多年冻土工程扰动区植被快速扩繁移植对浅层水热变化的影响

Influences of vegetation treated with rapid cultivation and transplant on the shallow soil temperature and moisture in engineering disturbed permafrost

在青海西藏±400 kV直流联网工程穿越的五道梁多年冻土塔基施工扰动区,采用植被快速扩繁移植技术对植被进行了移植并对移植后群落特征变化和浅层土壤的水热变化进行了研究.结果表明:塔基施工扰动区土壤养分流失严重,给施工后的植被恢复造成很大困难.采用植被快速扩繁移植技术对扰动区进行植被恢复后,扰动区多年冻土温度场能在短时间内趋于稳定,有利于塔基基础的稳定.同时,快速扩繁移植两年后植物群落盖度为(92.00±5.53)%,群落地上生物量和地下生物量分别达到2 471.08±186.73 g/m2,7 028.61±382.43 g/m2.可见,扩繁移植后人工植物群落特征表现出对多年冻土扰动区高寒干旱地区气候和土壤环境具有较好的适应性.只要采用高原乡土植物种类并采取相应的植被恢复技术措施,青藏高原多年冻土扰动区的植被快速恢复是可行的.

At the tower footing construction disturbance zone of ± 400 kV DC power transmission line from Qinghai to Tibet crossing through the Wudaoliang permafrost region, the technology of rapid cultivation and transplant of vegetation was used to restore vegetation rapidly. Changes in the vegetation community character- istics and the shallow soil temperatures and moistures were studied at the disturbed zone with rapid restoration. The results showed that at the disturbed zone, the soil nutrients were lost seriously, making the vegetation restoration to be very difficult. When the disturbed zone was restored with the technology of rapid vegetation cultivation and transplant, the temperature field of the disturbed permafrost zone could be stabilized in the short term, which was beneficial to the stability of the tower foundation. After two years of vegetation rapid cultivation and transplant, the plant community coverage reached （92.00±5.53）%, and the aboveground and below-ground community biomass reached 2471.08±186.73 g/m2 and 7028.61±382.43 g/m2, respectively. So, the artificial plant community characteristics of the vegetation treated with rapid cultivation and transplant showed a good adaptability to the cold-arid climate and soil environment of the disturbed permafrost zone. As long as native plant species were used and suitable vegetation restoration technologies were adopted, rapidvegetation restoration at the disturbed permafrost zones on the Qinghai-Tibet Plateau was feasible.