Title: Evidence-based evaluation of the cumulative effects of ecosystem restoration

Abstract

Evaluating the cumulative effects of large-scale ecological restoration programs is necessary to inform adaptive ecosystem management and provide society with resilient and sustainable services. However, complex linkages between restorative actions and ecosystem responses make evaluations problematic. Despite long-term federal investments in restoring aquatic ecosystems, no standard evaluation method has been adopted and most programs focus on monitoring and analysis, not synthesis and evaluation. In this paper, we demonstrate a new transdisciplinary approach integrating techniques from evidence-based medicine, critical thinking, and cumulative effects assessment. Tiered hypotheses are identified using an ecosystem conceptual model. The systematic literature review at the core of evidence-based assessment becomes one of many lines of evidence assessed collectively, using critical thinking strategies and causal criteria from a cumulative effects perspective. As a demonstration, we analyzed data from 166 locations on the Columbia River and estuary representing 12 indicators of habitat and fish response to floodplain restoration actions intended to benefit threatened and endangered salmon. Synthesis of seven lines of evidence showed that hydrologic reconnection promoted macrodetritis export, prey availability, and fish access and feeding. The evidence was sufficient to infer cross-boundary, indirect, compounding and delayed cumulative effects, and suggestive of nonlinear, landscape-scale, and spatial density effects. Onmore » the basis of causal inferences regarding food web functions, we concluded that the restoration program has a cumulative beneficial effect on juvenile salmon. As a result, this evidence-based approach will enable the evaluation of restoration in complex coastal and riverine ecosystems where data have accumulated without sufficient synthesis.« less

Authors:

Diefenderfer, Heida L. ^[1]; Johnson, Gary E. ^[1]; Thom, Ronald M. ^[1]; Buenau, Kate E. ^[1]; Weitkamp, Laurie A. ^[2]; Woodley, Christa M. ^[1]; Borde, Amy B. ^[1]; Kropp, Roy K. ^[1]

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+ Show Author Affiliations

1. Pacific Northwest National Lab., Sequim, WA (United States)
2. National Oceanic and Atmospheric Administration, Newport, OR (United States)

Publication Date:

2016-03-18

Research Org.:

Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1249268

Report Number(s):

PNNL-SA-104585
Journal ID: ISSN 2150-8925; 400403209

Grant/Contract Number:  

AC05-76RL01830

Resource Type:

Accepted Manuscript

Journal Name:

Ecosphere

Additional Journal Information:

Journal Volume: 7; Journal Issue: 3; Journal ID: ISSN 2150-8925

Publisher:

Ecological Society of America

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; causal criteria; critical thinking; cumulative effects; evidence-based medicine; fisheries; floodplain food web; habitat connectivity; hydropower mitigation; large-scale ecosystem restoration; salmon recovery; sustainability science; systematic review; tidal wetlands