15年实测氮沉降下竹仙洞小流域土壤酸化研究

Effect of Nitrogen Deposition in 15 Years on Soil Acidification in Zhuxiandong Catchment

以2000—2015年珠海竹仙洞水库小流域湿地松林、台湾相思林和灌木丛为样本,对其土壤属性指标进行相关性分析和主成分分析。结果表明,经过15年自然演替,3个群落的土壤可交换酸度呈下降趋势,其中台湾相思林和灌木丛酸度降低达到显著或极显著水平,受Al^(3+)含量影响较大;3个群落的可交换Mg^(2+)、K^(+)、Na^(+)在两种土层均有不同程度的显著下降,而可交换Ca^(2+)的变化仅在台湾相思林中显著;总氮、总碳含量均呈上升趋势。主成分分析显示,台湾相思林的生物量丰富、土壤腐殖质多,固氮作用强,故对氮沉降的酸缓冲能力更强。

Taking pine forest,Taiwan acacia forest,and shrub in Zhuxiandong Reservoir catchment in Zhuhai from 2000 to 2015 as samples,this study conducted correlation analysis and principal component analysis on their soil property indicators.The results showed that after 15 years of natural succession,the soil exchangeable acidity of the three communities showed a decreasing trend.Among them,the acidity of Taiwane acacia forest and shrubs decreased significantly or extremely significantly,which was greatly affected by Al^(3+)content.The exchangeable Mg^(2+),K^(+),Na^(+)of the three communities decreased significantly to varying degrees in two soil layers,while exchangeable Ca^(2+)changed significantly in Taiwan acacia forest.The content of total nitrogen and total carbon showed an upward trend.Principal component analysis indicated that the biomass of Taiwan acacia forest was rich,soil humus was abundant,and nitrogen fixation was strong,so the acid buffer capacity of nitrogen deposition was strong.