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Full-Text Articles in Life Sciences
Seasonal Shifts In C3 And C4 Resource Use By A Small Mammal Community Under Changing Precipitation Regimes, Alaina D. Pershall
Seasonal Shifts In C3 And C4 Resource Use By A Small Mammal Community Under Changing Precipitation Regimes, Alaina D. Pershall
Biology ETDs
In light of climate change and projections of increasing temperatures and aridity in the North American southwest, it is essential to understand how consumer populations will respond to changes in the resource landscape. Rainfall varies in timing and intensity and therefore the timing, proportion, phenology, and abundance of C3 and C4 plant resources vary seasonally and annually. Here we examine rodent resource use in the Chihuahuan desert and focus on two distinct precipitation pulses in this system, where spring C3 plants increase production in response to winter rains and C4 plants respond to summer monsoons. We …
Plant-Biocrust Interactions Mediated By The Fungal Loop, Eva Dettweiler-Robinson
Plant-Biocrust Interactions Mediated By The Fungal Loop, Eva Dettweiler-Robinson
Biology ETDs
Plant-microbial interactions influence biogeochemical cycles. Plants and biological soil crusts are primary producers in drylands. Biocrusts include cyanobacteria, lichens, mosses, algae, fungi, bacteria, and archaea on the soil surface, some of which fix atmospheric nitrogen. I investigated controls on biocrust carbon fluxes and their contribution to ecosystem fluxes, the incorporation of plant-derived carbon into biocrusts, and the role of soil fungi in promoting performance of plants and biocrusts. Biocrusts responded to temperature and moisture differently by biome. Biocrusts in grasslands/shrublands contributed >25% of total summertime ecosystem respiration, but biocrusts in savannas/woodlands contributed <1%. Biocrusts contributed <2% to GPP in any biome. To augment their native photosynthesis, biocrusts may include 16% plant-derived carbon. Fungal connections improved plant and biocrust performance and reduced differences in the CN ratio between organisms compared to when connections were impeded. Investigation of interactions among biocrusts, plants, and fungi has improved understanding of resource cycling in drylands.