不同退化演替阶段高寒草甸群落根土比和土壤理化特征分布格局

以高寒草甸不同退化演替阶段原生植被(primary vegetation, PV)、轻度退化(light degradation, LD)、中度退化(moderate degradation, MD)和重度退化(heavy degradation, HD)草甸为研究对象,分析了不同退化演替阶段高寒草甸群落根土比和土壤理化性质分异特征。结果表明:高寒草甸植物群落根土比随退化演替阶段的进行而增大,随土层深度的增加而显著减小。土壤容重随土层深度的增加而增大,而土壤含水量则随土层的加深而显著降低,土壤总氮、全磷、速效磷、速效钾随土层深度的增加而显著降低,硝态氮和全钾没有呈现出规律的变化。高寒草甸退化演替过程中,表层土壤(0~10 cm)养分含量(总氮、速效磷、速效钾)、土壤物理特征(土壤含水量和土壤容重)受退化影响较大。

Distribution Patterns of Ratio of Root to Soil and Soil Physical Chemical Characteristics at the Different Degraded Successional Stages in an Alpine Meadow

To explore the changes of ratio of root to soil and soil physiochemical properties, a yield experiment was carried out at different degraded successional stages (PV: Primary vegetation, LD: Light degradation, MD: Moderate degradation, HD: Heavy degradation) in Haibei Research Station of Alpine Meadow Ecosystem. The results showed that the ratio of root to soil increased with the degradation of alpine meadow, while significantly decreased with the increase soil depth. Meanwhile, soil bulk density significantly increased with the increase of soil depth, but soil water content, total nitrogen, total phosphorus, available phosphorus, and available potassium were significantly reduced. In the process of degradation, the grazing had a significant effect on the contents of topsoil (0～10 cm) nutrient (total nitrogen, available phosphorus, available potassium) and soil physical characteristics (soil water content, soil bulk density).