不同人工恢复林对退化红壤团聚体组成及其有机碳的影响

发布时间：2019-01-16 00:22

【摘要】：研究土壤团聚体的组成及其有机碳的分布,有助于从微观角度理解土壤结构与功能的相互作用。采用干筛法和湿筛法,研究南方红壤退化地实施人工恢复30年后,马尾松与阔叶复层林(PB)、木荷+马尾松混交林(SP)和阔叶林(BF)3种典型林分在0~60 cm土层的团聚体组成及其有机碳分布特征,分析土壤团聚体有机碳与总有机碳相关关系。结果表明:各恢复林分土壤机械稳定性团聚体质量分数,以2 mm粒径所占比例最大(均在60%以上),而在水稳性团聚体中,以0.05 mm粒径占优势。不同林分土壤团聚体结构破坏率顺序依次为BF(53.38%~84.27%)SP(52.22%~70.86%)PB(22.70%~47.83%)。机械稳定性和水稳性团聚体有机碳质量分数均以PB最高,随着土层深度的增加,各林分土壤团聚体有机碳质量分数呈下降趋势。水稳性大团聚体(0.25 mm粒径)有机碳质量分数总体高于相应土层的总有机碳质量分数,而微团聚体的(0.25 mm粒径)则低于后者,说明有机碳对于大团聚体的形成和水稳性具有积极作用。土壤团聚体有机碳与总有机碳的相关关系分析表明,土壤团聚体有机碳的增加,对总有机碳的积累具有正面影响。保留密度大、灌木(草)层盖度高的马尾松与阔叶复层林土壤团聚体的数量和质量更高;因此,在红壤侵蚀退化地森林恢复初期,可通过适当密植、增加林下灌草覆盖等措施,增加有机碳的输入,促进团聚体的形成和稳定,从而加速了退化土地的土壤结构改善和功能恢复。该研究可为南方严重红壤退化地生态恢复中的林分类型选择和优化配置提供科学依据。
[Abstract]:The study of the composition of soil aggregates and the distribution of organic carbon can help to understand the interaction between soil structure and function from the microscopic point of view. Dry and wet sieving methods were used to study the effects of artificial restoration of red soil on Pinus massoniana and broad-leaved laminated forest (PB),) after 30 years of artificial restoration of red soil in southern China. The aggregate composition and organic carbon distribution of three typical stands of (SP) and (BF) in 0 ~ 60 cm soil layer of Pinus massoniana mixed forest were analyzed, and the correlation between soil aggregate organic carbon and total organic carbon was analyzed. The results showed that the content of soil mechanical stability aggregates in each restored stand was the largest (above 60%) in 2 mm particle size, while in water stable aggregates, the particle size of 0. 05 mm was dominant. The order of failure rate of soil aggregate structure in different stands was BF (53.38% 54.27%) SP (and 70.86%) PB (22.703%). The content of organic carbon in soil aggregates of PB was the highest in both mechanical stability and water stable aggregates. With the increase of soil depth, the organic carbon fraction of soil aggregates in different stands showed a decreasing trend. The mass fraction of organic carbon of water stable large aggregate (0. 25 mm particle size) was higher than that of corresponding soil layer, while the content of micro aggregate (0. 25 mm particle size) was lower than that of the latter. It is concluded that organic carbon plays an active role in the formation and water stability of macroaggregates. The correlation analysis of soil aggregate organic carbon and total organic carbon showed that the increase of soil aggregate organic carbon had a positive effect on the accumulation of total organic carbon. The quantity and quality of soil aggregates of Pinus massoniana and broad-leaved forest with high density and high coverage of shrub (grass) layer were higher. Therefore, in the early stage of forest restoration in the degraded land of red soil erosion, we can increase the organic carbon input and promote the formation and stability of aggregates by appropriate close planting, increasing the forest and grass cover, etc. Thus, the soil structure improvement and function restoration of degraded land are accelerated. This study can provide scientific basis for the selection and optimal allocation of stand types in the ecological restoration of degraded red soil in southern China.
【作者单位】：南昌工程学院江西省退化生态系统修复与流域生态水文重点实验室;
【基金】：国家自然科学基金“生态恢复对红壤严重侵蚀地土壤水库重建的影响与机制”(31160179) 江西省自然科学基金目“侵蚀红壤碳吸存对植被恢复的响应及其微生物学机制”(20151BAB204033) 江西省高等学校“十二五”水土保持与荒漠化防治重点学科培育基金“红壤侵蚀地不同植被恢复模式对土壤团聚体有机碳的影响”
【分类号】：S714.2

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