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Research about Castle Valley, Utah

Source-linked reports with geographic coverage including Castle Valley, Utah.

4 recordsLinked to original sources
USGS2026

Experimental evidence of a biological soil crust degradation climate warming amplification feedback

Biological soil crusts – photosynthetic communities of cyanobacteria, lichens, and/or mosses living on soil surfaces – represent about 12% of the global land surface, yet their role in climate mitigation remains uncertain. Here we address this knowledge gap by integrating multiscale remote sensing techniques within a unique long-term climate manipulation experiment. Two decades of in situ climate warming and changes in monsoonal rainfall drove a major shift in biocrust community composition, including a ~ 27% decrease in fractional coverage of late-successional mosses and a ~ 36% increase in fractional cover of early-successional, lightly-pigmented cyanobacteria. This community shift, in-turn, resulted in a ~ 6.3% reduction in photosynthetic potential, ~14.1% increase in surface brightness, ~15.2% decrease in surface moisture, and a ~ 1.5% or ~0.3 °C increase in surface temperature under clear sky daytime conditions for every 10% increase in the relative cover of lightly-pigmented cyanobacteria. Our findings are evidence of a biocrust degradation climate warming amplification feedback, whereby climate warming drives biocrust functional degradation and a net reduction in climate mitigation potential, which further drives warming. This apparent warming amplification feedback is currently missing from process-based models, and thus current climate projections might underestimate the rate of climate warming across global drylands.

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USGS2020

Multiple mechanisms determine the effect of warming on plant litter decomposition in a dryland

In drylands, where soil fertility is typically low, plant litter decomposition provides particularly critical carbon and nitrogen inputs into soil. Although climate change is projected to increase the already large global extent of drylands, it is unknown how warmer temperatures will affect core ecosystem processes, such as plant litter decomposition, in these systems. To address this key unknown, we conducted a litterbag study in a long-term dryland warming experiment in southeastern Utah, USA. Unexpectedly, we did not find an overall effect of warming on leaf litter mass loss over time. Instead, our results indicated both positive and negative effects of warming on mass loss which offset one another. In particular, our findings suggested that a warming-induced degradation of biological soil crusts (soil surface community of mosses, lichens, and/or cyanobacteria that live in drylands worldwide) increased soil-litter mixing, thereby accelerating decomposition. Results also suggested that warming-induced decreases in litter moisture slowed decomposition. In addition to assessing mass loss, we found that warming lowered the carbon-to-nitrogen ratio of the decomposing litter. These results showed that warming did not alter the total litter mass-loss rates in this ecosystem, but that decomposition patterns were affected through more nuanced changes to both the biological and physical environment of dryland soils.

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USGS2017

Albedo feedbacks to future climate via climate change impacts on dryland biocrusts

Drylands represent the planet’s largest terrestrial biome and evidence suggests these landscapes have large potential for creating feedbacks to future climate. Recent studies also indicate that dryland ecosystems are responding markedly to climate change. Biological soil crusts (biocrusts) ‒ soil surface communities of lichens, mosses, and/or cyanobacteria ‒ comprise up to 70% of dryland cover and help govern fundamental ecosystem functions, including soil stabilization and carbon uptake. Drylands are expected to experience significant changes in temperature and precipitation regimes, and such alterations may impact biocrust communities by promoting rapid mortality of foundational species. In turn, biocrust community shifts affect land surface cover and roughness—changes that can dramatically alter albedo. We tested this hypothesis in a full-factorial warming (+4 °C above ambient) and altered precipitation (increased frequency of 1.2 mm monsoon-type watering events) experiment on the Colorado Plateau, USA. We quantified changes in shortwave albedo via multi-angle, solar-reflectance measurements. Warming and watering treatments each led to large increases in albedo (>30%). This increase was driven by biophysical factors related to treatment effects on cyanobacteria cover and soil surface roughness following treatment-induced moss and lichen mortality. A rise in dryland surface albedo may represent a previously unidentified feedback to future climate.

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