东莞主要森林群落的土壤基本性质和综合评价

Basic soil properties and comprehensive evaluation in forest communities in Dongguan, South China

以广东省东莞市的6种主要森林群落土壤为研究对象,分析其土壤物理化学特性,并通过主成分分析结合Norm值的方法,综合敏感性分析和相关分析,筛选出对土壤质量变化敏感的指标,确定了研究区域土壤质量评价的最小数据集(Minimum Data Set,MDS),进一步对不同森林群落的土壤质量进行了综合评价。研究结果表明,研究区域土壤质量评价最小数据集由土壤毛管持水量、总孔隙度、非毛管孔隙度、相对电导率、全氮、全磷、全钾、有机质、碱解氮、速效磷及速效钾等11个参数组成。各因子的土壤隶属度值显示,土壤速效磷和速效钾是该地区土壤质量的主要限制因子。土壤质量综合评价指数以桉树林得分最高,针阔混交林其次,荔枝林的得分最低。原因可能在于周期性的森林抚育和施肥措施改变了土壤结构,补充了土壤养分,使得桉树林土壤质量优于其他林型。总体上,研究区域的土壤肥力仍处于较低水平,土壤质量较差。

By taking the soils of six main forest communities in Dongguan city of Guangdong province as the studied objects,the soils physical and chemical properties were determined.The soil integrated quality index（SQI） was evaluated by using principal component analysis（PCA）,and combining with norm value method,and integrating methods of sensitivity and correlation analysis.Thus,the minimum data set（MDS） was determined,further,the soils qualities in different forest communities were comprehensively evaluated.The results show that the MDS included soil capillary capacity,total porosity,non-capillary porosity,relative electric conductivity,total nitrogen,total phosphorus,total potassium,organic matter,available nitrogen,available phosphorus and available potassium.From the magnitude of the soils membership values,the soil available P and K were the major limiting factors for soil quality in the areas.The SQI of Eucalyptus forest was the highest,and followed by that of mixed forest and Litchi chinensis forest.Periodic forest tending and fertilizer application changed the soil structure and supplementary of soil nutrients to the forest made the soil quality of Eucalyptus forest better than others.Generally,the soil fertility level was low and quality was poor in this area.