子午岭次生林植被演替过程的土壤抗冲性  

Soil anti-scouribility during vegetation succession of Ziwuling secondary forest

作　　者：周正朝[1] 上官周平[1] 

机构地区：[1]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室

出　　处：《生态学报》2006年第10期3270-3275,共6页Acta Ecologica Sinica

基　　金：国家重点基础研究发展计划资助项目(2002CB111502);中国科学院西部之光人才培养计划联合学者资助项目(2005LH01);国家自然科学基金资助项目(30230290)~~~

摘　　要：在水土流失极为严重的黄土高原地区,土壤抗冲性决定着土壤的可蚀性.于2004年5月在黄土高原惟一的次生林区——子午岭林区,通过原状土冲刷实验对不同植被演替阶段下的土壤抗冲性进行了研究.结果表明： （1）随植被的正向演替,表层土壤（0～15cm）的抗冲性明显增大,但亚表层（15～30cm）和底层（30～50cm）土壤抗冲性则没有太大的变化;（2）植物根系能显著的增强土壤抗冲性,土壤抗冲系数与单位土体根系表面积具有极显著的（p＜0.001）线性相关关系;（3）土壤抗冲系数随土壤中水稳性团聚体含量和微生物量的增加而增大,且其相关关系极显著（p＜0.001）.综合根系（x1）、水稳性团聚体（x2）以及微生物（x3）对土壤抗冲性的影响,建立黄土高原地区土壤抗冲性方程： y=-4.89＋1.27x1＋0.079x2＋1.94E-3x3 （R^2=0.914 p＜0.001）.In China, the Loess Plateau is well known for its high erosion rate and vulnerable ecosystem. The soil erosion by water has been considered the cause of the losses of plant nutrients and productivity, and off-site environmental problems have also become a concern in recent years. Vegetation is the main factor to improve the environment in which soil erosion and water loss occur. High soil erosion rate by water mainly relates to low soil anti-scouribility in the Loess Plateau. A great number of researches about soil anti-scouribility have been conducted in some regions whose vegetations are severely impaired. However, little attention has been paid to the changes of soil anti-scouribility in the succession process of vegetation communities. In the spring of 2004,five plant communities at different succession stages were investigated in Ziwuling secondary forest of Shaanxi Province. The soil anti-scouribilitys of the communities were measured with their undisturbed soil samples that had been exposed to a flow at a rate of 4 L/min on a washing flume slope of 15° for 15 min, and the root surface areas, water stable soil aggregates and soil microbes of the communities were also measured in the soil sampling plots. The objective of the study was to examine the change of soil anti-scouribility and its relation with the roots, water stable soil aggregates and soil microbes in the process of vegetation succession. The results indicated that ： （1） The upper soil layers had a higher soil anti-scouribility than the lower soil layers, and the soil anti-scouribilitys in the upper soil layers increased with the vegetation successions; nevertheless, the soil anti-scouribilitys did not varied much among different stages of the vegetation successions in the lower soil layers. （2） The soil anti-scouribilitys presented a positive and linear relationship with the root surface areas per unit soil volume, and the root surface areas alone explained more than 78 % of the variations in soil anti-scouribility. （3） The water

关 键 词：植被演替 土壤抗冲性 根系 水稳性团聚体 微生物 

分 类 号：S714[农业科学—林学]