高原鼢鼠干扰对高寒草甸植物群落地上-地下生物量分配格局和土壤理化性质的影响

Effects of plateau zokor Eospalax baileyi disturbance on the abovegroundbelowground biomass allocation pattern of plant communities and soil physicochemical properties in alpine meadow

中文关键词:生物量  分配  高原鼢鼠  干扰  高寒草甸  土壤

keywords:biomass  allocation  plateau zokor  disturbance  alpine meadow  soil

中文摘要:为明晰高原鼢鼠Eospalax baileyi不同干扰强度对高寒草甸植物生物量分配格局与土壤理化性质的影响，以高原鼢鼠栖息的高寒草甸为研究对象，设置无干扰（对照）、轻度、中度、重度和极重度5个干扰强度样地，调查各样地内植物群落地上生物量、地下生物量和土壤理化性质，分析不同干扰强度下植物地上-地下生物量分配格局及其与土壤理化性质的关系。结果表明：随着高原鼢鼠干扰强度增加，植物地上生物量呈先升高后降低的趋势，轻度干扰下植物地上生物量最高，为400.036 g/m²，显著高于对照，重度干扰下植物地下生物量最低，为812.885 g/m²，显著低于对照、轻度和中度干扰；高原鼢鼠干扰显著增加了土壤含水量，降低了土壤紧实度和土壤有机碳含量，土壤全氮、速效磷、硝态氮和铵态氮含量随着干扰强度增加均呈先升后降的趋势；轻度、中度和重度干扰下，植物生物量优先分配至地上部分，其中轻度和重度干扰下权衡指数最大，均为0.027；极重度干扰下，植物生物量优先分配至地下部分，权衡指数为0.029；植物地上-地下生物量权衡指数与土壤养分含量均呈负相关关系，与土壤含水量和pH呈正相关关系，但仅与土壤速效磷含量显著相关。

Abstract:To clarify the effects of different disturbance intensities of plateau zokor Eospalax baileyi on the plant biomass allocation pattern and the soil physicochemical properties in alpine meadow, five disturbance levels were established, namely no disturbance (control), light disturbance, moderate disturbance, heavy disturbance, and extremely heavy disturbance. Aboveground biomass, belowground biomass, and soil physicochemical properties in each plot were surveyed, and the relationships between the biomass allocation pattern and soil physicochemical properties under different disturbance intensities were analyzed. The results showed that the aboveground biomass of plants initially increased and then decreased with the increase of plateau zokor disturbance. The highest aboveground biomass of plants (400.036 g/m²) was observed under light disturbance, which was significantly higher than the control. The belowground biomass of plants under heavy disturbance (812.885 g/m²) was the lowest and significantly lower than the control, light and moderate disturbances; plateau zokor disturbance significantly increased soil moisture, decreased soil compaction and organic carbon. The contents of soil total nitrogen, available phosphorus, nitrate nitrogen, and ammonium nitrogen first increased and then decreased with increasing disturbance intensity; under light, moderate, and heavy disturbance, plant biomass was preferentially allocated to aboveground parts, with the highest trade-off index observed under light and heavy disturbance (0.027). Under extreme disturbance, the plant biomass allocation shifted towards the below-ground parts, with a trade-off index of 0.029; correlation analysis showed that the trade-off index for plant biomass negatively correlated with soil nutrient content, positively correlated with soil moisture and pH, but only significantly negatively correlated with available phosphorus content in the soil.