三峡库区杉木马尾松混交林土壤C、N空间特征  

Spatial structures of soilcarbon and nitrogen of China fir and Masson pine mixed forest in the Three Gorger Reservoir Areas

作　　者：林英华[1,2] 汪来发[1] 田晓堃[1,3,4] 杨延峰[1,2] 肖文发[1] 

机构地区：[1]中国林科院森林生态环境与保护研究所,国家林业局森林保护学重点实验室,北京100091 [2]中国林科院湿地研究所,北京100091 [3]中国林科院亚热带林业研究所,浙江富阳311400 [4]华中农业大学园艺林学学院,武汉430070

出　　处：《生态学报》2011年第23期7311-7319,共9页Acta Ecologica Sinica

基　　金：中央级公益性科研院所基本科研业务费专项资金(CAFRIF2007009)

摘　　要：自然和人为因素的强烈干扰直接影响三峡库区土壤C与土壤N贮量与分配特征。杉木马尾松混交林是三峡库区主要植被类型之一且分布面积最大,因而研究其不同干扰程度下土壤C、N分布特征对于准确评估三峡库区土壤C与N贮量具有重要意义。2008年秋季与2009年春季,采用对角线法取样法方法对三峡库区不同干扰条件下杉木马尾松混交林0—20cm土壤层中土壤C、N含量的季节与空间分布特征进行研究。结果显示,土壤N含量季节差异性显著,土壤C含量仅在人为严重干扰下呈季节性差异显著(P<0.05);干扰强度对秋季土壤C、N影响显著(P<0.05)。土壤C、N与土壤含水量、pH值均存在显著相关关系(P<0.01)。研究区酸性土壤(pH值介于4.59—5.15)增加了土壤C、N的固定与积累。土壤碳氮比与表层土壤矿质化程度和人为干扰有关,强烈人为干扰和地表状况减弱了土壤C、N空间相关性。地统计学分析表明,半方差函数的曲线球状模型较好地反映了无人为干扰条件下土壤C、N的空间结构特征。土壤C、N空间结构变化与灌木层盖度、坡度、季节及人类干扰有关。The stocks and distribution of soil carbon and soil nitrogen have been affected by disturbance of natural and artificial disturbance in the Three Gorges Reservoir region. China fir and Masson distributed vegetation type in the area but much natural vegetation has been changed pine mixed forest is the most widely , with the zonal vegetation replaced by natural or artificial coniferous forests, shrubs and shrub-herbs, and even bare land, resulting in ecosystem degradation This study assessed spatial variability and seasonal changes in soil carbon and nitrogen in this region under different disturbed conditions. In autumn 2008 and spring 2009, soil samples were collected to a depth of 20 cm using a 3.0 m × 3.0 m grid in 900m2（30.0 m × 30.0 m） plots in areas of different disturbance. Samples were collected from 294 sampling points to study the spatial variability and seasonal changes in soil carbon and nitrogen using geostatistics. Significant differences in soil nitrogen concentrations were found between seasons, and in soil carbon concentrations only following serious disturbance （P〈0.05）. The degree of disturbance had a significant effect on soil carbon and nitrogen concentrations in autumn （P〈0.05）, and both soil carbon and nitrogen concentrations were significantly correlated with soil moisture and pH （P〈0.01）. Acidic soil pH values between 4.59 and 5.15 contributed to soil carbon and soil nitrogen sequestration and accumulation in the area. The soil carbon to nitrogen ratio was related to the degree of soil mineralization and human disturbance The spatial autocorrelation between soil carbon and nitrogen was weakened by intensive human disturbance and condition of the earth＇ s surface status. The geostatistical analysis indicated that the semivariance graphs were expressed by the spherical model in areas with no human disturbance, and that there were significant differences in the spatial autocorrelation ranges between seasons, with the effective range （a）of soil carbon being 61.90

关 键 词：空间变异 半方差 取样数 季节 湖北 

分 类 号：S714[农业科学—林学]