COS 101-5 - Enhancing systematic conservation planning for rare amphibians with eDNA survey data

Abstract: Spatial conservation plans are required to optimally manage species of concern while considering other land use needs. Systematic conservation planning identifies areas within species’ ranges that can be conserved at minimal costs or disruption to other land uses. Cryptic species present challenges for conservation planning as the crucial first step is identifying where species exist on a landscape. In addition, understanding landscape-level risks that may undermine conservation actions is critical to designing robust conservation plans. Here, we present the results of a systematic conservation plan we developed to conserve threatened and endangered aquatic reptiles and amphibians in south coastal California. Our study area is a multi-use landscape with extensive areas of federal land managed by the Department of Defense and the US Forest Service. We combined a comprehensive eDNA sampling survey with the locations of previous detections to produce species distribution models for four amphibian species and a pond turtle. The use of eDNA overcomes many of the challenges associated with detecting cryptic species and also allowed us to quantify the distribution of chytrid fungus across the study area. We calculated costs as the opportunity costs of moving or removing existing built infrastructure (roads, buildings, military ranges). Combining information on the location of roads with the predicted distribution of chytrid fungus produced an estimate of the likelihood of conservation actions failing. We integrated our data on species’ distributions, land costs, and risks into a suite of Marxan analyses to identify priority locations for conservation. We then created maps that showed how the costs and land area required to meet different conservation goals influenced which sites had the highest priority for biodiversity conservation. Our results identified critical landscape areas for protection that balanced the needs of biodiversity and human land uses. Moreover, our results highlight that we can achieve conservation objectives with minimal disruption to important, high-value land uses such as airstrips, testing ranges, and buildings. However, we also demonstrate that conservation in highly-developed landscapes will require encroaching on lower dollar-value infrastructure, as achieving conservation goals was impossible if all areas containing any infrastructure were off-limits for conservation.