青藏公路取土场高寒草原植被的恢复进程

The alpine steppe vegetation restoration process of fountainhead region of Yangtze River

按照青藏公路建设和整修的不同阶段,利用样方调查植被空间分布变化,得出高寒草原植被的自然演替进程遵循以下规律,在工程结束2年,8年,26年后,群落植被覆盖度和生物多样性指标分别达到原生植被的2%～4%,6%～23%;32%～54%,46%～50%;95%以上和100%左右.青藏公路沿线高寒草原植被的人为破坏影响是明显的,植被的自然恢复需要20年左右的时间.工程建设破坏面积大于1500m2,植被难以恢复,土壤沙化和水土流失,影响周边地区生态环境质量.因此,在青藏铁路工程建设中首先应当减少对地形地貌的破坏,其次应当重视对地表土壤的保护并辅助人工植被恢复措施,促进植被的自然恢复.

At different stages of Tibet highway construction and repairment, the variation of alpine vegetation spatial distribution was investigated with quadrant investigation was used to analyze the natural succession course of alpine steppe vegetation abiding by following rule: at 2, 8 and 26 years after the completion of the construction project, the community vegetation coverage and biodiversity indices could reach respectively: 2%~4% and 6%~23%, 32%~54% and 46%~50%, above 95% and about 100% of the initial vegetation level. Along Tibet highway, the influence of artificial 20 years. However, in the region destroying of the alpine steppe vegetation was obvious, needing about 20 years for natural resonation. The destroyed area was greater than 1500m2, the vegetation could hardly be restored, soil was desertificated, and water was lost with soil eroded, and the bioenvironment quality of peripheral area was affected. Therefore, in this constructing project, first, the damage to terrain and landform should be reduced; second, the protection of surface soil should be emphasized with assist of artificial vegetation restoration measures to promote the natural restoration of vegetation.