland). There are also 2
subcontractors: Dr Stephen Rushton, University of Newcastle upon Tyne and Dr Richard
Bardgett, now at University of Lancaster. The project started in autumn 1998 and will run
for 6 years.
The project focuses on assessing the effects of fertiliser management practices on the
ecological attributes and productivity of unimproved mesotrophic/neutral grasslands.
15
Objectives
1. Identify whether optimum amounts and frequencies of application FYM exist for the
maintenance or enhancement of botanical interests of a range of unimproved or semiimproved mesotrophic/neutral grassland communities and quantify the effects of
deviations from these optima on botanical composition.
1.1 Identify whether differences exist between the impact of FYM and equivalent
amounts of nutrients applied as inorganic fertilizers on the botanical composition
and agronomic output of a range of unimproved or semi-improved
mesotrophic/neutral grassland communities.
1.2 Identify any differences between an organic pelleted fertilizer and equivalent
nutrient inputs applied as inorganic fertilizers in their impact on the botanical
composition and agronomic output of a range of unimproved or semi-improved
mesotrophic/neutral grasslands.
1.3 Identify any interaction between the use of FYM and lime inputs on the botanical
composition and agronomic output of a range of unimproved or semi-improved
mesotrophic/neutral grassland communities.
2. Quantify the agricultural productivity obtained from applying amounts of FYM that
maintain or enhance the botanical interests of unimproved or semi-improved
mesotrophic/neutral grassland communities and compare these outputs with those
achieved by applying equivalent amounts of inorganic fertilizer.
3. Quantify the impact of length of storage, disturbance/handling and exposure to the
prevailing weather on FYM nutrient composition, to enable variations in FYM nutrient
inputs to be taken into account.
4. Identify the impact of FYM applications on soil microbial communities, including
mycorrhizal fungi, compared with application of equivalent amounts of inorganic
fertilizer.
4.1 Identify whether broad-scale assessments of microbial communities are more
sensitive to changes in soil chemistry than higher plant communities and thus
would be a more robust early warning indicator for unsustainable fertilizer
practice.
5. Provide guidelines for sustainable fertilizer and liming practices for mesotrophic/neutral
semi-natural grasslands.
Progress
The project involves 3 large-scale field experiments, in Fermanagh, NI (sampling managed
by DANI), Pennine Dales (managed by ADAS) and Pentwyn, Mon., S Wales (a site owned
by the Gwent Wildlife Trust with IGER responsible for monitoring). At each site, there are
paired meadows representing unimproved species-rich meadows and, at least partially,
improved. In NI and S Wales, the grassland communities are MG5 and MG6 and in the
Pennine Dales, MG3 and MG6 respectively. There are 3 blocks of experimental treatments
in each meadow type at each site. The treatments involve 3 different rates of (locally
produced) FYM application, with the highest equivalent to those allowed through ESA
agreements. Applications are either annual or periodic at the same rate (thereby giving a
lower total application in the latter). Two different rates of inorganic fertiliser are applied at
the same frequencies as FYM. The amounts of inorganic N are based on FYM nitrogen
availabilities, as predicted by the ADAS Manure Nitrogen Evaluation Routine (MANNER),
with standard guidelines being used to calculate P and K levels. A significant inclusion in
the experimental design is the application of lime with and without FYM (at the intermediate
rate), and at the same frequencies as those for other treatments.
Although the main comparisons are between FYM and equivalent amounts of inorganic
fertilisers, the application of pelleted organic material is also tested in the English and Welsh
sites. In each case, organic pellets are compared with inorganic equivalents at 2 rates of
NPK, and applications are annual. Although the inclusion of these extra 4 treatments has
extended the experimental design, it is relevant to a derogation which is sometimes allowed.
16
The factorial random block design is based on small plots of 7m x 5m, with an all-important
race of 5m between plots.
The Pentywn experiment was visited (August 1999) and, although far too early for definitive
statements, there appeared already to be more spatial heterogeneity, bare ground and
seedling recruitment in those treatments involving higher rates of FYM. The latter, is of
course, particularly relevant as a precursor to increased species richness.
The project involves botanical monitoring (for cover and species richness), agronomic
assessments (dry matter yields, nutrient content and offtake of harvested hay), soil analyses
and soil microbial analyses. The latter has been delayed (from April to September 1999)
meaning that pre-treatment samples are not available. Hay cutting is to be followed by
aftermath grazing, ideally by sheep.
At 2 sites (Pennine Dales and S Wales), a composting experiment will enable the impact of
different storage conditions of the FYM on botanical composition to be predicted from the
response models derived from the main experiment. The main experiments have been set
up and are ongoing. Litter bags are used as a means of assessing decomposition rates.
Milestones
These have so far been met.
Relevance to MAFF
Clearly, the results from this project will be pivotal in defining the impact of various fertiliser
management practices on the vegetation composition and dynamics of neutral grasslands.
The inclusion in the experimental design of ‘paired’ unimproved and semi-improved hay
meadow communities will enable the rates and direction of change, in relation to NVC
communities, to be assessed. Results will underpin refinements of ESA, Countryside
Stewardship, and other agri-environment management agreements, involving fertiliser use
on neutral meadows to ensure environmental targets are met.
Visit was made on 9-10 August 1999, to IGER and the S. Wales field site.
BD1424: Methods of enhancing botanical diversity in upland ESA swards (Mr Jerry
Tallowin, IGER North Wyke)
General
This project is an extension of BD0317, with an additional 2 years funding (from 1998 2000). I understand a year’s retrospective funding was made available to cover the period
between the termination of BD0317 and the start of BD0336. BD0317 began under the
direction of Dr Andrew Jones, and, when he left IGER, Mr Jerry Tallowin was nominated as
the Contractor’s Project Officer. However, the proximity of the sites to Aberystwyth means
that Dr Ruaraidh Sackville-Hamilton and Mr Mike Hayes (IGER, Aberystwyth) effectively run
the project. The project includes subcontracts to ADAS Pwllpeiran and ITE Bangor, the
latter being responsible for the invertebrate sampling.
The project explores ways in which upland habitats, which have lost biodiversity as a result
of agricultural intensification, can be restored.
Objectives
1. To identify the long-term impact of different extensification managements on botanical
and invertebrate richness on a former species-poor agriculturally improved upland sward
through natural colonisation.
2. To identify the long-term impact of different extensification managements on soil nutrient
status and grassland productivity.
17
3. To identify the long-term impact of different extensification managements on the
establishment of sown wildflower species that have been selected as characteristic of
unimproved species-rich upland grasslands.
Progress
The project is based on an existing experiment, initiated in 1995, at ADAS Pwllpeiran
Research Centre and uses 20 year old previously improved upland pasture, dominated by
ryegrass. The experiment has 3 main management treatments, representing different
extensification practices. These comprise summer sheep grazing (April-Nov.), July hay cut
and hay cut followed by aftermath grazing. Each of these treatments is subject to +/- lime
application, as soil pH falls. Each of the 6 treatments is replicated 3 times. There is an
additional control treatment, with continued intensive management practice of annual
application of NPK, sheep grazing and periodic application of lime.
Vegetation monitoring is based on botanical species richness and composition and
assessment of the soil seed bank. Soil cores are taken to assess the invertebrate fauna, in
terms of major groups. These samples were still to be taken (at time of visit). In addition,
soil nutrient analyses and herbage yield and quality are recorded. To assess the receptivity
of the sward developing under the various management treatments, the establishment of
nine native wildflower species were assessed, based on the introduction of locally collected
seed.
During the first two years of BD0317, there were no significant treatment effects; a result
attributed to the slow rate of change in the cold upland environment. However, the results
are now encouraging in that there are dramatic shifts in the cover of the dominant grass
species under the different management treatments, with corresponding changes in yield
and in the number of forb species. Colonisation of forbs, from the seed bank and remnant
patches of unimproved grassland, is fastest in the combined hay cut/aftermath grazing
treatment. Introduced species do establish, but require regular defoliation to open up the
sward. The timing of these introductions is likely to be crucial, with a phased approach
being desirable, viz. a period of nutrient rundown followed by management for species
colonisation.
It will be interesting to see whether the invertebrates track the changes in the vegetation or
show a further lag time.
Milestones
Milestones, based on the collation of the 1998 data (02/01 and 01/01), have been met. The
field work for the final season of the project was ongoing, leading to the final data analyses
at the end of the project.
Relevance to MAFF
As a result of agricultural improvement, species-poor bent and fescue grassland now
dominate much of upland ESAs, with accompanying loss of biodiversity. Restoration of this
biodiversity is a key objective of higher tier ESA management agreements on upland
grasslands. The development of cost-effective methods for achieving this are needed, as is
an understanding of the processes involved and the time scale under which they operate.
Results so far suggest that in the medium term there are good prospects for diversification
through natural colonisation or species introductions.
Visit was made to IGER, Aberystwyth and to field site on 12-13 July 1999. Jerry
Tallowin, Ruaraidh Sackville-Hamilton, Mike Hayes and John Harvey (NT) were
present.
------
18
BD1425: Practical techniques to increase the biodiversity of agriculturally improved
grasslands (Dr Richard Pywell, ITE Monkswood)
General
This is a relatively new 4 year project in the AU. It aims to identify and test practical and
effective methods of diversifying the flora and invertebrate fauna of agriculturally improved
grassland. The project involves a consortium of ITE, IGER and CABI.
Objectives
1. To identify practical and cost-effective techniques to increase and maintain the
botanical diversity of grasslands on a range of fertile substrata.
2. Assess experimentally the effectiveness of combinations of practical treatments to
overcome the key constraints on enhancing the botanical diversity of productive
grassland, including:
 application of seed mixtures and small turves to overcome the lack of propagules of
desirable species;
 different intensities of livestock grazing and mechanical disturbance to overcome the
lack of suitable sites for germination, establishment and dispersal;
 different intensities of grazing and the use of hemi-parasitic plant species to control
excessive competition for space and resources;
 soil inoculation to overcome the lack of soil microbial groups important for ecosystem
function and stability;
 application of molluscicide to control excessive herbivory of seedling plant species by
molluscs;
 manipulation of the soil nutrient pools to maximise nutrient off-take and reduce
excessive soil fertility.
3. Investigate the ecological processes important in the establishment and dispersal of
wildflower species in grasslands under different restoration management regimes.
4. Examine changes in the composition and abundance of a range of key invertebrate
groups associated with the grassland communities.
5. Investigate changes in the soil microbial communities under different restoration
management regimes and determine how these might affect plant species germination
and establishment, community assembly, and other ecosystem functions.
6. Examine the agronomic implications of large-scale grassland diversification using these
approaches.
7. Evaluate and, where necessary, refine current restoration and management
prescriptions for agri-environment schemes as they apply to grassland diversification.
Progress
Two randomised replicated block trials have been established on typical agriculturally
improved grasslands in lowland Britain. One, at IGER, North Wyke is on Teign, and the
other in the Thames Valley on Stagno gley. Some difficulties were encountered initially in
locating an appropriate site in the latter region and in potential reliability of use over the
project period. The experiments are large scale (8 management paddocks of c. 1 ha each),
with treatment plots being 70 x 20m to enable use of agricultural machinery.
Two grassland management regimes, of contrasting intensity, are employed. These involve
an early July haycut, followed by aftermath grazing by sheep to maintain 2 sward heights, of
6-7cm and 2.5cm, the latter being typical of intensive restoration management. Treatments
comprise semi-factorial combinations of typical agricultural practices, with treatment
combinations based on practical experience and expert knowledge.
The main treatments include:
1. Seed broadcast into sward (‘hoof & tooth’)
2. Disc/harrow + Rhinanthus minor + disc/harrow + seed mix + roll
3. Disc/harrow + seed mix + roll
19
4. Slot-seeding into turf with herbicide spray
5. Deturfing in strips + disc/harrow + seed mix + roll
6. Cut three times in years 1 & 2, cut July year 3, then disc/harrow + seed mix + roll
7. N+K fertilize in years 1 & 2 and spring of year 3, then manage as in treatment 5
(1-5 to be sown in autumn of Year 2 and 6-7 in autumn of Year 3)
Three sub-treatments are applied to treatments 2, 3 and 5 only:
 control (no addition)
 + mollusc control
 + soil inoculation
The sub-treatment plots will be c.20 x 20m
Unfortunately, the Rhinanthus seed proved inviable and will be resown with the seed mixes
in autumn 1999. The seed was sown later than desirable because of a delay in setting up
the experiment, due to contract receipt. Species selection for seed mixes at the 2 sites is
based on frequency of occurrence in MG5 grasslands. Both grasses and forbs have been
sown. Broadcasting and slot seeding rates are based on rates applied in practice. Careful
analysis of seed weight and application rate for individual species has been critically
considered.
Pre-treatment vegetation sampling, including a detailed assessment of sward structure,
have been undertaken. Likewise, seed bank tests and sampling of invertebrates have been
undertaken on the improved sites and on nearby botanically diverse grasslands which will
function as target communities. Soil nutrient analyses and strategic sampling of the soil
microbial community has also been carried out.
Milestones
All have been met, though the lack of germination of Rhinanthus seed (Milestone 04/01) has
meant that meeting of part of 02/02 (Assessing Rhinanthus establishment in treatment 2) is
no longer relevant.
Relevance to MAFF
The results of this project will inform the revision and refinement of the current guidelines for
enhancing the biological diversity of agriculturally improved grasslands. The project will also
provide an opportunity to assess the agronomic implications of grassland diversification.
The nature of the experimental design and sampling procedures will enable mechanisms
and processes involved in grassland restoration to be appreciated, with a view to increasing
the ability to predict ‘success’ of diversification measures. The inclusion of the invertebrate
and soil microbial assemblages is an important component of the project, the former in
relation to UK BAP obligations and the latter in terms of the ‘healthy’ functioning of the
ecosystem.
A full discussion of this experiment took place with the whole consortium on 18
August 1999 and on 17 March 2000. Field visits to both sites.
-----BD1431: Development of botanical diversity in grassland following species
introduction (Mr Alan Hopkins, IGER, North Wyke, Dr Mike Burke, ADAS)
General
This project is a development of BD1402, the multi-site trial on permanent grassland (which
complements BD1404 on arable reversion). The trial was established in 1994 and
subjected to intensive botanical survey from 1995-1998. The techniques employed to
enhance botanical diversification were starting to demonstrate clear results by 1998,
especially in sites with lower nutrient status. It is therefore very appropriate that MAFF has
20
made further funding available to continue the trials on selected sites, to determine whether
species, once established, can persist and/or increase under typical agricultural
management.
The sites are to be managed by IGER and ADAS, the responsibility for individual sites being
shared between contractors.
Objectives
1. Investigate persistence and dispersal of re-introduced forbs and minor grasses on
former small-plot trial sites of permanent grassland subjected to botanical
enhancement, following their return to typical ESA-type farm management.
2. Investigate the dispersal of re-introduced forbs and minor grasses on to grassland
adjoining the former permanent grassland following the incorporation of the trial sites
into grassland subjected to typical ESA-type farm management.
3. Develop recommendations on the suitability of individual species for use in biodiversity
restoration, and thus refine assessments of the cost effectiveness of methods for
increasing species diversity of grassland.
Progress
The project forms a natural continuation of the multi-site trial under BD1402, with the fences
used to enclose the experimental plot being removed to allow typical agricultural practice.
Three of the six original permanent grassland sites were selected for botanical survey during
the 3-year period of the extension. These were Patcham (S Downs), Dolau (Radnor) and
Linton (Pennine Dales). The selection of sites was based on their potential for successful
enhancement of botanical diversity, likelihood for the site remaining under ESA
management, farmer co-operation and consistency of ownership and landscape features,
such as the potential for dispersal into the site, from adjacent species rich habitats. Annual
visits to the other three sites: Blackborough (Blackdown), High Ham (Somerset Levels) and
Melbury Abbas (S Wessex Downs) are to be made during Years 1 and 2, with more
extensive sampling in year 3.
Four replicates of five diversity enhancement treatments (turf removal, oversown following
rotovation at two levels, strip seeded and plug planted) plus a control are monitored in
respect of presence/absence of species in 16 cells of 3 quadrats, as in previous years, to
provide comparisons with the previous year. At the Radnor site (visited on 12/13 July 99),
introduced species are clearly apparent and are spreading into, inter alia, the control plots,
or recruiting from plug plants. Most conspicuous of these species are Prunella vulgaris,
Hypochaeris radicata and Lotus corniculatus. It is also encouraging that other species
(presumably resident in the seed bank or immigrant seed) are establishing (eg Hypericum
spp., Myosotis arvensis). At this site, there is an attractive integration of forbs and grasses
and an integral mixture of introduced and resident species. The ratio of grasses:forbs is
(visually) around 60:40 and there is a clear visual impact of the different treatments. The
successful establishment of introduced species at this site is clearly related to the low
nutrient status and also to its site management before the commencement of the
experiment (tightly grazed by sheep). The site is clearly well management by Peter Bowling.
In addition to the persistence of selected species (not all those introduced established
effectively) within the experimental treatment plots, some are spreading into the surrounding
field plot; most visually obvious are Leontodon hispidulus and Lotus corniculatus. This
spread is being assessed by a series of 1m² quadrats in arcs (2m, 10m and 30m) from the
experimental plot.
Milestones
Though early in the project period, relevant milestones (01/01 and 02/01) involving protocol
development have been met.
21
Relevance to MAFF
The results are of considerable relevance to the refinement of management options for land
in agri-environmental schemes. The enhancement, but more especially the maintenance, of
biodiversity is a key objective of MAFF’s environmental policy and payments under ESA and
Countryside Stewardship options. The technology transfer component of the project,
including on-site demonstrations, is the responsibility of ADAS, and will be of considerable
importance. Guidelines, based on the success ‘rating’ of plant species characteristics, and
the techniques employed for enhancing biodiversity will be a valuable outcome of the
project.
Visit was made to the Dolau (Radnor) site on 12-13 July 1999. A. Hopkins and P.
Bowling (IGER, Trawsgoed) were present.
-----BD1435: Changes in lowland grassland management: effects on invertebrates and
birds (Dr Rob Fuller, British Trust for Ornithology)
General
This is a new project in the AU, as it was incorporated from the Conservation in the Wider
Countryside R&D programme. It aims to assess how changes over recent decades in the
management of lowland grassland, typified by greatly increased inorganic fertiliser inputs
and production of silage, have affected biodiversity. The project explores the interaction
between vegetation, invertebrates and birds and assesses the relationships between
grassland management and the food resources (seeds and invertebrates) of birds.
Objectives
1. Review existing knowledge of the effects of grassland management on floristics,
vegetation structure, invertebrates and birds.
2. Determine variation in above-ground and soil invertebrate communities associated with
different grassland management systems.
3. Quantify the use made by birds of grassland under different management systems
during the spring and winter.
4. Assess how food resources for birds, especially invertebrates but also seeds, are
affected by grassland management practices (both directly and indirectly) through
factors, such as interactions between vegetation structure and invertebrates.
5. Provide guidelines for modifying lowland grassland management to enhance
invertebrate communities and increase food resources for birds. The potential of such
modifications on farm output will be quantified through the development of simple
models.
Progress
The project combines the preparation of a significant review and an intensive study of
vegetation, invertebrates and birds in two study areas.
A major review, jointly prepared by BTO, IGER and CABI Bioscience, has already been
completed and has been submitted for publication in a peer reviewed journal. The state of
existing knowledge on the relationships between vegetation (species composition and sward
structure), invertebrates and birds, and the potential role of grassland management in
affecting these relationships has been reviewed. This review has also enabled the
refinement of methods to be adopted in the project, a framework for the project and the
context for evaluating field results.
The core of the project is intensive work on vegetation, invertebrates and birds on selected
farms in two geographical regions (Devon) and (the Thames Valley). Four examples of
22
three farm types, representing different intensities of grassland management, are used.
These are:
1.
2.
3.
Dairy farms, typical of high intensity grass-based livestock systems (with average
annual nitrogen inputs of >250kg/ha).
Beef and sheep farms, typical of moderately intensive livestock systems (with average
annual nitrogen inputs of approximately 100 kg/ha).
Beef and sheep farms, typical of extensive livestock systems (with average annual
nitrogen inputs of <50 kg/ha). The extensive farms will also be selected on the basis
that they should contain some unimproved and botanically diverse grassland.
The study framework aims to encompass the need for spatial and temporal replication,
without compromising on effective level of sampling.
Vegetation is being recorded by cover estimates (in quadrats), sward height, biomass and
seed resources in autumn. Invertebrates, above- and below-ground, are being sampled by
four methods. Birds are being studied in the breeding season and in winter by 2 methods;
intensive work on the 24 study farms and extensive surveys by volunteers on a larger
sample of farms, in order to assess the generality of the results from the intensive study.
Results, after the first year of the project, indicate a close relation between vegetation
complexity and invertebrates, but a disturbing sparcity of birds in the first of the 2 regions
(Devon).
Although initially disappointing, within the context of the interaction between
vegetation, birds and invertebrates, the results have opened up the possibility of explaining
the decline in terms of the availability of food for birds. For this reason, consultations with
MAFF have led to a slight modification in the proposed experimental design. Instead of
sampling only Devon or Thames Valley sites in Years 1 and 3 of the project, respectively,
and a 50% subset of each in Year 2 (to give an estimate of temporal variability), it has been
agreed to sample all the Devon sites in Year 2, although the level of invertebrate sampling
will be lower in the extra 50%.
Milestones
All have been met to date, with the major review (Milestone 01/01) being submitted on time.
Relevance to MAFF
The project directly addresses the effects of changing management and production of
lowland grassland (greater fertiliser inputs, changes in fertiliser practice, reseeding, the
development of silage techniques and widespread efficient drainage and stocking patterns).
Implications for these changes in terms of biodiversity are substantial, though have been
inadequately studied. In particular, the interactions between different trophic levels has
been ignored, even though they may well provide insight into the mechanisms of the
decline. In addition, MAFF’s research has, to date, generally addressed the effects of
agricultural intensification on the biodiversity of arable farmlands, and thus this project on
grassland is valuable. The project will also provide information relevant to MAFF’s role as
lead Agency for implementing UK Biodiversity Action Plans for species and habitats
associated with farmland.
Meetings took place on 8 July 1999 and 7-8 March 2000, with Rob Fuller, Juliet
Vickery, Greg Conway, Jerry Tallowin, Liz Asteraki and Val Brown.
-----BD1436: Integrating farm management practices with Brown Hare conservation in
pastoral landscapes (Professor Stephen Harris, University of Bristol)
General
23
This project, initiated in 1997, was formerly a component of Conservation in the Wider
Countryside R&D programme. It addresses the reasons underlying the continued decline in
Brown Hare populations in pastoral landscapes. The decline in the species is attributed to
agricultural intensification. Thus, MAFF is the lead Agency for this species in relevant areas
of the UK Biodiversity Action Plan.
Objectives
1.1 To investigate the ecology and behaviour of brown hare populations in different pastoral
landscapes, including direct and indirect measurements of fecundity, survivorship,
movement, dispersal, diet and feeding behaviour.
1.2 To quantify land use in the three different pastoral landscapes, including measures of
stocking density, vegetation/crop diversity and land use pattern.
2.1 To determine the effects of different patterns of pastoral land use on hare abundance.
2.2 To determine the effects of different patterns of pastoral land use on hare population
dynamics.
2.3 To determine the effects of different patterns of pastoral land use on hare population
fragmentation.
3.1 To derive models to quantify the extinction risks for hare populations in pastoral
landscapes under different patterns of land use and farming practices.
4.1 To predict future trends in hare numbers in pastoral landscapes under different farming
scenarios.
4.2 To determine the best way in which the needs of hares can be integrated into current
farming practices, including assessing whether specific conservation measures need to
be introduced to ensure the long-term conservation of the species in pastoral
landscapes.
5.1 To identify priority areas for hare conservation within pastoral landscapes through the
use of cost-effectiveness analysis to identify the optimal form of any specific
conservation strategies that may be required which will satisfy both the requirements of
farmers and the needs of hares.
6.1 To produce a management plan providing guidelines for the long-term conservation of
hares in pastoral landscapes.
Progress
The 5-year project involves a consortium from the Universities of Bristol and York, though
the involvement of Piran White from York will be mainly in the later stages of the project.
The field component has been greatly enhanced by the organised involvement of
volunteers. Tony Robinson from English Nature has given invaluable support.
The Brown Hare has undergone an 80% decline in numbers since the turn of the century,
mainly attributed to agricultural intensification. The species is now included on the UK
Biodiversity Steering Group’s shortlist of threatened/declining species. For mammals, the
extent of its decline is second only to the water vole.
The project aims to understand the autecology of the species, to explain its and offer
suggestions for changes in farming practice to arrest the decline. It is interesting that,
although hare numbers have declined in both pastoral and arable landscapes, numbers in
mainly arable areas now appear stable or may even be increasing. While information exists
on the reason for the decline in arable systems, (mainly reflecting the change from spring
sown to winter sown cereals), it is lacking for pastoral systems. It is also pastoral systems
where increases in hare numbers, to meet the commitments of the BAP, are required.
So far the research has focused on the autecology of hares in pastoral landscapes and
particularly their fecundity and survivorship. Based on this information, the implications of
potential future changes in farming practice will be modelled and the cost effectiveness of
different management strategies for their conservation addressed. From these results, a
management plan for the species recovery in western pastoral areas will be produced.
24
The research is being ably undertaken by Dr Nancy Vaughan, the PDRA employed to
undertake the data collection. Transects, in a total of 16 arable and 16 pastoral sites within
‘pastural’ land classes in 3 sites (Lower Derwent Valley, Lleyn Peninsula and Somerset
Levels) have been employed to estimate hare numbers and farm and habitat details
recorded. A questionnaire for farmers has been prepared and, when approved by MAFF,
will be sent to 4000 farmers in counties which are predominantly pastural, to provide
additional information. Radio tracking is planned, in 2 main areas (both SSSI’s), to study
dispersal and habitat use. Although difficult to catch sufficient animals for marking, the
method will provide valuable information.
Post-mortem dietary analysis will enable feeding selectivity, nitrogen content and digestibility
to be assessed. An impressive array of means to secure specimens has been developed,
though the accumulation of numbers in pastoral areas (where population densities are low)
is proving slow. To date, 340 carcasses will provide data on age, reproductive output and
condition, phyto-oestrogen load, body condition, parasite load and morphology in addition to
diet. Much of these data will be used for development of population models.
Milestones
Progress is good and all relevant milestones have been met. Dates for milestones had to
be adjusted to accommodate the later than planned start date. Details are given in the first
Annual Report (submitted August 1998). There has been a reduction in the number of sites
in which radio tracking is being implemented. MAFF has been advised that this is because
of the very low population levels and the time taken to capture individual animals.
Relevance to MAFF
As might be expected, research on this high public interest species has generated press
coverage. A newsletter ‘Hares and Habitats’ outlines the aims and progress of the project.
The dramatic decline of the species, particularly in pastoral landscapes, is deserving of
support by MAFF and is particularly pertinent in relation to MAFF’s role as lead Agency for
the species in the UK Biodiversity Steering Group’s Action Plan (areas 5.1.1, 5.1.2., 5.1.3).
-----BD1440: Ecologically sustainable grazing management of lowland neutral grassland
and its effect on livestock performance (Mr Jerry Tallowin, IGER North Wyke)
General
This is a very recently started project which aims to identify optimum grazing management
for ecological value of species rich neutral grassland, based on sward structural criteria.
The impact of this grazing management on the growth of commercial beef cattle will be
assessed.
Objectives
Overall: To identify sward based criteria for grazing unimproved neutral grasslands that
provide optimal conditions for enhancing maintaining the wildlife interests of the grassland
and to quantify the agronomic value of the unimproved grassland.
Specific: To quantify the impact of different severities of grazing unimproved neutral
grasslands on:
1. cattle growth rate and intake
2. botanical composition
3. vegetation structure
4. invertebrate populations
5. soil nutrient status
25
Progress
At this very early stage in the five year project, energies have focused on site selection and
fencing. The experiment now has 3 replicates at a single site and involves imposing
different grazing intensities. There is also an area of 2ha of agriculturally improved
grassland, which will be managed to provide optimal conditions for growth of the beef cattle
and to achieve high utilisation of the sward. The height of the grazing treatments will be
assessed using a sward stick.
Severe grazing: The experimental plot will be continuously stocked with beef cattle to
maintain an average sward surface height in the range 6.0-8.0cm. This grazing pressure
provides optimal conditions for efficient grass utilisation and animal production on
agriculturally improved swards.
Moderate grazing: The experimental plot will be continuously grazed with beef cattle to
maintain an average sward surface height in the range 8.0-10.0cm.
Lenient grazing: The experimental plot will be continuously grazed with beef cattle to
maintain an average sward surface height in the range 10.0-12.0cm.
A full range of measurements will be undertaken to include:
 Agronomic and animal performance
 Botanical cover
 Vegetation height and spatial structure - including numbers of flowering plants,
belonging to selected families.
 Insect community structure - of key phytophagous groups, some of which will be good
indicators of swards of high conservation value, while others may be UK BAP species.
 Soil analyses
Agronomic consequences of grazing species-rich grasslands with commercial livestock will
be quantified in terms of animal performance and output allowing support payments by
MAFF and organisations such as CCW and EN to be calculated in an objective manner.
Milestones
Early milestones have been met.
Relevance to MAFF
The development of sustainable management agreements for enhancing/maintaining
wildlife interests of species rich neutral grasslands is currently impeded by the lack of swardbased criteria that can be used as management objectives. The results of this project will
provide sward-based criteria for refining/developing grazing management agreements for
unimproved or semi-improved neutral meadows within ESAs, CS and SSSIs that ensure
achievement of environmental objectives, such as maintenance or enhancement of
biodiversity.
The project will therefore provide a much clearer definition of sustainable management
systems for these grasslands and allow support payments by MAFF, CCW and EN to be
targeted and thus more environmentally effective.
Recreation of grassland on ex-arable land
BD1404 and BD1403: Multi-site experiments on the restoration of herb-rich meadows
- arable reversion (Dr Richard Pywell, ITE Monkswood and Dr Mike Burke, ADAS
Wolverhampton respectively)
Completion date 31/03/99.
General
26
This is one of two major multi-site experiments initiated in 1994 and focuses on
experimental techniques to study arable reversion (the parallel experiment focuses on the
diversification of existing grassland). The project is co-ordinated by Dr Richard Pywell is
responsible for ensuring standardisation of methodology, data collation, analysis and
interpretation of results. Both Contractor’s Project Officers are responsible for the site
management and data recording of selected sites. The ADAS Contract Officer is Dr Mike
Burke. The chemical analyses are undertaken by ADAS. The site management and data
recording of selected sites are shared by ITE and ADAS.
Objectives
Overall: Identify management procedures for restoration of herb-rich grassland in ESAs.
Specific:
1. Derive management prescriptions for markedly increasing botanically diverse swards
over a time-span of 3-5 years.
2. To successfully establish botanically diverse swards on arable land.
Progress
Identical experiments have been established on three calcareous sites (South Downs, South
Wessex Downs and Cotswolds and three acidic or neutral sites (Suffolk River Valleys,
Norfolk Broads and Upper Thames Tributaries). Common features of the treatments are (i)
the absence of fertilizer, (ii) cultivation and (iii) introduction of seeds. Each experiment has 6
treatments, in addition to a control of natural colonisation. The treatments include deep
ploughing, with the addition of either an ESA seed mix or a species-rich seed mix, with and
without a nurse crop (Westerwold’s Ryegrass), and shallow ploughing, with either an ESA
seed mix or a species-rich seed mix. The experiment is therefore semi-factorial. The sites
are cut in July, then shut up and grazed by sheep from November. A seed bank study was
undertaken on four of the sites by Richard Pywell, as an add-on task to test the seed to be
introduced for viability. At the end of the project, another seed bank trial was undertaken,
revealing considerable input of seed, into the seed bank from the sown species.
By the fifth year, there are clear treatment effects. At the Norfolk Broads site, sown species
have established well (particularly Lathyrus pratensis, Lotus corniculatus, Vicia cracca and
Leucanthemum vulgare).
It is particularly encouraging that some species (eg Lotus
corniculatus, Trifolium dubium and Hypericum radicata) are spreading between treatments.
Common trends are that the sowing of a nurse crop does not enhance botanical diversity
and that the ESA seed mix produces a sward of low species diversity. In the treatments
with the species rich mix, there is a dominance of forbs, but with a well integrated matrix of
grasses and forbs. Some sown species failed to establish or only did so sporadically. The
invertebrates are also showing clear treatment effects, with the species rich mixtures having
a wide array of bees, butterflies and hoverflies. Between sites, the results are variable and
apparently related to residual soil nutrients, soil type and depth.
Milestones
All have been met, with the exception of Milestone 20 and 21, the submission of the final
report to MAFF and manuscripts to scientific journals, which as of 19 July 1999 had not
been submitted. (I believe this was subsequently submitted.)
Relevance to MAFF
The multi-site experiment gives some idea of the treatments which may be imposed to
restore botanically diverse grassland on former arable land, and thereby meets one of the
main objectives of the ESA scheme, namely to enhance the quality of the rural landscape.
It also assesses options of different cost effectiveness. Although carried out in the context
of ESAs, results may have more general relevance to arable reversion. The comparison of
27
sites provided by the multi-site approach is of value in providing information relevant to the
targeting of sites.
Meeting took place at Hickling (Norfolk Broads) on 19 July 1999 with Richard Pywell,
Kevin Walker and Lynn Hunt.
-----BD1410: Seed mixtures for reversion of arable land to species-rich grassland (Dr
Francis Kirkham, ADAS Wolverhampton)
Completion date 31/03/99.
General
This project started as an investigative monitoring project, initiated in 1992, and was funded
under the ESA monitoring programme, since at that time R & D programmes supporting
ESAs had not started. The project explores the potential for a range of seed mixes,
including species diverse mixes introduced under Tier 3.1, within the South Downs ESA.
Since mid 1998, the project has been led by Dr Francis Kirkham, who replaced Mr Stephen
Peel.
Objectives
1. To assess the botanical development of fields and experimental plots for at least 6
years following sowing with a range of grass and forb species.
2. To measure the relative herbage production and nutritive value of key seeds mixtures
on plots.
3. Measure changes in soil nutrient status.
4. To suggest new guidelines for arable reversion seeds mixtures which will achieve
swards of diverse composition, whilst enabling viable livestock production systems to be
practiced.
Progress
The project involves a botanical survey of seven fields selected subjectively, to provide
geographical spread, from the twelve Tier 3.1 agreements which entered the ESA scheme
in 1992. The fields were managed according to the ESA management prescriptions for Tier
3.1, and details of management and seed mixtures are known. These range from 5-14
species. The developing flora has been monitored in a series of band transects by using
the standard DAFOR scale, ensuring consistency of sampling effort. Fields were sampled
annually from 1993-1995 and again in 1998. A comprehensive data set exists of a total of
194 plant species, including the number of sites at which the species is recorded, the modal
abundance score and species frequency. Dr Kirkham has innovatively categorised these
into life-history category and functional type (ruderal, competitor, stress tolerator). Of
particular interest are the unsown species that clearly enhance the diversity of the sward.
The number of unsown species varies from 26-84. Species rich mixes are not always
associated with the occurrence of high species richness, indicating other biotic or abiotic
features are important. The use of species rank/abundance models are proving valuable in
the comparison of sites.
One of the fields also has a finer scale manipulative experiment in which 7 different seed
mixes were sown, at 2 sowing rates, plus a control of natural colonisation. Annual sampling
was undertaken, though selective (and logical) reduction in the treatments sampled
occurred. Similar analyses to those undertaken at the field scale have been undertaken.
Main results (up to 1997) include the lack of difference in diversity enhancement between
the sowing rates. The simple species mixes (Chewings Fescue and Creeping Fescue) and
their combination proved difficult to sample because of identification problems, but the more
diverse seed mixes have yielded interesting results, with the more diverse seed mixes
28
allowing more colonisation by unsown species. These changing populations of unsown
species have contributed significantly to the botanical diversity of the sward. However, the
spread of Trifolium repens in 1998 may well impact on the less competitive species, as well
as on herbage N content, digestibility and total mineral content. Among the unsown
species, there was the expected successional pattern, with annual species being replaced
by perennial species.
There were no significant treatment differences in herbage yield and nutrient content of the
treatment plots. In addition, there was only a slight decline in these 2 parameters as a result
of a lower seed rate. However, initially, mixes containing certain legumes produced higher
yield and digestibility.
Milestones
These have been met, though, as of 29 July 1999, the final report had not been submitted. I
understand this was subsequently submitted to MAFF.
29
Relevance to MAFF
Clearly, evaluation of seed mixes is crucial to arable reversion. However, the biodiversity
benefits need to be balanced against the potential for loss in productivity. Between-site
replication is needed before guidelines can be realised, though this was not possible within
the experimental component of the project.
Meeting was held at ADAS Wolverhampton on 29 July 1999.
-----BD1414: Chalk grassland: enhancement of plant and invertebrate diversity through
Environmental Land Management Schemes (Dr Simon Mortimer and Prof Valerie
Brown, CABI Bioscience: Environment)
General
This project involves work on land in ESAs and Countryside Stewardship. It aims to build on
existing monitoring vegetation data for ESAs and to provide a comprehensive assessment
of the invertebrate fauna in a range of ESA and CS sites and to relate this to vegetation
characteristics. It includes both ex-arable land and existing chalk grassland.
Objectives
Overall: To assess the impact of various site factors and management practices on the
conservation and enhancement of the plant and invertebrate diversity of chalk grassland.
Specific (corresponding to provisions in the ESA and CS Schemes):
1. To identify the influence of site factors and management practices on the invertebrate
diversity of existing chalk grassland of known botanical composition.
2. To assess the effectiveness of supplementary measures aimed at enhancing the
colonisation of existing chalk grassland sites by plant and invertebrate species.
3. To study the development of plant and invertebrate communities of abandoned chalk
grassland sites after the clearance of scrub.
4. To identify factors important in promoting the successful development of plant and
invertebrate diversity of arable reversion sites.
5. To assess the effectiveness of supplementary measures in enhancing the colonisation of
arable reversion sites by plants and invertebrates typical of unimproved chalk grassland.
Progress
In 1998, attention was focused on sampling ESA field sites. In 1999, sites under
Countryside Stewardship have been the focus of fieldwork, as detailed in the project
proposal.
Multisite Survey
A total of 42 sites have been surveyed for this part of the contract. The invertebrate
communities of 32 chalk grassland sites in southern England were sampled on 3 occasions
between June and September 1999. Approximately half of these sites were chosen
because plant community data for 1998 were available from the Countryside Stewardship
Environmental Monitoring and Evaluation contract being carried out by the ITE. The
majority (11) of the remaining sites were within CS agreements on the same holdings. Sites
included improved, semi-improved and unimproved grasslands. Sampling was also carried
out on 10 arable reversion sites, of which 7 were surveyed for the above Monitoring and
Evaluation contract. A total of 630 invertebrate samples have been collected in 1999.
The majority of invertebrate samples from the 1998 field season have been sorted to Order,
and species identification within key groups is underway. Sorting and identification of 1999
invertebrate samples is currently ongoing.
30
Botanical data were also collected from all sampling locations, and are supplemented, on
some sites, by those already collected by ITE as part of the Countryside Stewardship
Environmental Monitoring and Evaluation contract. Computerisation of botanical data
collected during 1998 is complete, and ongoing for 1999 data. It is planned to relate the
invertebrate communities to variables derived from the botanical data collected, once all
data have been collected.
Experimental sites
(i) Hay spreading
The efficacy of spreading hay taken from areas of existing species-rich grassland as a
means of enhancing diversity is being studied. Four sites are being used: Brush Hill, Bucks
(permanent pasture), Cold Blow Farm, Kent (permanent pasture and arable reversion) and
Bockhill Farm, Kent (arable reversion). The invertebrate component of these experimental
sites was sampled 3 times between June and September 1999. Botanical data for all sites
were also collected between August and September. Initial results for Brush Hill show an
increase in diversity of forbs, and a decrease in the dominant coarse grasses, in some of
the experimental plots. Detailed analysis of these data, to identify the individual importance
of rotovation and hay spreading on species composition, is pending.
Suitable hay of local provenance was applied to 3 of these sites in October 1999. An
application rate equivalent to 20 tonnes per hectare was used on the Chilterns site in 1998.
A lower application rate was used in 1999, primarily because of the difficulty of obtaining
large quantities of suitable hay, but also to avoid the potential mulching or thatching effects
which may occur in undergrazed pastures. Additionally, a seed mixture recommended by
FRCA will be included within the design of the Bockhill Farm experiment. Samples of hay
randomly taken from the centre of the bales spread on to the Chilterns site in October 1998
were sorted and seeds identified and counted.
(ii) Scrub clearance
The development of vegetation and invertebrate communities following scrub clearance is
being assessed at three sites: Bacombe Hill (Bucks), Brush Hill (Bucks) and Whinless Down
(Kent). Replicate blocks of scrub were cleared on all 3 sites during the 1998-99 winter.
Sampling of the invertebrate communities on all sites took place on 3 occasions between
June and September 1999. Sampling on each site was located in areas cleared of scrub
during each of the preceding 5 years, and in the scrub remaining. Botanical data for Brush
Hill and Whinless Down were collected between August and September. Bacombe Hill was
the subject of an intensive survey of vegetation, soil seed bank and seed rain in 1998.
These data will be linked to invertebrate data to provide an understanding of the invertebrate
and plant community development following a chronosequence of scrub clearance.
A total of 552 invertebrate samples have been collected in 1999 for the experimental
component of this project.
Milestones
All milestones have so far been met.
Relevance to MAFF
The project will enable an assessment of the effectiveness of current management
guidelines for chalk grassland in the ESAs and CS in achieving the conservation and
enhancement of their plant and invertebrate diversity. It will also allow the modification and
development of management guidelines in these schemes. Combining results on insects
and plants should enable indicators to be established which will help target funding on those
sites most likely to produce environmental improvement.
A formal meeting of all scientists involved in the project took place at the end of
October 1999, when fieldwork was complete. Field sites were visited.
31
-----BD1431: Development of botanical diversity in grassland following species
introduction (Mr Alan Hopkins, IGER, North Wyke, Dr Mike Burke, ADAS)
(Included under page 21)
-----BD1434: Methods of accelerating development of chalk grassland on ex-arable land
(Dr Simon Mortimer, Prof Valerie Brown, CABI Bioscience)
Objectives
1. To follow the development of a sward under arable reversion in relation to different seed
sowing treatments and addition of stepping stones from target vegetation.
2. To investigate the relationship between the diversity of the seed mixture and the
suppression of weed species.
3. To investigate the colonisation by desirable chalk grassland species of sown and
unsown plots.
4. To study the invertebrate communities which develop on sown and unsown plots.
5. To determine the effects of the sowing treatments on soil properties.
Progress
The field experiment has 4 treatments (replicated x5) each of 10x10m. The treatments
were established in 1996 and comprise 2 diversities of sown species: low diversity (4
species sown) and high diversity (15 species sown). In addition, there are plots with natural
colonisation established in 1996 and plots subjected to continued crop cultivation (CCR:
1996-1999) and then left fallow. Integrated within this experiment is a ‘stepping stone’
experiment where soil and turves from the target calcareous grassland vegetation were
implanted. Extensive sampling has taken place annually. The extra year of sampling, as a
result of this contract, has demonstrated significant trends in the relative abundance of the
sown species. The abundance of leguminous species has decreased, while the perennial
grasses have increased. Some less competitive species amongst those sown are starting
to be excluded, particularly from the high diversity plots.
Weed suppression is greatest in the high diversity treatments, probably related to the
greater production of standing crop in these plots. The degree of weed suppression in the
low diversity plots is highly variable, depending on the identity of species sown in the
mixture. However, the high diversity plots are far more resistant to invasions, particularly of
weed species such as Cirsium arvense and Senecio jacobaea. An experiment was carried
out to assess differences in the invasibility of the plots of the main sowing experiment to
different plant species. Seeds sown in the autumn, rather than at the start of the project in
April, to mimic the timing of natural seed fall. The experimental design was supplemented
to include undesirable weed species (eg Rumex crispus, Cirsium vulgare) as well as
desirable chalk grassland species. In total, seeds of 4 weed species and 12 chalk
grassland species were sown. Some chalk grassland species have established well (eg
Primula veris, Ranunculus bulbosus), while, for other species, no seedlings have been
found (eg Hippocrepis comosa, Thymus polytrichus). Establishment of the weed species
has been poor. Establishment success has been greatest for both types of plant in the
natural colonisation and CCR plots, and lowest in the high diversity sown plots,
The plots of main sowing experiment and the stepping stone experiment were sampled
using a Vortis suction sampler, together with 2 chalk grassland sites (one of which was the
site of origin for the soil and turf for steeping stone treatment). Significant treatment
differences were found in the Coleoptera and Hemiptera (Heteroptera, Auchenorrhyncha)
32
faunas of sowing and natural colonisation treatments. In addition, a significant effect of the
steeping stone treatment was found on the Coleoptera assemblages present in the plots.
However, at this stage in succession, no experimental restoration treatment resulted in
assemblages which more closely resembled those of established chalk grasslands.
Differences between treatment plots can be attributed to differences in botanical
composition, canopy structure and amount of litter, but reflect preferences of a range of
common frequent grassland species. These may have rapidly colonised the site through
flighted dispersal or moving from hedgebank at field edge. Few species restricted in their
distribution to chalk grasslands have yet to colonise the plots.
Soil cores were taken from the plots of the main experiment, from the adjacent cropped field
and from 2 established chalk grassland sites. Levels of N were significantly higher in the
CCR plots than in the sown plots, but no difference was found between the natural
colonisation and the sown plots. Levels of P were significantly higher in the natural
colonisation and CCR plots than in the high diversity sowing treatment. These differences
probably reflect the result of the management of the plots by mowing in late summer and
removing clippings. Productivity is highest in high diversity plots, so offtake is likely to be
greatest. This will be especially true for P, as leguminous species are present in sown plots,
but almost absent from natural colonisation plots.
The soils from the high diversity sowing treatment plots showed no significant difference in
the levels of P compared with one of the chalk grassland sites (ADAS index 1). However,
major differences between the experimental plots in general and the established chalk
grassland sites were found for pH, N, K and organic matter. For these factors, the
experimental plots had significantly different values when compared with the chalk
grassland soils, but were not significantly different from the soils of the adjacent cropped
field.
The stepping stone treatment (consisting of turf and soil translocation from a neighbouring
chalk grassland) has effectively enhanced the colonisation of the site by chalk grassland
plant species. Many of the species introduced by this restoration treatment have started to
colonise the untreated areas, so that the stepping stone plots are successfully acting as
focal points for colonisation of the rest of the field. The plant species that are most
successfully introduced using this method are those with a persistent seed bank, especially
short-lived chalk grassland species associated with disturbed soil conditions. Several shortlived ‘turf-compatible’ species have also colonised (eg Euphrasia nemorosa, Blackstonia
perfoliata), as have several species of perennial forb (Viola hirta, Centaurea scabiosa).
Colonisation of the plots with the stepping stone treatment by chalk grassland graminoids
has been limited.
Milestones
All have been met.
Relevance to MAFF
The identification of practical and effective methods for promoting the development of
species-rich grassland on land taken out of intensive arable cultivation are essential for
achieving the policy objectives of the ESA and Countryside Stewardship schemes, together
with the wider objectives of the UK Biodiversity Action Plan.
6. Annual Meeting
The second annual meeting of the AU took place at Bradenham Manor, nr. High Wycombe,
Bucks. on 21 October 1999. The meeting focused on one of the themes of the AU, namely
Arable Reversion. This complemented the theme of the first annual meeting, viz. Grassland
Diversification. The meeting began with presentations from three relevant projects. After
lunch, there was an optional short field visit to one of the experiments (BD1434), described
in the morning session.
33
The afternoon comprised structured discussion groups on four topics, three relevant to the
morning’s session (1-3) and one on a general feature of the AU (4):
1. Species attributes for recruitment/establishment
2. Effects of nutrient dynamics
3. Significance of species interactions
4. Using data from volunteer schemes
The day concluded with an overview of each group’s discussions, followed by brief
concluding comments by Richard Brand-Hardy and Valerie Brown. The programme for the
meeting is given as Appendix 2, and a list of invitees as Appendix 3. Summaries from each
discussion group follow.
Report from Discussion Group 1: Species attributes for recruitment/establishment/
spread (chaired by Alan Hopkins)
The discussion followed the theme in a chronological way. Recruitment was seen to include
(i) recruitment to the newly establishing sward from the seed bank, (ii) from natural inward
dispersal (seed rain) and (iii) from artificially introduced seed. Establishment was considered
the phase from germination leading to successful plant development, spread received less
attention than it deserved.

Under existing guidelines for ESAs/CS caution was considered necessary before
artificially sowing anything, other than a basic grass mixture, if the reversion site was
near an existing species-rich site. However, there is limited information (for many
species at least) on the actual rate of seed rain from nearby sources, relative to the
potential seed production from such sites.

The attributes of particular species, in terms of adaptations to seed dispersal, are all part
of classical biology (adaptations for dispersal by air, through animals, explosive
dehiscence, etc). We avoided dwelling on this; review books such as Pijl (1982) and
Bunce and Howard (1990) are good source documents. Dispersal will vary according to
seed production cycles, between-year effects, factors that may affect seed quantity,
quality and viability. Seed persistence, dormancy and long-term viability are all factors
that affect recruitment from the seed bank. Species that are poor seed dispersers need
further consideration if we are serious about trying to encourage their establishment. In
the past, certain agricultural practices may have compensated for poor ‘natural’
dispersal mechanisms.

Germination is the first step in the establishment process and is affected by a range of
biotic and environmental factors. Arable sites are often relatively homogeneous
(especially in terms of soil fertility), but in some cases a degree of heterogeneity is
provided by stoniness, relict ridge and furrow surfaces, etc. Various environmental
triggers lead to germination. However, it was suggested that variations in soil
characteristics (such as microbial biomass, organic matter, etc) may affect the suitability
of the germination niche (as well as subsequent establishment) and this may warrant
further consideration/investigation. Alternatively, increasing the site heterogeneity may
enable the range of germination niches to be increased. There is a need to identify and
consider further the niche requirements of those species that are rare or which appear
difficult to establish.

Some digression into aspects of longer-term semi-natural grassland led to speculation
that plants of some perennial species may be clones of considerable age, a point
relevant to the subject of arable reversion. This hypothesis may explain why some
species, when introduced artificially, establish but do not spread. Further dispersal by
34
seed of some species may occur only in particular seasons when all the necessary
environmental factors coincide. A number of years may therefore be needed to achieve
an arable reversion sward containing all the target species.

Establishment and spread of species once germination has occurred is influenced
greatly by competition. For the less competitive species, there is a need for low fertility
refuges - this emphasises further the need for site heterogeneity. In the case of
establishment from artificially introduced species (whether by seed or single plants or
turves), it was agreed that there were many unknown factors affecting successful
establishment and spread. These included post-sowing management, time of year of
species introduction, the effects of staggering the introduction of different species in
successive years, as well as the possible effects of making the site more
heterogeneous.
Report from Discussion Group 2:
Chambers)
Effects of nutrient dynamics (chaired by Brian
Topics discussed:
1. Soil analysis
2. Plant analysis
3. Fertility of arable reversion grasslands
4. Targeting of arable reversion sites
1. Soil analysis
A standard soil analysis suite to characterise the fertility of soils was discussed and agreed
as:
 pH (water)
 extractable phosphorus - P (Olsen reagent)
 extractable potassium - K (ammonium nitrate)
 extractable magnesium - Mg (ammonium nitrate)
Results were best presented on a weight/volume (eg mg/litre) basis to reflect the fact that
plants grow in a volume of soil rather than a weight of soil. This approach also helps to
overcome soil density differences when comparing soils with different organic matter
contents, which has a marked influence when results are presented on a weight/weight
basis (eg mg/kg). Sampling depth should be 0-7.5cm as a standard for grassland soils.
The ADAS Index scale provides a simple ranking order for soil nutrient levels, which is
widely recognised throughout the agricultural industry.
Soil total nitrogen (N) measurements were suggested as a broad guide to the amount of
nitrogen that is likely to mineralise from the soil organic nitrogen pool, although the actual
amount that mineralises will depend on many other soil factors (eg temperature, moisture
content, texture, pH etc) and the quality of the soil organic matter (principally C:N ratio).
2. Plant analysis
The measurement of plant nitrogen (N) and P concentrations, and their expression on a
ratio basis, was felt to be a very useful measure of plant N and P supply from the soil. The
N:P ratio would also be useful in identifying where N or P supply was the limiting nutrient to
biomass growth. It was recommended that all field experiments should consider plant N and
P ratio measurements to assess soil nutrient supply. As the nutrient content changes
through the growing season, and is dependent on species composition, it is essential that
date of sampling and floral mix should be recorded.
3. Fertility of arable reversion grasslands
35
It is a common misconception that arable reversion grasslands are ‘fertile’. Certainly, the
majority of arable reversion grasslands will have higher extractable soil P and K levels than
extensive grasslands in the same area, reflecting inorganic fertiliser P and K additions to
increase soil nutrient supply levels during arable cropping. However, in terms of soil total N
and organic matter contents, arable reversion grasslands will have lower levels than
established extensive grasslands, as a result of soil nitrogen mineralisation and organic
matter oxidisation during arable cultivation. On reversion to permanent grasslands, soil total
N and organic matter levels will begin to accumulate, which may lead to immobilisation of
plant available N in the early reversion years. The low N-high P environment will tend to
encourage proliferation of legumes in the short term.
4. Targeting of arable reversion sites
There was discussion on using soil nutrient supply measurements as a means of targeting
arable reversion sites. The ‘worst’ sites for reversion were regarded as those with:
- low total nitrogen and organic matter levels
- high extractable P status (Index 2 or above).
These were situations where white clover had, on a number of sites, quickly dominated the
grassland flora, or where there had been so little grass growth that moss and bare ground
predominated and biomass yields were poor. Clearly, white clover should not be sown as
part of an arable reversion seed mixture. Strategies to enhance the competitive ability of
sown species were discussed, including the use of farmyard manure and inorganic fertiliser
N in worst case reversion situations.
The ‘best’ sites for reversion were regarded as those with:
- moderate total nitrogen and organic matter levels
- low extractable P status (Index 0 or 1).
In these situations, there is a more balanced nutrient supply which will enable sown species
to compete in an environment with moderate levels of N supply, and is likely to help control
clover spread and provide moderate levels of biomass production. Clearly, there will also be
a number of intermediate situations.
The targeting of sown species mixtures was also discussed, with more diverse mixtures
being sown on the ‘best’ sites and less diverse mixtures on the ‘worst’ sites. The problems
of introducing more diverse species at a later date were recognised. The aim of reversion
strategies should initially be to achieve extensive grassland communities, rather than a
specific NVC community.
Report from Discussion Group 3: Species interactions (chaired by Richard Bardgett)
The group was requested to focus on species interactions that may throw further light on the
attributes discussed by group one. The focus was again on establishment of species and
their continued survival and spread.
Key issues discussed:
1. Survivorship: which species fail, which ones succeed?
2. Establishment: main aspects to consider
3. Maximising diversity after establishment
1. Survivorship
(a) Successful species generally have the following characteristics:
 Generalists with no specialised habitat requirements
 Moderately robust perennials able to compete against other species
 Early flowering/seed set to allow seed production before modern hay cut dates
 High seed viability and rate of germination
36
 Good dispersal ability
 CSR strategy (Grime et al. 1987) and tending to be ruderals - competitors
 Appropriate life form and regeneration strategy
(b) Unsuccessful species generally have the following characteristics:
 Specialists
 Palatable to herbivores, especially molluscs
 Poor dispersal
 CSR strategy (Grime et al. 1987) tending towards being stress tolerators
 Small seeds/dormancy mechanisms that prevent rapid germination
2. Establishment
 Timing of sowing. Late-summer/autumn sowing enables some species to germinate
immediately in a warm seedbed and others to break dormancy overwinter for spring
germination.
 Species phenology: define time of flowering and seed set to identify the best time to
collect local seed.
 Regular cutting to remove arable weeds in first season.
 Initial control of herbivores to prevent seedling predation.
3. Management treatments to maximise diversity
(a) Periodic seed addition (overcomes seed limitation). Requires understanding of place of
species in successional sequence (ie early-, mid-, late- successional species).
(b) Maximising spatial variability in resources to provide microsites for establishment:
 Mechanical (cultivation and disturbance) to give micro-topographic variation
 Livestock grazing - dung and urine patches
 FYM addition to create variation in soil resource availability (patches of organic
nutrients and physical shelter)
 Architecture (3 dimensional structure)
(c) Temporal variation: cut date/grazing periodicity may allow occasional seed production
from late flowering species.
(d) Debilitation of dominants with hay rattle (Rhinanthus minor).
 Demonstrated in laboratory experiments and with some field trials
 Further understanding of this mechanism is needed
(e) Enhancing the contribution of mycorrhizas to the creation and maintenance of vascular
plant species diversity.
 Adversely influenced by high soil fertility?
 Beneficially influenced by soil organic matter?
 Enhanced with FYM and/or straw?
Report from Discussion Group 4: Use of data collected by volunteers (chaired by
Rob Fuller)
The discussion focused on the scope and requirements for using volunteers to collect data
in applied scientific projects dealing with interactions between agriculture and wildlife. That
volunteers can make an important contribution is well illustrated by the long-running projects
of the British Trust for Ornithology, which have involved large-scale involvement of
volunteers in the collection of annual data on population levels, breeding success, survival
and movements of birds. In addition, the BTO organises shorter-term projects that focus on
particular issues (eg impacts of land-use) or particular species of conservation concern.
Among the successes of this approach have been the quantification of declines in farmland
bird declines since the 1970s, demographic analyses of declining farmland birds and the
37
publication of three major atlases of bird distribution in Britain. Key points emerging from
our discussion are summarised under the following six headings which are not mutually
exclusive.
1. Why use volunteers?
 There are now several examples, especially for birds, of how volunteers can be used to
collect high quality data.
 Use of volunteers can enable extensive data to be gathered in an extremely costeffective manner, representing extremely good value for money.
 Many volunteers are both highly skilled and dedicated. Some volunteers are prepared to
undertake long-term projects that would be extremely difficult to fund on a purely
professional basis.
 Involvement of volunteers brings scientists into contact with the public and hence helps
to raise the public understanding of science.
 Data quality from volunteers can be very good, providing that the projects are well
organised (see below).
2. What types of questions can be tackled using volunteers?
 An invaluable contribution that volunteers can make is through participation in extensive
projects concerned with measuring widespread spatial distribution or temporal change in
species. These types of data are extremely expensive and difficult to collect with
professionals. Such projects may be basic survey and monitoring, or they may be
concerned with large-scale habitat relationships of species or even with measuring rates
of habitat change.
 There is, however, always scope for the gifted volunteer to undertake intensive work, but
in practice this is usually on issues, sites or species selected by themselves.
 Low-tech projects, needing minimum equipment, are generally the most appropriate for
volunteers.
 For the foreseeable future, ‘popular’ groups are likely to be the most appropriate ones
for extensive volunteer projects. These include dragonflies, butterflies, birds and ground
flora.
3. What is the scope for integrating volunteer and professional data?
 Volunteers can help to test the generality of findings derived from intensive local studies
by professionals. This is already being done in several projects on birds.
 Professionals are generally needed to design and analyse data collected by volunteers.
 Hand-picked volunteers may have a role in collecting data in some intensive studies that
are run by professionals.
4. Design, standardisation and training
 Variation between observers naturally adds to the ‘noise’ in volunteer data sets, but
large sample sizes help to override this.
 It is vital that careful attention is paid to the design of projects to ensure that forms and
instructions are clear and unambiguous. Pilot surveys are invaluable in this respect.
 Training is not always a realistic proposition where a very large number of observers are
being used. However, careful design of proformas and the provision of identification
assistance (BTO has recently started supplying observers with identification tapes for
some difficult surveys) and being open and honest about the skill requirements of
surveys can help considerably.
 Building up networks of reliable observers over a period of time is invaluable. BTO does
this through its Regional Representatives who are responsible for local organisation of
BTO surveys. Training courses are also extremely useful and are now being used by
the Mammal Society and BTO.
 Feedback to volunteers on results is essential to maintain enthusiasm.
 Use of regional organisers can have many advantages (eg checking observer quality,
interacting with local societies and landowners).
38


It is necessary to recognise that a considerable amount of time is likely to be spent in
responding to volunteer queries - but this is time well spent in the long-run.
Adequate time must be allowed to plan and organise a survey: volunteers need to be
informed well in advance about what they are being asked to do: this can also help to
judge likely coverage.
5. Limitations
 Observers often want to select their own sites or sample squares.
Therefore,
randomised surveys can be difficult, but not impossible. BTO now regularly organises
surveys on a random grid square basis.
 It is often difficult to predict take-up and sometimes the final coverage is not ideal. This
can be handled if the survey has adopted a stratified design. Important gaps can
sometimes be filled by professionals.
 Volunteers are not a finite resource and there can be problems of overloading. There is
a need to avoid competition between projects.
 Many volunteers do not like providing detailed data on anything other than the target
species, eg data on habitat quality.
 Volunteers do not always undertake the surveys they promise to do!
 Many volunteers are painfully slow at returning data.
6. Long-term potential
 There is a growing number of volunteers with increasing skill levels. This raises the
prospects for a growing number and variety of volunteer-based projects of increasing
complexity.
 There is opportunity for volunteers to collect long-term detailed population data. An
excellent example is a 20 year population study of Muntjac deer.
 Volunteers could become more involved in the monitoring of biodiversity initiatives by
long-term monitoring at specific sites.
 Volunteers may be able to contribute more to the project costs in future, eg through data
inputting and use of computer technology.
 Volunteers also have a role in giving feedback to landowners and site managers.
39
7. General Comments and Recommendations
During the course of the year, and at meetings and visits, a number of recurrent themes
have again become apparent. The key science issues have been covered in the context of
the review of research problems. The following serve as some additional comments and
suggestions.
Several of the recommendations in the 1998/9 report have already been considered by
MAFF and some acted upon. Issues pertaining to the ‘implementation of projects’, referred
to in the previous report, and still deemed relevant/important are appended.
Profile of Research of Assessment Unit

Contractors have responded well to opportunities to present research of the AU at
scientific meetings. It is particularly welcome when new scientific fora are involved. For
example, several presentations at the British Ecological Society Annual meeting featured
work of the AU.

The heightened debate on the balance between management for productivity and
diversity has focused attention on the research of the AU.

Several projects offered open days or site demonstrations to the user community and to
the general public.

The Annual AU Meeting attracts a high level of support from Contractors, MAFF, FRCA
and other relevant organisations. There is now a healthy exchange of ideas between
Contractors. Contractors have also applauded the opportunity to interact directly with
MAFF science and policy staff.
Management

The Assessment Unit is well managed for the Ministry by Dr Richard Brand Hardy and
good liaison exists with the Programme Advisor, involving regular telephone
conversations and meetings, as appropriate.

The regular update of BD14 projects received by the Programme Advisor is a welcome
and very useful addition this year.

Increased interaction with FRCA staff and project officers this year has been welcomed.
Site visits should perhaps be co-ordinated to optimise potential value to the Contractor.
Reporting

It would be helpful for the Programme Advisor to be kept informed of the receipt of
contract reports and copied them, if this practice was deemed appropriate by MAFF.

Several contractors have commented that acknowledgement of receipt and feedback on
contents of contract reports would be appreciated.
This is especially the case for
Reviews and Final Reports.

A tracking system for reports and a reminder to Contractors may be helpful. Several
reports have been late/very late in submission this year and regular requests for receipt
may be helpful.
Implementation of Projects
40

Wherever compatible with the aims of the project, uniform methodology should be
adopted.
This adds value to the results, by enabling comparability between
enhancement/restoration techniques and/or habitats. In particular, estimates of plant
species cover/abundance and vegetation structure need to be standardised.

In any multisite monitoring or experimental work, consistency (and of course quality) of
input is essential. There is much in favour of division of responsibility, such that one
person controls a particular activity across sites, cf controlling all activities at one site.

Some projects have involved (or will involve) a change in staffing or leadership at some
stage. It is critical that such transitions are well managed and that expertise from the
project is not lost. The effective hand-over of primary data sets is of utmost importance.

A writing-up period should be factored into the end of all projects to enable optimal
dissemination of results in a range of media. This particularly applies to the submission
of papers to scientific journals.

Projects should be 'reviewed' at an early stage to ensure validity of experimental design.
Wherever relevant and/or possible, pre-treatment sampling should take place to improve
statistical rigour. In many cases, this will involve an assessment of the existing
vegetation and, in some cases, the resident seed bank.

Data from MAFF-funded monitoring programmes should be available and easily
accessible to other contractors. This practice adds value-for-money and saves
unnecessary repetition. However, provision of information must be timely, so as not to
impede progress in projects.
41
Appendix 1. Programme Advisor: Terms of Reference
The Contractor will use its scientific expertise to contribute to the effective development,
execution, evaluation and communication of the Ministry-funded programme of research by
acting as Programme Adviser for the Species-Rich Grassland Assessment Unit and its
constituent Projects. This objective will be attained within the following terms of reference:
1. Through a check on the progress of all Projects within the Assessment Unit by at least
one annual visit.
2. By organising a meeting in mid-October 1999 of contractors, the Ministry, FRCA, and
other interested sponsors of research to review progress in the Assessment Unit,
exchange information about the Projects and facilitate co-ordination amongst the
contractors.
3. The production of a review of progress for each Project within the Assessment Unit and
for the Assessment Unit as a whole, with specific focus given to the achievement of
milestones, outputs and adherence to the agreed Project proposal. This review of
progress will form the basis of the final report referred to below and an interim report
produced at the end of September 1999.
4. The production of an agreed final report within four weeks of the termination date of the
Contract. This report, with two hard copies and one on disk, should consist of a
maximum of 20 pages, and must include an identification sheet, a one-page executive
summary and scientific report, with annexes of detailed information being added as
necessary.
5. By advising the Ministry on new research opportunities within the Assessment Unit
during the year and/or at the annual meeting of the Assessment Unit.
6. By encouraging the adoption of compatible and, where appropriate, uniform
experimental methodology in all projects within the Assessment Unit.
7. By actively promoting the objectives, methods and results of the Assessment Unit in cooperation with research contractors and the Ministry.
42
Appendix 2. Programme for Annual Meeting
Theme: Arable Reversion
Bradenham Manor, The Chilterns
21 October 1999
10.00
Introduction to the structure and science of the AU
10.30
Multi-site experiments on the restoration of
herb-rich grassland - arable reversion (1403/1404):
(45 minutes + 15 minutes discussion)
Valerie Brown
1. Rationale and experimental design
Richard Pywell
2. Responses of vegetation to experimental treatments
(i) Species richness and frequency
(ii) Soil nutrient dynamics
Richard Pywell
Mike Burke
3. What are the key messages?
Richard Pywell
Effects of different seed mixtures for the reversion
of arable land to species-rich grassland (BD1404)
(20 minutes + 10 minutes discussion)
Francis Kirkham
Methods of accelerating development of chalk
grassland on ex-arable land (BD1434)
(20 minutes + 10 minutes discussion)
Simon Mortimer
12.30
Lunch, followed by an optional short field visit
(led by Simon Mortimer)
14.00
Discussion Groups -
11.30
12.00
A scientist from the AU will chair each Group and in Groups 1-3 arable reversion will be the
main focus. Group 4 will address an issue that is important to the entire AU. It is hoped that
representatives from projects other than those featured in the morning will be prepared to
summarise their own relevant data. As far as possible, participants will be allocated to groups
before the meeting. Representatives from MAFF/FRCA and other organisations will be free to
join groups as they wish
1. Species attributes for recruitment/establishment - Alan Hopkins
2. Effects of nutrient dynamics - Brian Chambers
3. Significance of species interactions - Richard Bardgett
4. Using data from volunteer schemes - Rob Fuller
16.00 Tea
16.20 Discussion Group/Summaries
16.45
Views from MAFF/ FRCA
17.00 Close
43
Appendix 3. Invitees to the Annual Meeting
* Nancy Vaughan
* Valerie Brown (Chair)
Project Staff
* Jerry Tallowin (BD1424)
Rory Sackville-Hamilton
*
*
*
*
Rob Fuller (BD1435)
* Juliet Vickery
Liz Asteraki
* (Jerry Tallowin)
Alan Hopkins (BD1402/1403/1404/1431)
Richard Pywell
Michael Burke
James Bullock
* Brian Chambers (BD1429)
* Nigel Critchley
* Roger Smith (BD1408)
Juliet Frankland
* Deborah Millward
* Richard Bardgett
* Simon Peacock
* Robert Shiel
* Francis Kirkham (BD1410)
(Michael Burke) (BD1412)
* Iain Diack
*
*
*
*
*
*
* Simon Mortimer (BD1414.1434)
* Andrea Turner
* Martin Warren (BD1427)
* Tom Brereton
(Jerry Tallowin) (BD1415)
Jim McAdam
Steve Rushton
Dave Chadwick
Roger Smith
* Jo Goodyear
* Gerard Hoppé
(Brian Chambers)
(Richard Bardgett)
(Michael Burke)
(Francis Kirkham)
*
*
*
*
MAFF/FRCA
John Osmond
Ann Tarran
Peter Costigan
Richard Brand-Hardy
Frances Radcliffe
Tim Boulding
Michael Harm
Richard Belding
Andrew Cooke
David Glaves
David Hares
Neil Jackson
David Martin
Steve Peel
David Smallshire
Andy Swash
Other Organisations
Ian McClean, JNCC (Clare Burrows)
Will Peach, RSPB
Andy Evans, RSPB
Katharine Hearne, The National Trust
John Harvey, The National Trust
John Miles, SNH
Richard Jefferson, EN
Heather Robertson, EN
Rachel Thomas, EN
Mike Pienkowski, European Forum on
Nature Conservation and Pastoralism
Andy Roach, The National Trust
Peter Robertson, Game Conservancy Trust
(Tim Milson)
Sarah Webster, DETR
Names in parenthesis, previously mentioned in project listed.
* attendees
Stephen Harris (BD1436)
44
Confidential Annex: Priorities for Future Research
General
The portfolio of projects in the AU is already sound and relevant to MAFF’s policy and to the
increasing environmental pressures on agricultural land. To maximise effectiveness of the
AU’s R&D budget, it may be expedient to consider the following:
(i)
Much valuable baseline data, relevant to ESA and CS schemes, have been/or are
being acquired through MAFF’s Monitoring Programme and in some past and present
projects in this AU. There is a need to capitalise on these data and to integrate them
into new projects, wherever possible. Relevant data are also available from northern
Europe and from non MAFF-funded work.
(ii) Much disparate and sometimes unworked data exist which are relevant to certain
priorities in the AU. For relatively small financial input, ‘creative’ reviews may be
commissioned.
(iii) There is a growing need to focus attention on understanding the mechanisms
underpinning changes in habitat quality, or the effects of land management practices to
redress these changes. This approach steers away from site specific description and
leads to generalisations and confident predictions and/or recommendations. Further,
the tailoring of recommendations to specific situations is possible, once mechanisms
and species interactions are understood.
(iv) Addressing mechanisms (usually) involves rigorous field experimentation that may need
to be long-term, as changes in biodiversity are commonly slow to occur. Results from
restoration management tend to gain momentum with time and thus long-term projects
are sometimes necessary.
(v) Increasingly, the science of the AU requires a multidisciplinary approach. Consortia of
different organisations give excellent value for money. However, the funding level must
be realistic for the work involved.
Clearly, within an AU with such a wide scope, there is a wealth of topics warrenting
attention. Here, I have specifically focused on areas relevant to MAFF policy, where
information is needed to (i) modify existing prescriptions for diversification measures, (ii)
provide more sympathetic management of grasslands for biodiversity and productivity and
(iii) new areas of research. These are categorised under issues relating to:

Diversification

Productivity

Management

New initiatives
No priority is implied.
1
Diversification Issues
The AU now includes several successful projects addressing techniques for enhancing
biological diversity, without compromising productivity to an undesirable extent. The results
of these projects have highlighted the need for additional research to fine-tune the
guidelines/prescriptions forthcoming from this work and, more especially, in targeting sites
for diversification measures.
1. Spatial configuration of intervention practices
Several techniques, currently being assessed within the AU, are unrealistic on the field scale
(plug plants, soil inocula, turf transplants, severe disturbance or the addition of Rhinanthus
to reduce the competitive ability of the vigorous grasses), but may be applied to small areas
to serve as ‘foci’ for outward dispersal by seed and/or vegetative growth. Such spread of
species is already being demonstrated in several projects in the AU, especially when
nutrient input is constrained. Field tests of the spatial configuration which optimises spread
of ‘desirable’ plant species and associated organisms would enable more realistic uptake of
these options within a real farm situation. Additionally, there is sound ecological theory to
underpin some of the concepts involved, which would increase the scientific rigour of such
work.
2. Significance of spatial heterogeneity of grassland
It is well known that maximum co-existence of plant species, and hence biodiversity, is
achieved in a heterogeneous habitat, which provides different species with different
amounts and types of resources (eg light, nutrients). Thus, a key objective in grassland
management should be the creation of habitat heterogeneity, both before and after
establishment or reseeding. There are two key issues of importance here: (i) how can
structural heterogeneity be achieved and subsequently retained without compromising
productivity? and (ii) what is the extent of biodiversity enhancement? Within the AU, some
projects are already addressing innovative ways which have the potential of imposing more
structural heterogeneity on the sward (eg severe disturbance, addition of Rhinanthus to
reduce the competitive ability of the grasses), but the issue of structural heterogeneity per
se is not being fully addressed. Furthermore, there are two components of structural
complexity: the vertical structure of the sward and its horizontal ‘patchiness’. Again, there is
a fair body of ecological work to inform, especially in terms of the importance of structural
complexity to ‘rarer’ plant species and their associated, often specialist, invertebrate fauna
as well as small mammals and birds.
3.
Significance of landscape - scale characteristics in targeting sites for
diversification
There is a growing awareness of the importance of landscape in relation to the success of
diversification (and conservation) initiatives. This is an area which has received more
attention in mainland Europe than in the UK, due mainly to the research of Baudry and
colleagues in France. The concept of ‘graininess’ of the landscape is a significant issue in
determining the potential for natural colonisation of, mainly, arable areas. Essentially, finedgrained landscapes with many small parcels of land under different land use are more
conducive to successful diversification measures than the course grained landscapes of, eg
East Anglia or parts of SW England. Such research could also be extended to target areas
optimal for diversification measures or, indeed, other land-use on a farm scale. The
research would involve review, survey and a modeling component.
4.
Optimal management before and after the implementation of diversification
techniques
It is now clear that specific diversification treatments can be applied which can elevate the
species richness of grassland swards. However, results from ongoing, and recently
completed, projects within the AU are revealing a certain degree of stochasticity in the
results obtained. Some of the variability can be simply attributed to nutrient levels, but it is
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clear that more sympathetic management both pre- and post-treatment (especially relevant
to the addition of seed mixtures) could do much to alleviate many of the difficulties imposed
by high nutrient levels. Furthermore, many of the more desirable components of seed
mixes are both costly and difficult to obtain in large supplies (eg local provenances). Thus,
when sites are targeted for restoration, there is a need to optimise success of relatively low
seed application rates. A range of relatively simply imposed measures needs to be tested,
eg manipulating the timing of cutting and/or grazing to produce a sward of high receptivity to
seed application and amenable to the early, critical stages of establishment. Sequential
sowing of species, based on sound knowledge of their ecological requirements, is another
and related treatment which needs to be assessed. The commissioned review (BD1433)
should provide relevant information.
5.
Plant strategies which optimise dispersal and the persistence of species under
diversification management
An outcome of the 1998/99 AU assessment was for MAFF to commission a review
(BD1433) to investigate the seed characteristics of different plant species seeds which
make species amenable to diversification treatments. From BD1402-04 (multi-site
experiments) and BD1434, it has become clear that certain species are predisposed to high
levels of dispersal (by seed or vegetative spread) and, more importantly, persistence in a
closed sward. A short review of species success in these respects, in specific situations
(soil type and nutrient level), would do much to inform on the species that should be
included in seed mixes. Failure of species to establish or spread is costly and impacts
negatively on the perception of intervention techniques to enhance diversity. Information is
available in the ecological/restoration literature, but needs collating.
6.
Factors influencing success in the addition of hay as a means of enhancing
biodiversity
There is some, mainly anecdotal, evidence that the addition of hay from species rich
grassland can enhance biodiversity of plant species and associated organisms. Indeed, this
is already being clearly demonstrated in BD1414, even after one year. If this is indeed the
case, it is a powerful, relatively easily applied and cost effective means of enhancing
biodiversity in arable reversion or the diversification of existing grasslands. However,
relatively little is known about the optimal timing and rate of application. It would appear that
higher rates act in a negative way, actually reducing seedling recruitment because of the
thatching and mulching effect of the hay. The timing of application, the feasibility of
sequential applications (to target plant species with different reproductive phenology) and
the best means of collection and spread warrant further attention. For example, certain
harvesting methods may have adverse effects on propagules or the mobile invertebrate
fauna. A simple, but rigorous, field experiment would be needed to fine tune guidelines and
optimise benefits from this prescription under CS.
Currently, supplement payments for hay spreading (RX) are too low for the option to be
widely taken up. Research should inform policy as to the potential environmental benefit,
fine-tune guidelines and provide a basis for modification of payments.
Productivity Issues
7.
Reasons underpinning the decline in productivity during the course of arable
reversion
Generally, the early stages of arable reversion, that involve standard seed mixes, have
reasonable levels of productivity. However, after the first two or three years, there is
commonly a substantial decline in productivity with the result that farmers are frequently
applying for derogations to add nutrients. Additionally, on shallow calcareous soils, as the
productivity declines, moss establishment can become a problem, impeding recruitment
from seed and closure of the sward. The reasons underpinning this decline need to be
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explored by sound agronomic assessments and the exploration of techniques to address the
problem.
8. Improved understanding of the nutrient quality of hay
Diversification and other management techniques commonly introduce new plant species
into the sward, or modify the percentage contribution of particular species of grass or forb.
Apart from the obvious desirability of knowing the forage quality of species, there is a fair
amount of anecdotal evidence that certain species may have negative effects on hay quality.
For example, Rhinanthus is known to cause overheating, while Plantago possesses toxins.
A short review may be useful is collating a rather disparate set of information and establish
whether further research is indeed necessary. The outcome could be an appreciation of the
balance between biodiversity quality of the species and the resulting hay quality.
Management Issues
9. Effects of normal farm practice on associated biodiversity
Associated biodiversity, agrobiodiversity or functional biodiversity, is a new concept that
mainly relates to the valuable biodiversity associated with agricultural systems (this may be
considered in terms of organisms beneficial to ecosystem function or productivity). Results
from BD1435 are giving a clear indication that the biodiversity (in this case of birds and
invertebrates) is being strongly influenced, inter alia, by silage cutting. Indeed, the reduction
in biodiversity is much greater than would be expected from a mere reduction in vegetation
structure. Moreover, recovery at best is very slow. While farming practice in relation to
birds has received some attention, that for invertebrates (especially pollinators) has not.
During the establishment of diversification measures, this may be particularly critical.
10. Scrub: targeting sites for optimal environmental benefit under CS
Scrub clearance is an option under CS. In lowland Britain, scrub is a seral, transitory
vegetation type, determined mainly by grazing pressure and rabbit population densities. It is
generally deemed an undesirable habitat within the context of agricultural land, even though
its nature conservation value has recently been highlighted by English Nature, particularly in
the context of birds and some invertebrate groups, mainly the butterflies and moths. At
present, the extent of scrub cover is used to determine level of payment under CS, with
higher payments for clearing higher density scrub: SS, SA, SB and SC (from base payment
to clearance of >75%). These criteria may well be ill advised, as scrub which has reached a
high level of canopy closure will have lost many of the ‘typical’ grassland species and have a
much reduced propagule supply. Even if cleared, it may never revert to grassland of any
quality or productivity. At present, judgement on sites is mainly subjective. Research is
needed to assess critical thresholds on different soil types (with different characteristic scrub
communities) and thereby determine optimal scrub cover for payments. It is likely that more
environmental benefit may be gained from clearing larger areas with lower scrub cover,
while allowing areas with higher cover to revert to woodland, as successional dynamics
would predict. However, the dynamics of this transitory, and often cyclical vegetation type,
are little known so that the higher payments could well be in vain. I consider scrub to be a
priority, but the basic concept would apply equally well to bracken.
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New Initiatives
10. Significance and role of biotic interactions in the soil
Traditionally, and understandably, there has been much emphasis on the importance of
abiotic factors relating to soil structure and nutrient levels in the agri-environment. However,
recent, mainly ecological, research is clearly demonstrating the importance of soil
biodiversity, the dynamics of that diversity and, more especially, the interactions between
the soil biota and the plant. In arable reversion, the change from bacterial to fungal
microbial pathways is particularly relevant. Therefore, ways of accelerating this transition
are of importance. The same applies to methods of diversification in grasslands, since the
transition will increase the efficacy of the plant symbiotic mycorrhizal fungi, with concomitant
effects on plant species richness and performance.
Research within the AU is
demonstrating a time lag between the establishment of plant species and that of its
associated diversity. Minimising this lag will enhance the quality of the developing, or
diversifying sward, as well as its productivity. Management methods to accelerate this lag
need to be explored, but within the context of an assessment of the functioning of the soil
biota. There is a growing, and somewhat disparate global literature, on this topic and a
critical review might be a logical first step.
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