肃南、肃北草地类型及草地植物物种多样性现状

“草场类型和草地植物资源调查”于2007-2008年在甘肃省肃南裕固族自治县和肃北蒙古族自治县实施。调查共测定草本植被样方226个,灌丛植被样方125个,草灌乔植被样方32个;现场标图约22500km²,调查路线长18500km。按照《中国草地类型的划分标准和中国草地类型分类系统》确定肃南县草地类型有9类、18个亚类、24组、29型;肃北县草地类型有9类、17个亚类、19组、29型;采集植物标本986份381种,分属53科,176属;其中牧草类植物300种。肃北、肃南草场的总体状况在退化,局部地方保护较好;除气候因素外,超载过牧是加速草场退化的主要原因,其次为鼠害;蝗虫不是造成草场植被退化的原因。调查区草地植物的物种多样性没有遭到大的破坏,但各种群的优势度变化较大,表明群落中种群关系已经发生了变化,生物多样性受到威胁。

The present situation of grassland and plant diversity in Sunan and Subei county

Investigation on grassland sorts and grassland plant resource was carried out in Sunan Yuguor and Subei Mongolian Autonomous County, Gansu province in 2007-2008. 226 grass quadrates, 125 shrub quadrates, and 32 mixture quadrates were tested; 22 500 km² of investigation area were labeled on the topographic map. The investigation route was 185 000 km. According to the “Chinese Grassland Divisional Criteria and Chinese Grassland Classification System”, It was sure that the grassland in Sunan county embraced 29 types of 24 forms belonged to 18 subclasses in 9 classes, respectively; and the grassland in Subei county were 29 types of 19 forms from 17 subclasses in 9 classes. 986 plant samples of 381 species from 176 genera of 53 families were collected. Among the plants, 300 species were forage grass. The general situation of grassland in Sunan and Subei counties was degradation. Partial area is preserved well; beside climate factor, overgrazing is the key cause that induced the grassland degradation; the next reason is the rodent damage. Grasshopper is not the cause bringing grassland degradation. The species diversity of grassland plant in the investigation area has not been destroyed greatly. However, the species dominance in the plant community had a large variation, which shows that the change of species relation in the community has already taken place. The biodiversity is suffering threat.