The US Fish and Wildlife Service (USFWS) Desert Tortoise Recovery Office (DTRO) coordinates a range-wide recovery effort for the Mojave population of the desert tortoise. The tortoise is both an indicator and flagship species for the Mojave desert ecosystem, and is central to many conflicts over land use, including the current debate over solar energy development. Managing human and financial resources for species recovery is a challenging problem, given the complexity of desert tortoise ecology and the variation in agency management and jurisdiction across the four states in this species’ range.

The Redlands Institute and the USFWS are cooperatively developing a spatial decision support system (SDSS) to better understand, evaluate and monitor the cumulative effects of both conservation and development activities on tortoise recovery. Using best-available scientific data and expert-derived decision criteria, the system can assess threats and species status, and compare the relative value of alternative management actions in recovering the species.

At its core, the DTRO SDSS models the relationships among threats to the tortoise, stresses to the population, demographic impacts and recovery actions. The system uses spatial characterizations of existing threats along with a weighted threat-stress conceptual model to estimate changes in stresses for tortoise populations in response to specific recovery actions. When information about proposed management actions and their efficacy in reducing a specific threat-stress mechanism is provided, the system can estimate the relative value of those recovery actions.

This model system can be applied to other species and multi-species landscapes, and to impact assessment for landscape changes and proposed development. For this reason, this project has attracted the attention of the Bureau of Land Management (BLM) and the California Energy Commission (CEC) for evaluation of potential solar energy development in the Mojave. With their support, the DTRO SDSS will be extended for conducting spatially explicit and fully documented cumulative impacts analyses of solar energy projects on the desert tortoise. By providing access to sound and transparent scientific information and decision support technology, we hope to reduce environmental conflict.