PARENT SESSION
Oral Session #61: Arid Lands Restoration.
Presiding: S. Loftin
Wednesday, August 7. 1:00 PM to 4:45 PM. Mohave Meeting Room, TCC.
Abandonement history and successional trends in Sonoran Desert agricultural old-fields.
MARTINEZ, MARIA1,2, CASTELLANOS, ALEJANDRO*,1, MURRIETA, JOAQUIN2, HALVORSON, WILLIAM3, CASTILLO, REYNA1, ESPEJEL, ILEANA4, 1 UNIVERSIDAD DE SONORA, HERMOSILLO, SONORA, MEXICO2 RESERVA DE LA BIOSFERA "EL PINACATE"., SAN LUIS RIO COLORADO, SONORA, MEXICO3 US GEOLOGICAL SURVEY, TUCSON, ARIZONA4 UNIVERIDAD AUTONOMA DE BAJA CALIFORNIA, ENSENADA, BAJA CALIFORNIA
ABSTRACT- Plant succession within Sonoran Desert areas have been characterized by changes in species density and cover rather than species replacement. Beginning in 1945, excesive ground water use, lead in less than two decades, to a decrease in cultivated area at La Costa de Hermosillo. Financial breakdown and saline water intrusion were compounded problems for abandonement of large areas previously open to cultivation three decades before. Using differences in years since abandonement, patterns of old-field succession were studied. Contrary to natural succession patterns found in deserts, different successional trends and species replacement were found, both in fields within or out of the saline intrusion area and close or not to seed dispersion sources from patches of natural vegetation. Ecophysiological characteristics of dominant plant species as well as a marked decrease in heteromyids rodent composition and feeding guilds contributed further to differences found in the successional patterns.
KEY WORDS: arid lands succession, gas exchange, water and nitrogen resource use, Sonoran Desert