ECOLOGICAL ANALYSIS OF ARTHROPOD DIVERSITY AND DEVELOPMENT OF A MONITORING PLAN FOR GETTYSBURG NATIONAL MILITARY PARK AND EISENHOWER NATIONAL HISTORIC SITE

Technical Report NPS/NER/NRTR—2009/143

Ke Chung Kim and Denise A. Piechnik

Institutes of Energy and the Environment
The Pennsylvania State University
Center for BioDiversity Research
Land and Water Research Building
University Park, PA 16802

December 2009

U.S. Department of the Interior
National Park Service
Northeast Region
Philadelphia, Pennsylvania
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Executive Summary

This project is the follow-up to an earlier project, Inventory of Invertebrates at Gettysburg National Park (GETT) and Eisenhower National Historic Site (EISE), with Special Reference to Forest Removal completed in 2001. As the General Management Plan for GETT recommended, the National Park Service has cleared forested land to restore the open vistas of the 1863 battle landscapes and is managing some forested lands as woodlots. To detect possible impacts from this landscape modification on ecological communities and the ecosystem at large, we inventoried and assessed invertebrate biodiversity in GETT/EISE. This inventory serves as baseline data for GETT/EISE invertebrate biodiversity at sites with critical habitats. Our ecological analysis was used to develop a preliminary monitoring plan in an effort to establish sustainable natural resources management of GETT/EISE arthropod diversity.

We summarize the ecological analyses, produce useable databases based on the GETT/EISEarthropod inventory, and develop monitoring recommendations for GETT/EISE managers. With the inventory and monitoring information, we are establishing necessary baseline information. We updated the specimen identifications and used the database to determine major community gradients which may influence community membership of various habitat types in the GETT/EISE ecosystem. We characterized land-use patterns with respect to Lepidoptera, a sensitive arthropod group with many specialist taxa.

These ecological analyses use arthropod diversity to detect environmental gradients within the GETT/EISE ecosystems and to discern which measured environmental factors may influence arthropod biodiversity in GETT/EISE. These findings represent an initial characterization of GETT/EISE arthropod biodiversity. The community characterization and inventory can be used and applied to future monitoring efforts to detect relevant changes locally and at the landscape level. Guild composition and family-taxa diversity were reported and used, in part, to develop an efficient monitoring plan for specific taxa and overall arthropod diversity. Land-use evaluation with respect to Lepidoptera richness and abundance was used to determine target types of land uses that would affect Lepidoptera the most should they be altered (e.g., cutting or mowing). Furthermore, these analyses were used to recommend monitoring approaches for overall biodiversity, specialists groups, and detection of potential pests. Results of the ecological analysis, based on the GETT/EISE Biodiversity Database, were used to determine which major factors correlated with existing community structure, including guilds, richness, and evenness comparisons of the sampled sites.

This Technical Report presents: 1) the arthropod taxa that are unique to particular habitats, plant associations, and land-use categories; and 2) an experimental design for monitoring arthropod taxa at GETT/EISE, which includes: a) suggestions for arthropod groups that can be used as surrogates for overall arthropod diversity; b) recommendations of at-risk or important taxa to monitor in addition to the surrogate taxa; and c) efficient sampling designs to monitor the surrogate taxa and species of special concern (e.g., at-risk or ecologically important taxa).

We also provided the Annotated List of Arthropods in the Gettysburg National Military Park and Eisenhower National Historic Site; a list of taxa that are closely associated with specific habitats that we surveyed (i.e. those disproportionately found in only one habitat), with which, resource managers could track which taxa may be lost if the habitat is lost or altered; Land-use categories within the GETT/EISE and Lepidoptera habitat quality designations; Site-specific data and GPS coordinates for arthropod sampling sites and Lepidoptera surveys.

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To read or download the report, please click here (1.9 MB).