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Grantee Research Project Results

Grantee Research Project Results

Direct and Indirect Effects of Logging in Headwater Streams: The Role of Patch Dynamics in Structuring Aquatic Invertebrate Communities

EPA Grant Number: F6E11020
Title: Direct and Indirect Effects of Logging in Headwater Streams: The Role of Patch Dynamics in Structuring Aquatic Invertebrate Communities
Investigators: Griswold, Marcus
Institution: University of Florida
EPA Project Officer: Jones, Brandon
Project Period: August 21, 2006 through August 11, 2008
Project Amount: $111,172
RFA: STAR Graduate Fellowships (2006)
Research Category: Academic Fellowships , Aquatic Ecosystems , Fellowship - Aquatic Ecology and Ecosystems



Fragmentation and habitat loss in watersheds due to logging practices alters organic matter input and allows for the growth of macrophytes and algae in streams, creating patchy landscapes in aquatic systems. The overall objective is to quantify the response of stream macroinvertebrates (abundance and composition) to changes in autochthonous (macrophytes) and allochthonous (leaf litter) sources under two forestry management regimes: intact buffer zone and 50% removal of the buffer zone. Within this objective, I plan to address the following questions:

  1. How does macroinvertebrate species composition and abundance change with patch type, size and quality?
  2. How do spatial and temporal changes (e.g. stability) in leaf pack formation and macrophyte growth alter invertebrate community structure and colonization patterns?
  3. How does habitat availability and type alter invertebrate movement patterns? This question will focus specifically on (1) how patch type and amount affect habitat selection, and (2) whether matrix quality enhances connectivity between patches.


Field experiments will be utilized to examine the relationship between patch type, size, and stability on macroinvertebrate community structure. Initially the relationship between resource availability and macroinvertebrate species composition will be examined in four experimental watersheds. Instream manipulations of patches will be utilized to examine colonization patterns and movement ability between patch types in an effort to model movement patterns between patches.

Expected Results:

The results of this research will provide valuable information to forestry and watershed management officials; allowing for refinement of regulations concerning the minimum amount of forest cover that must be maintained near streams in order to preserve aquatic invertebrate community structure. In addition, results from movement studies will be used to predict the amount of each patch type needed to allow sensitive macroinvertebrates to exist.

Supplemental Keywords:

Patch dynamics, logging, headwater streams, behavior, coastal plain, riparian, Environmental Monitoring, Ecosystems, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystem,, RFA, Scientific Discipline, Water, Water & Watershed, Environmental Monitoring, Ecology and Ecosystems, Watersheds, urbanization, logging, nitrogen loading, landscape change, wood debris, stream ecosystems, nitrogen inputs, stream macroinvertibrates, aquatic ecosystems, water quality, forested watershed, watershed assessment, patch dynamics, groundwater, land use

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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