Nitrogen deposition and UV stressor impacts in Canyonlands National Park as affected by climatic pulse events

 

Principal Investigator:

Co-Investigators:
  Jayne Belnap
U.S. Geological Survey-Biological Resources Division
Canyonlands National Park
2290 S W Resource Blvd.
Moab, UT 84532-3298
Phone: (435) 719-2333
e-mail: jayne_belnap@usgs.gov
Martyn M. Caldwell, Utah State University
James R. Ehleringer, University of Utah
David Evans, University of Arkansas
Robert F. Sanford Jr., University of Denver
 

Park: Canyonlands National Park [CANY]

 

Project Summary:

          Historically, arid systems in the western US and arctic are thought to have derived much of their nitrogen from nitrogen-fixing components of the biological soil crusts. These crusts, which can represent up to 70% of the living cover (often referred to as cryptobiotic crusts), are consolidated matrices of cyanobacteria, lichens, mosses, algae and fungi that are ubiquitous on undisturbed soil surfaces. Increased nitrogen deposition, increased UV-B, and land-use change are likely to cause large changes in the integrity and sustainability of the arid ecosystems through impacts of these stressors on the biological crusts. Altering the function of cryptobiotic crusts will directly affect critical ecosystem processes such as soil carbon and nitrogen transformations, and this in turn will have a direct impact on productivity of higher plants. Through a series of field nitrogen-deposition and UV-augmentation experiments, we will quantify, the direct impacts of these stressors on biological crusts, soil carbon and nitrogen dynamics, and higher plants within Canyonlands NP. We will also identify and quantify the anthropogenic sources of nitrogen deposition that are likely to impact ecosystem dynamics.

          Canyonlands National Park is an ideal site because of several long-term (30 yr) research and monitoring efforts directed at understanding the response of arid ecosystems to anthropogenic change. The proposed research will provide the scientific basis for understanding the response of arid ecosystems to the interaction of anthropogenic nitrogen deposition, increased UV-B radiation, and land-use change. Biological soil crusts are the keystone component of arid ecosystems in the western United States and will provide large-scale information about the "health" of these arid ecosystems. The research results will improve our understanding of anthropogenic stressors by quantifying and further defining the relationships between biological crusts, soil carbon and nitrogen transformations, and higher plant sustainability-performance in arid lands. Results will apply to 65 national park units and 300 million acres of federal land, including four national parks with UV-B monitors (Canyonlands, Denali, Big Bend, and Grand Canyon National Parks).

 

FINAL REPORT: Nitrogen Deposition and UV Stressor Impacts in Canyonlands National Park as Affected by Climatic Pulse Events (methods) (tables 1 2 3 4 5 6 7) (figures 1 2)

2002 Canyonlands PRIMENet Meeting Presentation

Bowker et al., "Temporal Variation in Community Composition, Pigmentation, and F v /F m of Desert Cyanobacterial Soil Crusts" in Microbial Ecology

2001 PRIMENet Meeting Presentation: Nitrogen Deposition and UV Stressor Impacts in Canyonlands National Park (R.D. Evans, A. Pilmanis, S. Schaeffer, J. Ehleringer, S. Schwinning, R. Sanford, M. Caldwell, S. Flint, J. Belnap, S. Phillips)

Nitrogen Deposition and UV Stressor Impacts in Canyonlands National Park as Affected by Climatic Pulse Events: Semi-Annual Progress Report: 7/1/00 to 2/1/01 (Figures)

2000 PRIMENet Meeting Presentation: Effects of N-pluses on two perennial grasses in Canyonlands National Park (Susan Schwinning)

Belnap et al., 2004. Response of desert biological soil crusts to alterations in precipitation frequency. Oecologia 141:306-316.

Schwinning S. et al., 2004.Thresholds, memory, and seasonality: understanding pulse dynamics in arid/semi-arid ecosystems, Oecologia, 141(2):191-193.

For more information on this field station site visit http://sbsc.wr.usgs.gov/CLFS/clfs.html.

For more background information on biological soil crusts link to http://www.soilcrust.org/.

Soilcrust fact sheet

 

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