Download Oulanka Research Station, FINLAND September 8th – 11th, 2014

Biodiversity loss in freshwater ecosystems: causes and consequences
Oulanka Research Station, FINLAND
September 8th – 11th, 2014
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Acknowledgements
NORBS 2014 has been based on voluntary work by the organizing and scientific committees. Their
contribution and quality of work have been tremendous and of vital importance. Special thanks go
to plenary speakers for their contribution; Brendan McKie (Swedish Agricultural University,
Sweden), Sonja Jähnig (Leibniz Institute for Freshwater Ecology and Inland Fisheries, Germany),
Charles Hawkins (Utah State University, USA), Ian Donohue (University of Dublin, Ireland), and N.
LeRoy Poff (Colorado State University, USA). Without them this would not have been possible.
We acknowledge our sponsors for financial support: Maj and Tor Nessling Foundation, Federation
of Finnish Learned Societies, and Thule institute, University of Oulu.
Thank you!
The organizing committee of the NORBS 2014 consisted of following people:
Professor Timo Muotka, University of Oulu
Director Riku Paavola, Oulanka Research Station
Postdoc Jussi Jyväsjärvi, University of Oulu
Postdoc Pauliina Louhi, University of Oulu
Phd student Kaisa-Leena Huttunen, University of Oulu
The scientific committee of the NORBS 2014:
All organizers listed above and
Senior research scientist Jukka Aroviita, Finnish Environment Institute
Senior research fellow Heikki Mykrä, Thule institute
NORBS 2014, Oulanka Research Station, Finland
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DETAILED SCHEDULE
Monday 8 September
20:00
Arrival at Oulanka Research Station
Get together
Tuesday 9 September
08:00-09:00 Breakfast
9:15-10:00
Opening words and introduction of the Oulanka Research Station (Timo
Muotka, Riku Paavola)
Chair: Jan Herrman
10:00-10:45 Plenary talk
Brendan McKie, Swedish Agricultural University, Uppsala, Sweden: Björn
Malmqvist’s laboratory: Insights into the relationship between detritivore diversity
and litter decomposition from boreal streams
A short break
10:50-11:10 Jonas Persson: Can the CNP stoichiometry of Nordic EPT invertebrates help us
understand their organic pollution tolerance?
11:10-11:30 Mikko Tolkkinen: Anthropogenic disturbance decreases functional stability in
streams
11:30-11:50 Kaisa Mustonen: Experimental manipulation of flow and sedimentation: effects on
stream communities and ecosystem processes
12:00-13:00 Lunch
Chair:
13:10-13:55 Plenary talk
Sonja Jähnig, Leibniz Institute for Freshwater ecology and Inland Fisheries,
Berlin, Germany: Assessing effects of global change on stream benthic
invertebrates
A short break
14:00-14:20 Romain Sarremejane: Modeling of future stream macroinvertebrate communities
under climate change
NORBS 2014, Oulanka Research Station, Finland
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14:20-14:40 Mari Annala: Community structure and concordance of three taxonomic groups in
multi-stressed streams
14:40-15:00 Mira Grönroos: Assessing the strength of distance decay of community similarity at
hierarchical spatial scales
15:00-15:30 Coffee break
Chair: Riku Paavola
15:30-16:15 Plenary talk
Charles Hawkins, Utah State University, Logan, USA: Predictability and
vulnerability of freshwater biodiversity to landscape alteration and climate change
A short break
16:20-16:40 Mika Nieminen: Assessing the impacts of forestry and peat mining on boreal
headwater streams using the chironomid pupal exuviae technique
16:40-17:00 Riccardo Fornaroli: Predicting the constraint effect of environmental characteristics
on macroinvertebrate density and diversity using quantile regression mixed model
17:00-17:20 Henn Timm: Identification guide to freshwater macroinvertebrates of Estonia
17:30
Dinner
18:00
Sauna & social
Wednesday 10 September
8:00-9:00
Breakfast
Chair: Pauliina Louhi
09:00-9:45
Plenary talk
Ian Donohue, University of Dublin, Ireland: Biodiversity loss and the stability of
ecosystems
A short break
9:50-10:10
Jarno Turunen: Restoration of sediment-stressed forest streams has little effects on
benthic biodiversity and ecosystem functions
10:10-10:30 Peter Wiberg-Larsen: Restoration of River Skjerne – did biodiversity of
macroinvertebrates and macrophytes improve?
10:30-10:50 Jan Herrman: Tench population size regulating invertebrate numbers: a conservation
management tool?
11:00-12:00 Lunch
12:30-16:30 Field trip
NORBS 2014, Oulanka Research Station, Finland
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17:30
Departure for Oivanki (Conference dinner)
18:30-19:00 Introduction to River Oulankajoki and Oulanka Nature Park (slide show by Dr.
Pirkko Siikamäki, Finnish Forest and Park Services)
19:00-22:00 Conference dinner
Thursday 11 September
08:00-09:00 Breakfast
Chair: Leonard Sandin
09:00-09:45 N. LeRoy Poff, Colorado State University, Ft. Collins, USA: Using traits-based
approaches to project biodiversity loss and functional shifts in stream benthic
communities under rapid climate change
A short break
09:50-10:10 Annika Vilmi: Unravelling the drivers of freshwater diatom biodiversity in the context
of large-lake assessment
10:10-10:30 Kimmo Tolonen: Do different facets of littoral macroinvertebrate diversity respond
similarly to ecological gradients in a large boreal lake?
10:30-10:50 Kaisa-Leena Huttunen: Habitat complexity enhances the stability of stream
macroinvertebrate communities
10:50-11:15 General assembly: Is there a future for Norbs?
11:15-12:00 Lunch, Adjourn
NORBS 2014, Oulanka Research Station, Finland
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PLENARY
BJÖRN MALMQVIST’S LABORATORY: INSIGHTS INTO THE
RELATIONSHIP BETWEEN DETRITIVORE DIVERSITY AND LITTER
DECOMPOSITION FROM BOREAL STREAMS
Brendan G. McKie
Department of Aquatic Sciences & Assessment, Swedish University of Agricultural Sciences, P.O. Box 7050,
SE-75007 Uppsala, Sweden
[email protected]
http://www.slu.se/vatten-miljo/brendan-mckie
Björn Malmqvist was one of the Nordic region’s leading stream and river ecologists, who
combined a love of traditional, species-focused natural history with strongly question driven
research, which drew on his broad knowledge of the wider ecological literature. This is
demonstrated above all by the insight shown in his foray during the late 1990’s into the field of
biodiversity-ecosystem functioning (B-EF) research. B-EF research investigates how ecosystemlevel processes, such as primary production or detrital decomposition, vary with biodiversity,
most often expressed as species richness. In the late 1990’s, B-EF research focused largely on the
process of plant productivity in terrestrial grasslands. While decomposition was measured as an
additional parameter in some terrestrial studies, the early experiments and field studies conducted
by Björn and his colleagues demonstrated the full potential of aquatic detrital food webs as model
systems for B-EF research. Indeed, as a result of Björn’s pioneering research, our current
understanding of how detritivore diversity affects leaf decomposition is based very largely on
studies of boreal stream food-webs.
Biodiversity is declining catastrophically in most ecosystems worldwide, and streams and rivers are
no exception, with multiple human disturbances driving losses of species at local and regional
scales. Most of the early stream B-EF research was conducted in laboratory microcosms, and
these results indicate that increasing the species richness of detritivores often has positive effects
on leaf decomposition and related ecosystem processes, though several examples of neutral and
negative relationships also have been observed. However, the relevance of much of the
laboratory-based research for predicting the likely effects of biodiversity loss in nature remains
unclear, given the high degree of spatio-temporal dynamism in both environmental conditions and
community composition and diversity that characterises stream environments. Indeed, after a
decade of laboratory-based research, we remain unable to address some basic questions of key
management relevance. For example, the importance of biodiversity for functioning in streams
relative to other biotic and abiotic drivers remains unclear, as does the extent to which
biodiversity can help buffer human impacts on functioning, and it is not possible to predict when
and where biodiversity will be important for functioning in situ. To address these shortcomings,
stream B-EF research has been shifting towards more field-based research, with a greater
emphasis on the diversity of functional traits rather than species. Findings from these field studies
provide strong evidence that biodiversity can be as important a driver of ecosystem functioning as
other important abiotic and biotic drivers in situ, but not universally. Development of a framework
for predicting exactly when and where species loss will have its greatest impact remains challenging.
NORBS 2014, Oulanka Research Station, Finland
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PLENARY
ASSESSING EFFECTS OF GLOBAL CHANGE ON STREAM BENTHIC
INVERTEBRATES
Sonja Jähnig
Leibniz Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany
[email protected]
Stream ecosystems are impacted in many ways, both directly and indirectly, e.g. by climate change
and through interactions with other stressors such as land-use change, structural degradation or
pollution by nutrients. Significant, widespread consequences have been observed and are further
expected for the freshwater fauna. I will present different approaches to assess the vulnerability of
stream biota to global change like species distribution models (SDMs), integrated modelling, or
threshold analyses. SDMs inform about large scale potential effects from climate change, as shown
for Europe and North America. Learning from the current range distributions of species and
which environmental variables shape them we simulated how these ranges may shift through time
under climate warming and land use change scenarios. However, these large-scale SDMs do not
consider riverine characteristics sufficiently. To integrate stream specific data into SDMs is a
challenging task that requires the integration of detailed datasets or hydrologic and hydraulic
models. Yet, this promises further insights into combined effects of climate change, resulting
possible flow changes, land use alterations and related water quality issues. Our research shows
that drivers and pressures acting at large spatial scales influence and even limit macroinvertebrate
assemblages. Both aspects have implications for applied issues, like local management measures
such as restoration, or monitoring, e.g. on the detection of climate sensitive zones.
NORBS 2014, Oulanka Research Station, Finland
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PLENARY
PREDICTABILITY AND VULNERABILITY OF FRESHWATER
BIODIVERSITY TO LANDSCAPE ALTERATION AND
CLIMATE CHANGE
Charles Hawkins
Utah State University, Department of Watershed Sciences and Ecology Center, 5210 Old Main Hill, Logan,
Utah 84322-5210, USA
[email protected]
Landscape and waterway alteration has severely altered the local and regional biodiversity of
freshwater ecosystems on most of the planet. Climate change is expected to further affect
freshwater biodiversity by directly affecting thermal and hydrologic regimes including those of
systems that have largely escaped the effects of landscape alteration. In this talk I will summarize
work my lab has conducted in collaboration with others to better understand the predictability
and vulnerability of freshwater ecosystems to human-caused stress. Much of our work has
involved use of large data sets produced by the USEPA, other agencies, and my lab to develop and
link climate, water temperature, hydrologic, and biodiversity models. From this work we have
discovered that local assemblage composition can be well predicted from 4-5 hydrologic, thermal,
and geomorphic variables; predictability of composition decreases and beta diversity increases with
decreasing drainage density, increasing aridity, and increasing nutrient concentration; climate
change may have as large of an effect on local biodiversity as that of landscape alteration; and
vulnerability of individual water bodies to climate change will be variable and contingent on local
factors that mitigate thermal and hydrologic response to climate change. These model results
represent hypotheses in need of experimental testing.
NORBS 2014, Oulanka Research Station, Finland
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PLENARY
BIODIVERSITY LOSS AND THE STABILITY OF ECOSYSTEMS
Ian Donohue
Department of Zoology, School of Natural Sciences, Ireland and Trinity Centre for Biodiversity Research, Trinity
College Dublin, Ireland
[email protected]
Ecological networks are tightly interconnected, such that the extinction of a single species can
initiate a sequence of events triggering additional species losses. However, strong perturbations
such as species loss can destabilize ecosystems in a variety of frequently unanticipated and
unpredictable ways. I will discuss how explicit appreciation of the multifaceted nature of ecological
stability is essential in order to understand the true potential for perturbations to destabilize
ecosystems. I will also show how microevolution may be as important as species extinctions in
shaping the response of communities to environmental change.
NORBS 2014, Oulanka Research Station, Finland
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PLENARY
USING TRAITS-BASED APPROACHES TO PROJECT BIODIVERSITY
LOSS AND FUNCTIONAL SHIFTS IN STREAM BENTHIC
COMMUNITIES UNDER RAPID CLIMATE CHANGE
N. LeRoy Poff
Colorado State University, Ft. Collins, USA
[email protected]
Predicting responses of aquatic species and communities to climate change is a key scientific
challenge. By linking species attributes to dominant environmental drivers that vary across the
landscape, a traits-based approach can be used to help explain current variation in species
abundance and local community structure. Similarly, by linking species occurrence or abundance
to variable thermal and hydrologic conditions across large spatial extents, it is possible to evaluate
species assemblage responses to projected changes in temperature and precipitation expected
under rapid climate change. Species’ vulnerability to deviations in temperature and precipitation
depends on the sensitivity of individual species to changing conditions – this varies among species
and across species’ ranges. In addition, vulnerability reflects the projected exposure of species
populations to local climate-induced changes in temperature and flow conditions – this also varies
geographically. In this presentation, the rationale for using traits-based approaches to predict
species and community responses to climate change will be presented, along with a specific
analysis that evaluates sensitivity of 88 widely distributed benthic insect species across broad
spatial gradients of temperature and streamflow conditions in 251 “reference” stream reaches
across 12 states and 8 ecoregions in the western United States. Using downscaled climate change
projections, site-specific vulnerability of species to projected shifts in temperature and flow is
quantified to assess risk of species deletions and associated reductions in biodiversity and changes
in community function from local to ecoregional scales.
NORBS 2014, Oulanka Research Station, Finland
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CAN THE CNP STOICHIOMETRY OF NORDIC EPT INVERTEBRATES
HELP US UNDERSTAND THEIR ORGANIC POLLUTION
TOLERANCE?
Persson, J.(1)
(1)
The Norwegian Institute for Water Research (NIVA), Gaustadalléen 21 NO-0349 Oslo Norway
[email protected]
Macroinvertebrate pollution scores that rely on that macroinvertebrate taxa differ in their
tolerance to organic pollution are routinely used to monitor running waters. However, the
mechanisms behind these taxonomic differences in tolerance are relatively unexplored. I will test if
the tolerance levels of macroinvertebrates are related to their stoichiometric composition (carbon
(C), nitrogen (N), phosphorus (P).
The N and P content of aquatic autotrophs are relatively flexible; in contrast, they are constrained
within narrower ranges in heterotrophs. This observation leads to the question whether
macroinvertebrates with higher nutrient content, and presumably high nutrient requirements, are
more likely to be found in more nutrient-rich (i.e., polluted) sites, containing food with higher
nutrient content.
The present study will focus on the stoichiometric variation within the Nordic EPT taxa (May-,
Stone- and Caddis-flies), which are very important in environmental monitoring. Their CNP
stoichiometry will be related to BMWP tolerance scores, taxonomy, and functional groups.
NORBS 2014, Oulanka Research Station, Finland
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ANTHROPOGENIC DISTURBANCE DECREASES FUNCTIONAL
STABILITY IN STREAMS
Tolkkinen M. (1), Mykrä H.(2), Markkola AM. (3), Muotka T. (3)
(1)
Finnish Environment Institute, Oulu Office, P.O.Box 413, FI-90014, University of Oulu, Finland,
[email protected]
(2)
Thule Institute, P.O. Box 7300, FIN-90014, University of Oulu, Finland
(3)
Department of Biology, P.O. Box 3000, 90014 University of Oulu, Finland
Compelling evidence shows that species diversity may enhance temporal stability of ecosystem
function, suggesting that disturbance-induced loss of biodiversity could destabilize ecosystem
function. In temporally varying environments, however, functional stability is often regulated by the
same environmental factors that also shape diversity, and these other factors could be more
important drivers of stability than diversity per se. Using field experiments conducted during three
consecutive years we examined the effects of anthropogenic disturbances in creating temporal
variability of fungal communities and leaf litter decomposition in boreal streams. Temporal
variability of decomposition rates was higher in disturbed sites than in near pristine reference
sites. Despite the higher degree of variation in decomposition rates in disturbed sites, there were
no differences in mean decomposition rates among the stream groups. Among-year variability of
decomposition rates was positively related to among-year variability in water chemistry and fungal
OTU evenness. Fungal communities in disturbed sites were less diverse and more dominated by a
few key taxa than communities in reference sites, yet they were as stable as those at reference
sites. Our results outline the need to examine variability of ecosystem processes, because
responses to anthropogenic stress may be overlooked by focusing solely on mean rates.
NORBS 2014, Oulanka Research Station, Finland
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EXPERIMENTAL MANIPULATION OF FLOW AND SEDIMENTATION:
EFFECTS ON STREAM COMMUNITIES AND ECOSYSTEM PROCESSES
Mustonen K.(1), Mykrä H.(2), Louhi P.(3), Tolkkinen M.(4), Alioravainen N.(5), Lehtinen
S.(6), Markkola A.(7), Marttila H.(8), Tammela S.(9), Klöve B.(10), Huusko A.(11), Muotka
T.(12)
(1)
Thule Institute, P.O. Box 7300, FI-90014 University of Oulu, Finland, [email protected]
Thule Institute, P.O. Box 7300, FI-90014 University of Oulu, Finland, [email protected]
(3)
Department of Biology, P.O. Box 3000, FI-90014 University of Oulu, Finland, [email protected]
(4)
Finnish Environment Institute, P.O. Box 413, FI-90014 University of Oulu, Finland, [email protected]
(5)
Department of Biology, P.O. Box 3000, FI-90014 University of Oulu, Finland, [email protected]
(6)
Department of Biology, P.O. Box 3000, FI-90014 University of Oulu, Finland, [email protected]
(7)
Department of Biology, P.O. Box 3000, FI-90014 University of Oulu, Finland, [email protected]
(8)
Water Resources and Environmental Engineering Research Group, P.O. Box 4300, FI-90014 University of Oulu,
Finland, [email protected]
(9)
Water Resources and Environmental Engineering Research Group, P.O. Box 4300, FI-90014 University of Oulu,
Finland, [email protected]
(10)
Water Resources and Environmental Engineering Research Group, P.O. Box 4300, FI-90014 University of Oulu,
Finland, [email protected]
(11)
Finnish Game and Fisheries Research Institute, Manamansalontie 90, FI-88300 Paltamo, Finland, [email protected]
(12)
Department of Biology, P.O. Box 3000, FI-90014 University of Oulu, Finland, [email protected]
(2)
Stream ecosystems are affected by multiple abiotic stressors, and species responses to different
stressors may differ from those predicted based on the individual effects of each stressor alone.
Using 12 artificial streams we examined the individual and interactive effects of flow and fine
sediments (sand grain size < 2mm) on benthic macroinvertebrates and ecosystem processes (leaf
litter breakdown rate; algal biomass accrual). Sediment addition had a negative effect on benthic
algal biomass and microbial leaf breakdown rates, whereas responses of macroinvertebrates were
more variable. Algal biomass increased in high-flows, whereas in low-flows both microbial and
macroinvertebrate-induced leaf breakdown rates were enhanced. This study reveals the
complicated nature of the interaction between flow and sedimentation in lotic ecosystems, and
how variably community and ecosystem-level factors respond to these stressors, highlighting the
importance of the use of multiple measures of stream ecosystem health.
NORBS 2014, Oulanka Research Station, Finland
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MODELING OF FUTURE STREAM MACROINVERTEBRATE
COMMUNITIES UNDER CLIMATE CHANGE
Mustonen K.(1), Sarremejane R. (2), Mykrä H. (3, 4), Marttila H. (5), Muotka T.(6,4)
(1)
Thule institute, University of Oulu, Finland, [email protected]
Thule institute, University of Oulu, Finland, [email protected]
(3)
Thule institute, University of Oulu, Finland, [email protected]
(4)
Finnish Environment Institute, Paavo Havaksen tie 3, 90570 Oulu.
(5)
Water Resources and Environmental Engineering Research Group, University of Oulu, Finland,
[email protected]
(6)
Department of Biology, University of Oulu, Finland, [email protected]
(2)
At the northernmost latitudes, air temperature is predicted to increase steeply by the end of the
century. Precipitation and snow-fall are also predicted to change with potentially significant effects
on flow regimes. In boreal regions, water temperatures are unlikely to exceed the upper
physiological limits of warm-water species, but cold-water species may be unable to escape the
novel thermal regimes and their distributions may be strongly affected by global warming. Lotic
organisms are also likely to confront novel flow regimes, in particular in headwater streams with
low and variable discharges. We used site-specific modeled air temperatures and flow regime
indices to predict the future macroinvertebrate community composition of 240 sites sampled
across Finland. We developed a River Invertebrates Prediction and Classification System
(RIVPACS)-type model to predict the present-day composition of macroinvertebrate communities
and to evaluate potential future changes in composition of these communities. The final model was
built using six environmental variables related to flow and temperature. Preliminary results
revealed changes in observed to expected (O/E) ratios of macroinvertebrate taxa when predicted
communities were compared to present day communities. More analyses will be conducted to
identify the species and stream types most vulnerable to climate change.
NORBS 2014, Oulanka Research Station, Finland
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COMMUNITY STRUCTURE AND CONCORDANCE OF THREE
TAXONOMIC GROUPS IN MULTI-STRESSED STREAMS
Annala, M.(1), Mykrä, H.(2,3), Tolkkinen, M.(3), Kauppila, T.(4), Paasivirta, L.(5), Muotka,
T.(1,3)
(1)
(2)
(3)
(4)
(5)
Department of Biology, P.O. Box 3000, FI-90014, University of Oulu, Finland
Thule Institute, P. O. Box 7300, FI-90014, University of Oulu, Finland
Finnish Environment Institute, Oulu Office, P.O. Box 413, FI-90014, University of Oulu, Finland
Geological Survey of Finland, P.O. Box 1237, FI-70211, Kuopio, Finland
Ruuhikoskenkatu 17 B 5, FI-24240, Salo, Finland
Studies on the interactive effects of multiple stressors on biological communities have focused on
individual or population-level responses in laboratory microcosms, while field-based studies on
community-level responses are rare. We examined the influence of natural vs. human-induced
stress and their interaction on the community composition of diatoms, bryophytes and
macroinvertebrates. We further assessed the effects of underlying environmental gradients on
community concordance among the biological groups and identified the most important
environmental variables structuring these communities. We sampled 12 sites in each of the four
stream categories: circumneutral reference, circumneutral impacted, naturally acidic and naturally
acidic impacted streams. Both natural (low pH, high metal concentrations) and anthropogenic
(forest drainage) stressors affected community composition of all three taxonomic groups, but
only invertebrates showed an interactive response with communities differing between reference
and impacted sites but only in the circumneutral region. Community concordance was relatively
high among all pairs of communities, diatoms being most strongly concordant with the other
groups. Although diatoms showed the greatest concordance with invertebrates, diatom and
bryophyte communities responded most similarly to the environmental gradients. Our results
implicate that communities typical to naturally acidic streams are at least equally sensitive to
additional stressor as those in circumneutral streams.
NORBS 2014, Oulanka Research Station, Finland
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ASSESSING THE STRENGTH OF DISTANCE DECAY OF
COMMUNITY SIMILARITY AT HIERARCHICAL SPATIAL SCALES
Grönroos M.(1), Oksanen J. (2), Heino J. (3)
(1)
Natural Environment Centre, Finnish Environment Institute, Biodiversity, Oulu, Finland,
[email protected]
(2)
Department of Biology, University of Oulu, Oulu, Finland, [email protected]
(3)
Natural Environment Centre, Finnish Environment Institute, Biodiversity, Oulu, Finland,
[email protected]
Environmental filtering and dispersal are two major factors structuring ecological communities. In
stream systems, understanding the roles of these two factors could benefit, for example,
restoration and bioassessment. One problem with correlative approaches is that high and limited
dispersal rates may produce similar patterns. Here, we tested the idea that comparing the patterns
at two hierarchical spatial scales would differentiate between high and low dispersal rates. For
instance, high dispersal rates should lead to stronger spatial structuring at small scale compared to
the larger scale and limiting dispersal should lead to an opposite situation. To study which factors
structure stream insect communities, we used a dataset collected from ten streams draining into
the River Oulankajoki (10 riffle sites from each stream, i.e. altogether 100 sites) and compared the
decay of community similarity within streams (small scale) and across streams (large scale). The
distance decay pattern along the geographical gradient suggested that high dispersal rates and
environmental filtering are the main processes in this system. However, the distance decay pattern
along the environmental gradient was more in line with what was expected for limiting dispersal.
We conclude that more research is needed to better differentiate the processes structuring
stream communities.
NORBS 2014, Oulanka Research Station, Finland
17
ASSESSING THE IMPACTS OF FORESTRY AND PEAT MINING ON
BOREAL HEADWATER STREAMS USING THE CHIRONOMID PUPAL
EXUVIAE TECHNIQUE
Nieminen M. L. (1,4), Ärje J. (2), Raunio J. (3), Meissner K. (4)
(1)
University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University
of Jyväskylä, Finland, [email protected]
(2)
University of Jyväskylä, Department of Mathematics and Statistics, P.O. Box 35, FI-40014 University of Jyväskylä,
Finland, [email protected]
(3)
Water and Environment Association of the River Kymi, Tapiontie 2C, FI-45160 Kouvola, Finland,
[email protected]
(4)
Finnish Environment Institute (SYKE), Freshwater Centre, Survontie 9A, FI-40500 Jyväskylä, Finland,
[email protected]
Thirty percent of Finland’s total land area is covered by peatlands, 55% of which have been drained
for forestry and 0.6% is used for peat production. Despite the small total area used, peat
production is locally focused, and can thus have significant and measurable local impacts on aquatic
ecosystems.
Our aim was to test the effectiveness of the chironomid pupal exuvial technique (CPET) in the
ecological assessment of small peatland draining headwater streams that receive drainage waters
from forestry and peat mining areas. We collected data from 120 streams located within peatland
covered boreal catchments. Community analyses were run together with GIS data determined for
each sites’ catchment area and various environmental measurements from each site.
New insights into the aquatic impacts of peatland use were obtained through the inclusion of
Chironomidae genus-level information and areas for further research related to CPET and its use
in headwater streams were identified. Although chironomid genus level information is currently
largely underused, CPET is a viable option for freshwater monitoring of peatland use effects.
NORBS 2014, Oulanka Research Station, Finland
18
PREDICTING THE CONSTRAINT EFFECT OF ENVIRONMENTAL
CHARACTERISTICS ON MACROINVERTEBRATE DENSITY AND
DIVERSITY USING QUANTILE REGRESSION MIXED MODEL
Fornaroli R.(1), Cabrini R. (1), Sartori L. (1),Marazzi F. (1),Vracevic D. (1), Mezzanotte V.(1),
Annala M. (2), Canobbio S. (1)
(1)
(2)
DISAT, University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milano, Italy, [email protected]
Department of Biology, University of Oulu, PL 3000 90014, Oulu, [email protected]
Various factors, such as habitat availability, competition for space, predation, temperature, nutrient
supplies, presence of waterfalls, flow variability and water quality control the abundance,
distribution and productivity of stream-dwelling organisms. Each of these factors can influence the
relationship between the density of organisms and a single environmental gradient and inflate
variability.
In our study, we used quantile regression mixed models and Akaike’s information criterion as an
indicator of goodness to examine two different dataset, one belonging to Italy and one belonging
to Finland.
In the Italian dataset, the relationships among five macroinvertebrate families and three physical
habitat characteristics were studied (water velocity, depth and substratum size); in the Finnish
dataset instead we have studied the relationships between taxa richness and 16 environmental
characteristics (both chemical and morphological).
We have found limiting relationships in both dataset. All these relationships were then validated
using data different from those used in the model development phase.
These relationships are quantitative and can be used to predict the range of macroinvertebrate
densities or taxa richness as a function of environmental characteristics. They can be used for
management purposes in habitat-based models and in the development of ecological indices.
NORBS 2014, Oulanka Research Station, Finland
19
IDENTIFICATION GUIDE TO FRESHWATER
MACROINVERTEBRATES OF ESTONIA
Timm H. (1)
(1) Centre for Limnology, Estonian University of Life Sciences, 61117 Rannu, Tartumaa, Estonia,
[email protected]
Macroinvertebrates are so diverse that their identification keys usually include only higher taxa
(genera, families or orders), not the total fauna. In Estonian freshwaters, about 1600 different
species of macroinvertebrates have been found so far. Two popular keybooks that comprise their
major groups were published in Estonia (in 1956 and in 2008) but scientific guides for the whole
fauna were still missing. The adequate foreign keys are scattered in numerous sources: about 20
different books or files were needed to identify the common environmental indicators. Even these
keys miss some local species, although they introduce many exotic or redundant representatives.
Thus, a new guide to Estonian freshwater macroinvertebrates was composed. It is best suited for
last-instar larvae and water-living adults of the taxa with known bioindicative values. The guide
includes 435 species or higher taxa and consists of 18 identification keys to different animal groups
(both in Estonian and English). The keys are supplemented by 153 figures with >1500 original
photos. List of names, environmental preferences, feeding types and frequencies of occurrence are
added.
NORBS 2014, Oulanka Research Station, Finland
20
RESTORATION OF SEDIMENT-STRESSED STREAMS HAS LITTLE
EFFECTS ON BENTHIC BIODIVERSITY AND ECOSYSTEM
FUNCTIONS
Turunen J.T.(1), Muotka T. (2), Louhi P. (3), Tolkkinen M. (4), Aroviita J. (5)
(1)
Finnish Environment Institute, Freshwater Centre, PO Box 413, 90014 University of Oulu, Finland,
[email protected]
(2)
University of Oulu, Department of Biology, PO Box 413, 90014 University of Oulu, Finland,
[email protected]
(3)
University of Oulu, Department of Biology, PO Box 413, 90014 University of Oulu, Finland,
[email protected]
(4)
Finnish Environment Institute, Freshwater Centre, PO Box 413, 90014 University of Oulu, Finland,
[email protected]
(5)
Finnish Environment Institute, Freshwater Centre, PO Box 413, 90014 University of Oulu, Finland,
[email protected]
Excessive sedimentation due to intensive land use by agriculture and forestry is a predominant
stressor to stream ecosystems. We studied the effects of small-scale catchment and in-stream
restoration on benthic macroinvertebrate diversity and ecosystem functioning by comparing (i)
restored streams (N=9), (ii) sediment-stressed streams (N=11), and (iii) near-natural streams
(N=10) in northern Finland. The excessive sedimentation in our study area was mainly caused by
sand originating from forest drainage activities. Macroinvertebrate community composition in the
restored streams differed significantly from the near-natural streams, but not from the sedimentstressed streams. Similarly, macroinvertebrate diversity in the restored streams was significantly
lower than in the near-natural streams, but did not differ from the sediment-stressed streams.
However, ecosystem functioning measured by leaf litter breakdown rate was similar among the
stream groups. The results thus indicate that sedimentation may degrade biodiversity but not
necessarily key ecosystem functions. Overall, our results suggest that current management
measures do not reduce streambed sedimentation sufficiently to enhance benthic biodiversity.
NORBS 2014, Oulanka Research Station, Finland
21
RESTORATION OF RIVER SKJERN – DID BIODIVERSITY OF
MACROINVERBRATES AND MACROPHYTES ‘IMPROVE’?
Wiberg-Larsen P. (1), Baattrup-Pedersen A.(2), Kristensen E.A. (3), Kronvang B. (4),
Hansen R.R. (5)
(1)
Institute of Bioscience, Aarhus Universitet, Vejlsøvej 25, DK-8600 Silkeborg, [email protected]
Institute of Bioscience, Aarhus Universitet, Vejlsøvej 25, DK-8600 Silkeborg, [email protected]
(3)
Alectia A/S, Skanderborgvej 190, DK-8260 Viby J, [email protected]
(4)
Institute of Bioscience, Aarhus Universitet, Vejlsøvej 25, DK-8600 Silkeborg, [email protected]
(5)
Institute of Bioscience, Aarhus Universitet, C.F.Møllers Allé 8, DK-8000 Aarhus C, [email protected]
(2)
During 1999-2003 the lower 19 km of River Skjern and its valley was restored from its former
highly regulated form, creating a meandering 25 km long reach, a stream delta, several new small
tributaries, ponds and lakes, and wet meadows. The main purpose of the project was to reduce
nutrient loading of the recipient, Ringkøbing Fjord, which was in a bad ecological state, Further,
the project should restore the ecological quality of the river itself, and increase its biodiversity and
recreational value. With a total price of 37 million €, the restoration project is the largest and
most expensive in Denmark ever. But has it been worth the price? And have we obtained the
goals and gained biodiversity? We have tried to answer these questions based on monitoring data
from before, one year after, and ten years after the restoration. We also included unique historical
data from before the regulation of the stream in the 1960’s in order to put the recent physical and
biological development into a “pristine” perspective. The data and analyses included stream
morphological parameters like total area, area of backwaters, width, depth, and substrate
composition, whereas we biologically focused on macroinvertebrate EPT taxa and macrophytes.
NORBS 2014, Oulanka Research Station, Finland
22
TENCH (TINCA TINCA) POPULATION SIZE REGULATING
INVERTEBRATE NUMBERS; A CONSERVATION MANAGEMENT
TOOL? –– EXPERIENCES FROM A SMALL BIRD LAKE ON THE
ISLAND OF ÖLAND, SE SWEDEN
Herrmann J (1), Ekstam B (1)
(1)
Linnaeus University, Department of Biology, SE-391 82 Kalmar, Sweden, [email protected]
Large-scale reduction of (white)fish, thereby cascading to reduce phytoplankton production has
worldwide been practiced for decades. In Knisa mosse, a shallow calcareous lake (18 ha) lake on
the island of Öland, SE Sweden, the bottom-feeding fish tench (Tinca tinca) was introduced several
decades ago, now dominating the fish community. Presumed to be a key species, controlling
benthic and pelagial invertebrates, the tench population was over eight years (May-June) by netting
substantially reduced from high densities, hopefully favouring invertebrates, these offering more
food for ducks and waders (shore birds), Due to resource shortage, the tench population was
allowed to re-increase. Standardized multi-mesh gill net fishing was performed before, during, and
after the reduction years (August). Number of individuals and average size of caught tenches
clearly declined, due to fishing, and reversed after fishing ceased. Several invertebrates, as
chironomids, copepods, and cladocerans, also some mayfly, gastropod and mussel species,
responded positively to tench reduction, i.e. increased in numbers. Unfortunately most of them
also declined at tench recovery, while other bottom taxa showed less clear numerical changes.
The ultimate objective, tench reduction favouring water birds, seems partially corroborated as an
increase of ducks and geese, but last years’ of birds still seems unclear.
NORBS 2014, Oulanka Research Station, Finland
23
UNRAVELLING THE DRIVERS OF FRESHWATER DIATOM
BIODIVERSITY IN THE CONTEXT OF LARGE LAKE ASSESSMENT
Vilmi A.(1), Karjalainen S. M. (2), Hellsten S. (3), Heino J. (4)
(1)
Finnish Environment Institute, P.O. Box 413, FI-90014, University of Oulu, [email protected]
Finnish Environment Institute, P.O. Box 413, FI-90014, University of Oulu,
[email protected]
(3)
Finnish Environment Institute, P.O. Box 413, FI-90014, University of Oulu, [email protected]
(4)
Finnish Environment Institute, P.O. Box 413, FI-90014, University of Oulu, [email protected]
(2)
Freshwater ecosystems face a variety of anthropogenic pressures, and different approaches and
indicator groups are used to study the effects of those pressures on ecosystem structure and
function. Diatoms are a widely used indicator group because they occur in all kinds of freshwater
ecosystems and they react relatively quickly to changes in the environment. An ongoing debate
centres on whether diatoms are ubiquitously dispersed or if they show spatially-structured
biodiversity patterns. Understanding of the spatial structuring of diatom communities should also
be associated with the assessment of lake ecosystem state. We aimed to determine the main
drivers, both environmental and spatial, influencing the diatom assemblages, diatom indices and
diversity indices. The statistical methods used were variation partitioning through distance-based
RDA and distance-based linear models. Our results showed that spatial variables were more
strongly related to our response variables than environmental variables. Thus, it seems that spatial
factors are more important than water chemistry in determining freshwater diatom biodiversity in
stony littorals of large lakes. These findings imply that mass effects (i.e. high dispersal rates) are
likely to interfere with species sorting (i.e. environmental filtering). Acknowledging the importance
of spatial processes is hence important in the context of large lake assessment.
NORBS 2014, Oulanka Research Station, Finland
24
DO DIFFERENT FACETS OF LITTORAL MACROINVERTEBRATE
DIVERSITY RESPOND SIMILARLY TO ECOLOGICAL GRADIENTS IN
A LARGE BOREAL LAKE?
Tolonen K.T.(1), Vilmi A.(2), Karjalainen S. M.(3), Hellsten S.(4), Heino J.(5)
Finnish Environment Institute, P.O. Box 413, FI-90014 University of Oulu, Finland (all authors)
1
[email protected]
2
[email protected]
3
[email protected]
4
[email protected]
5
[email protected]
Understanding of biodiversity patterns requires information about both environmental filtering and
dispersal processes. In this context, the spatial scale of a study is essential because patterns and
processes are scale dependent. Studies on the diversity and structure of lake assemblages have
generally been focused on among-lake scales, while only few studies have examined within-lake
patterns in biodiversity. In a large boreal lake, we sampled littoral macroinvertebrates from 81
littoral sites with stony substrate. We examined how different facets of biodiversity respond to 1)
local environmental conditions and 2) within-lake spatial location of a site. Studied facets of
diversity were species richness, diversity, evenness, taxonomic distinctness, taxonomic diversity,
functional richness, diversity and functional evenness. Unexpectedly, we found that the diversity of
littoral invertebrates was not clearly related to any of the measured water chemistry variables.
Instead diversity was significantly spatially structured. This finding suggests that high dispersal rates
between sites interfere with environmental filtering, thereby complicating understanding of
diversity-environment relationships. Such spatially-structured variation in diversity and underlying
mechanisms should explicitly be acknowledged in the assessment of lake ecological status.
NORBS 2014, Oulanka Research Station, Finland
25
HABITAT COMPLEXITY ENHANCES THE STABILITY OF STREAM
MACROINVERTEBRATE COMMUNITIES
Huttunen K-L.(1), Mykrä H.(2), Astorga A.(3), Paavola R.(4), Muotka T.(1,5)
(1)
Department of Biology, University of Oulu, Finland
Thule Institute, University of Oulu & Finnish Environment Institute, Freshwater Centre
(3)
Centro de Investigación de Ecosistemas de Patagonia, Chile
(4)
Thule Institute, University of Oulu
(5)
Department of Biology, University of Oulu & Finnish Environment Institute, Natural Environment Centre
(2)
We studied the temporal turnover of macroinvertebrate communities in 23 near-pristine boreal
streams across 14 years using Bray-Curtis distance as the measure of among-year dissimilarity. We
related temporal turnover to environmental stability, habitat complexity and productivity using
multimodel inference. We hypothesized that high environmental stability, high habitat complexity
and high productivity would lead to low temporal variation (high stability) in community structure.
Effects of total abundance and species richness on temporal turnover were controlled for using
rarefied samples and null models, respectively. The dominant factor related to temporal turnover
was macrophyte cover (habitat complexity), followed by bed movement (environmental stability)
and periphyton chl-a (productivity). Streams with high macrophyte cover supported more stable
communities, whereas, against our expectations, the relationship between among-year similarity
and bed disturbance index was negative, suggesting that disturbance acts as a habitat filter that
selects for highly tolerant species. Most of the temporal variation in biological communities was
caused by species with intermediate abundances. Instead, the core species of the community were
generally present each year and exhibited limited inter-annual rank shifts.
NORBS 2014, Oulanka Research Station, Finland
26
NORBS 2014, Oulanka Research Station, Finland