Background:

There are several large military installations on the Atlantic Coastal Plain that protect important ecosystems including blackwater streams, a distinctive resource that supports a high diversity of vertebrates and invertebrates. Degradation of blackwater streams can result in a significant loss of biodiversity and adversely affect nutrient cycling, natural mechanisms of water purification, and other valuable ecological functions of floodplain ecosystems. The Department of Defense is committed to the recovery of degraded ecosystems but is constrained by lack of reference models that specify end-states representative of relatively undisturbed conditions. Reference model development in the Southeast is difficult because of extensive regional development, invasion of nonnative species, legacy impacts, and climate changes that have degraded and fragmented the natural landscape. Successful ecosystem recovery on military lands requires ecological reference models that are appropriate yet achievable and congruent with mission requirements. It also necessitates methods for assessing ecosystem status, measuring progress towards recovery objectives, and identifying useful recovery strategies.

Objective:

The objective of this project is to develop ecological reference models and an assessment framework for blackwater streams and other types of streams on the Atlantic Coastal Plain. Specific objectives include (1) development of ecological reference models that represent realistic and desirable end-states for the biological recovery of coastal plain streams, (2) assessment of the relationships between the reference models and land use in watersheds on military bases, and (3) development of a framework for assessing, displaying, and communicating the status of coastal plain streams in relation to reference model objectives.

Process/Technology Description:

Reference models are being developed that represent stream ecosystems under minimal human disturbance. In addition to reference models, best-attainable models are being developed to represent the best conditions currently achievable given disturbances resulting from mission-essential military activities. These models are based on data collected from minimally disturbed stream sites or from historical reconstruction and predictive modeling where minimally disturbed sites are unavailable. Streams are being characterized on the basis of physical and chemical data at multiple spatial scales and sampled to assess fish and macroinvertebrate community composition. These data are being used to develop models that consist of four hierarchical levels of attributes representing the regional landscape (emphasizing connectivity to source pools and dispersal routes), the watershed, the stream habitat, and the biotic condition of the stream. All model specifications are represented by measures of central tendency and variability to represent the diversity naturally associated with stream ecosystems. The assessment framework utilizes multivariate statistical methods and multimetric indices to conceptualize the severity of degradation and progress towards recovery goals. Feasibility of recovery is assessed by comparing the hierarchical classes of model attributes. Work is being conducted at Fort Benning, Georgia; the Savannah River Site (DOE), South Carolina; Fort Bragg, North Carolina; and Fort Stewart, Georgia.

Expected Benefits:

Ecological recovery programs for coastal plain streams cannot be successful without end-state objectives that are specific and well-documented. The ecological reference models produced by this study provide the guidance needed by resource managers for prudent, goal-oriented recovery efforts that produce cost-effective and quantifiable results. The assessment framework will facilitate efficient resource use and successful program management by providing practical methods for measuring levels of degradation relative to recovery objectives, assessing progress towards recovery goals, and determining the feasibility of recovery. (Anticipated Project Completion - 2013)

Contact Information:

Dr. Michael Paller
Savannah River National Laboratory
Building 773-42A
Aiken, SC 29808
Phone: (803) 725-5250
Fax: (803) 725-7673
E-mail: michael.paller@srnl.doe.gov