Desert Plant Response to Solar Energy Development - Trophic Interactions, Rare and Invasive Species, and Management Implications
December 17, 2020
Energy Research and Development (500)
Electric Program Investment Charge - EPIC
Steve Grodsky, Ph.D., Karen E. Tanner Rebecca, R. Hernandez, Ph.D.
While California deserts are prioritized as environments for solar energy development, the effects of this development on desert plants are poorly understood. Solar energy helps reduce the risks of climate change for society at large, but local disturbance from solar development in desert ecosystems may negatively affect native plants and promote colonization by invasive species. The researchers in this project quantified the effects of concentrating solar power development, including site preparation and heliostat density, on soils, Mojave milkweed (Asclepias nyctaginifolia), and the queen butterfly (Danaus gilippus), using Ivanpah Solar Electric Generating System in the Ivanpah Valley, California as a model system. In Barstow, California, the researchers quantified the effects of simulated photovoltaic solar panels on three annual plant species, including the congeners Eriophyllum mohavense and E. wallacei and the exotic invasive annual Sahara mustard (Brassica tournefortii). At Ivanpah, the researchers determined that site preparation using bulldozing created uninhabitable soil conditions for nearly all plants and that preconstruction, plant-conservation islands of undeveloped desert within Ivanpah Solar Electric Generating System, known as halos, are effective for Mojave milkweed conservation and maintenance of Mojave milkweed-queen butterfly trophic interactions. For desert annuals, the researchers determined that microhabitat alteration from simulated photovoltaic panels did not affect reproduction for any of the species focused on, but effects of altered water availability and soil temperature may have population-level effects on these species over time and with varied climatic conditions. The team’s results indicate that solar energy development in the Mojave Desert may have adverse effects on some desert plants and that the level of impact may be regulated, to some extent, by informed site preparation and management practices. The team’s research provides a platform for future studies of the solar energy-ecosphere nexus in California’s deserts and informs management for plants at solar facilities of methods to reduce environmental mitigation costs and ecological damage.