Recovery after fire
Monitoring ecosystem status and recovery potential is critical for natural resource management. Recent evidence in ecological studies suggest a fundamental link between ecosystem physical structure and function, including resistance and recovery. Resistance and recovery properties of the imperiled Great Basin ecosystems are of critical utility in management with direct ties to abiotic and biotic site characteristics. Our work demonstrates that UAS surveys can provide novel insights into community resistance and resilience by measuring physical structure across a range of spatial scales. Specifically, we investigated how vegetation structure, measured as structural heterogeneity, responds to wildfire effects and recovery processes and whether the response is scale-dependent. We conducted a survey of a representative set of shrub stands that partially burnt between 1996 and 2015, and span a wide range of abiotic conditions. We found that shrubland structural heterogeneity was sensitive to wildfire effects and shrub recruit abundance, but this sensitivity was scale-dependent and different for the two ecological processes. Wildfire effects were most prominent at the intermediate scale resolutions (2.34 m), while the abundance of shrub recruits required higher resolution structural information (0.29 m). Surprisingly, structural heterogeneity at the very fine resolution (< 0.30 cm) was superfluous and did not provide additional value to the predictive models of recruit abundance. Our project demonstrates a low-cost monitoring framework for quantitative measures of shrubland resistance and recovery potential. We demonstrate how UAS platforms can provide landscape-level data while optimizing the resolution and extent of the survey for the ecological process of interest.