Ecosystems and Biodiversity: overview of

Transcription

1 Ecosystems and Biodiversity: overview of mechanistic studies David Chandler, Walter Dodds, Mark Eberle, Michelle Evans-White, Keith Gido, David Hoeinghaus, Tony Joern, Angela Laws, Justin Murdock, Jesse Nippert, Jim Thorp

2 Ecosystems and Biodiversity: overview of mechanistic studies Natural History Collections Integration Modeling Ecoforecasting Mechanistic Studies

3 Terrestrial Studies

4 What is the physiological plasticity and potential for adaptive evolution in Panicum virgatum in response to altered precipitation and N deposition? 4 native genotypes in the Central Plains Objective 1: Measure the ecological responses of P. virgatum to projected changes in precipitation and nitrogen deposition Objective 2: Assess the presence and expression of genetic variation within and among populations to changes in precipitation and nitrogen deposition Objective 3: Model productivity responses to changes in precipitation and nitrogen deposition to assess potential future ecosystem change resulting from the physiological i l plasticity of natural populations Nippert et al., pending NSF support

5 We are manipulating rainfall timing and soil N availability using the Mesocosm facility at the Konza Prairie. P. virgatum genotypes are planted in replicated individual mesocosm cells (64 total) and receive 1 of 4 rainfall treatments and 1 of 2 nitrogen deposition treatments (8 total). All mesocosm cells (and genotypes) receive the same amount of annual precipitation as per the native site, but the timing of rainfall is altered according to climate change predictions for the Central Plains Seasonal rainfall distribution Equal 50 / 50 Growingseason / Dormant season Ambient 75 / 25 2 rainfall intervals every 12 days Altered every 6 days Ambient +N +N +N +N ambient N or +N (5g/m 2 ) added to each rainfall treatment

6 How will species interactions vary with climate change? Temperature, Food quality, etc ( ) ( ) Altered temperature and food quality, which are predicted to vary with climate change, have potential to affect invertebrate species interactions. (+)/( ) Potential for non linear, indirect interactions make predictions difficult without an understanding of underlying mechanisms Understanding the mechanisms will enable us to make predictions about responses of other systems to climate change. Laws and Joern, pending NSF support

7 Field Experiments Treatments: Temperature (ambient, increased, decreased) Food Quality (ambient, decreased) Grasshopper Density (high, h low) Predation Risk (predators present, absent) Measure grasshopper performance (survival, body mass, fecundity) in each treatment

8 Grasshopper fecundity at Konza The relative importance of biotic and abiotic factors in controlling fecundity in grasshopper populations is not well understood Conducting a long term survey of 4 grasshopper species in eight watersheds at Konza to measure fecundity Management practices (fire, bison grazing) Grasshopper density Food quantity and quality Weather/temperature Hatching phenology Orphulella speciosa

9 Aquatic Studies

10 Eco-Forecasting in the Kansas River: Species, Communities, i and the Ecosystem James H. Thorp and KU River Ecology Lab Grad Students (Brian O Neil, Sarah Schmidt, and Bradley William)

11 Ecoforecasting in the Kansas River: KU River Ecology Lab

12 Eco-Forecasting Research Strategies for the Kaw Predictions of Climate Change Models [Changes in Precipitation & Runoff Patterns] [Results from other EPSCoR & national scientists] Changes in River Hydrogeomorphology gy [Direct effects from altered hydrology and indirect effects from altered channel geomorphology] [River Ecology group at KU] Microalgal Community Structure and Net Ecosystem Metabolism [Sarah Schmidt] Zoobenthic Community Structure [Brian O Neill] Species Distributions s [Bradley Williams]

13 Community & Ecosystem Effects [see posters for details] Microalgal Community Structure Zoobenthic and Net Ecosystem Metabolism Community Structure [Sarah Schmidt; Ph.D. project] [Brian O Neill; Masters; going g on to Ph.D] Effects on NEM from variation in geomorphic complexity (longitudinal & lateral) and hydrologic changes (amount & variability) Differences in algal community in thalweg and slackwater areas Contribution of benthic algae & phytoplankton to photosynthesis Changes in microbial loop (future project) Masters Research: Effects of hydrogeomorphic changes on benthic community diversity, it species composition, and density (emphasis on chironomid midges) Ph.D. Research: [In development but topic related to eco-forecasting in Great Plains rivers]

14 Effects on Species Distribution [see poster for details] [ Bradley Williams; Ph.D. project ] Mdi Medium Spatial ilscale Large Spatial lscale (river network; valley-to-reach) (ecoregional and above) Models emphasizing hydrogeomorphic patches and river complexity (e.g., the Riverine Ecosystem Synthesis; Thorp et al. 2006, 2008) and the ecological importance of Functional Process Zones (FPZs) Models emphasizing temperature, water hardness, and river network connectivity (e.g., Garp) KU Biodiversity Institute KU River Ecology Lab

15 Ecoforecasting in the Kansas River: Land use effects on metabolism and diversity

16 Patterns in metabolism and diversity in Kansas River basin

17 Patterns in Stream Metabolism in the Kansas River Basin Land cover data In-stream habitat Dissolved l d nutrients t Benthic and sestonic algae Nutrient Limitation via diffusing substrata DO (mg/l) /2/07 12:00 8/3/07 0:00 8/3/07 12:00 8/4/07 0:00 8/4/07 12:00 Time

18 Patterns in Macroinvertebrates and Fishes Across a Productivity Gradient in the Kansas River Basin Metabolism Water Wt chemistry it Benthic organic matter standing stocks In-stream habitat

19 Ecoforecasting in the Kansas River: nutrient loading and aquatic consumers Gido et al., pending NSF support

20 Theoretical predictions: grazer x nutrient interactions

21 Experimental Stream: Konza Prairie

22 Measuring ecosystem responses Structure Algal filament length Algal l biomass Chlorophyll a extracted from natural pebbles Particulate Organic Matter (POM) Macroinvertebrate abundance Function Gross Primary Productivity (GPP) Nutrient retention

23 Preliminary results: grazer and nutrient ti tloding Algal biomass (chl a mg/m2) Periphyton C:N ratio Fish biomass (g/m 2 ) Fish biomass (g/m 2 ) 10 Nutrient loading (x ambient) Nutrient loading (x ambient) Periphyton quantity controlled by nutrient loading Periphyton quality controlled by grazers and nutrient loading

24 Summary Terrestrial studies Effects of precipitation p and nutrient on physiology of P. virgatum Effects of temperature and food quality on trophic it interactions ti in grassland dfood web Aquatic studies Climate and hydrogeomorphic effects on Kansas River ecosystem, communities and species distributions Effects of land use on stream metabolism and biodiversity Effects of nutrient loading and grazers on stream ecosystem structure t and dfunction