Download Kildare`s Hedgerows

Kildare’s
Hedgerows
Kildare
Heritage
Series
1
An Action of the County Kildare Heritage Plan
The 2006 Kildare Hedgerow Survey
Kildare’s network of hedgerows is a huge asset to the county for agriculture, landscape, water quality, carbon sequestration, employment and our wild flora and fauna.
The 2006 County Kildare Hedgerow Survey was initiated by the Heritage Office of
Kildare County Council as an action of the County Kildare Heritage Plan. The survey
was conducted by Neil Foulkes and funded by Kildare County Council and the
Heritage Council. The aim of the survey was to record the extent, species composition, structure, condition and management of the county’s hedgerows.
In the summer of 2006 field recording of hedgerows was carried out using a standard methodology in 18 sample 1km squares distributed evenly around the county,
covering approximately 1% of the total area of the county. Within each sample
square a maximum of 10 hedges were randomly
selected for detailed study.
The status of Kildare’s hedges
Hedges were traditionally planted to define land boundaries and as stockproof barriers and shelter for livestock and crops. In the 1950s and ’60s, many of Kildare’s
hedgerows were removed to create larger fields for agriculture. More recently the
wildlife benefits of our hedgerows have been recognised and maintenance of our
hedges is encouraged under the Rural Environment Protection Scheme (REPS).
The 2006 County Kildare Hedgerow Survey found there is wide contrast in the structure and composition of the county’s hedgerows, from the precisely managed hedges
on studfarms and tillage land to the less formal hedges on less intensively managed
lands to the west of the county.
The total length of hedgerow in County Kildare was estimated at 10,305km. Average
hedgerow density was 5.92km per square kilometre.
Approximately 19% of the hedges recorded were classed as ‘species-rich’ (i.e. with
five or more native woody species in a 30m strip), with the majority of these found
in the north of the county.
Today, most of Ireland’s trees are found in our hedgerows, and hedgerows act as suboptimal woodland-edge habitat for an array of species. A hedgerow provides not just
a single habitat; it contains three layers: the tree layer, shrub/hedge layer and ground
layer.
Cover images: Blackthorn sloes (JB); germander speedwell (ZD); blackbird (KCC).
This page: Blackthorn (ZD); cowslip (KCC); hedgerow plants (KCC).
What species are found in Kildare’s hedges?
The 2006 Hedgerow Survey found a wide variety of shrub and
tree species in Kildare’s hedgerows. A total of 45 shrub and tree
species, including 20 native species, were recorded.
Woody Climbers
Shrubs
Ground flora
Some 37 shrub species, including 18 natives, were recorded in
the hedge layer. Whitethorn (or ‘hawthorn’) is the most frequently occurring shrub. Other common shrub species include
ash, elder, blackthorn, and privet. Hazel, holly, willow, elm, gorse,
spindle, oak, guelder rose and crab apple are also found.
Ground flora recorded in Kildare’s hedges included bird’s foot
trefoil, bittersweet, bladder campion, bluebell, burdock, butterbur, charlock, chickweed, columbine, common field speedwell,
common poppy, common reed, cowslip, cranesbill, creeping
cinquefoil, dog violet, field pansy, field wood-rush, figwort, garlic mustard, germander speedwell, greater stitchwort, hedge
roundwort, herb robert, hop trefoil, knapweed, lords and ladies,
marsh bedstraw, meadow vetchling, meadowsweet, nipplewort,
ox-eye daisy, primrose, quaking grass, red dead nettle, red valerian, rosebay wilowherb, vetch, St. John’s Wort, tormentil, wild
strawberry, yellow iris and wood avens.
Bramble was recorded in 94% of the surveyed hedges. Wild
roses were recorded in 62%, while honeysuckle was recorded in
just 11% of hedges.
Trees
The most common tree species recorded include ash,
whitethorn, sycamore, oak, beech and willow. Other species
recorded were birch, crab apple, wild cherry, holly, elm, black
poplar, alder, elder and maple.
Wild Cherry
2%
Snowberry
2%
Guelder Rose
Oak
4%
5%
Spindle
Crab Apple
5%
6%
Wild Plum
6%
Beech
Holly
7%
8%
Gorse
10%
Sycamore
12%
Hazel
13%
Willow
15%
Elm
15%
Privet
43%
Blackthorn
48%
Elder
Ash
51%
57%
93%
Hawthorn
0%
10%
20%
30%
40%
50%
60%
70%
Frequency of occurrence of main shrub species in sampled hedges in Co. Kildare
80%
90%
100%
Landscape & Tourism
The Value of
Hedgerows form an integral part of
our traditional Irish ‘green’ landscape,
endowing the
countryside with a distinctive and
attractive appearance. Therefore they
are an important asset for tourism.
A refuge for
wild plants and insects
With pressure on most of our
habitats the hedgerow provides a
refuge for many of our wild plants and
invertebrates. Relatively free from pesticides and insecticides a healthy
ground flora can develop.
Shelter for livestock
and crops
A hedge provides shelter 15 times its
own height on its leeward side and
three times its height on the windy
side.
As stock-proof barriers, hedges also
separate animals, preventing nose-tonose contact, and trapping airborne
pathogens, thereby reducing the
spread of diseases, such as brucellosis
and tuberculosis.
Images anti-clockwise from left: Hedge
landscape (JB); pyramidal orchid (ZD);
horse (JB); laid hedge (NF); canal scene;
whitethorn haws (JB); rabbit burrow
(JB); baby fox (JB).
Centre: whitethorn in blossom (KCC).
Carbon sequestration
Hedgerows cover approximate 1.5% of the
land area of the country and therefore play
a role in meeting Ireland’s obligations
under the Kyoto Protocol.
Employment
Hedgelaying and maintenance
provides rural employment in a
traditional skill.
f Hedgerows
Habitat corridors
Our wild animals are shy, often nocturnal creatures that avoid open
spaces, where they are vulnerable to
predation and human activity.
The hedgerow network provides safe
routes for travel between breeding
sites and feeding areas.
Six of our ten native bat species
make particular use of hedgerows
during hunting expeditions and as
they travel between roosting sites.
Birds of prey, such as the sparrowhawk and barn owl fly along
hedgerows during hunting trips.
A ‘home’ for wildlife
With such a lack of woodland in
Ireland, hedgerows provide an alternative woodland-edge habitat for
wildlife. Badgers often excavate setts
under hedgerows, and hedgehogs, rabbits, squirrels, pine martens, foxes and
stoats can also be found here. Twothirds of our bird species nest in
hedgerows.
Above left: the entrance to a rabbit
burrow under a hedge
A source of food
Reduce flooding and pollution
Hedgerows contribute a great deal to water quality. The hederows’ root
systems regulate the movement of water through the landscape, absorbing and recycling nutients, thus reducing the risk of pollution, while also
reducing the potential for flooding and preventing siltation in waterways.
Hedgerow fruits provide food
for hungry birds over winter.
Quality of hedges in County Kildare
A series of ‘favourable conditions’ were identified to guide conservation practice for
hedges with a high biodiversity value. These favourable conditions are:
- Average height at least 2m
- Average width at least 1.5m
- Less than 10% gaps, with no individual gap wider than 5m
- Base of woody component closer than 50cm to ground
- Less than 10% introduced non-native species
23% of all hedges sampled in Kildare passed all of these favourable standards. 18.8%
were classed as species-rich (i.e. with five or more native woody species in a 30m strip)
and of these 41% passed the above criteria for favourable conditions. This means 7.7%
of the total hedges sampled were found to be both species-rich and in favourable
condition – an identical finding to the County Offaly survey but some way below the
14.5% in Co. Laois.
Lack of height and width is an issue in some hedges but is relatively easy to rectify. Of
much more significance are the excessive level of gaps and the poor base structure in
many of the county’s hedges. This is associated with lack of management intervention.
Non-native species such as wild privet, beech and sycamore also make some hedges
less favourable for wildlife and the conservation of our biodiversity.
Images from top: mature oak (NF); Lords and ladies (KCC); frog (KCC).
60%
56%
% of hedges surveyed
50%
48%
40%
30%
23%
20%
10%
10%
9%
7%
0%
Favourable
Too low
Too narrow
Too gappy
Are Kildare’s hedges in favourable condition?
Base not
dense
Excessive
non-natives
Construction of our hedgerows
Most hedges are of a standard construction, with a single line of shrubs planted on
the side of a hedge bank, often with an associated drain. Stone walls are not a common feature of Kildare hedges. Over 80% of hedges are part of boundaries that have
been in existence since at least the time of the first Ordnance Survey in 1837-1838.
The double ditch is a unique feature of Co. Kildare’s hedges, with 2.5% of the surveyed hedges constructed in this way.
Good hedgerow management
Good management prolongs the life of a hedge, but care must be taken not to
adversely impact on the biodiversity value of the hedgerow. Tall, wide hedgerows are
better for wildlife than short, narrow ones, especially if there are hedgerow trees.
Kildare’s hedgerows were found to contain a high proportion of trees and lots of
young trees which is good news for the sustainability of the resource. Occasional
saplings of all species, should be selected and allowed to grow to maturity, giving a
range of ages of trees within the hedgerow.
The Wildlife Act 2000 prohibits the cutting of hedges during the period 1st March to
31st August inclusive, during bird nesting season. Ideally hedges should be trimmed
in February as this leaves nuts and berries over autumn and winter as a food source
for hungry animals, and avoids harming nests. Don’t cut hedges more than once in a
three-year cycle (except at points on roadsides where safety takes precedence).
Where hedgerows are cut they must be cut to an A-shaped profile. Fencing wire
should not be attached to hedgerow trees or shrubs.
When planting a new hedge, you should always plant native species and a variety of
species. More species means more types of food for insects and birds; and the flowering season is extended which is good for bees and butterflies. It is important to
source plants of local provenance. Some nurseries stock common species such as
whitethorn that may have come from as far away as Eastern Europe.
Effort should be made to preserve the grass layer along the hedge. By doing so the
ground flora is allowed to develop. The quest for neatness should not take precedence over conservation of our native species. Instead, the grass verge, a refuge for
many of our wild flowers could be cut at intervals. Cutting in September will encourage late summer flowers; July cutting will encourage spring flowers.
Tree layer
Ground layer
Hedge layer
(trimmed to
A-shape)
Threats to our hedgerows
Old hedges are often removed unnecessarily and
replaced with fencing, or non-native planting
which does not have the same wildlife value. Here
a native hedge is retained. In addition to their
wildlife value, hedgerows provide privacy and
shelter for rural homes. (KCC)
Hedgerow removal for agricultural purposes is not likely to be significant due
to the protection offered through the Rural Environment Protection Scheme
(REPS). However, loss through deterioration in quality and ageing is likely to be
a factor on farms if rates of rejuvenation are not increased. Repair of degraded
hedgerows involves substantially higher costs than the routine maintenance of
hedges in good condition.
Direct hedgerow loss through removal for development purposes is likely to
be an ongoing problem into the future. Often this involves short lengths to
facilitate access and sight-lines for new one-off houses. Loss rates are relatively small but do contribute to habitat fragmentation. It is estimated that 420km
of hedgerow were removed in Ireland for rural dwellings in 1999 alone.
More stringent guidelines are required for planting new hedgerows for both
agriculture and motorway development. Issues noted in this survey included
the use of non-native species, foreign provenance seed, poor quality planting
stock and planting too close to fences, leading to browsing by livestock.
Although County Kildare currently holds a valuable hedgerow resource,
appropriate efforts must be made if this resource is to be improved and sustained into the future.
Native hedge removed and replaced with a timber
post and rail fence. (KCC)
Further information
For further information or to request a detailed copy of the 2006 Hedgerow Survey Report, please contact :
Bridget Loughlin, Heritage Officer, Kildare County Council, Aras Chill Dara, Devoy Park, Naas, Co. Kildare.
Phone 045-980840 Email: [email protected]
www.kildare.ie/countycouncil/Heritage
The following leaflets are available on the KCC Heritage website:
Conserving Hedgerows, The Heritage Council
Hedgerow Rejuvenation, Teagasc
Planting New Hedgerows, Teagasc
Routine Trimming of Hedgerows, Teagasc
The Value of Hedgerows, Teagasc
Text by Juanita Browne. Photographs by Kildare County Council, Neil Foulkes, Juanita Browne and Zoe Devlin. Cover photograph by Tony Keane.