摘要
以贵州中部喀斯特地区由乔木林、灌木林和灌草丛等不同退化程度生态系统中的优势物种根际土壤为研究对象,测定其C、N、P全量及有效态质量分数,分析各优势物种根际土壤的养分变化。结果表明:3个生态系统中不同优势物种根际各类土壤养分质量分数变化较大,其中,土壤C、N、P养分为乔木林中园果化香根际土壤质量分数最高,白枥根际养分质量分数最低。可溶性有机碳质量分数为乔木林中最低,其平均水平不超过10 mg·kg-1。土壤磷素的供给能力为乔木林的园果化香和刺秋相对较强,其中园果化香中达到1.5%。而且优势树种间根际土壤有效态养分质量分数的差异明显高于全量养分,说明喀斯特地区根际土壤养分差异性主要受植被因素的影响,土壤有效态养分较全量养分对植被群落演替的响应更为灵敏,而且根际土壤养分质量分数和形态的变化与土壤有机碳质量分数有显著的正相关关系,这进一步说明喀斯特地区植被类型的变化对土壤养分的循环利用具有重要的影响作用。
The experiment was performed to understand the impact of degradation level on the rhizosphere soil nutrients in the Karst ecosystems.The rhizosphere soil was separated from the fine roots of different dominant vegetations under three different vegetation types（forest,shrubs and grassland） in Karst mountainous area from Guizhou province,and further analysed for the C,N and P,pools（total and available contents）.The results showed that both total and available pool of nutrient was highest for the rhizosphere of Plotycarya longipe under forest and was lowest for rhizosphere of Quercus fabric under forest as well.However,the dominant vegetations of forest resulted in the lowest,10 mg/kg,pool of the average DOC（soluble organic C） in the rhizosphere.The P activation of Platycarya longipes and Kalopanax septemlobus Koidz in the rhizosphere under Forest was higher than others,particularly the P activation of Platycarya longipes was about 1.5%.Nutrient availability showed a prompt response to vegetation degradation.Moreover,a strong significant positive correlation was observed between the soil organic carbon,total nitrogen and available nitrogen.This indicated that the pool of soil nutrient was influenced by the change of dominant vegetation types in the Karst ecosystems.
出处
《生态环境学报》
CSCD
北大核心
2011年第2期276-280,共5页
Ecology and Environmental Sciences
基金
国家"973"重点基础研究发展计划项目(2006CB403205)
关键词
喀斯特
土壤养分
优势物种
根际土壤
Karst
soil nutrient
dominant vegetation
rhizosphere soil
