Submitted to: IEEE IGARSS Annual Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 17, 2000
Publication Date: July 24, 2000
Interpretive Summary: Significant differences have been measured in radiance, reflectance, and temperature from the landscape surface of shrub and grass communities at the U.S. Fish and Wildlife Service's Sevilleta National Wildlife Refuge in central New Mexico. The shrub communities have 3 to 5% higher radiance when compared with the grass communities. Temperatures of the landscape surface were 3 to 5 degrees Ceslsius higher at the shrub when compared wit the grass communities. Studies by the University of New Mexico indicate that shrubs are slowly invading the grass communities. If shrubs continue to expand into the grassland areas significant effects on the energy and water balances of the Sevilleta rangelands can be expected.
Ground, aircraft, and satellite data are being used to monitor changes in the vegetative, physical, thermal, and radiometric properties of two ecosystems (grass and shrub) typical of the Sevilleta rangeland. This is a companion project to JORNEX  at the USDA ARS Jornada Experimental Range in southern New Mexico where similar measurements have been made since 1995. Remote sensing campaigns have been made at Sevilleta in May/June and September/October of 1997, 1998, 1999, and 2000. Data from the different platforms are used to evaluate landscape properties at a range of scales. Radiance measured at ground and aircraft platforms was 3 to 5% higher at the shrub site when compared with the grass site. Temperatures of the landscape surface were 3 to 5 degrees Celsius higher at the shrub when compared with the grass site by 1 pm local time. These differences could have significant effects on the energy and water balances of the Sevilleta rangelands if shrubs continue to expand at the expense of the grassland.