Progress 09/01/08 to 08/31/13
Outputs
Target Audience: The project provided science-based data to support decisions by government regulators. The project also provided information for turfgrass managers, farmers, seed producers and land managers that are responsible for right-of-ways, golf courses, roadsides, parks, conservation areas and public open space. One publication was provided in an open access journal which allows anyone to download the results. Changes/Problems: No major challenges were experienced with regard to achieving the research goals. However, a no-cost extension of one year was necessary due to several issues common to field research (e.g. weather, delays in plant growth, time to recruit graduate students). What opportunities for training and professional development has the project provided? The research provided training and professional development for three PhD students and several undergraduates. Professional development included various activities such as speaking at national and regional conferences. Training in responsible conduct of research (research ethics) was provided to two PhD students. How have the results been disseminated to communities of interest? The results were provided through scientific papers, oral presentations and posters at national and local conferences. One paper was published in an open access journal (PlosONE) making the results available to anyone in the United States and other countries. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
All three of the major goals were acheived during the grant period. These accomplishments included: 1) habitat suitablity model for creeping bentgrass in a cultural landscapes surrounding a golf course, 2) regional botanical survey demonstrating taxonomy and distribution of Agrostis and Panicum species, 3) a gap colonization field experiment demonstrating the competition of herbicide resistant Agrostis species in different types of agricultural and natural plant communities. Project results are relevant to decision-makers tasked with ecological risk assessments for trangenic grasses developed for turf or biofuels.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Ahrens, C. and C. Auer. 2012. Annual Glyphosate Treatments Alter Growth of Unaffected Bentgrass (Agrostis) Weeds and Plant Community Composition. December 2012, Volume 7(12):e50643
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Ahrens, C and CA Auer. 2012. Genetic relationship between cultivated and feral creeping bentgrass (Agrostis stolonifera) in a cultural landscape. Weed Science 60(4):583-588
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Progress 09/01/11 to 08/31/12
Outputs
OUTPUTS: Ecological risk assessment is a framework in which science-based knowledge about crop biology, novel traits (transgenes) and the environment is used to predict environmental impacts. This project has focused on ecological risk assessment for two genetically engineered grasses, Agrostis stolonifera (creeping bentgrass) and Panicum virgatum (switchgrass). Two peer-reviewed papers have been published, one has been accepted for publication, and one manuscript is in review. Presentations have been made at local, national and international conferences. Results were presented to USDA regulators in APHIS-BRS. The research team has included three PhD graduate students and three undergraduates. One output has been the cross-disciplinary training of these graduate students in plant taxonomy and ecology, geospatial information systems (GIS), and ecological risk assessment. The students have taken classes, performed research, and networked at professional meetings. One PhD student has graduated and moved to a postdoctoral position in plant population genetics in Australia. PARTICIPANTS: Co-Principal Investigator: Dr. Thomas Meyer, Associate Professor, Natural Resources and Environment, University of Connecticut; Graduate students: Collin Ahrens, Geoffrey Ecker, Jinwon Chung; Postdoctoral Fellowship: Dr. Collin Ahrens. All graduate students and postdoctoral fellows received training during the period through courses, presentations, networking, and research activities. TARGET AUDIENCES: Scientists, risk assessors, land managers, biotechnology companies, crop breeders, federal agencies. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Creeping bentgrass (Agrostis stolonifera, CB) is a non-native turfgrass that has been engineered for novel traits such as herbicide resistance. It is also a common weed in most of the U.S. Six years ago, there was almost no information about CB distribution, dispersal or gene flow to support ecological risk assessment. Our first study showed that CB and its sexually-compatible bentgrass relatives are widely distributed in Northeastern U.S. habitats such as roadsides (Ahrens, Ecker and Auer, 2011). Coastal and inland ecoregions contained CB and six other closely-related bentgrass species. Next, we combined ecological surveys and mathematical modeling to describe bentgrass habitats around a Connecticut golf course. We identified several ecological variables controlling bentgrass distribution and used them to create a habitat suitability map (Ahrens et al, 2011). The map showed that 36% of the cultural landscape could support weedy bentgrasses, and that weedy bentgrass populations were already co-located with state-listed animal and plant populations. In the next study, we used microsatellite markers to analyze DNA sequences in CB collected from the golf course and five weedy populations. Approximately 3% of the weedy CB plants had genetic sequences from cultivated CB (Ahrens and Auer, in press). In another study, we analyzed the impact of annual glyphosate applications on Agrostis growth, reproductive potential, and plant community composition (Ahrens and Auer, in review). Results showed that a glyphosate resistance trait alters the potential for growth and reproduction in three habitat types. Another component of the grant proposal was the study of switchgrass (Panicum virgatum), a native grass cultivated for various purposes including livestock forage and wildlife habitat restoration. Recently, switchgrass has been engineered to improve its utility as a lignocellulosic biofuel crop. Our research showed that switchgrass is native to our coastal ecoregion and is also found in specific inland habitat types (Ahrens, Ecker and Auer, 2011). At present, we continue to work on elucidating Panicum species distribution, taxonomy, and interspecific hybridization. Publications are expected in the next year.
Publications
- Ahrens, C and CA Auer. 2012. Genetic relationship between cultivated and feral creeping bentgrass (Agrostis stolonifera) in a cultural landscape. Weed Science (accepted and in press)
- Ahrens, CW and CA Auer. Annual glyphosate treatments alter growth of unaffected bentgrass (Agrostis) weeds and plant community composition. In review (2012)
- Ahrens, C. and C. Auer. 2011. Genetic relationships of feral creeping bentgrass populations to cultivated turfgrass on the golf course. Botanical Society of America (poster)
- Auer, C., Ecker, G., Ahrens, C., Chung, J., and T. Meyer. 2011. Switchgrass biogeography and pollen release in the U.S. 11th International Symposium on Biosafety of Genetically Modified Organisms, Buenos Aires, Argentina (poster)
- Auer, CA. 2012. Understanding the receiving environment: Switchgrass and creeping bentgrass in New England. USDA-APHIS (oral presentation)
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Progress 09/01/10 to 08/31/11
Outputs
OUTPUTS: During the past year, research results have been disseminated through one new peer-reviewed journal article and presentations at national and international scientific meetings. The publication in Plant Ecology reported on our study on bentgrass and switchgrass distribution in seven habitat types in two ecoregions. This papers describes the habitats likely to have grass populations for plant gene flow, disturbance, and selection pressure (e.g. herbicide management). More specifically, the study identified habitats that could be impacted by transgene flow from genetically engineered creeping bentgrass or switchgrass. This information could be useful to land managers and risk assessors. An additional important output has been the cross-disciplinary training of three graduate students in plant ecology, geospatial information systems (GIS), and ecological risk assessment. The students have taken classes, performed research, and networked at professional meetings. One student completed his PhD during this past year. PARTICIPANTS: Co-Principal Investigator: Dr. Thomas Meyer, Associate Professor, Natural Resources and Environment, University of Connecticut; PhD Graduate students: Collin Ahrens, Geoffrey Ecker, and Jinwon Chung; Postdoctoral Fellowship: Dr. Collin Ahrens. Graduate students and postdoctoral fellows received training during the period through academic courses, presentations at professional meetings, networking, and research activities. TARGET AUDIENCES: Risk assessors, land managers, biotechnology companies, crop breeders, federal agencies, and scientists. PROJECT MODIFICATIONS: One-year no cost extension was requested and approved to complete research projects.
Impacts
As the results from two research projects have already been published, we outline here the results of a third project. A manuscript is in preparation with a full description of the methods and results. This study explored a gap in knowledge regarding the impact of herbicide selection pressure on feral turfgrass plants with and without a herbicide resistance trait. In particular, this project examined the effect of glyphosate application on the vegetative growth and reproductive potential of two cultivated, weedy Agrostis (bentgrass) species: A. stolonifera (creeping bentgrass, CB) and A. gigantea (redtop, RT). CB is a weedy turfgrass species used on golf courses and in other areas. RT is a weedy bentgrass used for forage, erosion control, and other purposes. Five research plots were established in a natural meadow, an agricultural hayfield, and an agricultural wasteland in the Northeastern U.S.; a 2x2 factorial with random complete block design included subplots with introduced bentgrasses (CR or RT) and two management regimes (one glyphosate application per year or unsprayed control). CB and RT plants were protected with plastic to mimic the glyphosate resistance trait. At the end of the 3-year study, plant community composition had shifted (99% CI) in glyphosate-treated subplots in the four hayfield and natural meadow plots. Glyphosate also decreased plant species richness in two of those plots. Soil nitrate levels were higher in sprayed subplots than controls. In all plot locations, glyphosate treatment improved Agrostis plant survivorship, bentgrass growth (tiller number, biomass), and reproductive potential (number of flowers) compared with bentgrass in unsprayed subplots. This study showed that annual glyphosate applications can alter plant community composition and confer advantages to weedy Agrostis plants. This advantage could translate into increased trait dispersal in weedy Agrostis populations through pollen-mediated gene flow, seed dispersal, and vegetative spread. Thus, herbicide resistant bentgrass could add to the current weed management challenges in agricultural fields, cultural landscapes, and natural areas.
Publications
- Auer, C., Ecker, G, Ahrens, C., Chung, J, and T. Meyer. Switchgrass biogeography and pollen release in the Northeastern U.S. 11th International Symposium on Biosafety of Genetically Modified Organisms, Buenos Aires, Argentina, November, 2010 (poster)
- Ecker, G. 2011. Gene flow in Panicum virgatum. Graduate Research Forum, University of Connecticut, March, 2011 (oral presentation)
- Ahrens, C, Ecker, G, and C. Auer. 2011. The intersection of ecological risk assessment and plant communities: an analysis of Agrostis and Panicum species in northeastern U.S. Plant Ecology 212:1629-1642.
- Auer, C. 2011. Small RNAs for crop improvement: Applications and considerations for ecological risk assessments. Chapter In: Non-coding RN As in Plants. Editors: V.A. Erdmann and J. Barciszewski. Springer Publishing
- Ahrens, C. and C. Auer. 2011. Genetic relationships of feral creeping bentgrass populations to cultivated turfgrass on golf course. Botanical Society of America (oral presentation)
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Progress 09/01/09 to 08/31/10
Outputs
OUTPUTS: During the past year, research results have been disseminated through a peer-reviewed journal article and presentations at national and regional scientific meetings. The publication reported the results of our study on bentgrass distribution and habitat suitability modeling. The habitat suitability modeling approach could be applied to risk assessment, monitoring, and/or management of many different crop species, weeds, or invasive plants. Thus, it may find a relatively wide audience among land managers. An additional important output has been the cross-disciplinary training of three graduate students in plant ecology, geospatial information systems (GIS), modeling, and ecological risk assessment. The students have taken classes, performed research, and networked at professional meetings. PARTICIPANTS: Co-Principal Investigator: Dr. Thomas Meyer, Assoc. Professor, Natural Resources and Environment, University of Connecticut. Graduate Students at the University of Connecticut: Collin Ahrens (Plant Science), Geoffrey Ecker (Plant Science), and Jinwon Chung (Natural Resources). Each graduate student received inter-disciplinary training in plant ecology, geospatial information systems, ecological modeling, botanical survey techniques, and ecological risk assessment. Each graduate student participated in presentations and professional meetings. One undergraduate student received training and experience in scientific methods. TARGET AUDIENCES: Target Audiences: scientists, land managers, crop breeders, biotechnology companies, federal agencies. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Here we outline the results of the second research project completed during the grant period. The research goal was to characterize the natural and managed plant communities that support grass species in the Panicum and Agrostis genera. This is a fundamental step in predicting the likelihood of pollen-mediated gene flow, and characterizing containment and monitoring issues. Agrostis and Panicum are important genera for this study because they contain grass species that have been genetically-engineered (GE) for plant management traits (e.g. herbicide resistance), biofuels production traits, and stress tolerance traits. In the Panicum genus, switchgrass (Panicum virgatum) has been chosen as a potentially valuable lignocellulosic feedstock for ethanol production. In the Agrostis genus, creeping bentgrass (Agrostis stolonifera) is a non-native turfgrass planted on almost every golf course in the U.S. Our field study was conducted over two years (2009-2010) and consisted of 190 transects targeted to 10 habitat types in two ecoregions (inland and coastal Northeastern U.S.). Habitat types in the study included undisturbed core forests, herbaceous meadows, roadsides, wastelands, hayfields, corn fields, and coastal edge. Seven Agrostis species and four Panicum species were identified. Agrostis species occupied a wider variety of habitats than Panicum species, although both genera contain species that are treated as weeds. Transects with Agrostis species had higher plant species diversity than transects lacking Agrostis. This was not true for Panicum. Grasses in both genera had a high frequency of occurrence in managed habitats, such as roadsides, and they frequently co-occurred with invasive plants. The implications of these distribution patterns with regard to pollen-mediated gene flow, containment, and environmental impact will be discussed in our next publication.
Publications
- Ahrens, C.A., Chung, J., Meyer, T. and C.A. Auer. 2010. Agrostis (bentgrass) distribution survey and habitat suitability maps support ecological risk assessment in cultural landscapes. Weed Science (accepted and in press)
- Ahrens, C., G. Ecker, and C. Auer. 2010. Research on plant community assemblage for Agrostis supports ecological risk assessment for genetically engineered Agrostis stolonifera. Botanical Society of America National Meeting (poster)
- Ecker, G., Ahrens, C., and C. Auer. 2010. Switchgrass (Panicum virgatum) biogeographic distribution study for ecological risk assessment. Botanical Society of America National Meeting (poster)
- Chung, J., Ahrens, C.A., Meyer, T. and C.A. Auer. 2010. Predicting bentgrass habitat in a cultural landscape using logistic regression, ecological factors, and GIS. Connecticut Conference on Natural Resources (oral presentation)
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Progress 09/01/08 to 08/31/09
Outputs
OUTPUTS: Research results have been disseminated to academic audiences, federal government agencies, and the broader public. Scientific audiences have included ecologists (Ecological Society of America, 2009) and plant biologists (American Society of Plant Biologists, 2008). Two presentations have been given to federal agencies responsible for the regulation of genetically-engineered crops (Environmental Protection Agency, Office of Research and Development, Virginia, 2008, and USDA, Biotechnology Regulatory Services, Maryland, 2008). Two presentations have been made to groups focused on preventing or controlling invasive plant species in the U.S. (2009). Two presentations have been made to people active in the management of natural areas (Connecticut Conference on Natural Resources, 2009) and golf courses (Plant Science Turf Management Field Day, 2008). One full length scientific publication has been submitted to a scientific journal under the title: Predicting bentgrass (Agrostis) habitats to support ecological risk assessment of genetically engineered turfgrass. Publication is pending. Training of graduate students during the past year has included the opportunity to present research results at regional and national conferences. Ahrens, C. and C. Auer. 2008. When Hybrids Go Wrong: How Hybridization Can Create Invasive Species. Connecticut Invasive Plants Working Group. (presentation) Ahrens, C. and Auer, C. 2008. Transgenics in our backyard. Department of Plant Science Field Day. Storrs, CT. (presentation) PARTICIPANTS: Co-Principal Investigator: Dr. Thomas Meyer, Assoc. Professor, Natural Resources and Environment, University of Connecticut Graduate student: Collin Ahrens, Plant Science, University of Connecticut Graduate student: Geoffrey Ecker, Plant Science, University of Connecticut Graduate student: Jinwon Chung, Natural Resources and Environment, University of Connecticut All graduate students received training in their discipline through research activities and relevant courses. Collin Ahrens was mentored in the art of public presentation of his research results. He presented posters or talks at both regional and national conferences. TARGET AUDIENCES: Target Audiences: scientists, land managers, crop breeders, biotechnology companies, federal agencies. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
A number of research projects have been initiated since the beginning of the grant period (9/1/08). One of these projects has been completed; the results of this particular project are summarized here. The bentgrasses (Agrostis species) comprise a widely distributed and adaptable group of native species, cultivated turfgrasses, and weedy perennial grasses in the U.S. Biotechnology has produced Agrostis stolonifera (creeping bentgrass) with resistance to the herbicide glyphosate for use on golf courses, raising questions about gene flow and the possibility of negative environmental impacts after commercialization. These questions should be answered in the context of the relevant ecosystems, cultural landscapes, land management practices, herbicide applications, and environmental features that need to be protected. This project documented the bentgrass species and the spatial distribution of favorable habitats in an 8.5 km2 site surrounding a golf course in the northeastern U.S. We generated a habitat suitability map (HSM) and a favorable environments map (FEM) by surveying 289 field plots for bentgrass presence/absence, observing relevant ecological factors, creating multivariate logistic regression models, and applying models to geospatial information layers. Four non-native Agrostis species and two native species were well established in natural plant communities and managed landscapes. A. stolonifera was common outside of the golf course, and its abundance exceeded what was expected based on herbarium accessions for the region. The FEM showed that the most favorable bentgrass habitat covered 36% of the study site and included common land use features such as home lawns, a power line right-of-way, a railroad right-of-way, and mowed recreational fields. Bentgrass populations near the golf course were found to co-occur with habitat identified as critical for threatened or endangered animal species. For predictive ecological risk assessments, observations about bentgrass distribution and habitat suitability maps provided spatial information about areas that could potentially support populations of transgenic bentgrasses produced by pollen-mediated gene flow, seed dispersal, or vegetative propagules. These habitat maps could also be valuable tools for future monitoring, containment, and/or land management programs around golf courses. We believe that this habitat modeling approach could be extended to predictive ecological risk assessments, risk management plans, and monitoring projects for a variety of genetically-engineered plants and ecosystems.
Publications
- Ahrens, C., Chung, J., Meyer, T., and Auer, C. 2009. Is the habitat suitable Using geospatial information, modeling, and field surveys to predict plant distribution. Conference: Invasive Plants in the Northeast of Asia and America: Trading Problems Trading Solutions. Storrs, CT. (abstract)
- Auer, C., Frederick, R. 2009. Crop improvement using small RNAs: applications and predictive ecological risk assessment. Trends in Biotechnology 27:644-651
- Auer, C. 2008. Ecological risk assessment and regulation for genetically-modified ornamental plants. Critical Reviews in Plant Sciences 27:255-271
- Ahrens, C., Chung, J., Meyer, T., and Auer, C. 2009. Characterizing bentgrass distribution with spatial and biological data to support ecological risk assessment in Connecticut. Ecological Society of America, annual meeting. Albuquerque, NM. (abstract)
- Ahrens, C., Chung, J., Meyer, T., and Auer, C. 2009. Modeling Bentgrass Distribution to Assess Ecological Risk. Connecticut Conference on Natural Resources. Storrs, CT. (abstract)
- Ahrens, C. and Auer, C. 2008. Drought and Salinity Tolerance of Common Agrostis Species. Northeast-American Society of Plant Biology, annual meeting. (abstract)
- Ahrens, C., Chung, J., Meyer, T., and Auer, C. 2009. Characterizing bentgrass distribution with spatial and biological data to support ecological risk assessment in Connecticut. College of Agriculture and Natural Resources, Storrs, CT. (abstract)
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