BIOLOGICAL SOIL CRUSTS: EFFECTS OF ENVIRONMENTAL CHANGE ON DRYLAND MICROBES

作者：Mariah T. Patton · 发表于：UNM’s Digital Repository (University of New Mexico) · 年份：2026 · 研究领域：Biocrusts and Microbial Ecology、Mycorrhizal Fungi and Plant Interactions、Planetary Science and Exploration

Climate change is increasing rainfall variability, altering nutrient availability, and causing warming in drylands, which comprise approximately ~36% of Earth's terrestrial surface. These expanding ecosystems contribute the most to interannual variability in the global carbon cycling. Biological soil crusts (biocrusts)—often called the "skin of the Earth"—are critical components of dryland surfaces, consisting of successional microbial communities dominated initially by Cyanobacteria and later by a more diverse composition with other bacteria, archaea, lichen, fungi, and algae. These communities play essential roles in soil aggregation, erosion prevention, and carbon and nitrogen cycling. However, our ability to predict biocrust responses to environmental change is limited by incomplete understanding of how multiple stressors interact and whether biocrusts retain legacy effects that could impair post-disturbance recovery. Through long-term field experiments manipulating nutrients (nitrogen and phosphorus additions), inter- and intra-annual rainfall variability, and warming across the Chihuahuan and Sonoran Deserts, we investigated biocrust responses to multiple environmental changes. We found that nitrogen addition consistently reduces cyanobacterial biomass and diversity in biocrusts regardless of rainfall regime, soil nutrient status, warming treatment, or desert location. Additionally, Cyanobacteria and carbon-related measurements (including soil organic matter and microbi...