---

作 者 ：谢锦升,杨玉盛,陈光水,朱锦懋,曾宏达,杨智杰

期 刊 ：生态学报 2008年 28卷 2期 页码：702~709

关键词：土壤团聚体；有机碳；植被恢复；退化红壤；

Keywords:soil aggregate, organic carbon, vegetation restoration, degraded red soil,

摘 要 ：土壤有机碳对土壤团聚体的形成与稳定具有重要影响。研究了植被恢复对侵蚀退化红壤团聚体稳定性的影响，在此基础上探讨了有机碳在团聚体中的分布及有机碳与团聚体稳定性的关系。红壤侵蚀裸地大团聚体水稳定性程度低，植被恢复后大团聚体稳定性显著提高。裸地各级团聚体有机碳含量基本相似，植被恢复后，有机物质输入的增加促进了团聚体的形成，从而改变了土壤团聚体有机碳含量和分配比例。大团聚体对有机碳具有一定的富集作用，有机碳含量高于全土和微团聚体、粉粒及粘粒有机碳含量，大团聚体有机碳恢复速度也快于微团聚体以及粉粒与粘粒有机碳的恢复速度。植被恢复使裸地0~10cm土层大团聚体有机碳占总有机碳的比例从15%左右增加到32%~42%。土壤中增加的有机碳约41%~51%储存在大团聚体中，24%~38%储存在微团聚体中，20%~31%储存在粉粒及粘粒中。团聚体稳定性的增强与土壤有机碳含量密切相关，植被恢复时间越长，土壤有机碳含量越高，土壤团聚体水稳性程度也越好。

Abstract:Soil organic carbon plays a major role in the formation and stabilization of soil aggregates. However, our knowledge on the relationship between organic carbon and stable aggregate is not clear in the restoring process of degraded red soil. Red soil developed by granite has been eroded severely in southern China. Hetian town(25°33′-25°48°N, 116°18′-116°31′E) was one of the typical regions, located in Changting County, Fujian Province, China. The water stability of soil aggregates in five soils (include bare land; three ecosystems which were restored from severely eroded land to Pinus massoniana forest, Castanea mollissima plantation and Paspalum notatum Flugge grassland; protected second forest- next to the village) was measured with dry sieve and wet sieve, then different size aggregates (wet sieve) and whole soil were analyzed for organic carbon content. The influences of vegetation restoration on water stability of soil aggregates, organic carbon distribution in different size aggregates and relationship between organic carbon and stability of aggregate were discussed.
The stability of macroaggregate was lower in bare land than that in Pinus massoniana plantation forest, Castanea mollissima plantation and Paspalum notatum Flugge grassland, and the best one was in protective second forest. Organic carbon contents of different size aggregates were not changed in bare land. However, after vegetation restorated, organic carbon content and distribution proportion in different size aggregates were changed since organic material inputs increased. The macroaggregate had greater organic carbon content than the whole soil, microaggregate and silt and clay particles. The restoration speed of organic carbon in macroaggregate was faster than that in microaggregate and silt and clay particles. The proportion of organic carbon in macroaggregate comprised of about 15% of total organic carbon in 0-10cm soil layer of bare land, and the data were between 32% and 42% in other soils. After vegetation restored, the increase of carbon accumulated in soil macroaggregate, microaggregate and silt and clay particles accounted for 41%-51%, 24%-38% and 20%-31% of total increased carbon, respectively. The water stability of soil aggregates was related to soil organic carbon content. The higher concentrations of total organic carbon were recorded in the soils with higher aggregate stability.

---