Grantee Research Project Results

Accumulation of an Invasive Plant and its Impact on Adirondack Lake Ecosystems

EPA Grant Number: F6E61477
Title: Accumulation of an Invasive Plant and its Impact on Adirondack Lake Ecosystems
Investigators: Urban, Rebecca A.
Institution: Binghamton University
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2006 through September 1, 2008
Project Amount: $102,236
RFA: GRO Fellowships for Graduate Environmental Study (2006) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Aquatic Ecology and Ecosystems , Fellowship - Aquatic Systems Ecology

Objective:

Invasive species can cause extinctions of native species and fundamentally alter ecosystem processes. A freshwater species expanding into oligotrophic Adirondack Mountain lakes is the rootless submersed macrophyte Utricularia inflata.  This plant has been found to inhibit growth of the native isoetid dominant Eriocaulon aquaticum, indirectly changing sediment chemistry (by lowering redox potential) in such a way that may increase rates of release of nutrients and potentially toxic metals into lake water. I plan to investigate this interaction and its significance to freshwater lakes.

The objectives of this research are to test the following hypotheses:

1. The presence of U. inflata will alter lake chemistry due ultimately to suppression of isoetids
2. Increasing nutrients in the water column will stimulate U. inflata (a positive feedback!). The resultant decrease in light availability will further suppress isoetids.
3. Shading by U. inflata largely accounts for its impact on isoetids.
4. Wave action and water depth influence the distribution and success of the rootless U. inflata within lakes, and thus its local impact.

Approach:

I will conduct greenhouse experiments using 1200-liter experimental tanks at Binghamton University’s Research Greenhouse to determine the effect of Utricularia inflata on the release of substances from sediment into the water column, and the consequences of this release for subsequent Utricularia growth. Field experiments and aquatic plant surveys will be conducted in Adirondack Mountain lakes to study distribution patterns within and among lakes as they are shaped by water-mediated dispersal and growth of plant fragments.

Expected Results:

This research will provide greater insight into how invasive species indirectly change ecosystems. Utricularia inflata may ultimately cause elimination of isoetids, with drastic effects on ecosystem processes. Lakes that are now clear, softwater, oligotrophic lakes containing isoetids may soon be changed.

This research will also determine the factors that favor an accumulation of U. inflata, thus aiding in the identification of lake sites where control efforts may be most needed.

Supplemental Keywords:

invasive species, submersed macrophytes, nutrients, sediment chemistry, freshwater lakes, aquatic ecology, Utricularia inflata, Eriocaulon aquaticum, isoetids,, Scientific Discipline, Water, Ecosystem Protection/Environmental Exposure & Risk, Restoration, Environmental Monitoring, Ecology and Ecosystems, Aquatic Ecosystem Restoration, exotic plant species, nutrient loading, invasive plant species, wet prairie restoration, ecological recovery, aquatic ecosystems, environmental rehabilitation, nitrogen compounds, sediment chemistry, ecological impact

Progress and Final Reports:

2007

Final