Warming and Precipitation Manipulation Experiments
Contact: Jeff Dukes
Email: jeffrey.dukes@umb.edu
Site Location: Boston, Massachusetts, USA
Latitude: 42.39 decimal degrees
Longitude: -71.22 decimal degrees
Mean Annual Temperature:
Mean Annual Precipitation:
Biome: Old field
Experimental Manipulation: 2 water levels, 5 heating levels
Technology: rainout shelter
Start Date: Spring 2007
End Date:
Key Research Questions:
Key Findings:
Web Site:
Publications:
Contact: Jayne Belnap
Email: jayne_belnap@usgs.gov
Site Location: Moab, Utah, USA
Latitude: 38.67 decimal degrees
Longitude: -109.42 decimal degrees
Mean Annual Temperature: 14 degrees Celsius
Mean Annual Precipitation: 211 mm
Biome: Desert scrub
Experimental
Manipulation: 2 C soil
warming using infrared (IR) lamps, double summer rainfall frequency
Technology: Infra-red lamps
Start Date: November 2005
End Date: Ongoing
Key
Research Questions: This project is using manipulative and natural field
experiments to test four hypotheses: (1) increased temperatures or an increase
in the number of summer precipitation events will alter the species composition,
abundance, activity time and physiological function of crust lichens, mosses,
and bacteria; (2) increased temperatures or an increase in the number of summer
precipitation events will alter the species composition, abundance, activity
time and physiological functioning of subsurface soil biota; (3) alterations in
the abundance, species composition, activity times, and physiological
functioning of the soil biota will affect soil processes and vascular plant
performance; and 4) negative impact of increased temperature and/or summer
precipitation is mediated by increased rates of drying in crust and soil.
Key Findings:
1) Increased frequency of
summer precipitation led to dramatic changes in the moss component of the
crusts, regardless of heat treatment. Living moss cover declined 20% in watered
plots while remaining essentially unchanged in control plots after just one
season. 2) We measured 20% mortality in the C4 grass Hilaria
growing within IR plots, and none in control plots after one year. 3) Nematode
and flagellate abundance did not change through the summer, while amoebae and
ciliate abundance increased during summer. The abundance of ciliates increased
more in warmed than non-warmed plots.
Web
Site: www.met.utah.edu/cgi-bin/droman/meso_base.cgi?stn=PPCUT&unit=0&time=LOCAL
EVENT
Contact: Anke Jentsch
Email: anke.jentsch@ufz.de
Site Location: Bayrueth, Germany
Latitude: 49.95 decimal degrees
Longitude: 11.57 decimal degrees
Mean Annual Temperature: 7.8 degrees Celsius
Mean Annual Precipitation: 709 mm
Biome: Grassland and shrubland
Experimental Manipulation:
Technology:
Start Date: 2005
End Date: Ongoing
Key Research Questions:
Key Findings:
Web Site:
Publications:
Contact: Sune Linder
Email: sune.linder@ess.slu.se
Site Location: Vindeln, Sweden
Latitude: 64.12 decimal degrees
Longitude: 19.45 decimal degrees
Mean Annual Temperature:
Mean Annual Precipitation:
Biome: Forest
Experimental Manipulation: Air warming
Technology: Whole-tree chambers
Start Date: 1987
End Date: Ongoing
Key Research Questions:
Key Findings:
Web Site:
Contact: Scott Bridgham
Email: bridgham@uoregon.edu
Site Location: Zim, Minnesota, USA
Latitude: 47.57 decimal degrees
Longitude: -93.58 decimal degrees
Mean Annual Temperature:
Mean Annual Precipitation:
Biome: Wetland
Experimental Manipulation: Air and soil warming
Technology: Infra-red
Start Date: July 1994
End Date:
Key Research Questions:
Key Findings:
Web Site:
Minnesota Peatlands Publications
Contact: Yiqi Luo
Email: yluo@ou.edu
Site Location: Norman, Oklahoma, USA
Latitude: 34.98 decimal degrees
Longitude: -97.52 decimal degrees
Mean Annual Temperature:
Mean Annual Precipitation:
Biome: Grassland
Experimental Manipulation: Air warming
Technology: Infra-red
Start Date: December 1999
End Date: Ongoing
Key Research Questions:
Key Findings:
Web Site:
Oklahoma Tall Grass Prairie Publications
Contact: Arne Stuanes
Email: arne.stuanes@umb.no
Site Location: Telemark County, Norway
Latitude: 59.02 decimal degrees
Longitude: -8.30 decimal degrees
Mean Annual Temperature: 5 degrees Celsius
Mean Annual Precipitation: 994 mm
Biome: Heathland
Experimental Manipulation: Water added by a sprinkler system. Snow removed
Technology:
Artificial watering of 2 small
headwater catchments to simulate increased precipitation in late summer and
autumn (3 years). Snow removal from 2 small catchments to simulate milder
winters compared to 2 catchments covered by insulating mats during winter to
simulate a permanent snow cover (2 years).
Start Date: 1 January 2003
End Date: 31 December 2007
Key Research Questions:
Key
Findings: Longer
periods with frozen soil increased the release of organic C and N. Increased
precipitation in summer gave the same result. Simulated summer rainstorms
increased the leaching of organic C. This C had a stronger color compared to the
control catchments. The leaching of ammonium and nitrate increased with
increased precipitation during summer and autumn, but the effect was more
unclear during winter. There seems to be a stronger relationship between the
leaching of ammonium and organic N than between nitrate and organic N. Winters
with little snow and long periods with frozen soil seems more important for the
leaching of C and N than winters with frequent freezing/thawing.
Web Site: http://www.climatechange.no/clue
Contact: Diana Wall
Email: Diana@nrel.colostate.edu
Site Location: Antarctica
Latitude: -77.63 decimal degrees
Longitude: 162.88 decimal degrees
Mean Annual Temperature:
Mean Annual Precipitation:
Biome: Polar desert
Experimental Manipulation: Air warming and water addition
Technology: otc
Start Date: December 1999
End Date: Ongoing
Key
Research Questions: How
does increased temperature and water affect soil biogeochemistry and soil fauna?
Key Findings:
Web Site:
Publications:
Texas Warming and Rainfall Manipulation (T-WaRM) Project
Contact: David Briske
Email: dbriske@tamu.edu
Site Location: College Station, Texas, USA
Latitude: 30.56 decimal degrees
Longitude: -96.35 decimal degrees
Mean Annual Temperature: 19.8 degrees Celsius
Mean Annual Precipitation: 992 mm
Biome: Post Oak Savanna
Experimental
Manipulation: Rainfall
exclusion and continuous warming both independently and in combination.
Long-term mean annual rainfall is shifted from summer to spring and autumn with
increased event sizes during these seasons of the year.
Technology: Rainfall
manipulation is supported by greenhouse poly over metal framing associated with
an overhead irrigation system that supplies reverse osmosis water. Continuous
warming is supplied by Kalglo infrared lamps suspended over individual plots.
Start Date: March 2003
End Date: Ongoing
Key Research Questions:
Key Findings:
Web Site: Rangeland.tamu.edu/research/nigec/index.html