@article {JRN54595,
	title = {Leaf litter decomposition is rapidly enhanced by the co-occurrence of monsoon rainfall and soil-litter mixing across a gradient of coppice dune development in the Chihuahuan Desert},
	journal = {Journal of Arid Environments},
	volume = {129},
	year = {2016},
	pages = {111-118},
	abstract = {<p class="rtejustify">Shrub encroachment, a common occurrence in drylands over the past 150 years, has the potential to alter the redistribution of soil and soil resources by wind and water. This may affect decomposition via soillitter mixing (SLM). SLM can accelerate decomposition, but its contributions and relationship with abiotic controls, particularly in the context of shrub encroachment, are unknown. To better understand the spatiotemporal relationships between decomposition and shrub encroachment, we conducted a 24 month decomposition study aimed at understanding how placement of litter on either up or downwind sides of dunes in association dune volume affected litter decomposition. There was little decomposition in the first six months of the experiment, with 97.2\% of mass remaining despite high exposure to solar radiation. Decay occurred in synchrony with monsoons and SLM, suggesting precipitation during the monsoon season plays an important role in facilitating both SLM and decomposition. Litter placements across a gradient of shrub volumes had no effect on decomposition rates and SLM, but litter placement on the downwind side of dunes had a positive influence on soil-microbial film development. Ultimately, monsoons rainfall and SLM promoted decomposition across a gradient of shrub encroachment in this dryland ecosystem.</p>
},
	keywords = {biogeochemical cycling, carbon cycling, litter decomposition, nutrient cycling, photodegradation, Prosopis, shrub encroachment},
	doi = {10.1016/j.jaridenv.2016.02.014},
	url = {files/bibliography/JRN00651.pdf},
	author = {Hewins, Daniel B. and Heather L. Throop}
}
@article {49853,
	title = {Soil-litter mixing accelerates decomposition in a Chihuahuan Desert grassland},
	journal = {Ecosystems},
	volume = {16},
	year = {2013},
	month = {03/2013},
	pages = {183-195},
	chapter = {183},
	abstract = {Decomposition models typically under-predict decomposition relative to observed rates in drylands. This discrepancy indicates a significant gap in our mechanistic understanding of carbon and nutrient cycling in these systems. Recent research suggests that certain drivers of decomposition that are often not explicitly incorporated into models (for example, photodegradation and soil\&ndash;litter mixing; SLM) may be important in drylands, and their exclusion may, in part, be responsible for model under-predictions. To assess the role of SLM, litterbags were deployed in the Chihuahuan Desert and interrelationships between vegetation structure, SLM, and rates of decomposition were quantified. Vegetation structure was manipulated to simulate losses of grass cover from livestock grazing and shrub encroachment. We hypothesized that reductions in grass cover would promote SLM and accelerate mass loss by improving conditions for microbial decomposition. Litter mass decreased exponentially, with the greatest losses occurring in concert with summer monsoons. There were no differences in decay constants among grass cover treatments. A significant, positive relationship between mass loss and SLM was observed, but contrary to expectations SLM was independent of grass cover. This suggests that processes operating at finer spatial scales than those in our grass removal treatments were influencing SLM. Shifts in litter lipid composition suggest increased bacterial contribution to decomposition through time. SLM, which is seldom included as a variable controlling decomposition in statistical or mechanistic models, was a strong driver of decomposition. Results are discussed in the context of other known drivers of decomposition in drylands (for example, UV radiation and climate) and more mesic systems.},
	keywords = {arid, carbon cycle, decomposition, dryland, dust, erosion, livstock grazing, phospholipid fatty acids, Prosopis, shrub encroachment, soil-litter mixing},
	doi = {10.1007/s10021-012-9604-5},
	url = {/files/bibliography/13-019.pdf},
	author = {Hewins, Daniel B. and Steven R. Archer and Gregory S. Okin and McCulley, Rebecca L. and Heather L. Throop}
}
