论文部分内容阅读
新建青藏铁路特殊的地理位置和生态环境的特殊性、敏感性及脆弱性决定了植被恢复和重建的重要性。通过实地考察,采用β多样性分析了青藏铁路沿线(格尔木—拉萨段)植被生物多样性及生境分割程度,并讨论了环境因素对植被分布的影响。结果表明植被物种及优势种种数均随海拔高度的升高而增大;从整体看,铁路沿线植被β多样性在相邻群落间的指数值要比不相邻群落间的指数值小,但也存在不符合此规律的情况,如一、三生态类型区间的Whittaker指数值(2.05)小于一、二生态类型区间的Whittaker指数值(2.12),这可能与各生态类型区内人为因素及环境因素的影响有关;年平均温度、年均降水量以及土壤含水量对物种丰富度及生物多样性指数有一定的影响;人类活动也是植被丰富度的影响因素之一。
The special geographical location of the new Qinghai-Tibet Railway and the particularity, sensitivity and vulnerability of the ecological environment determine the importance of vegetation restoration and reconstruction. Through field investigation, the β biodiversity was used to analyze the vegetation biodiversity and habitat fragmentation along the Qinghai-Tibet Railway (Golmud-Lhasa section) and to discuss the influence of environmental factors on the vegetation distribution. The results showed that the vegetation species and the dominant species number increased with the elevation above sea level. On the whole, the β diversity of vegetation along the railway line was lower than that between the non-adjacent communities The Whittaker index value (2.05) of one or three ecotypes interval is less than the Whittaker index value (2.12) of one or two ecotype interval, which may be related to the human and environmental factors in each ecotype area The annual average temperature, average annual precipitation and soil water content have certain impacts on species richness and biodiversity index. Human activities are also one of the influencing factors of vegetation richness.