退化亚高山草甸恢复过程中地上生物量和适宜载畜量分析

Analysis on Above-ground Biomass and Appropriate Stock Capacity of Degraded Sub-alpine Meadow during Restoration Process

2012—2018年,以香格里拉退化亚高山草甸为研究对象对其实施连续封育,测定和分析恢复演替过程中植被地上生物量和植物学组成及其变化趋势,并运用中度干扰假说判断试验区退化草地的适宜封育年限和适宜载畜量。结果表明:与退化区相比较,封育第1年、第2年和第5年均显著提高了草地地上生物量,封育期间草地地上生物量呈现幂函数型增长趋势;草地的抵抗力和恢复力分别为518.8g/m^2和56.3个月;封育第5年草地中不可饲用植物(包含有毒有害植物)仍然占到29.2%,适宜载畜量2.81~3.37个羊单位/hm^2。该试验表明封育结合其他措施,将有利于更加有效地改善草地质量和提高草地生产力。

In this study, the degraded sub-alpine meadow in Shangri-La City, locating in the northwest part of Yunnan Province, was chosen as the subject investigated and was continuously enclosed from 2012 to 2018. Above-ground biomass and botanical composition of vegetation in restoration succession was determined and assessed, and both of their variation trends were characterized. Furthermore, intermediate disturbance hypothesis was used to evaluate the reasonable enclosure period and stocking capacity. The results showed that compared to the degraded areas, the significant higher above -ground biomass was observed in the enclosed plots at the first, second and fifth year of enclosing;the above -ground biomass of the grassland was increased as power function model during the enclosure period, and the resistance and resilience of the grassland was 518.8 g/m^2 and 56.3 months;at the fifth year of enclosure, the non-forage species (including poisonous and harmful species) still accounted for 29.2% of all the species of vegetation, and the suitable stocking capacity was 2.81 -3.37 ewe equivalent per hectare. In conclusion, weeds removing in combination with enclosure during pasture restoration succession is conductive to improve pasture quality and increase pasture productivity in a more efficient way.