Factors limiting vegetation recovery processes after cessation of cropping in a semiarid grassland in Mongolia

摘要

Land degradation in an abandoned field, such as the loss of palatable species for livestock and low species richness, is a serious problem in Mongolia where the dominant land use is livestock grazing historically. Here, we show the factors limiting vegetation recovery processes after cessation of cropping in a semiarid grassland. We selected fields abandoned in 1990 (CA18), 1999 (CA9), and 2006 (CA2) and continuously grazed grassland (CGG) as a control site. Plant species cover and soil were sampled during summer (June-July) 2008. Soil physicochemical properties were analyzed. Low similarity index of an early succession stage, CA2, with CGG was associated with abundant P and coarse sand. The proportion of coarse sand was not abundant in middle stage (CA9) because of domination by perennial rhizomatous species. In the later stage (CA18), the fine sand proportion did not increase; however, the dominant species were associated with fine sand in CGG. The results suggest the limiting factors of recovery processes in abandoned Mongolian cropland are abundantly available P and coarse sand at an early succession stage (CA2). The small proportion of fine sand in CA18 indicated that the impacts of cropping in Mongolia persist for a long time. Published by Elsevier Ltd.