Effects of Hydrological Factors on Northeast Upland Streams' Ecological Conditions

1. Effects of Hydrologic and Environmental Factors on Ecological Conditions of Upland Streams in the Northeast, USA. National Monitoring Conference May 7-11, 2006 Jonathan G. Kennen, NJWSC, West Trenton, NJ Karen R. Murray NYWSC, Troy, NY Karen M. Beaulieu, CTWSC, East Hartford, CT

2. There are many mechanisms by which hydrology impacts biota. Requirements Stressors Sources High Water Temperature Poor Riparian Buffers Poor Riparian Buffers Healthy Water Chemical Pollutants Point Sources High Turbidity Construction Substrate Suitability (low DO) Sedimentation Channel Erosion Refugia Physical Habitat Insuf. Woody Debris Historic Sediment Impervious Surfaces/Stormwater Interstitial Habitat Altered Flows (algal bloom) Excess Nutrients Livestock & Poultry Use of Pesticides& Fertilizers Altered Food Webs Food (Algae, Meiofauna) Invasive Species Introductions Excess Competitors Few Competitors & Predators Excess Predators Reservoirs Connections to Other Populations Road Crossings • J. Kennen, NJWSC, West Trenton, NJ Movement Barriers

3. Multiple stressors can have additive and/or synergistic effects ? + x –

4. Stream hydrology differs – can have linear, threshold, or even a delayed response to disturbance ? biotic integrity disturbance ? biotic integrity disturbance

5. “I asked you a question buddy, what’s the minimum flow we need to protect aquatic species in this here Basin?”

6. Project Objectives • Identify important environmental and hydrological parameters • Discern disturbance gradient from biota • Describe relations with observed ecological patterns • Use sound science to identify key variables water managers can use to improve stream quality

7. Scope • 77 upland watersheds • Range of urban intensity • 7 NAWQA study units • 1993-2002

8. Data Requirements • Quantitative invertebrate riffle samples • Gaging station co-located at or near aquatic invertebrate sampling site • Hydrologic data needed for a minimum of 3 or more years • Quantitative invertebrate riffle samples • Gaging station co-located at or near aquatic invertebrate sampling site • Hydrologic data needed for a minimum of 3 or more years • Quantitative invertebrate riffle samples • Gaging station co-located at or near aquatic invertebrate sampling site • Hydrologic data needed for a minimum of 3 or more years

9. Data Compilation • Hydrologic descriptors (Hydrological Integrity Assessment Process –171 Variables) • Quantitative invertebrate (density –numbers/m2) • Assemblage metrics and indices • GIS Data –“Roads Corrected” Land use / cover, etc.

10. Invertebrate Data Environmental Variables (Standardize, Transform, Assess Colliniarity) (>527 vars.) Ordination (NMDS) PCA/Corr. [=data reduction] (76 vars.) Final Set of Variables Extract Axis Scores (+/- 37 vars.) Multiple Linear Regression (MLR) (Axis Score = disturbance gradient) General Analytical Approach

11. Why use Ordination? • Reduces complexity of community data while retaining structure • Derives environmental gradients based on biota • Places sites with similar communities close together, those with dissimilar communities far apart

12. Disturbance Gradient Concept Excellent High Ecosystem Integrity Very Good Good Assemblage Condition Fair Poor Low Ecosystem Integrity Very Poor Natural Moderate Radical Minimal High Serious Anthropogenic Disturbance

13. NE Ecoregions Level of Disturbance Very High High Moderate Minimum Distribution of Sites Coded by Relative Position Along the Disturbance Gradient

14. Ordination Color Coded (high to low) by Percent Riparian Forest % Rip. Forest Low Medium High Disturbance Gradient

15. Dist. Grad. Richness of Sensitive EPT Taxa Dist. Grad. Richness of Tolerant Taxa Relations with assemblage structure and function Strong relations with metrics further support interpretation as a disturbance gradient.

16. Dist. Grad. Decline in Core Forest Dist. Grad. Decline in % Riparian Forest Relations with Land Use & Configuration Relations show the extent of anthropogenic effects and help target attributes that may be useful from a LU planning perspective.

17. Relations with assemblage structure Tolerant species increase Sensitive species decrease

18. Regression Model using Disturbance Gradient as Response Variable Results of significant (p<0.05) MLR model –disturbance gradient is response variable

19. EPT Richness Percent Riparian Forest Example –Percent Riparian Forest Significant linear relations observed –no defined inflection point. % of Omnivores Variability of January Flow

20. Summary of Findings • Patterns in biota are highly related to stream degradation. • Environmental alterations are related to changes in the biotic integrity across a disturbance gradient. • Riparian forest areas lessen the effects of human-induced landscape and hydrologic alterations. • Intolerant taxa become less prevalent as streams become more degraded.

21. Management Implications • Relations between invertebrate assemblage metrics and environmental and flow attributes can be used to: • target levels of riparian coverage that are protective of structural complexity and/or meet designated aquatic life use • or. . target portions of the flow regime that are protective of biological integrity

22. Management Implications