Applying cumulative effects to strategically advance large-scale ecosystem restoration.

International efforts to restore degraded ecosystems will continue to expand over the coming decades, yet the factors contributing to the effectiveness of long-term restoration across large areas remain largely unexplored. At large scales, outcomes are more complex and synergistic than the additive impacts of individual restoration projects. Here, we propose a cumulative-effects conceptual framework to inform restoration design and implementation and to comprehensively measure ecological outcomes. To evaluate and illustrate this approach, we reviewed long-term restoration in several large coastal and riverine areas across the US: the greater Florida Everglades; Gulf of Mexico coast; lower Columbia River and estuary; Puget Sound; San Francisco Bay and Sacramento-San Joaquin Delta; Missouri River; and northeastern coastal states. Evidence supported eight modes of cumulative effects of interacting restoration projects, which improved outcomes for species and ecosystems at landscape and regional scales. We conclude that cumulative effects, usually measured for ecosystem degradation, are also measurable for ecosystem restoration. The consideration of evidence-based cumulative effects will help managers of large-scale restoration capitalize on positive feedback and reduce countervailing effects.

Storm-driven particulate organic matter flux connects a tidal tributary floodplain wetland, mainstem river, and estuary.

The transport of terrestrial plant matter into coastal waters is important to regional and global biogeochemical cycles, and methods for assessing and predicting fluxes in such dynamic environments are needed. We investigated the hypothesis that upon reconnection of a floodplain wetland to its mainstem river, organic matter produced in the wetland would reach other parts of the ecosystem. If so, we can infer that the organic matter would ultimately become a source for the food web in the mainstem river and estuary. To accomplish this, we adapted numerical hydrodynamic and transport modeling methods to estimate the mass of particulate organic matter (POM) derived from the annually senescent aboveground parts of herbaceous marsh plants (H-POM). The Finite-Volume Community Ocean Model (FVCOM), parameterized with flow, tide, and aboveground biomass data, simulated H-POM mobilization from fluid shear stress during tidal exchange, flooding, and variable river flow; entrainment into the water column; transport via channel and overland flow; and entrapment when wetted surfaces dry. We examined export from a recently reconnected, restoring tidal emergent marsh on the Grays River, a tributary to the Columbia River estuary. Modeling indicated that hydrologically reconnecting 65 ha at the site resulted in export of about 96 × 103  kg of H-POM, primarily during pulsed storm flooding events in autumn and early winter. This exported mass amounted to about 19% of the summer peak aboveground biomass measured at the site. Of that 19%, about 48% (47 × 103  kg) was deposited downstream in the Grays River and floodplain wetlands, and the remaining 52% (50 × 103  kg) passed the confluence of the Grays River and the mainstem estuary located about 7 km from the study site. The colonization of the restoring study site largely by nonnative Phalaris arundinacea (reed canarygrass) may have resulted in 18-28% lower H-POM mobilization than typical marsh plant communities on this floodplain, based on estimates from regional studies of marshes dominated by less recalcitrant species. We concluded that restored floodplain wetlands can contribute significant amounts of organic matter to the estuarine ecosystem and thereby contribute to the restoration of historical trophic structure.

An expert panel process to evaluate habitat restoration actions in the Columbia River estuary.

We describe a process for evaluating proposed ecosystem restoration projects intended to improve survival of juvenile salmon in the Columbia River estuary (CRE). Changes in the Columbia River basin (northwestern USA), including hydropower development, have contributed to the listing of 13 salmon stocks as endangered or threatened under the U.S. Endangered Species Act. Habitat restoration in the CRE, from Bonneville Dam to the ocean, is part of a basin-wide, legally mandated effort to mitigate federal hydropower impacts on salmon survival. An Expert Regional Technical Group (ERTG) was established in 2009 to improve and implement a process for assessing and assigning "survival benefit units" (SBUs) to restoration actions. The SBU concept assumes site-specific restoration projects will increase juvenile salmon survival during migration through the 234 km CRE. Assigned SBUs are used to inform selection of restoration projects and gauge mitigation progress. The ERTG standardized the SBU assessment process to improve its scientific integrity, repeatability, and transparency. In lieu of experimental data to quantify the survival benefits of individual restoration actions, the ERTG adopted a conceptual model composed of three assessment criteria-certainty of success, fish opportunity improvements, and habitat capacity improvements-to evaluate restoration projects. Based on these criteria, an algorithm assigned SBUs by integrating potential fish density as an indicator of salmon performance. Between 2009 and 2014, the ERTG assessed SBUs for 55 proposed projects involving a total of 181 restoration actions located across 8 of 9 reaches of the CRE, largely relying on information provided in a project template based on the conceptual model, presentations, discussions with project sponsors, and site visits. Most projects restored tidal inundation to emergent wetlands, improved riparian function, and removed invasive vegetation. The scientific relationship of geomorphic and salmonid responses to restoration actions remains the foremost concern. Although not designed to establish a broad strategy for estuary restoration, the scoring process has adaptively influenced the types, designs, and locations of restoration proposals. The ERTG process may be a useful model for others who have unique ecosystem restoration goals and share some of our common challenges.

Export of macroinvertebrate prey from tidal freshwater wetlands provides a significant energy subsidy for outmigrating juvenile salmon.

Tidal freshwater wetlands linking terrestrial, riverine, and saline habitats are critical areas for material processing and exchange. Once historically widespread, herbaceous marsh and forested tidal freshwater wetlands especially are now highly degraded worldwide. Additionally, quantitative assessments of hydrology and material exchange from these systems are lacking compared to lotic and estuarine (saltmarsh) habitats. Here we investigate macroinvertebrate and energy export from tidal marsh and forested wetlands and consider potential benefits from this ecological process to endangered Pacific salmon in a large tidal freshwater system, the Columbia River (USA). Macroinvertebrate (salmon prey) concentration, water velocity, and discharge were measured at several wetland habitat types (forested swamp, emergent marsh, and restored marsh). We used these data to compute prey flux and transport metrics. Then, applying literature values to calculate prey energy equivalents and juvenile salmon metabolic requirements, we estimated the potential energy subsidy available to juvenile salmon. Numerically, larval stages of aquatic insects were the predominant type of prey exported from the wetlands, with Diptera chironomid fly abundance exceeding other groups. Energetically, however, non-chironomid dipterans and hemipteran prey comprised most of energy transport due to their higher energetic content (energy density × mean weight). We determined the prey energy transported from the sampled tidal channels was sufficient to meet energetic needs of tens to thousands of juvenile salmon per day, depending on prey production and hydrography. The prey taxonomic composition differed among organisms exiting forested swamp, emergent marsh, and restored marsh habitats with corresponding differences in energy transport, but all habitat types supported similar numbers of juvenile salmon. We conclude that macroinvertebrate prey exported from varied tidal freshwater wetlands likely provide significant benefits to juvenile salmon over a larger ecological footprint than the wetland area would suggest.

Bibliotherapy as a treatment for depression in primary care.

This study was designed to determine whether a physician-delivered bibliotherapy prescription would compare favorably with the prevailing usual care treatment for depression in primary care (that often involves medication) and potentially offer an alternative. Six family physicians were trained to write and deliver prescriptions for cognitive-behavioral bibliotherapy. Thirty-eight patients were randomly assigned to receive either usual care or a behavioral prescription to read the self-help book, Feeling Good (Burns, D. D. (1999). Feeling good: The new mood therapy. New York: HarperCollins). The treatment groups did not differ in terms of overall outcome variables. Patients in both treatment groups reported statistically significant decreases in depression symptoms, decreases in dysfunctional attitudes, and increases in quality of life. Although not statistically significant, the mean net medical expenses in the behavioral prescription group were substantially less. This study provided empirical evidence that a behavioral prescription for Feeling Good may be as effective as standard care, which commonly involves an antidepressant prescription.