Summary: Ecological Applications, 17(6), 2007, pp. 1809­1823
Ó 2007 by the Ecological Society of America
INTERRELATIONSHIPS AMONG SHRUB ENCROACHMENT,
LAND MANAGEMENT, AND LITTER DECOMPOSITION
IN A SEMIDESERT GRASSLAND
HEATHER L. THROOP
1
AND STEVEN R. ARCHER
School of Natural Resources, University of Arizona, P.O. Box 210043, Tucson, Arizona 85721-0043 USA
Abstract. Encroachment of woody plants into grasslands, and subsequent brush
management, are among the most prominent changes to occur in arid and semiarid systems
over the past century. Despite the resulting widespread changes in landcover, substantial
uncertainty about the biogeochemical impacts of woody proliferation and brush management
exists. We explored the role of shrub encroachment and brush management on leaf litter
decomposition in a semidesert grassland where velvet mesquite (Prosopis velutina) abundance
has increased over the past 100 years. This change in physiognomy may affect decomposition
directly, through altered litter quality or quantity, and indirectly through altered canopy
structure. To assess the direct and indirect impacts of shrubs on decomposition, we quantified
changes in mass, nitrogen, and carbon in litterbags deployed under mesquite canopies and in
intercanopy zones. Litterbags contained foliage from mesquite and Lehmann lovegrass

Source: Archer, Steven R. - Savanna/Woodland Ecology Lab., School of Natural Resources and the Environment, University of Arizona

Collections: Environmental Sciences and Ecology