Species Status Assessment Tools Webinar Series
A new method for forecasting range-wide demographic and genetic viability across broad regions under changing climates.
Species Status Assessment Tools Webinar Descriptions
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Novel Methods for Population Viability Analysis to Inform Species Status Assessment (00:45:31)
Presented by Dr. Seth Wenger, Director,River Basin Center, University of Georgia. April 7, 2015.
Government agencies and NGOs involved in species conservation regularly conduct conservation planning to identify populations which are at risk or secure, and to target locations where management interventions can provide the greatest conservation benefit. Although ideally this planning would be guided by formal population viability analyses (PVA) to determine the probability that each population will persist, with and without management actions, in practice most conservation planning relies on indirect surrogates of viability such as extent of habitat occupied or patch size. This is due primarily to a lack of accessible, data-driven methods for PVA that can be used across broad spatial scales. We have developed a new statistical "SpatioTemporal Population Viability Model" (ST-PVM), based on classic population models, that combines field data with remotely-sensed data to deliver simultaneous estimates of carrying capacity, inter-annual variability, and viability for many populations across large areas. Remotely-sensed spatial covariates describe habitat size and quality, while temporal variability is modeled as a function of variables such as temperature and flow. Importantly, the approach can leverage information from well-sampled areas to extrapolate to poorly sampled or even unsampled populations, under current and future climates. We conducted a pilot study of Lahontan cutthroat trout (LCT; Oncorhynchus clarkii henshawi), a federally threatened subspecies of cutthroat trout native to the Great Basin. We assembled data from 38 populations of LCT sampled between 1 and 12 times between 1992 and 2013. The model proved successful in generating estimates of extinction probability and carrying capacity for all populations, although we are still assessing accuracy of these estimates and identifying potential improvements. This new modeling framework fills a crucial gap, connecting population ecology relying on extensive field collections with landscape ecology methods that rely on broad-scale Earth observations, and has broad applicability for conservation planning and management by making range-wide quantitative PVA approachable for many taxa of conservation interest.