青藏高原区退化高寒草甸植被和土壤特征

高寒草甸约占青藏高原草地的46.7%,是我国草地生态系统重要的组成部分。近年来,在气候变化和人为活动的影响下,高寒草甸生态系统退化严重,植被和土壤均呈现出不同的退化趋势。在大空间尺度上表现为草地覆盖度下降,杂草类植被增加,土壤退化甚至沙化;在微观尺度上,退化高寒草甸的土壤粒径、土壤微生物和土壤酶也发生改变。本研究从高寒草甸物种多样性、植物群落结构、植被生物量、土壤物理性质、土壤微生物、土壤酶和土壤养分等方面,分析了高寒草甸生态系统退化过程中植被和土壤的变化特征,提出当前研究中存在的一些不确定性和有待深入研究的问题,为全面了解高寒草甸的退化机制和规律、有效干预高寒草甸生态系统和恢复生态功能提供科学依据。

Vegetation and soil characteristics of degraded alpine meadows on the Qinghai-Tibet Pla-teau,China: A review

Alpine meadows account for 46.7% of grassland area on the Qinghai-Tibet Plateau, which is an important part of grasslands in China. Under the effects of climate change and human activities in recent years, alpine meadow has been degraded seriously. Vegetation and soil have shown different degradation trends. At large spatial scales, the degraded alpine meadows are characterized by decreases of vegetation coverage, increases of weed vegetation, soil degradation and even desertification. At the micro-scale, soil particle size, soil microorganisms, and soil enzymes in degraded alpine meadows changed. We analyzed the changes of vegetation and soil during the degradation of alpine meadow ecosystems by considering species diversity, plant community structure, plant biomass, soil physical properties, soil microorganisms, soil enzymes, and soil nutrients. We put forward some uncertainties in the current research and problems that needed further study. This review provided a scientific basis for a comprehensive understanding of the degradation mechanisms and patterns of alpine meadows, effective intervention in alpine meadow, and restoration of ecological function.