Abstract Detail

Biogeography

Ahrens, Collin [1], Meyer, Tom [2], Auer, Carol [3].

Modeling current switchgrass (Panicum virgatum) distribution in New England.

The Energy Independence and Security Act (EISA) has set a national goal for renewable liquid fuels and lignocellulosic biofuels crops are expected to be an important part of this effort. Among the most promising biofuels crops is the native, perennial switchgrass (Panicum virgatum). Switchgrass is well adapted to habitats outside cultivation and our challenge is to predict the impact of switchgrass biofuel crops in New England by increasing our understanding of their distribution and ecology. The goal of this study was to survey native and feral switchgrass populations and model the probability of their occurrence across New England. To ascertain its current distribution, a botanical survey (2011) examined switchgrass at points along secondary highways to gather data on abundance, edaphic features, and position. Survey routes were designed to cross gradients such as mean temperature, elevation, precipitation, and urban areas. Correlation coefficients between variables were calculated and each variable was run in a linear regression model to calculate its significance. Three significant and non-correlated variables were used in two Bayesian models: a GLM model and a spatially explicit hierarchical GLM model. Model performance was equal based on area under the curve (AUC: 0.844 and 0.842 respectively), but the normal GLM model performed better under other performance tests. For both models, average yearly temperature was the most significant variable, with elevation playing a role. Urban area was only significant for the GLM model but not for the spatially explicit model. This study elucidates the current distribution of switchgrass in New England, and the mapped range represents a departure from native switchgrass habitat (coastal New England habitat). It shows that crop-to-wild gene flow could occur due to large-scale switchgrass production. In addition, the significance of average temperature in current distribution patterns suggests that continued climate change could increase suitable habitat for switchgrass.

Broader Impacts:

1 - University Of Connecticut, Department Of Plant Science, 111 W. Main St, # 2, Stafford Springs, CT, 06076, USA
2 - University of Connecticut, Department of Natural Resources and the Environment, U-4087, 1376 Storrs Road, Storrs, CT, 06269-4087, USA
3 - University Of Connecticut, Plant Science, 1390 Storrs Road, U-4163, Storrs, CT, 06269, USA

Keywords:
switchgrass
Bayesian modeling
species distribution modeling
Panicum virgatum.

Presentation Type: Oral Paper:Papers for Topics
Session: 2
Location: Franklin B/Hyatt
Date: Monday, July 9th, 2012
Time: 8:30 AM
Number: 2001
Abstract ID:213