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ARS Home » Plains Area » Las Cruces, New Mexico » Range Management Research » Research » Publications at this Location » Publication #413042
Research Project: Knowledge Systems and Tools to Increase the Resilience and Sustainablity of Western Rangeland Agriculture

Location: Range Management Research

Title: Stressing the small stuff: How biocrusts respond to altered precipitation

Author
item Young, Kristina
item REED, SASHA - Us Geological Survey
item SALA, OSVALDO - Arizona State University
item TUCKER, COLIN - Forest Service (FS)
item FINGER-HIGGENS, REBECCA - Us Geological Survey
item STARBUCK, MEGAN - Us Geological Survey
item DARROUZET-NARDI, ANTHONY - University Of Texas - El Paso

Submitted to: Ecological Society of America (ESA)
Publication Type: Proceedings
Publication Acceptance Date: 3/1/2024
Publication Date: 8/9/2024
Citation: Young, K.E., Reed, S., Sala, O., Tucker, C., Finger-Higgens, R., Starbuck, M., Darrouzet-Nardi, A. 2024. Stressing the small stuff: How biocrusts respond to altered precipitation. Ecological Society of America (ESA). Abstract.

Interpretive Summary:

Technical Abstract: The ways dryland organisms respond to changes in precipitation frequency and duration can vary with organism type and this variation is thought to be related, at least in part, to a species' strategy to manage reserves (i.e., carbohydrates and nutrients). This is a central tenet of the pulse-reserve paradigm, but has yet to be tested within biological soil crusts (biocrusts), important primary producers that live on the soil surface in drylands worldwide. Here, we administered a gradient of watering amounts and frequencies (ranging from small, frequent watering to large, infrequent watering) to biocrusts with different hypothesized pulse-reserve strategies (moss dominated vs. cyanobacteria dominated biocrust). We examined carbon utilization and physiological metrics (chlorophyll content, Fv/Fm, Y(II)) to test for differences in responses between the biocrust types. After four months of precipitation treatments, we found evidence to support the inclusion of biocrust communities into the pulse-reserve paradigm. Our results showed differential reserve management strategies within cyanobacteria and moss crusts, which appear to align with the two ends of the reserve management continuum. Specifically, moss crust showed evidence of large biomass gain during prolonged pulses, and, to a lesser extent, lost reserves at the initiation of short pulses (akin to a torpid response), while cyanobacteria crust maintained CO2 uptake at the initiation of the smallest pulse size but did not exhibit an increase in uptake as pulses got larger and longer (akin to a nimble response). These findings extend a foundational theory within dryland ecology to biocrust communities and processes, enabling the folding of these important dryland primary producers into frameworks for managing and modeling dryland organisms.