Graduate Student: Natalia Montano

Autumn olive is a nitrogen-fixing, exotic, invasive shrub that was originally planted for wildlife habitat and erosion control throughout the eastern United States .  Now, it has become naturalized and commonly invades abandoned pastures and open areas, particularly in the lower Midwestern states.   We started a series of studies in 2002 investigating nitrogen cycling and export associated with autumn olive stands in southern Illinois.  We found that net N mineralization and nitrification rates as well as soil water nitrate concentrations were significantly higher in autumn olive stands compared to adjacent open field areas.  Also, we found that the proportion of autumn olive in small headwater watersheds was positively correlated with stream nitrate concentrations.  In 2007, we initiated a follow-up study assessing the impacts of autumn olive control on soil nitrogen cycling and soil water nitrogen concentrations.  This line of research has demonstrated additional negative ecosystem consequences of invasion beyond losses in biodiversity.

Graduate Student:  Bridget Harrison

With increasing energy prices, natural gas exploration has greatly increased in the central Appalachians, particularly in the Marcellus shale formation.  Cross country pipelines are being built throughout this region to handle the increased gas production. Pipelines can be constructed on slopes as great as 70%, so effective erosion control measures are a necessity to protect the quality of headwater streams.   In the Monongahela National Forest in West Virginia, Bridget is measuring erosion rates on multiple pipeline segments with different slope steepness, aspects, and seeding rates to determine what factors influence erosion.  She aims to help refine existing best management practices on pipelines to minimize sediment transport to streams.  This is a cooperative research project with Pam Edwards, a forest hydrologist with the Northeastern Forest Research Station, Parsons, WV.

 

Historically, forest riparian buffers and grass filter strips have been established with a constant width, usually 100 feet or less, to trap sediment and nutrients from surface runoff in agricultural fields.  The prevailing assumption is that most of the surface runoff enters the buffers in the form of sheet flow.  Field surveying and sampling throughout southern Illinois has challenged this assumption, as we have found that the vast majority of surface runoff from row crop fields is in a concentrated form when it enters a buffer.  Traditional, fixed width buffer designs are generally not effective at handling concentrated surface runoff.  Thus, we are in the process of developing and field testing a variable width buffer design to address concentrated flow through a funded USDA NRCS Conservation Innovation Grant.  Buffers will be wider in concentrated flow areas and narrower in sheet flow areas for a total buffer area equal to or less than traditional designs.

Impacts of Invasive Species, Autumn Olive, on Water Quality

Sediment Transport from Cross Country Gas Pipelines in the

Central Appalachians

Variable Width Riparian Buffers for Concentrated Flow

Current Funded Research Projects

Watershed Science Research Group 

Department of Forestry

 

Critical Source Areas for Nutrient Transport in Agricultural Watersheds

Graduate Student: Derek Evans

Excess phosphorus and nitrogen export from agricultural watersheds is a significant concern for the agricultural community as it can contribute to the eutrophication of downstream water bodies.  Also, farmers are seeking tools to help them manage nutrients inputs more efficiently.  Derek is assessing critical source areas for phosphorus and nitrogen transport in small agricultural watersheds in central Illinois.  He is determining hot sports for surface runoff with datalogging soil moisture sensors and GIS modeling and paring those with detailed soil test data.  By examining nutrient export characteristics over storm hydrographs he hopes to identify where these  critical source areas occur in the fields, so they can be managed to minimize nutrient transport.