Potential benefits and risks of solar photovoltaic power plants on arid and semi-arid ecosystems: an assessment of soil microbial and plant communities

Abstract

Exponential increase in photovoltaic installations arouses concerns regarding the impacts of large-scale solar power plants on dryland ecosystems. While the effects of photovoltaic panels on soil moisture content and plant biomass in arid ecosystems have been recognized, little is known about their influence on soil microbial communities. Here, we employed a combination of quantitative PCR, high-throughput sequencing, and soil property analysis to investigate the responses of soil microbial communities to solar panel installation. We also report on the responses of plant communities within the same solar farm. Our findings showed that soil microbial communities responded differently to the shading and precipitation-alternation effects of the photovoltaic panels in an arid ecosystem. By redirecting rainwater to the lower side, photovoltaic panels stimulated vegetation biomass and soil total organic carbon content in the middle and in front of the panels, positively contributing to carbon storage. The shade provided by the panels promoted the co-occurrence of soil microbes but inhibited the abundance of 16S rRNA gene in the soil. Increase in precipitation reduced 18S rRNA gene abundance, whereas decrease in precipitation led to decline in plant aboveground biomass, soil prokaryotic community alpha diversity, and dehydrogenase activity under the panels. These findings highlight the crucial role of precipitation in maintaining plant and soil microbial diversities in dryland ecosystems and are essential for estimating the potential risks of large-scale solar power plants on local and global climate change in the long term.

High-throughput sequencing-based analysis of the composition and diversity of the endophyte community in roots of Stellera chamaejasme

“…The annual precipitation in the NMC area is the highest among the three sample points, indicating that precipitation and endophyte diversity are closely related. Previous studies have shown that differences in precipitation will lead to differences in soil microorganisms, and annual precipitation is positively correlated with soil microbial diversity 42 , 43 . In addition, among the three sample points, the NMC sample point has the highest pH and salinity value (pH 8.5, salinity 3 ms/cm), followed by XGYZ (pH 8.2, salinity 0.05 ms/cm).…”

“…Existing studies have shown that not only different plants have different endophytic community structures, but also there are generally differences in the endophytic community structures of the same species under different geographical conditions, such as the medicinal plants Codonopsis pilosula , Astragalus membranaceus , and Forsythia suspensa on the Qinghai-Tibet Plateau. Such geographical differences also exist in the diversity of endophytes 42 .…”