Ecological Stressors

To effectively manage an ecosystem, resource managers need a way to evaluate its health and ability to function. Metrics that indicate ecosystem condition - or indicators - can be used to help determine how well management strategies work.

Sudden Marsh Dieback - SMD - has been documented for the past two decades throughout coastal areas of the United States. With these large-scale diebacks comes the loss of ecosystem functions and services. USGS scientsts use field work and greenhouse studies to investigate the factors that control the resilience and resistance of coastal salt marshes to SMD.

When it comes to hurricanes, wind and storm surge effect vegetation differently. USGS anlyzes these differences following Hurricane Sandy to help inform management on storm mitigation and long-term planning.

Understanding systems sometimes requires approaches that allow for both the discovery of the a system's structure and the estimation of its implications. Structural Equation Modeling - SEM - is one tool scientists use to better understand the complex world in which we live.

The Coastwise Reference Monitoring System was designed to monitor the effectiveness of restoration actions at individual sites, as well as across the entire Louisiana coast.

Mangroves will compete with salt marsh plants in transitional areas, and recent studies have documented the expansion of mangroves into marsh habitats. To better understand the plant community dynamics in this transition zone, USGS scientists are tracking vegeation changes over time in south Florida.

This study will employ a space for time substitution to show long-term effects of rising sea-level and increasing salinity on vegetation community structure, primary production and decomposition. Productivity and decomposition rates will be estimated for four wetland plant community types defined by salinity zones and dominant plant species.

In light of the increase in hurricane frequency and intensity, there is concern about the resilience and sustainability of coastal wetlands. Models can be used to investigatethe impacts of future hurricanes on wetland morphology along the northeast coasts in areas like Jamaica Bay, New York, an area impacted by Hurricane Sandy.

Wetlands vary in their abilities to keep up with sea-level rise; they either adjust vertically and/or move inland. USGS is working with partners around the world to measure rates of surface elevation change relative to local sea-level rise.

Tegus are breeding, they have a diverse diet, and they are established in areas throughout South Florida. USGS is tracking this problematic reptile species to better understand their movements and habitat use to help managers prevent dispersal into new areas.

Sediment deposition serves an important role in the long-term maintenance of coastal marshes. USGS investigates the mechanisms of coastal marsh elevation regulation to help predict marsh sediment requirements under various sea level rise scenarios.

Green-Tree Reservoirs are used as a management tool by National Wildlife Refuges throughout the Southeast United States, but data suggests that forest productivity has declined in these areas. USGS investigates the effects of climate and flooding on tree growth and mortality to assist refuge managers adapt management strategies.