CONSERVATION EFFECTS ASSESSMENT PROJECT
A. Ecological Evaluation of the Influence of Conservation Practices on Headwater Streams
Problem: Headwater streams in agricultural watersheds have been impacted by past farming and land management practices. Many headwater streams in the midwestern United States have been constructed or modified for draining excess water from agricultural fields. Management of these streams continues to focus on the removal of excess water without considering the effects of these practices on the biota. Additionally, these and other agricultural practices have increased erosion rates, degraded farmland, and impacted downstream water resources that provide drinking water to many rural and urban communities. Conservation practices are seen as one method to reduce erosion rates, improve water quality, and restore headwater streams within agricultural watersheds. However, comprehensive evaluations of the impact of conservation practices on the physical, chemical, and biological characteristics of unchannelized or channelized headwater streams (i.e., agricultural drainage ditches) are lacking.
Research Objective: Evaluate the impact of conservation practices on the physical, chemical, and biological characteristics of headwater streams.
Management Implications: This research will provide information that can be used to identify the conservation practices and/or combination of conservation practices that will provide the greatest environmental benefits.
1) Evaluating the influence of herbaceous riparian buffers on habitat and aquatic communities (fishes and macroinvertebrates) within agricultural drainage ditches in the Upper Big Walnut Creek watershed, Ohio. Collaboration with K. King and N. Fausey, USDA-ARS Soil Drainage Research Unit.
2) Evaluating the influence of nutrient and pesticide management on aquatic communities in headwater streams and agricultural drainage ditches in the agricultural drainage ditches in Ohio and Indiana. Collaboration with R. Gillespie, Indiana University-Purdue University Fort Wayne, K. King, USDA-ARS Soil Drainage Research Unit, and D. Smith, USDA-ARS National Erosion Research Laboratory.
3) Evaluating the influence of ditch maintenance on habitat and aquatic communities within agricultural drainage ditches in the Upper Big Walnut Creek watershed, Ohio. Collaboration with K. King and N. Fausey, USDA-ARS Soil Drainage Research Unit.
5) Conducting literature review to synthesize current status of information related to the management and ecology of agricultural drainage ditches. Collaboration with R. Gillespie, Indiana University-Purdue University Fort Wayne.
B. Guidelines for Designing Ecological Assessments of Conservation Practices
Objective: Provide guidance on designing sampling protocols to evaluate the ecological effects of conservation practices on agricultural streams.
This is a cross-location project with F. D. Shields Jr. and S. S. Knight, USDA-ARS, National Sedimentation Laboratory and one of the first joint projects of the CEAP Ecology Working Group. We have developed five guiding principles for designing ecological assessments of conservation practices and these principles have been adopted as the standard protocol for designing ecological assessments as part of the ARS CEAP Watershed Assessment Study. Additionally, the guiding principles have been used to design ecological assessments of conservation practices in ARS watersheds in Ohio and Indiana. Our guiding principles and an example of their application have been summarized in a peer review manuscript published in the Journal of the American Water Resources Association.
C. Evaluation of the Ecological Benefits of a Gully Erosion Control Structure
Problem: Gully erosion is one of the most severe forms of erosion and can decimate riparian zones and agricultural fields within agricultural watersheds. Previous research evaluating gully erosion control structures have focused on documented their effectiveness in erosion control. Information on the effectiveness of gully erosion control structures in restoring riparian zones and providing ecological benefits is lacking. Specifically, gully erosion is prevalent within incised watersheds in Mississippi and drop pipes are primary erosion control method. Thousands of these structures have been installed along incised watersheds in Mississippi.
Objective: Evaluate the effectiveness of drop pipe in restoring riparian habitats for amphibians and reptiles in Mississippi.
This is a cross-location project with F. D. Shields Jr. S. S. Knight, and C. M. Cooper, USDA-ARS, National Sedimentation Laboratory and joint project of the CEAP Ecology Working Group. Field research for this project was conducted between 1994 and 1998 when I worked at the National Sedimentation Laboratory. Previous publications from this research have documented the influence of the restored riparian habitats on fishes (Smiley et al. 1999), birds (Maul et al. 2002, Smiley et al. 2007), and vertebrate communities (Cooper et al. 1997, Smiley et al. 1997, Shields et al. 2002). We observed that amphibian and reptile diversity and abundance were the greatest when drop pipe installation resulted in forested riparian wetlands with mean habitat areas > 1000 m2 and mean pool volumes > 420 m3. Our results suggest that this gully erosion control structure is capable of creating needed wetland habitats for amphibian and reptile communities within riparian zones impacted by agriculture and stream channelization. However, present drop pipe installation practices focus on erosion control without consideration of habitat creation. Our results also suggest that altering the installation design to improve its effectiveness in creating forested riparian wetlands will increase the ecological benefits resulting from this conservation practice. This research has been published in the journal Ecohydrology.
WRSIS ECOLOGY RESEARCH
Wetland Reservoir Subirrigation Systems (WRSIS) were designed as a water recycling system that would capture agricultural runoff, treat the water within a created wetland, and store the water intended for subirrigation in a reservoir. One result of installing this water recycling system is that it creates two types of wetlands within agricultural landscapes. It creates a shallow wetland designed for reducing nutrients from the agricultural runoff (WRSIS wetlands) and it also creates deep wetland designed to store water (WRSIS reservoirs). Previous WRSIS ecology research has focused on the shallow wetlands designed for nutrient treatments and no ecology information from the deeper reservoirs are available. Understanding the differences in the habitat and aquatic vertebrates between the different wetland types will assist with developing management guidelines for this system that will assist with reducing nonpoint sources of pollution and to provide ecological benefits. This is a collaboration with B. Allred, USDA-ARS Soil Drainage Research Unit).
Objective: Compare the habitat and aquatic communities (fishes, amphibians, and reptiles) within WRSIS wetlands and reservoirs.
Management Implications: Understanding the differences in the habitat and aquatic vertebrates between the different wetland types will assist with developing management guidelines for this system that will assist with reducing nonpoint sources of pollution and to provide ecological benefits.
*In conclusion, the above research describes my individual research goals. If you are interested in further information on how my research is combined with that of my USDA-ARS colleagues then please see associated CRIS Projects.