Sexual Reproduction Is Not Responsible for Caragana Shrub Encroachment in Grasslands

Shrubs tended to increase their abundance as climatic aridity and grazing intensity increased in the Inner Mongolian grassland. Increasing shrub was believed be due enhanced reproduction. However, effects of on sexual reproduction shrubs grassland remain largely unclear. In this study, we conducted field experiments with Caragana microphylla examine variation aspects (seed production, seed vigor, sapling establishment) along a gradient (subhumid, semiarid, arid, dry arid zones) (fenced, mildly grazed, severely grazed). We then quantified population growth rate based production establishment rates. Our objective evaluate whether is main mechanism for encroachment into grasslands. found that decreased quantity vigor but shrubs. Under ungrazed conditions, did not affect rates, while under stresses reduced Grazing establishment, Climatic negative reproduction, intensified conclusion, aridity, grazing, combined had Therefore, could fully explain increasing grazing. Clonal might considerable importance understanding