西南峡谷型喀斯特坡地土壤养分的空间变异特征  

Characteristics of spatial variation of soil nutrients in sloping field in a gorge karst region, southwest China

作　　者：范夫静[1,2,3] 宋同清[1,3] 黄国勤[2] 曾馥平[1,3] 彭晚霞[1,3] 杜虎[1,3] 鹿士杨[1,3] 时伟伟[1,2,3] 谭秋锦[1,3,4] 

机构地区：[1]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125 [2]江西农业大学农学院,南昌330045 [3]中国科学院环江喀斯特生态系统观测研究站,广西环江547100 [4]广西大学林学院,南宁530004

出　　处：《应用生态学报》2014年第1期92-98,共7页Chinese Journal of Applied Ecology

基　　金：中国科学院战略性先导科技专项(XDA05070404;XDA05050205);中国科学院"西部行动"计划项目(KZCX2-XB3-10);"十二五"国家科技支撑计划项目(2011BAC09B02);国家自然科学基金项目(31370485;31370623;U1033004;31100329);广西科技项目(桂科攻1123001-9C);广西特聘专家项目资助

摘　　要：基于网格（20m×20m）取样，采用经典统计学和地统计学方法，研究了西南峡谷型喀斯特坡地土壤养分的空间异质性和分布格局．结果表明：峡谷型喀斯特坡地土壤养分含量为中等和强变异，变异性大小顺序为：速效磷〉全钾〉有机质〉碱解氮〉全氮〉全磷〉速效钾，pH值表现为弱变异，有机质表现为中等程度的变异；不同土壤养分具有良好的空间自相关性，其自相关函数均表现出由正相关向负相关方向发展，拐点为80～100m，其中全钾和速效磷的Moran，较小，其他指标较大；不同土壤养分的空间变异特征不同，全钾和速效磷最佳拟合模型为指数模型，块金值与基台值的比值[C0／（C0＋C）]和变程（A）很小，分形维数（D）较高，空间相关性强烈；其他土壤养分指标的最佳拟合模型均为球状模型，C0／（C0＋C）、A和D均呈中等程度的空间相关；Kriging分析表明，pH值、有机质、全氮、全磷和碱解氮呈凹型分布，速效磷和速效钾呈斑块状分布．植被、地形、人为干扰和高异质性的微生境是造成峡谷型喀斯特坡地土壤养分格局差异的主要因素．Based on a grid （20 m ×20 m） sampling, spatial heterogeneity and pattern of soil nutri- ents in sloping field in the gorge karst region, southwestern China, were explored by using classical statistics and geostatistics methods. The results showed that soil nutrient contents in slope field in the canyon karst region were more abundant, where pH value had a weak variation and the soil or- ganic matter （SOM） had a moderate degree of variation. All the soil nutrients had moderate or strong variation with an order of available phosphorus （AP） 〉 total potassium （TK） 〉 SOM 〉 alka- line nitrogen （AN） 〉 total nitrogen （TN） 〉 total phosphorus （TP） 〉 available potassium （AK）. All of the soil nutrients had a good spatial autocorrelation and the autocorrelation function performed in the same law of developing from positive to negative direction with the inflection point ranged from 80 to 100 m. In addition, the Moran＇ s I was small for TK and AP while large for other nutri- ents. Characteristics of spatial variation differed among soil nutrients. Exponential model fitted best for TK and AP, in which the ratio of nugget to sill （C0/（ C0＋C） ） and the range （A） were small and the fraetal dimension （D） was high, showed a strong spatial correlation. Spherical model fitted best for other soil nutrients, with C0/（ C0＋C） , the range （A） and D showing a moderate autoeorre-lation. Kriging analysis clearly indicated that pH, SOM, TN, TP and AN were distributed in a con- cave pattern, while AP and AK had fragmented patch distribution. Therefore, vegetation, topogra- phy, human disturbance and strong heterogeneity of microhabitats are main factors leading to the differences in patterns of soil nutrients on the sloping land in the gorge karst region.

关 键 词：土壤养分空间变异 空间分布格局 坡地峡谷型喀斯特 

分 类 号：S158[农业科学—土壤学]