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Few old-field succession studies have been conducted in arid ecosystems and there is some question if classical secondary succession occurs in arid environments. In order to determine if old-field succession does occur under arid conditions, We sampled 40 previously-cultivated sites abandoned over a period of 29-80 years in the Owens Valley, California. We compared vegetation development at these 40 old fields to vegetation composition on 17 adjacent uncultivated reference sites. We were interested in determining if 1) seral communities could be identified, 2) these communities expressed predictable and progressive patterns, and 3) if so, whether the seral patterns indicated divergent or convergent successional pathways.

The 57 sites separated into 6 separate seral communities. Two seres were identified, one progressing toward a big sagebrush late-seral community and the other with fourwing saltbush as the characteristic species. Based on multivariate statistical analysis, the two seres were likely to continue on divergent pathways for 100-140 years, after which the saltbush sere may converge toward the late-seral sagebrush community. Both localized and broad-scale factors were important in defining successional patterns in this arid environment. Our results support the concept that classical old-field succession does occur in arid regions. (C) 2012 Elsevier Ltd. All rights reserved.