Mojave Global Climate Change
Global climate change in the Mojave Desert
Primary Collaborators: Stan Smith and Dene Charlet: University of Nevada, Las Vegas; Bob Nowak, University of Nevada, Reno; Cheryl Vanier, Tuoro University
Predicted global changes in the Mojave Desert ecosystem include both climate and land use change. Our sites at the Nevada Desert FACE Facility and the Mojave Global Change Facility on the Nevada Test Site in southern Nevada address the following global change parameters:
Nevada Desert FACE Facility (NDFF)
(FACE= Free Air Carbon Dioxide Enrichment)
CO2
- Deserts are predicted to show the greatest response to rising CO2 levels
- Current CO2 levels are 380 µmol/mol.
- Predicted CO2 levels are 550 µmol/mol by 2050.
Mojave Global Change Facility (MGCF)
Nitrogen
- Desert systems are thought to be N limited.
- N deposition rates are increasing in the Las Vegas area as seen in the Los Angeles Basin.
- Predominate precipitation in the Mojave is in the winter.
- Some general circulation models predict the Mojave Desert will receive more precipitation in the summer.
- Recreation and rapid development in southern Nevada is causing substantial increases in soil disturbance.
My projects related to ecosystem responses to global change at NDFF and MGCF include:
- Perennial plant productivity
- Annual plant responses
- Insect responses
- Rabbit herbivory on Larrea tridentata
- Long-term plant community dynamics
- Trophic level responses using isotopes
Joshua Tree National Park
Nitrogen Deposition
There is a stark nitrogen deposition gradient across Joshua Tree NP, where higher rates of N deposition occur on the west side of the Los Angeles Basin. Nitrogen deposition is likely to affect N concentrations in plants tissues and thus higher trophic levels that depend on plant tissues for consumption. We examined the effects of N deposition on seed N content and how harvester ants may respond to increases in N concentrations.