ARS | Publication request: QUANTIFYING CHANGES IN CARBON POOLS ACCOMPANYING SHRUB INVASION OF A DESERT GRASSLAND

Submitted to: US-International Association for Landscape Ecology
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2002
Publication Date: April 23, 2002
Citation: MITCHELL, K.A., PETERS, D.C., MONGER, H.C., HERRICK, J.E. QUANTIFYING CHANGES IN CARBON POOLS ACCOMPANYING SHRUB INVASION OF A DESERT GRASSLAND. 17TH ANNUAL SYMPOSIUM OF THE US-INTERNATIONAL ASSOCIATION FOR LANDSCAPE ECOLOGY. 2002. ABSTRACT P. 110

Technical Abstract: Coincident with a worldwide increase in the abundance of woody plants within former grasslands, desert grasslands through the southwestern U.S. have experienced a substantial increase in the abundance of shrubs during the last century. These changes in grassland structure have had important implications for ecosystem carbon cycling and rates of carbon sequestration. Building on a history of biogeochemistry research conducted at the Jornada Experimental Range in southern New Mexico, we measured and modeled above and below-ground carbon storage in black grama grasslands (Bouteloua eriopoda) and mesquite (Prosopis glandulosa) and creosotebush (Larrea tridentata) shrublands across the Jornada basin. Our research approach combined direct field measurement of carbon pools, extensive use of existing Jornada datasets and simulation modeling using the CENTURY model in an effort to scale field-based measurements to landscape-level estimates of carbon pools. Our results refute the commonly held thesis that carbon storage shifts from below to aboveground with shrub invasion of grasslands, but overall net ecosystem carbon remains the same. Landscape-level mapped estimates of carbon pools indicate that the desert grassland ecosystem of the Jornada basin may have served as a carbon sink during the last century.