高寒草地土壤有机碳含量同植物功能群数量特征关联度或然性初探

The Impossible Relationships Between Plant Functional Groups and Organic Carbon Content under Different Land Utilization Types in Alpine Grassland

采用逐次回归分析法及主成分分析法,对青藏高原高寒草地不同土地利用方式(草甸、草原、人工草地、农田)的67块样地植物功能群数量特征同土壤有机碳含量的耦合性进行分析,以明晰土地利用格局或植被演替对土壤有机碳同植物群落数量特征的影响。结果表明:青藏高原植物-土壤系统有机碳含量在草地利用模式变化或演替过程中具有较强的解释能力。土壤有机碳含量同植物功能群数量特征关联度的或然性受到草地的利用模式、利用强度和利用历史等因素的影响。人工生态系统土壤有机碳含量同地上植物功能群数量特征之间无明显的耦合关系;健康草地生态系统土壤有机碳含量容易同放牧顶级群落优势种数量特征建立一定的耦合关系。退化草地生态系统土壤有机碳含量容易同提高限制性土壤养分的植物功能群建立耦合关系。

Using the principal component analysis and stepwise regress to analysis the plant functional groups quantitative characteristics and soil organic carbon content in alpine grasslands under the different land use types （meadow, grassland, pasture, cropland）, the results showed that： principal component could extract four principal components, soil organic carbon played a very important roles in the research factors. The relationships between soil organic carbon contents and community plant functional groups were affected by land use pattern, land use intensity and land use history. It was difficult to make the rela- tionships between soil organic carbon contents and plant functional groups in artificial ecology systems. And it was easy to establish the relationships between the soil organic carbon contents and dominance species parameters in healthy grasslands, while it was easy to establish the relationships between soil organic carbon contents and the parameters which could enhance restrictive soil nutrition.