Day: November 16, 2011

Mapping Plant Functional Types at Multiple Spatial Resolutions Using Imaging Spectrometer Data

/ Matt Artz

GIScience & Remote SensingGIScience & Remote Sensing, Volume 48, Number 3 / July-September 2011

Abigail N. Schaaf, Philip E. Dennison, Gregory K. Fryer, Keely L. Roth, and Dar A. Roberts

“Imaging spectrometer data have been used to map plant functional types (PFTs—plant species grouped by similarities in their resource use, ecosystem function, and responses to environmental conditions) at spatial resolutions of 30 m and finer, but not at coarser spatial resolutions that may be necessary for global PFT mapping. This study uses spatially resampled Airborne Visible InfraRed Imaging Spectrometer (AVIRIS) data acquired over the Wasatch Mountains of northern Utah, USA to examine changes in PFT classification accuracy as spatial resolution is degraded from 20 to 60 m. Accuracy was dependent on the spatial resolution of the classified data and the spatial resolution of endmembers used in the multiple endmember spectral mixture analysis classifier.”

Landscape Genetics Shed Light on Deer Dispersal and Population Contact in the Wisconsin – Illinois Chronic Wasting Disease Zone

/ Matt Artz

The Wildlife Society, Hawaii 2011The Wildlife Society, 18th Annual Conference,  05-10 November 2011, Waikoloa, Hawaii

Stacie Robinson, Mike Samuel, Davin Lopez, and Paul Shelton

“Chronic Wasting Disease (CWD) is an important management concern for Wisconsin’s white-tailed deer population; understanding animal movement and dispersal is crucial to disease surveillance and controlling spread of infection. Though CWD was recently discovered in the Midwest, it has likely been present for decades, and appears to be increasing in prevalence and distribution. Landscape genetics offers powerful tools to examine population connectivity, and thus potential disease connectivity, on a landscape scale. However, it is challenging to detect dispersal patterns and population contact rates for white-tailed deer, adaptable habitat generalists able to traverse varied landscapes. We used landscape genetics, recently developed multivariate and spatial statistics, to describe population structure of deer relative to CWD outbreaks. Our study spanned S Wisconsin and N Illinois, including two distinct disease foci in the eastern and western sides of the area. Using a spatial principle components analysis (SPCA), we detected biologically based genetic gradients. Factor scores from the SPCA were mapped in ArcGIS to visualize genetic variation across the landscape and used in a geographically weighted regression to explain ecological factors shaping connectivity between populations. Sharp contours, showing more rapid genetic differentiation between neighboring populations, coincided with major highway corridors, and the rate of genetic change across the landscape was most dramatic in the fragmented plains ecosystem around the eastern CWD core. Higher connectivity around the western CWD core suggesting dispersal follows more of a diffusion process through the continuously forested deer habitat in this ecosystem. Our research indicated that farther reaching and less predictable movement of the disease is likely from the eastern CWD core. Our findings, suggest that CWD monitoring and potential control strategies should be tailored to the specific levels of population connectivity and potential movement around each outbreak.”