亚热带退化森林不同恢复方式对土壤团聚体胶结物质及稳定性的影响

退化森林的恢复一直是林业和生态学研究的热点。良好的森林土壤结构有助于林木生长发育，作为土壤最基本的结构单元，土壤团聚体组成和稳定性是衡量土壤肥力和质量的重要指标，其团聚结构的形成依靠土壤胶结物质。然而，土壤胶结物质与团聚体稳定性之间的关系尚不确定。为探明亚热带退化森林的不同恢复方式对团聚体稳定性的影响及其潜在机制，以自然恢复的次生林为对照(CK),选取了亚热带三种常见的人工林：一代杉木林(P1)、二代杉木林(P2)和黄山松林(P3),测定土壤团聚体稳定性及其胶结物质的含量，并分析了各胶结物质对团聚体稳定性的影响。研究发现：不同森林恢复方式显著影响了土壤pH值、碳氮比、速效磷含量、团聚体的组成和稳定性。所有森林类型中，三种人工林的团聚体稳定性显著高于CK,P2的大团聚体所占比例最大，团聚体稳定性最高。恢复方式显著影响了土壤游离氧化铁含量、菌根密度和易提取球囊霉素相关土壤蛋白(EEG)含量。团聚体稳定性与游离氧化铁含量、菌根密度呈正相关，但与EEG含量呈负相关。研究结果表明，亚热带退化森林的人工恢复比自然恢复更有助于增强土壤团聚体稳定性，土壤游离氧化铁、菌根密度和EEG是显著影响团聚体稳定...

Effects of different restoration approaches of subtropical degraded forests on bonding materials and stability of soil aggregate

The restoration of degraded forest has been a hot topic in forestry and ecology. As a basic structural unit of soil, soil aggregate composition and stability are important indicators of soil fertility and quality, and the formation of soil aggregate relies on aggregate bonding materials. However, the relationship between aggregate bonding materials and aggregate stability is uncertain. To explore the effects of different restoration approaches of degraded subtropical forests on aggregate stability and its underlying mechanisms, we compared the secondary forest (natural restoration) as a control (CK), with three different common subtropical plantations which were: (1) first-generation Cunninghamia lanceolata (P1), (2) second-generation C. lanceolata (P2), and a Pinus. taiwanensis plantation (P3). We measured the aggregate stability and the contents of different aggregate bonding materials, and then analyzed the influence of these materials on soil aggregate stability. Results showed that forest restoration approach significantly affected soil pH, C/N, available phosphorus, as well as the composition and stability of aggregate. Among all the forests, the aggregate stability was significantly lower in CK than in the other three plantations, and P2 had the greatest proportion of large aggregates and the highest aggregate stability. The forest restoration approach also significantly affected soil free Fe oxide content, mycorrhizal density, and easily extractable glomalin-related soil protein (EEG). Aggregate stability was positively correlated with free Fe oxide content and mycorrhizal density, but negatively correlated with EEG. For subtropical degraded forests, the results indicated that artificial restoration was better than natural restoration to enhance soil aggregate stability, with soil free Fe oxide, mycorrhizal density and EEG being the main bonding materials that significantly affected the aggregate stability.