Dust, biocrusts, and Valley Fever

Mon, 01 Jan 0001 00:00:00 +0000

Biological soil crusts help stabilize dryland soils, shape belowground microbial communities, and reduce dust emissions. As climate change and land disturbance alter biocrust integrity, these changes may have consequences that extend beyond ecosystem function to human exposure to dust and dust-associated microbes. This project explores links among biocrust condition, soil fungal communities, dust generation, and environmental health in the southwestern United States. A central goal is to understand whether biocrust disturbance changes the composition of soil fungal communities in ways that may influence the movement or environmental occurrence of dust-associated pathogens, including the fungus that causes Valley Fever. The project combines ecological sampling, fungal community profiling, spatial analysis, and targeted work in microhabitats where soil disturbance and fungal reservoirs may overlap. A growing component of this work focuses on community-engaged dust monitoring, household and neighborhood-scale exposure questions, air-quality data, dust analysis, and possible intervention approaches such as indoor air filtration. This project asks how changes to desert surfaces may connect ecosystem degradation, airborne dust, microbial exposure, and environmental justice.

Variation in biocrust photosynthesis

Mon, 01 Jan 0001 00:00:00 +0000

Desert mosses experience long periods of drying interrupted by brief windows of hydration, making photosynthesis highly dependent on when, where, and how water becomes available. This project examines how biocrust-forming mosses vary in photosynthetic traits across desert environments that differ in precipitation seasonality, temperature, and atmospheric drying demand. We are especially interested in whether seasonal shifts in photosynthetic performance reflect flexible physiological plasticity, longer-term differentiation among populations, or some combination of both. Using field collections, controlled growth experiments, pigment analyses, and chlorophyll fluorescence approaches, this work asks how desert mosses balance carbon gain with protection from excess light, heat, and drought. By comparing natural variation with responses under shared growth conditions, we aim to better understand how much of this variation is environmentally responsive and how much may reflect fixed differences among populations. This project contributes to broader efforts to predict how changing precipitation regimes and warming may affect biocrust carbon balance in dryland ecosystems.

Biocrusts | MEEP Lab @ SFSU

Dust, biocrusts, and Valley Fever

Variation in biocrust photosynthesis