Changes in fine root decomposition of primary Pinus koraiensis forest after clear cutting and restoration succession into secondary broad-leaved forest
Changes in fine root decomposition of primary Pinus koraiensis forest after clear cutting and restoration succession into secondary broad-leaved forest
复制标题
红松原生林皆伐及恢复演替次生阔叶林后细根分解的变化
DOI：
10.1016/j.apsoil.2020.103785
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发表时间：
2021-02-01
影响因子：
4.8
通讯作者：
Qi, Dandan
中科院分区：
文献类型：
--
作者：
Fu, Yanmei;Feng, Fujuan;Qi, Dandan
细根分解是陆地生态系统养分吸收和碳交换的主要机制之一，森林演替对细根分解有重要影响。本文采用凋落物袋法比较了红松原生林（PK）和阔叶次生林（SF）细根分解速率，并深入分析了PK和SF细根分解过程的差异。结果表明，PK的细根分解明显快于SF。总体而言，SF细根中主要营养元素的质量百分比（%）显著高于PK，表明PK能更有效地通过细根分解归还土壤养分。研究还发现，从PF到SF的演替导致了土壤微生物群落组成的显著变化，并降低了土壤酶活性。结构方程模型进一步表明，细根K和木质素是影响细根分解的关键基质水平因子，而放线菌和真菌PLFA生物量的变化在所有功能群中起着最重要的作用。最后，我们确定细根降解是由多酚氧化酶和酸性磷酸酶酶活性驱动的。本研究阐明了细根基质和土壤理化性质之间复杂的相互作用，并演示了它们如何影响细根分解通过土壤微生物。由于这些变化持续很长一段时间，次生林将经历更大的困难，恢复到原来的原始红松阔叶林植被。
Fine root decomposition is one of the primary mechanisms by which nutrient uptake and C exchange occur in terrestrial ecosystems, which will be likely affected by forest succession. Herein, we compared the fine root decomposition rates of primary Korean pine forest (PK) and secondary broad-leaved forest (SF) using the litter bag method; then conducted an in-depth analysis of differences in the PK and SF fine root decomposition process. Our results demonstrated that the fine root decomposition in PK was significantly faster than that in SF. In general, the percent (%) mass of the main nutrient elements remaining in SF fine roots was significantly higher than that in PK, indicating that PK can more efficiently return soil nutrients through fine root decomposition. We also found that the succession of PF to SF induced significant alternation of the microbial community composition and decreased activities of soil enzymes. Structural equation modeling further demonstrated that fine root K and lignin were the key substrate-level factors affecting fine root decomposition, while actinomycetes and fungi PLFA biomass change played the most important role among all the functional groups. Finally, we determined that fine root degradation was driven by polyphenol oxidase and acid phosphatase enzymatic activities. This study elucidates the complex interactions between fine root substrate and soil physiochemical properties and demonstrates how they affect fine root decomposition via soil microorganisms. Given that these changes continue over long time scales, the secondary forest will experience increased difficulty return to the original primary Korean pine broad-leaved forest vegetation.