Spatial habitat modeling for a threatened plant in a prairie sand dune landscape
Lowe, Sarah Heather
In 1998, hairy prairie-clover was listed as threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and subsequently afforded protection under the Species at Risk Act in 2004. Hairy prairie-clover, being a habitat specialist species confined to areas of sparsely vegetated to bare sand, may provide an indication of the loss of a once viable natural mixed-grass prairie and sand dune landscape indicative to southern Saskatchewan. Therefore, critical habitat identification for hairy prairie-clover is of particular concern, not only to provide conservation efforts for this particular species, but also for bare sand and sand dune environments which are some of the most sensitive landscapes on the prairies. The goal of this thesis is to identify and spatially delineate areas of critical habitat for hairy prairie-clover within the range of a known metapopulation in the Dundurn sand hills south of Saskatoon, Saskatchewan. This research was divided into two specific objectives: 1) to investigate the spatial relationship between bare sand habitat for hairy prairie-clover and other land cover classes, and 2) to study the relationship between habitat configuration and hairy prairie-clover occurrence. To achieve the first objective, the desired output was a land cover classification of the study site at an appropriate spatial and temporal resolution. Wavelet analysis revealed that the optimum spatial resolution for bare sand identification and delineation in the study site was between 2-5 m. Analysis of field spectroradiometer measurements throughout the growing season concluded that the early and late growing seasons were best for spectrally discriminating between land cover classes. A multi-resolution, multi-temporal land cover classification using object-oriented methods resulted in an overall classification accuracy of 79% with a user’s and producer’s accuracy of 85% for bare sand. Grassland comprised the matrix of the area covering 45.5% of the study site. Aspen and shrub were the most dominating landscape elements comprising 25.5% and 19.2% of the study site respectively. Bare sand made up only 6.0% of the study site while juniper was the least persistent class comprising only 2.7% of the study site. The desired output from objective two was a critical habitat landscape mosaic for hairy prairie-clover. Patch scaled metrics were calculated for bare sand patches identified in the land cover classification from objective one. Binary logistic regression was used to identify which metrics could explain and predict hairy prairie-clover occurrences. Results showed that almost 29% of the variation in bare sand patch occupancy could be explained by the size, shape, and degree of isolation of a sand patch as well as the amount of vegetation on a sand patch in the early growing season. Based on these variables, 18.8% of sand patches in the study site were predicted to be unsuitable hairy prairie-clover habitat, 45.7% were predicted to be marginally unsuitable, 32.7% were predicted to be suitable, and 2.8% were predicted to be marginally suitable. Overall prediction accuracy was about 61% with 80% of occurrences and 54% of non-occurrences being correctly predicted.
DegreeMaster of Science (M.Sc.)
CommitteeKamal, Mohammad; Henderson, Darcy
Copyright DateApril 2011