Population distribution pattern of Aconitum leucostomum in Ili grassland, Xinjiang

Natural grassland weeds poisonous problem of Ili River valley is serious. Aconitum leucostomum were scaled intoⅠ, Ⅱ and Ⅲ bunch grade according to the number of strains bunch basal leaves before its reproductive growth because this specie was the dominant. Four different aggregate indices and Moristia index Iδ distribution pattern determination method were employed to study A.leucostomum population structure and distribution pattern in different plots under free grazing or fencing with mowing. In free grazing plot and fencing with mowing plot, grade Ⅰ A.leucostomum were clumped, gradeⅡ A.leucostomum randomly distributed. grade Ⅲ A.leucostomum evenly distributed in free grazing plot and randomly distributed in fencing with mowing plot. After four consecutive years fencing in growing season, it was beneficial to A.leucostomum seed germination and was profitless for population control.