高原鼢鼠挖掘对植物生物量的效应及其反应格局

EXCAVATING EFFECTS OF PLATEAU ZOKOR ON THE PLANT BIOMASS AND THEIR RESPONSE PATTERNS IN ALPINE MEADOW

高原鼢鼠取食洞道处 ,在植物根系受损条件下 ,主要测定各类植物生物量变动的格局。原生植被样区 ,取食洞道回填土壤后 ,单子叶植物地上生物量显著增加 ,双子叶植物地上生物量及地下总生物量显著降低。植物地上总生物量与取食洞道的厚度密切相关。土层厚度 <5cm的取食洞道 ,植物地上及地下生物量显著下降 ;土层厚度 >1 0cm ,植物地上及地下生物量无显著变化。高原鼢鼠长期栖息植被退化的斑块地 ,在取食洞道区域 ,单子叶及双子叶植物地上生物量和地下总生物量均显著降低。结果验证了本文提出的地下啮齿动物对双子叶直根类植物的存活具有负效应 。

The research work was conducted in alpine meadow north of Qinghai Province in 1998 We mainly explored the plant biomass which roots had been impaired by excavation of plateau zokor The results showed that the above and belowground biomasses of dicotyledons were obviously decreased at first colonizing, and the biomasses of monocotyledons over burrows in which the excavated soil was backfilled was significantly increased in primary vegetation In contrast, both the above and belowground biomass were significantly decreased in the area that soil layer thickness is 3-5 cm only over burrows in which have been used continually in all season However, there were not statistically distinct effects on the overlying vegetation where the burrows were under 10 cm in the same vegetation area But whatever above and belowground biomass greatly decreased in the overlying vegetation of burrows where plateau zokors colonized over 10 years in which the vegetation was obviously different with surrounding environment The results indicated the hypothesis that the excavation under ground by plateau zokor caused negative effect for the dicotyledons of taproots, but could promote the growth and development of the monocotyledons to some extent was correct