Canopy closure and litter management in coniferous plantation modulate the bacterial community to increase soil nitrogen mineralization and understory medicinal tuber yield

作者：Haotian Xue, Yefei Yu, Qianqian Zhang, Caixian Tang, Touqeer Abbas, Qiumei Teng, Yuqi Wang, Jinhui Luo, Yongchun Li · 发表于：Agriculture Ecosystems & Environment · 年份：2026 · DOI：10.1016/j.agee.2026.110308 · 研究领域：Soil Carbon and Nitrogen Dynamics、Mycorrhizal Fungi and Plant Interactions、Biocrusts and Microbial Ecology

Forest canopy closure and litter management are critical factors regulating ecosystem processes, yet their interactive effects on soil nitrogen (N) cycling, microbial communities, and the production of understory tuberous medicinal plants remain elusive. This study investigated the impacts of varying canopy closure levels (low, medium, and high) and litter treatments (cover and removal) on these processes. Decreasing canopy closure significantly decreased soil moisture but increased soil temperature and net nitrification with canopy closure being a primary driver of N mineralization. Compared with litter cover, litter removal enhanced N mineralization and net ammonification only under high canopy closure. Canopy closure significantly altered microbial community composition by modifying soil temperature and moisture, whereas litter treatment had minor effects. Under low canopy closure, aerial stem length, rhizome length and tuber yield of understory medicinal herb Corydalis yanhusuo were 20 % – 42 %, 20 % – 61 %, and 156 % – 729 % higher than moderate and high canopy closures, respectively. Litter removal increased tuber yield only under low canopy closure. Structural equation modeling revealed that bacterial communities, particularly functionally important taxa, played a central role in N mineralization and plant productivity. These findings suggest that canopy closure, rather than litter treatment, predominantly regulates soil N mineralization and microbial functionality wit...