Reference Concepts in Ecosystem Restoration and Environmental Benefits Analysis: Principles and Practices

Transcription

1 Reference Concepts in Ecosystem Restoration and Environmental Benefits Analysis: Principles and Practices Sarah J. Miller Research Ecologist, Fluvial Geomorphologist U.S. Army Engineer Research and Development Center Environmental Laboratory Bruce A. Pruitt and Craig J. Fischenich, U.S. Army Engineer Research and Development Center Environmental Laboratory Chuck H. Theiling, U.S. Army Corps of Engineers, Rock Island District Shawn B. Komlos, U.S. Army Corps of Engineers, Institute for Water Resources 31 July 2014 Conference on Ecological and Ecosystem Restoration US Army Corps of Engineers

2 Environmental Benefits Analysis Program References Miller, S. J., B. A. Pruitt, C. H. Theiling, J. C. Fischenich, and S. B. Komlos Reference concepts in ecosystem restoration and environmental benefits analysis (EBA): Principles and practices. EMRRP Technical Notes Collection. ERDC TN- EMRRP-EBA-12. Vicksburg, MS: U.S. Army Engineer Research and Development Center. Pruitt, B. A., S. J. Miller, C. H. Theiling, and J. C. Fischenich The use of reference ecosystems as a basis for assessing restoration benefits. EMRRP Technical Notes Collection. ERDC TN-EMRRP-EBA-11. Vicksburg, MS: U.S. Army Engineer Research and Development Center

3 Ecological Reference Basic Definition a conceptual, spatial, or temporal comparison a target, benchmark, standard, model, or template from which or to which a site, state, process, or range of ecosystem biological integrity, structure, function, condition, or relative health are compared Institutionally reference has commonly come to represent a high functioning condition or restoration target, though the functional definition is broader First step in characterizing ecosystem reference condition is classification, from which condition indices have been developed for rapid asst. 3

4 reference condition A reference condition is the set of attribute values or quantifiable characteristics of the reference ecosystem. Physical, chemical, or biological parameters of ecosystem structure or function can be represented by a single value or a distribution. Wetlands River Basins SAV Sea Grass Coastal Stream Corridors

5 Reference Condition Types Applicable to Aquatic Ecosystem Restoration (modified from Stoddard et al. (2006)). Table from S.J. Miller, B.A. Pruitt, C.H. Theiling, J.C. Fischenich, and S.B. Komlos Reference Concepts in Ecosystem Restoration and Environmental Benefits Analysis (EBA): Principles and Practices Historical Condition Pre-Agriculture (HCPA) Prior to intensive agricultural activity, meaning, " very low pressure, without the effects of major industrialization, urbanization and intensification of agriculture, and with only very minor modification of physicochemistry, hydromorphology and biology. (Wallin et al. 2003) Historical Condition Pre-Industrial (HCPI) Prior to industrialization and urbanization in areas of influence to the ecosystem (DuFour and Piegay 2009) Historical Condition Pre-Disturbance (HCPD) Prior to major impact or specific alteration or disturbance in an ecosystem (DuFour and Piegay 2009) Minimally Disturbed Condition (MDC) Least Disturbed Condition (LDC) Best Attainable Condition (BAC) A condition representing the absence of local human disturbance, while recognizing that minimal disturbance may be present due to human activities affecting regional / global processes (e.g., climate change, deposition of atmospheric contaminants below the threshold required to have measurable impact on an ecosystem, etc.). A condition representing the least amount of human disturbance or alteration in the current landscape context. In other words, the best of what is left. The BAC represents a potential condition that could be achieved following the implementation of all available BMPs at a site. The BAC reflects BUILDING a desired STRONG future condition given current constraints.

6 Future 6 Figure from Bruce A. Pruitt, Sarah J. Miller, Chuck H. Theiling, and J. Craig Fischenich The Use of Reference Ecosystems as a BUILDING STRONG Basis for Assessing Restoration Benefits

7 Part 2 Reference Approaches A reference approach is a set of assumptions and techniques for characterizing and applying reference ecosystems and reference conditions to practices associated with ecosystem restoration. The reference approach establishes how and which data are collected and analyzed to represent selected reference conditions 7

8 Reference Approach: Historical Reference Description Use a selected historical reference condition within project area (can be applied as off-site analogous approach if conditions are met) Applicable Reference Condition HCPI or HCPA, HCPD if a specific isolated event caused disturbance Requirements / Assumptions Requires the right data type / resolution to set targets matched to objectives; if on-site, may not require classification Benefits Opportunity to characterize adjustment of processes to known stressors, if stressors not in flux or pre-disturbance data are proximal, can represent target reference condition or MDC Limitations Stressors may have changed, other parameters may be changing, constraints may eliminate historical reference from consideration as target reference condition 8

9 Using Historical Reference Data to Calibrate Habitat Models Case Study: Missouri River s Cottonwood Management Plan (Omaha/Kansas City Districts) Reference conditions for the model based upon GLO-based vegetative data and GIS representation of landuse conversions over time Data was normalized (scaled 0-1) and used to calibrate the model Suitability Index (SI) Overall Study Area Relative Complexity of Supporting (Non-Forested/Shrub) Habitats (INTERSPERS) 9 9

10 Reference Approach: On-site Analogous Reference Description Use present, on-the-ground conditions within project footprint to determine reference Applicable Reference Condition LDC most likely Requirements / Assumptions Requires enough on-site information to determine degree of function and degradation and to set targets; may require consideration of broader watershed conditions Benefits Low mobilization costs, parallel stressors, many parameters equal (e.g., hydrology) Limitations May not represent target reference condition, may not represent range of condition, may not represent ecological trajectory 10

11 11 BUILDING STRONG

12 Reference Approach: Off-site Analogous Reference Description Use present, on-the-ground, ecologically representative conditions outside project footprint to determine reference Applicable Reference Condition LDC most likely, MDC possible Requirements / Assumptions Requires enough information at a suitable off-site location to determine degradation and set target, comparable class of system with parallel stressors, measurable P/C/B parameters Benefits More likely to find reference that can help define target reference condition with parallel stressors, parameters Limitations May not represent range of condition, may not represent target reference condition, more cost to locate and characterize another site, may not represent ecological trajectory 12

13 Project Site Before 13

14 Project Site After Reference Reach Project Function Reference Function 14

15 Reference Approach: Regional Index Description Use a range of existing reference sites to reflect a continuum of conditions Applicable Reference Condition Any available Requirements / Assumptions Requires classification and considerable data to characterize the range of the condition to evaluate degradation and set targets Benefits Highly robust representative of full range of conditions, puts projects into context, best characterization of target reference condition, can speed overall assessment time and reduce cost for subsequent projects once developed Limitations Requires sufficient data to develop index. This can take time and might be too costly for a single project 15

16 Minnesota River Basin Fish IBI 16

17 Reference Approach: Virtual (or constructed) Reference Description Use a combination of sources to represent target reference condition for given physical setting, other constraints Applicable Reference Condition Any of HCPI, HCPA, HCPD, MDC or LCD in combination with site or other data Requirements / Assumptions Typically requires data from multiple sources, BPJ, and models Benefits Highly flexible if good information is available, high resolution in defining target condition, best for use in settings with many constraints, costs can be low if existing models, BPJ, and collaborative processes are used Limitations Highly dependent on good information, good interpretation/analysis of available information, can be quite reliant on models, and subject to notable debate, costs can be high if requiring new or extensive modeling 17

18 Using Reference Data to Calibrate Habitat Models Case Study: Middle Rio Grande Bosque Ecosystem Restoration Feasibility Study (Albuquerque District) Quality of The Fit Reference Datasets Reference conditions for the model Must be politically palatable and reasonable Must include a large number of sites from the region Must represent important aspects of pre-historical conditions Step 3: Calibration Ecosystem Response Models May use minimal disturbance as the surrogate for pre-historical conditions, given the difficulty of establishing pre-historical conditions Must be uniform across political boundaries and bureaucracies (e.g., Federal, State, and local). Model Verification Fitted Values 30 sites were considered either reference standard (optimal) or sub-optimal and were chosen to represent the range of conditions existing within the reference domain Data was normalized (scaled 0-1) and used to calibrate the model Average Native Sedge Canopy for the Watershed + the Standard Deviation for the Average Value 35% + 40% = 75% SI = 1.0 Burks-Copes, K. A., and A. C. Webb A Bosque Riparian Community Index Model for the Middle Rio Grande, Albuquerque, New Mexico. Model Documentation Draft Report. U.S. Army Engineer Research and Development Center, Environmental Laboratory, Vicksburg, MS. Average Native Sedge Canopy for the Watershed = 35% SI =

19 Critical Limitations How to Address Them Limitations of all the above reference approaches can be addressed by continuing to compile organized regional reference datasets using intentional documentation and adaptive management improving the quality of tools and techniques for defining robust reference condition databases and models More refined characterization of range and quality of reference condition through a regional approach will enable better identification and description of functional thresholds for ecosystem restoration targets Regional indices or reference indices that benefit multiple projects / programs if data collection is implemented at the project scale 19

20 Thank You! Sarah J. Miller Research Ecologist, Fluvial Geomorphologist U.S. Army Engineer Research and Development Center Environmental Laboratory US Army Corps of Engineers 20