Grantee Research Project Results
2001 Progress Report: Chinese Tallow Invasions into the Endangered Coastal Prairie: Causes and Consequences
EPA Grant Number: R828903Title: Chinese Tallow Invasions into the Endangered Coastal Prairie: Causes and Consequences
Investigators: Siemann, Evan , Grace, James , Rogers, William
Institution: Rice University
EPA Project Officer: Packard, Benjamin H
Project Period: June 1, 2001 through May 31, 2004 (Extended to May 31, 2005)
Project Period Covered by this Report: June 1, 2001 through May 31, 2002
Project Amount: $381,687
RFA: Exploratory Research to Anticipate Future Environmental Issues (2000) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Water , Aquatic Ecosystems
Objective:
Chinese Tallow Tree (Sapium sebiferum) is a major invader in the southeast United States, which aggressively displaces native plants. Our research focuses on the mechanisms that allow S. sebiferum to establish in endangered coastal prairies and transform them into biotically depauperate forests.
The main objective of this research project is to understand how abiotic conditions interact with biotic factors to influence the likelihood, severity, and impacts of S. sebiferum invasions into coastal prairie. Specifically, we address the following questions: How do fire (annual or periodic), soil fertility, and herbivores interact to influence S. sebiferum invasion? How do flooding, soil fertility, and herbivores interact to influence S. sebiferum invasion? How important is local recruitment limitation versus local conditions in determining the likelihood and severity of S. sebiferum invasion?
Progress Summary:
Fire Experiment
We designed this experiment and began the semi-annual fertilization treatments in spring 2000. We burned the plots annually in 2000, 2001, and 2002. Another set of plots was burned only in 2000. In 2003, all burn plots will again be burned. We initiated the S. sebiferum seed addition subexperiment in fall 1999 and spring 2000. We planted the S. sebiferum seedlings in spring 2000. Preliminary results indicate strong facilitation of S. sebiferum invasion by fertilization. To date, annual burns have reduced S. sebiferum invasion, while the one-time burn has promoted invasion, more than no burning at all.
Flood Experiment
In the original proposal, we described an experiment with a two-level water treatment (control versus flooded). We added another treatment in which water from extreme precipitation events is pumped out of the plots. The experimental design addresses explicitly the range of variation that is present for the frequency of extreme precipitation events in the Gulf Coast in models of future climate. We designed this experiment and began the semi-annual fertilization treatments in spring 2002. At this time, we installed the water control structures and the subsurface pumps. We added S. sebiferum seeds for the recruitment limitation experiment in spring 2002. We planted S. sebiferum seedlings for the other subexperiment in spring 2002. Preliminary results show the facilitation of S. sebiferum invasion by fertilization. No overall significant effects of water manipulations occurred in the first growing season, but S. sebiferum invasion was inhibited in the drought plots compared to control plots.
Future Activities:
We will continue the fire and flood experiments through the next reporting period.
Journal Articles:
No journal articles submitted with this report: View all 30 publications for this projectSupplemental Keywords:
animal, ecological effects, ecology, Gulf Coast, soil, tallgrass prairie, terrestrial, Chinese Tallow, East Texas, Texas, TX, Tallow Tree invasions, abiotic, bioindicator, biopollution, carbon, ecological effects, ecological exposure, exploratory research, forest, futures research, invasive plants, invasive species, nitrogen, prairie, tall grass prairie, tallgrass, terrestrial., RFA, Scientific Discipline, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Ecosystem/Assessment/Indicators, Ecosystem Protection, State, Forestry, Ecological Effects - Environmental Exposure & Risk, Ecological Risk Assessment, Ecology and Ecosystems, Exp. Research/future, Futures, bioindicator, ecological effects, ecological exposure, Tallow Tree invasions, forest, carbon, Texas, biopollution, East Texas, prairie, tall grass prairie, abiotic, exploratory research, Texas (TX), tallgrass, terrestrial, terrestrial habitat loss, invasive species, invasive plants, Chinese Tallow, futures researchRelevant Websites:
http://www.ruf.rice.edu/~siemann Exit
Progress and Final Reports:
Original AbstractThe 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.