Karst grassland forage quality and its determinants in Guizhou Province of Southwest China

Forage quality is a key property of grassland ecosystems. In this study, grassland forage qualities were measured at 373 sampling sites throughout Guizhou Province in the karst mountain region of Southwest China, and the factors affecting it were explored. The forage quality level of most plant species was categorized into four levels: (1) preferred forage species; (2) desirable forage species; (3) consumed but undesirable forage species; and (4) non-consumable or toxic forage species. High temperature and precipitation appeared to facilitate the growth of preferred forage species, but limited the growth of other plants. Increasing soil pH had a positive impact on the number and biomass of preferred forage plants, but a negative influence on other plants, especially non-consumable or toxic plants. Both GDP and population density had a positive correlation with the number and biomass of preferred forage species, while such correlations for other levels of forage species tended to be negative. Grazing could lead to a decrease in the preferred forage species. Therefore, it is suggested that by focusing on soil improvement in grassland and maintaining an appropriate grazing intensity, global warming and rapid economic growth in Guizhou Province will likely contribute to increase the forage quality of karst grasslands in Southwest China.

Automated summary

This study investigated the grassland forage quality and its influencing factors in the karst mountain region of Guizhou Province, Southwest China. The forage quality was categorized into four levels, with high temperature and precipitation promoting the growth of preferred forage species. Increasing soil pH had a positive impact on preferred forage plants but a negative influence on others. GDP and population density were positively correlated with preferred forage species, while grazing led to a decrease in their abundance. Improving soil quality and managing grazing intensity can enhance forage quality in the region.