Scholarlink

Aims <p>Nitrogen (N) mineralization underpins plant-available N and forest productivity. In subalpine forests, root-associated fungal indicators and microbial association patterns may co-vary with belowground N dynamics, yet how legacy and localized disturbance contexts shape these relationships remains unclear.</p> Methods <p>We compared two adjacent <i>Picea asperata</i> stands in western Sichuan, China, representing a natural forest–plantation legacy contrast, and applied a localized root-trenching treatment to reduce root-derived inputs within each stand. We integrated phospholipid fatty acids (PLFA) profiling, shotgun metagenomics, extracellular enzyme assays, litter decomposition, and net N mineralization measurement.</p> Results <p>Relative to the natural forest, the plantation showed lower denitrification and assimilatory nitrate transport gene abundances, lower net N mineralization, and higher C- and N-acquiring hydrolytic enzyme activities. Trenching responses were forest-type- specific: in the natural forest, trenching was associated with increased path length and lower nitrification; in the plantation, it co-varied with higher values of several co-occurrence topology metrics and elevated oxidative enzyme activities. However, most measured microbial functional groups and most N-metabolism-related gene categories showed limited trenching-related differences. Nonetheless, structural equation modeling described context-dependent statistical associations: higher N-acetyl-β-D-glucosaminidase activity was associated with lower net N mineralization in the forest-type contrast model, whereas lower co-occurrence network modularity was associated with lower net N mineralization in the trenching-based model.</p> Conclusions <p>Both the legacy and local disturbance context was associated with different microbial indicators and co-occurrence patterns linked to selected N-related responses. These stand-specific findings reflect context-dependent statistical associations and require broader multi-site replication before generalization.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Context-dependent links between microbial co-occurrence topology and nitrogen mineralization in two adjacent subalpine Picea asperata stands

  • 期刊论文

  • 发表日期：

    2026年6月15日

查看全文
  • Lixia Wang,
  • Haoying Gao,
  • Shuangjia Fu,
  • Lin Xu,
  • Li Zhang,
  • Han Li,
  • Chengming You,
  • Sining Liu,
  • Hongwei Xu,
  • Jiao Li,
  • Bo Tan,
  • Zhenfeng Xu

摘要

Aims

Nitrogen (N) mineralization underpins plant-available N and forest productivity. In subalpine forests, root-associated fungal indicators and microbial association patterns may co-vary with belowground N dynamics, yet how legacy and localized disturbance contexts shape these relationships remains unclear.

Methods

We compared two adjacent Picea asperata stands in western Sichuan, China, representing a natural forest–plantation legacy contrast, and applied a localized root-trenching treatment to reduce root-derived inputs within each stand. We integrated phospholipid fatty acids (PLFA) profiling, shotgun metagenomics, extracellular enzyme assays, litter decomposition, and net N mineralization measurement.

Results

Relative to the natural forest, the plantation showed lower denitrification and assimilatory nitrate transport gene abundances, lower net N mineralization, and higher C- and N-acquiring hydrolytic enzyme activities. Trenching responses were forest-type- specific: in the natural forest, trenching was associated with increased path length and lower nitrification; in the plantation, it co-varied with higher values of several co-occurrence topology metrics and elevated oxidative enzyme activities. However, most measured microbial functional groups and most N-metabolism-related gene categories showed limited trenching-related differences. Nonetheless, structural equation modeling described context-dependent statistical associations: higher N-acetyl-β-D-glucosaminidase activity was associated with lower net N mineralization in the forest-type contrast model, whereas lower co-occurrence network modularity was associated with lower net N mineralization in the trenching-based model.

Conclusions

Both the legacy and local disturbance context was associated with different microbial indicators and co-occurrence patterns linked to selected N-related responses. These stand-specific findings reflect context-dependent statistical associations and require broader multi-site replication before generalization.