CAREER: Breaking Ground: Uncovering the Fate of Biocrust Microbiome in Arid and Semi-Arid Lands

Arid and semi-arid lands cover a large fraction of Earth’s surface and support the livelihoods of hundreds of millions of people. Many of these landscapes are changing. A critical, but often overlooked, component of healthy drylands is biological soil crusts (“biocrusts”), thin, living soils formed by communities of microorganisms. Biocrusts stabilize soil, support nutrient cycling, and regulate dust emissions, thereby protecting soil fertility and human health. Biocrusts are sensitive to environmental stress, particularly exposure to strong daily and seasonal temperature variations that characterize dryland environments. Recent research suggests that abrupt or extreme events may be more disruptive to biological systems than average conditions alone. This project seeks to improve understanding of how biocrust microorganisms respond to temperature volatility, knowledge that is essential for predicting biocrust persistence and guiding efforts to maintain and restore dryland soil function. By advancing soil microbiology research, supporting education and training, and informing land management practices, this project advances science and contributes to national priorities in biotechnology, agriculture and workforce development. The project integrates laboratory experiments, global data analysis, and education-focused research to examine how biocrust microorganisms respond to temperature fluctuations. First, controlled mesocosm experiments will be used to define the thermal tolerance range of biocrust microbial communities and to identify thresholds at which community composition and metabolic function shift. Microbial activity and community structure will be characterized using genomic sequencing and functional assays. Results from these experiments will guide analyses of a global biocrust survey dataset spanning diverse dryland regions to evaluate whether similar microbial responses are observed across natural thermal gradients. Second, the project will focus on keystone cyanobacteria of the genus Microcoleus, which dominate biocrust biomass and drive carbon fixation and soil stabilization. Using microfluidic SoilChips that enable direct microscopic observation, the research will measure physiological, metabolic, and behavioral responses of these organisms to temperature variability, including tradeoffs between thermal tolerance and other cellular functions. Educational components are integrated throughout the project, including a hands-on SoilChip curriculum implemented in partnership with high schools in dryland regions, where student-generated data will contribute directly to research outcomes. An accompanying online gallery highlighting biocrust scientists will serve as a public-facing educational resource that increases awareness of biocrust research and careers in soil science. Together, these activities advance fundamental understanding of soil microbial resilience while strengthening education and research capacity in dryland systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.