阿里高寒荒漠草地种子库特征与土壤环境的关系

The Relationship between Ngari Alpine Desert Grassland Seed Bank Characteristics and Soil Environment

针对青藏高原高寒草地的土壤种子库研究,可为该区域草地生物多样性保护以及退化生态系统恢复与重建、退化土地治理提供理论依据。本研究以阿里地区高寒荒漠草地土壤种子库与土壤为研究对象,通过进行土壤理化性质分析和土壤种子库萌发试验,对区域种子萌发数量与土壤理化性质间的关系进行相关性分析及冗余分析。结果表明:在阿里地区的高寒草地上所取的9个样地的27个土壤样品中共萌发了28粒植物种子,总计11个种,分属8科10属,其中禾本科和莎草科占比最高分别为39%和25%。通过对土壤理化性质与种子库萌发结果对比分析表明:土壤PH值、土壤含水量与种子库植物萌发呈显著负相关(P<0.01),土壤全氮、有机碳、碱解氮、与萌发数间显著负相关(P<0.05),土壤全钾、土壤粒径D90与萌发数间显著正相关(P<0.05)。本研究结果对阿里地区维持高寒草地植物群落稳定性及抑制高寒草地退化态势具有重要意义。

To study the soil seed bank of alpine grasslands on the Tibetan Plateau and provide theoretical basis for the conservation of grassland biodiversity in the region as well as the restoration and reconstruction of degraded ecosystems and degraded land management, this study took the soil seed bank and soil of alpine desert grasslands in the Ngari region as the research object, and conducted correlation analysis and redundancy analysis on the relationship between the number of regional seed germination and soil physical and chemical properties by soil physical and chemical property analysis and soil seed bank germination test. The results showed that 28 plant seeds, with a total of 11 species belonging to 8 families and 10 genera,were germinated in 27 soil samples from 9 sample plots taken in the alpine grasslands of the Ngari region, with the highest percentages of 39% and 25% for Gramineae and Salicaceae,respectively. The comparative analysis of soil physical and chemical properties and seed bank germination results showed that soil p H value and soil water content were significantly negatively correlated with seed bank plant germination(P<0.01), while soil total nitrogen, organic carbon, alkali-hydrolyzable nitrogen were also significantly negatively correlated with germination number(P<0.05), but soil total potassium and soil particle size D90 were significantly positively correlated with germination number(P<0.05). The results of this study are of great significance for maintaining the stability of plant communities and inhibiting the degradation of alpine grassland in Ngari area.