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Future projected climatic trends indicate overall increases in temperature and environmental stochasticity throughout much of the North American rangelands. Understanding how organisms might respond to changing climatic conditions has become increasingly important as species' requirements (i.e., niche conservatism) may restrict or change behavioral patterns. For instance, thermal stress from extreme heat has been shown to restrict movement patterns and space use of terrestrial vertebrates, in which organisms select certain vegetation cover as a thermal refugium during times of thermal stress. Though thermal conditions (operative temperature) may be modified by vegetation structure such as woody cover, an understanding of how the vegetation may physically influence the mechanisms ultimately determining operative temperatures is still lacking. We sought to determine how two shrub species, sand sagebrush (Artemisia filifolia) and aromatic sumac (Rhus aromatic), alter the physical mechanisms that may result in lower operative temperatures during heat events (>30�C) within a semi-arid rangeland in Beaver county, Oklahoma. Starting in 2015, we monitored operative temperatures within a treatment (underneath the shrub canopy) and compared these temperatures to a control (1 m outside the shrub canopy). While recording temperatures, we measured physical conditions underneath and within the shrubs to relate back to operative temperatures. These conditions included: light reflectance and absorption, photosynthetic active radiation (PAR), light reflectance of soil underneath the shrub, wind permeability/turbulence, sonic temperature, soil temperature, and moisture along a transect within the shrub's crown. Traditional structure measurement techniques (i.e, crown spread, crown depth, and shrub height) were used to relate shrub structure to temperatures. Finally, a field LiDAR was used to obtain point clouds of shrubs, which allows us to measure shrub structure in 3-dimensional space. Pilot data was obtained in August of 2015 and subsequent data will continue to be collected during the summer of 2016.