鼎湖山主要森林类型土壤交换性阳离子含量及其季节动态特征  

Concentrations of exchangeable cations of soil and their seasonal dynamics in three representative forests of Dinghushan Biosphere Reserve

作　　者：江远清[1] 莫江明[1] 方运霆[1] 李志安[1] 

机构地区：[1]中国科学院华南植物园鼎湖山森林生态系统定位研究站

出　　处：《广西植物》2007年第1期106-113,共8页Guihaia

基　　金：国家自然科学基金(30270283;30670392);广东省自然科学基金(021524);中国科学院知识创新工程领域前沿项目(KSCX2-SW-133);中国科学院华南植物研究所所长基金~~

摘　　要：研究鼎湖山自然保护区马尾松林、马尾松荷木混交林和季风常绿阔叶林三种代表性森林类型表层土壤（0～20cm）交换性阳离子含量及其季节动态。结果表明：土壤交换性阳离子含量因元素种类、森林类型和季节不同而异。三种森林土壤交换性阳离子含量都表现为：Al^3＋〉H^＋〉K^＋〉Ca^2＋、Mg^2＋、Na^＋。几乎所有调查的阳离子含量在阔叶林显著高于马尾松林和混交林，但后两者之间大多数阳离子含量差异不显著。鼎湖山森林土壤可交换性阳离子含量虽然较高，但盐基饱和度却很低。马尾松林、混交林和阔叶林土壤可交换性阳离子含量在1997年6月份分别为：58．3、84．5和118．7mmolc／kg，盐基饱和度分别为：5．5％、3．2％和4．5％。三种森林土壤交换性Ca^2＋、Mg^2＋、K^＋和H^＋含量季节差异极显著（P〈0．001），但交换性Al^3＋含量只在马尾松林土壤存在极显著的季节性差异（P〈0．001）。同一元素季节变化大小程度趋向马尾松林〉混交林〉阔叶林。森林土壤交换性Ca^2＋、Na^＋和H^＋含量与土壤pH值相关关系不明显，但交换性Mg^2＋、K^＋和Al^3＋与土壤pH值间呈极显著负相关。Concentrations of exchangeable cations of soil and their seasonal dynamics in three representative forests （pine,pine and broadleaf mixed, monsoon evergreen broadleaf forests）of Dinghushan Biosphere Reserve in southern China were studied. Mineral soils（0-20 cm depth）were collected in June 1997 ,September 1997 ,December 1997 ,and March 1998, and were analyzed for soil pH, concentrations of organic carbon, total N and P, available P and exchange- able cations for each sampling date. Results showed that concentrations of exchangeable cations varied depending on cation types,forests and sampling dates. Concentrations of exchangeable cation were highest for Al^3＋ , followed by H^＋ , and lowest for Ca^2＋ , Mg^2＋ and Na^＋ in all three forests. The pine and mixed forests were similar in concentrations of most exchangeable cations, however, both of them were significantly lower than the broadleaf forests. Effective cation exchange capacity in Dinghushan forest soils（CECe, sum of Ca^2＋ , Mg^2＋ , K^＋ , Na^＋ , H^＋ and Al^3＋ ）was relatively high,but base saturafion（BS,percent of base cations to CECe）was relatively low. CECe in June 1997 was estimated to be 58. 3,84. 5 and 118.7 mmolc/kg for the pine, mixed and broadleaf forest, respectively, and corresponding BS was 5.5 %, 3.2 % and 4. 5 %,respeetively. Concentration of exchangeable cations varied greatly among sampling dates in all three forests,with seasonal maximum being 1.6～3. 6,1.4～2.2,1.6～2. 8,2. 1～3. 2 and 1.1～1.8 times of seasonal minimum for exchangeable Ca^2＋ , Mg^2＋ , K^＋ , H^＋ and Al^3＋ , respectively. Seasonal variations was greatest in the pine forest,followed by the mixed forest,with respective to a given cation. Soil pH values showed significantly negative correlation with concentrations of exchangeable Mg^2＋ , K^＋ and Ak^3＋ , but not with exchangeable Ca^2＋ ,Na^＋ and H^＋.

关 键 词：森林土壤 交换性阳离子 季节动态 PH值 鼎湖山 

分 类 号：Q948[生物学—植物学] S153.6[农业科学—土壤学]