Recent Topics Posters
Yadav-Pauletti, Sunita , Culley, Theresa .
Using GIS to investigate habitat fragmentation effects on genetic structure of Viola pubescens within urban and agricultural areas.
It is widely accepted that habitat fragmentation adversely affects populations but researchers are only recently beginning to evaluate the important role that the landscape matrix plays in how populations respond to fragmentation. Viola pubescens is a perennial understory herb found in deciduous forests of Eastern North America. Early spring flowers in V. pubescens are chasmogamous (primarily out-crossing) and late spring flowers are cleistogamous (selfing). The natural forest habitat of this species has become increasingly fragmented as forests have been converted to agriculture and urban land use. The primary goal of this research was to assess whether habitat fragmentation, i.e. measured quantitatively using a GIS, has affected the genetic structure and population variation of V. pubescens within urban and agricultural landscapes. Genetic analyses using 12 microsatellite loci showed that 11 urban and agricultural populations in Ohio are significantly different from each other (theta = 0.230 in urban populations; 0.184 in agricultural populations). While correlations between various genetic variables and land use were not significant, there was a variation in the response of genetic variables to land use type. Data were also analyzed in the program FRAGSTATS at the class level (i.e. for each land use type within a 3 km buffer around each population) and at the landscape level (i.e. all land use categories within the whole buffer). Regression analyses showed that the metrics of Mean Patch Area and Number of Patches were not good predictors of genetic variables for any land use type at the class level (Forest, Agriculture, and Urban). At the landscape level, the number of alleles per locus (A) and number of alleles per polymorphic loci (Ap) regressed against Landscape Patch Index (a metric that represents the % area covered by the largest patch) and Number of Patches showed the highest explained variance (r2 = 0.49 and 0.46 respectively, p =0.06). These results indicate that both urban and agricultural populations show a high level of overall genetic diversity, both populations are structured and that landscape elements only moderately affect genetic diversity in V. pubescens. Given that urban and agricultural populations were significantly different from one another, we may expect that fragmentation is beginning to have an effect on differentiation. However, fragmentation may show mixed effects because population sizes typically remain large in this relatively common herb.
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1 - University of Cincinnati, Biological Sciences, 614 Rieveschl Hall, Cincinnati, OH, 45221, USA
2 - University Of Cincinnati, Department Of Biological Sciences, 614 Rieveschl Hall, Cincinnati, OH, 45221-0006, USA
Presentation Type: Recent Topics Poster
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM