Research Accomplishment Reports 2007

Evaluating Streamside Management Zone Effectiveness in Forested Headwater Catchments of Central Appalachia

C. Barton
Department of Forestry

 

Project Description

Forestry best management practices (BMPs) are designed to reduce nonpoint source pollution (NPSP). Previous work at the University of Kentucky has demonstrated that forestry BMPs lessen NPSP, however, the importance of specific BMP recommendations, such as the width and disturbance allowed within a riparian zone, are unknown. We need better information on the controls that influence riparian zone effectiveness and the generation of NPSP.

A project has been initiated to examine forest harvesting impacts and the role of BMPs on water quality and aquatic biota in eastern Kentucky watersheds. Ten forested watersheds in the University of Kentucky's Robinson Forest (Breathitt Co., KY) were selected: eight will be harvested; the remaining two will be uncut controls. Four duplicated riparian zone treatments will be imposed on the harvested watersheds. Treatments were initially developed to examine three levels of riparian zone width and four levels of disturbance: one-half, 1x and 2x the current recommendation levels for Kentucky forestry BMPs. Prior to harvesting, a two-year monitoring period was initiated to fully characterize water quantity and quality relationships between the selected watersheds. Storm flow hydrographs and statistical relationships between event magnitude and hydrologic response were developed for each watershed. Statistical relationships for water chemistry at the perennial and intermittent section of each stream were developed. Initial data indicated that one watershed (upper Clemons Fork) was statistically different with respect to water quality. Problems arose in 2007 pertaining to regulatory permission for installing the one-half current BMP recommendation. As a result, the one-half current BMP treatment was dropped from the study.

Accomplishments to date include:

1. Selection of sites, characterization of stream geometry and morphological metrics, flume and weir installation, hydrologic monitoring, water chemistry monitoring, vegetation monitoring in riparian and upland zones, avian community monitoring, herpetofaunal characterization of stream and riparian areas and characterization of macroinvertebrate communities within the stream systems;

2. Storm flow hydrographs and statistical relationships between event magnitude and hydrologic response for each watershed;

3. Statistical relationships for water chemistry at perennial and intermittent sections of each stream were developed;

4. Timber has been marked for treatment installation;

5. Egress rights for timber removal off privately owned lands have been secured;

6. Request for proposals for timber harvesting has been advertised and selection of the commercial timber contractor will occur in March 2008;

7. Training and educational experience for eight graduate students actively involved in the project (5 from the University of Kentucky, 2 from Western Kentucky University and one from Indiana University of Pennsylvania) and numerous undergraduate interns continues;

8. Seven presentations have been given at national forums;

9. Six on-site tours for water quality/natural resource professionals (approximately 200 in attendance) have been performed.

Impact

Forestry best management practices (BMP) are designed to reduce nonpoint source pollution (NPSP). Even though many states have adopted BMPs for forestry, specific recommendations pertaining to the riparian zone are not well established and are particularly lacking for the Appalachian Region. Streamside management zones (SMZ) are an example of a riparian zone BMP that is implemented to provide a buffer between upland management practices and the stream.

The importance of SMZs in maintaining hydrologic function and filtering sediment is obvious, but is not well quantified. Most SMZs are sized according to surface topography with the intent of lessening sediment transport, but consideration to nutrient and carbon transport, stream temperature, stream biological communities and terrestrial fauna must also be considered to fully evaluate their effectiveness. As such, a replicated experiment to investigate the effect of SMZ size on these parameters has been initiated. The ultimate goal of this research is to develop streamside management zone BMPs that are appropriate for the Central Appalachian Region. Given the variability of current streamside management zone BMPs in the region, some are likely excessive or lacking with respect to the effectiveness of controlling NPSP and/or impacting biological communities that utilize these systems. BMPs that are lacking lead to enhanced NPSP and damage to biota while those that are excessive lead to costly, unneeded BMP implementation. In either case there is a cost, one environmental/ecological and one economic.