Background

Deadwood contains a large reservoir of carbon and nutrients in forest ecosystems, its decomposition has considerable effects on forest soil chemistry and biota. Tree functional group and nutrient inputs both have a significant influence on wood decomposition rates. However, little is known about how these factors interactively influence soil biogeochemistry through wood decomposition.

Methods

We examined the effects of nitrogen (N) and phosphorus (P) addition on wood decomposition of different angiosperm and gymnosperm tree species in a three-year period in a subtropical forest. We explored the outcomes for the underlying soil nutrients, microbial biomass, and saprotrophic fungal communities.

Result

We found that P addition, rather than N, significantly increased total C, P, as well as microbial biomass C and P concentrations in the soil beneath deadwood. These effects were particularly pronounced in the soil beneath angiosperm wood compared to gymnosperm wood, likely related to the higher decomposition rates of angiosperm wood and its sensitivity to P. Similarly, the presence and abundance of soil saprotrophic fungal communities was strongly associated with P addition, where specific fungal responses were more pronounced under angiosperm wood than gymnosperm wood.

Conclusion

Our study underscores the pivotal role of tree functional group in modulating the response of soil nutrient dynamics and fungal community structure beneath decomposing wood in a subtropical forest. These insights are critical for developing predictive models of soil nutrient cycles, which can help manage forest ecosystems more effectively in the face of global environmental changes.

中文翻译：

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树木功能群介导养分添加对腐烂木材下土壤养分和真菌群落的影响

 背景

枯木在森林生态系统中含有大量的碳和养分库，其分解对森林土壤化学和生物群产生相当大的影响。树木功能组和养分输入都对木材分解速率有重大影响。然而，关于这些因素如何通过木材分解相互作用影响土壤生物地球化学，人们知之甚少。

 方法

我们研究了亚热带森林中氮 （N） 和磷 （P） 添加对不同被子植物和裸子植物树种在三年内木材分解的影响。我们探讨了底层土壤养分、微生物生物量和腐生真菌群落的结果。

 结果

我们发现，添加 P 而不是 N，显着增加了枯木下土壤中的总 C、P 以及微生物生物量 C 和 P 浓度。与裸子植物木材相比，这些影响在被子植物木材下面的土壤中尤为明显，这可能与被子植物木材较高的分解速率及其对 P 的敏感性有关。同样，土壤腐生真菌群落的存在和丰度与 P 添加密切相关，其中被子植物木材下的特异性真菌反应比裸子植物木材更明显。

 结论

我们的研究强调了树木功能群在调节亚热带森林分解木材下土壤养分动态和真菌群落结构响应中的关键作用。这些见解对于开发土壤养分循环预测模型至关重要，这有助于在面对全球环境变化时更有效地管理森林生态系统。