Grantee Research Project Results

Predicting Return of Ecosystem Services Based on Impacts of Invasive Ecosystem Engineers

EPA Grant Number: F13F11164
Title: Predicting Return of Ecosystem Services Based on Impacts of Invasive Ecosystem Engineers
Investigators: Wigginton, Rachel Diane
Institution: University of California - Davis
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2014 through September 1, 2016
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2013) RFA Text |  Recipients Lists
Research Category: Fellowship - Ecology , Academic Fellowships

Objective:

This research seeks to address three main objectives: (1) Determine how pre-restoration habitat modification by ecosystem engineers alters the success of salt marsh restoration and the recovery of ecosystem services; (2) explore the connection between restoration and ecological feedbacks, such as food web recovery and carbon sequestration, which provide a measure of restoration success; and (3) examine the effects of the restoration state (e.g., active replanting vs. passive restoration) on the success of restoration and ecosystem service recovery.

Approach:

This approach will utilize the large-scale hybrid Spartina eradication effort currently being executed by California Coastal Conservancy’s Invasive Spartina Project. Four categories of sites were chosen, representing four different restoration states: (1) invaded marsh: invasive hybrid Spartina present, no current restoration; (2) passive restoration: hybrid Spartina removed, no active revegetation; (3) active restoration: hybrid Spartina removed, revegetated with native S. foliosa; (4) uninvaded marsh: S. foliosa present, never displaced by hybrid Spartina. Sites will be sampled for both habitat alteration and ecological response data in order to fully assess the relationship between restoration state and site characteristics. Preeradication data are available from some sites and will be used to assess the degree of habitat alteration prior to eradication and compare it with current data following Spartina eradication (pre-eradication data were taken between 2000 and 2004). Ecological response data, including food web development and carbon sequestration, will serve as indicators of ecosystem recovery.

Expected Results:

This research is expected to yield several valuable outcomes. First, it will explore the utility of active versus passive restoration on restoration success using food web development and carbon sequestration as success metrics. Second, the relative effect of the restoration state will be assessed and the effects of site-specific characteristics on outcomes will be better understood. Third, this project utilizes a large-scale manipulation already planned by the Invasive Spartina Project, giving timely feedback to the agency for current and future endeavors and gaining important information about restoration ecology, which can be applied in other marsh systems. This work also will provide direct tests of the predictions from ecological theory and from prior empirical studies of native and invasive species in salt marshes. The prediction is that restored and treated sites will achieve food webs equivalent to pre-invasion marshes as native plants replace invasive species, but without the negative consequences of the invaders. Carbon sequestration likely will be initially highest in sites restored with active restoration as compared to treated sites with only passive restoration. However, these initial differences are not likely to persist.

Potential to Further Environmental/Human Health Protection

After the damage caused by Hurricane Katrina and, more recently, Hurricane Sandy, coastal residents have a renewed appreciation for the services that coastal marshes provide. With better understanding of some of the fundamental characteristics, which increase the probability of restoration success, strategies can be developed for more rapid and more efficient restoration practices. In particular, this study will permit assessment of the more capital-intensive active restoration and to what degree this approach results in more successful restoration of the key ecosystem services that human communities need: carbon sequestration, flood abatement, coastline protection, erosion control and water filtration. These last four services directly apply to two of EPA’s “Seven Priorities for EPA’s Future.” Restoration of salt marshes will directly affect the health and prosperity of countless coastal communities in the United States, helping to clean up communities. Second, EPA has been charged with protecting America’s waters. This project addresses all of the major challenges pointed out by the seven priorities and helps develop an effective, innovative approach to returning ecosystem services.

Supplemental Keywords:

ecosystem services, salt marsh, restoration

Progress and Final Reports:

2015

Final