Partial shading by solar panels delays bloom, increases floral abundance during the late-season for pollinators in a dryland, agrivoltaic ecosystem

Abstract

Habitat for pollinators is declining worldwide, threatening the health of both wild and agricultural ecosystems. Photovoltaic solar energy installation is booming, frequently near agricultural lands, where the land underneath ground-mounted photovoltaic panels is traditionally unused. Some solar developers and agriculturalists in the United States are filling the solar understory with habitat for pollinating insects in efforts to maximize land-use efficiency in agricultural lands. However, the impact of the solar panel canopy on the understory pollinator-plant community is unknown. Here we investigated the effects of solar arrays on plant composition, bloom timing and foraging behavior of pollinators from June to September (after peak bloom) in full shade plots and partial shade plots under solar panels as well as in full sun plots (controls) outside of the solar panels. We found that floral abundance increased and bloom timing was delayed in the partial shade plots, which has the potential to benefit late-season foragers in water-limited ecosystems. Pollinator abundance, diversity, and richness were similar in full sun and partial shade plots, both greater than in full shade. Pollinator-flower visitation rates did not differ among treatments at this scale. This demonstrates that pollinators will use habitat under solar arrays, despite variations in community structure across shade gradients. We anticipate that these findings will inform local farmers and solar developers who manage solar understories, as well as agriculture and pollinator health advocates as they seek land for pollinator habitat restoration in target areas.

Low cost climate station for smart agriculture applications with photovoltaic energy and wireless communication

“…Agrivoltaics [42] , which is the co-location of crops and PV systems, is growing rapidly and has been shown to improve water efficiency [43] and increase productivity of land [8] , [44] , [45] for a wide array of plant-based crops including lettuce [46] , [47] , spinach and strawberries [45] , wheat [9] , rice [48] , grapes [49] , potato, celeriac, clover grass and winter wheat [50] . Agrivoltaics has also been found to be beneficial both economically and environmentally in several forms of pasture-based animal husbandry as well such as sheep [51] , [52] , rabbits [53] , [54] and honey bees [55] . Due in a large part to climate destabilzation from anthropogenic climate change globally farms face increasing pressure from extreme weather events and shrinking margins [56] , [57] .…”

Opportunities for agrivoltaic systems to achieve synergistic food-energy-environmental needs and address sustainability goals

“…Recent attention has been placed on the role of AV-habitat systems that integrate native habitat enhancement as a means to conserve biodiversity and restore associated ecosystem services [Walston et al, 2018[Walston et al, , 2021Hernandez et al, 2019;Dolezal et al, 2021;Graham et al, 2021;Electric Power Research Institute (EPRI), 2022]. In these configurations, most of the focus has been placed on the creation and maintenance of pollinatorfriendly seed mixes of regionally native grasses, forbs, and other wildflowers, within the solar infrastructure footprint, that attract and support native insect pollinators by providing food sources, refugia, and nesting habitat ("solar-pollinator habitat"; Walston et al, 2018Walston et al, , 2021.…”

Feed the bees and shade the streams: riparian shrubs planted for restoration provide forage for native bees

“…During searches, we systematically walked sites, counting every blooming stem present and tallying (but not catching) every foraging bee observed, recording the plant species on which the bee was observed. Like other pollinator studies (e.g., Roof et al 2018;Graham et al 2021), blooming stems were defined as easily distinguishable individual flowers (e.g., Viola adunca, Rosa spp.) or tight clusters of flowers on a stem (e.g., Noccaea fendleri).…”