不同林分类型对土壤团聚体稳定性及有机碳特征的影响

发布时间：2018-05-25 05:02

本文选题：不同林分 + 土壤团聚体　；参考：《北京林业大学学报》2016年05期

【摘要】：基于野外调查和室内分析,对人工杉木林、马尾松林、桉树林、毛竹林、天然林5种不同林分下0~20 cm、20~40 cm土层土壤水稳性团聚体稳定性及各粒级土壤团聚体有机碳分布特征进行研究。结果表明:1)0~20 cm土层,土壤水稳性团聚体质量百分含量随粒级的减小先下降后上升,主要以0.5~0.25 mm粒级最低;5种林分条件下各土层均以0.25 mm的大团聚体为主,随土层加深,大团聚体含量减少。2)各林分土壤平均质量直径(MWD)和几何平均直径(GMD)值变化趋势相似,均呈现为0~20 cm土层大于20~40 cm土层;林分间土壤MWD、GMD值则表现为天然林最大,桉树林最小;分形维数(D)在2个土层均以桉树最大,杉木林最小;3)5种林分各粒级团聚体中有机碳的含量均随土层的加深而减少;0~20 cm土层,各林分有机碳含量随着团聚体粒级减小呈现先增大后减小再增大的趋势,最大值主要出现在5~2 mm粒级,而有机碳贡献率则表现为先减小后增大的趋势。不同林分MWD、GMD差异分析结果表明,天然林土壤结构优于其他4种人工林,团聚体稳定性更高,而桉树林最低。随着土层深度变大,土壤水稳性团聚体稳定性下降;土壤团聚体有机碳含量表现为天然林最大、桉树林最小。
[Abstract]:Based on field investigation and indoor analysis, artificial Chinese fir forest, Masson pine forest, eucalyptus forest, Phyllostachys pubescens forest were studied. The stability of soil water stable aggregates and the distribution characteristics of organic carbon in soil aggregates of 0 ~ 20 cm ~ 20 ~ 40 cm soil layer under 5 different stands of natural forest were studied. The results showed that the mass percent content of soil water stable aggregates decreased first and then increased with the decrease of grain size, and the main soil layers were 0.25 mm large aggregates under the condition of 0.5 ~ 0.25 mm lowest grain grade and 5 species stands, and with the deepening of soil layer, the content of soil water stable aggregates decreased firstly and then increased with the decrease of grain size, the results showed that the mass percent content of soil water stable aggregates decreased firstly and then increased with the decrease of grain size. The variation trend of soil mean mass diameter (MWD) and geometric mean diameter (GMDD) of each stand were similar, which showed that the soil layer of 0 ~ 20 cm was larger than 20 ~ 40 cm soil layer, while the GMD value of soil MWDN was the largest in natural forest and the smallest in eucalyptus forest. The fractal dimension (D) was the largest in eucalyptus in the two soil layers, and the content of organic carbon in the aggregates of each grain grade in the 5 stands of Chinese fir forest decreased with the deepening of soil layer, and the content of organic carbon in 20 cm soil layer decreased with the deepening of soil layer. The content of organic carbon in each stand increased first and then increased with the decrease of aggregate grain size. The maximum value appeared in the grain size of 5 ~ 2 mm, while the contribution rate of organic carbon decreased first and then increased. The results of GMD analysis showed that the soil structure of natural forest was better than that of the other four plantations, and the stability of aggregates was higher than that of eucalyptus, while that of eucalyptus was the lowest. With the increase of soil depth, the stability of soil water stable aggregates decreased, and the organic carbon content of soil aggregates was the largest in natural forests and the smallest in eucalyptus forests.
【作者单位】：北京林业大学水土保持学院水土保持与荒漠化防治教育部重点实验室;
【基金】：广西水利厅“广西水土保持效应指标体系与生态补偿标准研究”课题(201401005-01-B)
【分类号】：S714.2

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