Pollinators and insect populations are once again thriving after native grasses and wildflowers were reintroduced at two American solar farms built on agricultural land, a study has found.
Why it matters: Insect populations have been steadily declining in recent decades due to habitat loss, pesticides and climate change. The expansion of single-crop commercial farming is partly to blame.
The latest: Researchers at the US Department of Energy’s Argonne National Laboratory and National Renewable Energy Laboratory have published the results of a five-year field study on two solar sites in southern Minnesota. Both sites were built on retired farmland.
Native grasses and flowering plants were reintroduced in early 2018. Five years later, total insect abundance had tripled, while native bee numbers were up 20-fold. The most numerous insect groups observed were beetles, flies and moths.
The researchers also found that pollinators from the solar sites visited soybean flowers in adjacent crop fields, providing additional pollination services.
“This research highlights the relatively rapid insect community responses to habitat restoration at solar energy sites,” said Lee Walston, an Argonne landscape ecologist and environmental scientist. “It demonstrates that, if properly sited, habitat-friendly solar energy can be a feasible way to safeguard insect populations and can improve the pollination services in adjacent agricultural fields.”
The researchers said appropriate siting of habitat-friendly solar energy on marginal farmland can preserve prime farmland and make it more productive, while at the same time meeting clean energy goals.
They added that agrivoltaics, where crops are grown under raised solar panels, are another effective way to support insect conservation.
Yes, but: Additional research is needed to understand the feasibility of habitat-friendly solar across different regions and to meet different ecological goals, such as conserving a target insect or wildlife species, the authors said.