Effects of Elevated CO sub(2) on Fine Root Dynamics in a Mojave Desert Community: A FACE Study

• Published in: Global change biology Vol. 12; no. 1; p. 61
• Main Authors: Phillips, Donald L, Johnson, Mark G, Tingey, David T, Catricala, Christina E, Hoyman, Toni L, Nowak, Robert S
• Format: Journal Article
• Language: English
• Published: 01.01.2006
• Subjects: Ambrosia; Larrea
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/j.1365-2486.2005.01085.x

The effects of elevated CO sub(2) on production, mortality and standing crops of fine root length over 2 years in a free-air CO sub(2) enrichment (FACE) facility in the Mojave Desert of southern Nevada, USA were determined. Three replicate 25 m diameter FACE rings were maintained at ambient and elevated CO sub(2) atmospheric concentrations. The seasonal dynamics were similar for ambient and elevated CO sub(2): fine root production peaked in April-June, with peak standing crop occurring about 1 month later and peak mortality occurring during the hot summer months, with higher values for all three measures in a wet year compared with a dry year. Fine root turnover ranged from 2.33 to 3.17 year super(-1) and was not significantly different among CO sub(2) treatments, except for community transect tubes where it was significantly lower for elevated CO sub(2). For community transects, development of the difference in fine root standing crops occurred primarily through lower stimulation of fine root production in the elevated CO sub(2) treatment.