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Title: Early exposure to UV radiation overshadowed by precipitation and litter quality as drivers of decomposition in the northern Chihuahuan Desert

Abstract

Dryland ecosystems cover nearly 45% of the Earth’s land area and account for large proportions of terrestrial net primary production and carbon pools. However, predicting rates of plant litter decomposition in these vast ecosystems has proven challenging due to their distinctly dry and often hot climate regimes, and potentially unique physical drivers of decomposition. In this study, we elucidated the role of photopriming, i.e. exposure of standing dead leaf litter to solar radiation prior to litter drop that would chemically change litter and enhance biotic decay of fallen litter. We exposed litter substrates to three different UV radiation treatments simulating three-months of UV radiation exposure in southern New Mexico: no light, UVA+UVB+Visible, and UVA+Visible. There were three litter types: mesquite leaflets ( Prosopis glandulosa, litter with high nitrogen (N) concentration), filter paper (pure cellulose), and basswood ( Tilia spp, high lignin concentration). We deployed the photoprimed litter in the field within a large scale precipitation manipulation experiment: ~50% precipitation reduction, ~150% precipitation addition, and ambient control. Our results revealed the importance of litter substrate, particularly N content, for overall decomposition in drylands, as neither filter paper nor basswood exhibited measurable mass loss over the course of the year-long study, whilemore » high N-containing mesquite litter exhibited potential mass loss. We saw no effect of photopriming on subsequent microbial decay. We did observe a precipitation effect on mesquite where the rate of decay was more rapid in ambient and precipitation addition treatments than in the drought treatment. Overall, we found that precipitation and N played a critical role in litter mass loss. However, photopriming had no detected effects on mass loss over the course of our year-long study. These results underpin the importance of biotic-driven decomposition, even in the presence of photopriming, for understanding litter decomposition and biogeochemical cycles in drylands.« less

Authors:
 [1]; ORCiD logo [2];  [3];  [4];  [5];  [6];  [7];  [8]
  1. Rhode Island College, Providence, RI (United States)
  2. Bergen Univ., Bergen (Norway). Norwegian Research Centre (NORCE). Bjerknes Centre for Climate Research.
  3. Loyola Univ., New Orleans, LA (United States)
  4. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
  5. Univ. of New Mexico, Albuquerque, NM (United States)
  6. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  7. Arizona State Univ., Tempe, AZ (United States)
  8. Univ. of Lisbon, Lisbon (Portugal).
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1493383
Alternate Identifier(s):
OSTI ID: 1501854
Report Number(s):
PNNL-SA-140950
Journal ID: ISSN 1932-6203
Grant/Contract Number:  
AC05-76RL01830
Resource Type:
Published Article
Journal Name:
PLoS ONE
Additional Journal Information:
Journal Volume: 14; Journal Issue: 2; Journal ID: ISSN 1932-6203
Publisher:
Public Library of Science
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; drylands; litter decomposition; precipitation manipulation; rainout shelter; photodegradation

Citation Formats

Hewins, Daniel B., Lee, Hanna, Barnes, Paul W., McDowell, Nathan G., Pockman, William T., Rahn, Thom, Throop, Heather L., and Canário, João. Early exposure to UV radiation overshadowed by precipitation and litter quality as drivers of decomposition in the northern Chihuahuan Desert. United States: N. p., 2019. Web. doi:10.1371/journal.pone.0210470.
Hewins, Daniel B., Lee, Hanna, Barnes, Paul W., McDowell, Nathan G., Pockman, William T., Rahn, Thom, Throop, Heather L., & Canário, João. Early exposure to UV radiation overshadowed by precipitation and litter quality as drivers of decomposition in the northern Chihuahuan Desert. United States. doi:10.1371/journal.pone.0210470.
Hewins, Daniel B., Lee, Hanna, Barnes, Paul W., McDowell, Nathan G., Pockman, William T., Rahn, Thom, Throop, Heather L., and Canário, João. Mon . "Early exposure to UV radiation overshadowed by precipitation and litter quality as drivers of decomposition in the northern Chihuahuan Desert". United States. doi:10.1371/journal.pone.0210470.
@article{osti_1493383,
title = {Early exposure to UV radiation overshadowed by precipitation and litter quality as drivers of decomposition in the northern Chihuahuan Desert},
author = {Hewins, Daniel B. and Lee, Hanna and Barnes, Paul W. and McDowell, Nathan G. and Pockman, William T. and Rahn, Thom and Throop, Heather L. and Canário, João},
abstractNote = {Dryland ecosystems cover nearly 45% of the Earth’s land area and account for large proportions of terrestrial net primary production and carbon pools. However, predicting rates of plant litter decomposition in these vast ecosystems has proven challenging due to their distinctly dry and often hot climate regimes, and potentially unique physical drivers of decomposition. In this study, we elucidated the role of photopriming, i.e. exposure of standing dead leaf litter to solar radiation prior to litter drop that would chemically change litter and enhance biotic decay of fallen litter. We exposed litter substrates to three different UV radiation treatments simulating three-months of UV radiation exposure in southern New Mexico: no light, UVA+UVB+Visible, and UVA+Visible. There were three litter types: mesquite leaflets (Prosopis glandulosa, litter with high nitrogen (N) concentration), filter paper (pure cellulose), and basswood (Tilia spp, high lignin concentration). We deployed the photoprimed litter in the field within a large scale precipitation manipulation experiment: ~50% precipitation reduction, ~150% precipitation addition, and ambient control. Our results revealed the importance of litter substrate, particularly N content, for overall decomposition in drylands, as neither filter paper nor basswood exhibited measurable mass loss over the course of the year-long study, while high N-containing mesquite litter exhibited potential mass loss. We saw no effect of photopriming on subsequent microbial decay. We did observe a precipitation effect on mesquite where the rate of decay was more rapid in ambient and precipitation addition treatments than in the drought treatment. Overall, we found that precipitation and N played a critical role in litter mass loss. However, photopriming had no detected effects on mass loss over the course of our year-long study. These results underpin the importance of biotic-driven decomposition, even in the presence of photopriming, for understanding litter decomposition and biogeochemical cycles in drylands.},
doi = {10.1371/journal.pone.0210470},
journal = {PLoS ONE},
number = 2,
volume = 14,
place = {United States},
year = {2019},
month = {2}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1371/journal.pone.0210470

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