| Nitrogen
deposition and UV stressor impacts in Canyonlands National Park as
affected by climatic pulse events |
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Principal
Investigator: |
Co-Investigators: |
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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
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Martyn M. Caldwell, Utah State University
James R. Ehleringer, University of Utah
David Evans, University of Arkansas
Robert F. Sanford Jr., University of Denver |
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Park: Canyonlands National Park [CANY] |
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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).
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
