Solar energy development impacts flower-visiting beetles and flies in the Mojave Desert

Abstract

Deserts support a high diversity of insect pollinators and vascular plants with which pollinators have coevolved. Deserts are increasingly prioritized as recipient environments for ground-mounted solar energy development, which represents a novel, anthropogenic disturbance in desert ecosystems and drives land-use change across desert landscapes. Pollinators confer ecosystem services, yet anthropogenically driven land-use change has played a large role in their decline globally. Our objective was to elucidate relationships between solar energy development and non-bee insect flower visitors (i.e., beetles, flies, moths, and wasps) at Ivanpah Solar Electric Generating System (ISEGS, 392 MW) in the Ivanpah Valley of the Mojave Desert. We used blue vane traps to collect non-bee insect flower visitors in treatments that represent different solar energy development decisions, including two types of site preparation practices (blading and mowing) and establishment of habitat patches in solar fields, replicated across three power blocks in ISEGS and in undeveloped control sites surrounding ISEGS. We determined that count and taxa richness of non-bee insect flower visitors and counts of individual non-bee insect flower visitor taxa were greater in undeveloped controls than in ISEGS. Our results indicate that disturbance from solar energy development negatively affected non-bee insect flower visitors, including beetles and flies, and that small habitat patches within solar fields in ISEGS largely did not support non-bee insect flower visitors. Disruption of non-bee insect flower visitor communities from solar energy development in deserts may lead to cascading effects on biodiversity, including potential decreases in globally imperiled and highly valuable cacti populations dependent on insect pollination. Losses in biodiversity from solar energy development in deserts may be eliminated by alternative siting (e.g., contaminated lands, rooftops), while gains can be achieved by sustainable decision making guided by solutions-oriented, collaborative research and techno-ecological synergies.