Ecological situation and management of Bothriochloa ischaemum grasslands in China

Abstract

Abstract Bothriochloa ischaemum grasslands cover a large area of central China. A total of 81 grassland quadrats of 2 m × 2 m were established randomly in nine counties of central China. Data for species composition, abundance, coverage and height, plus several environmental variables were measured and recorded in each quadrat. Dry biomass and productivity for three associations within three counties were also determined. Species data of importance values were used in the two‐way indicator species analysis (TWINSPAN) and the detrended correspondence analysis (DCA) ordination. A total of 11 main grassland associations were distinguished by the TWINSPAN classification; all of them being secondary vegetation. Each association had its own characteristics in composition, structure, productivity and environment. The results of DCA show that the distribution of B. ischaemum grasslands and associated species are closely related to longitude, that is, related to a moisture gradient. Precipitation was one of the most important factors affecting the distribution of the studied grasslands. In addition, topographic factors, such as elevation, aspect, slope and soil types, were also correlated to grassland vegetation. The distribution of grassland associations was consistent to that of their dominant species. TWINSPAN and DCA revealed the same ecological gradients in this study. These grasslands are important for regional development of animal husbandry and economy, although their productivity is not very high. Effective protocols for the conservation and management of B. ischaemum grasslands are needed.