Aims

The soils of riparian ecosystems harbor a significant amount of organic carbon (C) and are susceptible to anthropogenic disturbances. However, the warming response of soil organic carbon (SOC) decomposition in riparian ecosystems has received limited attention.

Methods

In this study, we quantified the thermal sensitivity (Q₁₀) of SOC decomposition across a mean annual precipitation (MAP) gradient ranging from 1270 to 1416 mm in the riparian zones of the Three Gorges Reservoir.

Results

Our findings indicate that the Q₁₀ ranged from 1.1 to 2.1. Notably, MAP exerts a negative effect on Q₁₀ by positively affecting the decomposability of SOC (D_SOC) and soil pH, collectively explaining 52.5% of the variation in Q₁₀. Among the factors studied, D_SOC emerged as the most critical determinant of Q₁₀ variation. The observed negative correlation between D_SOC and Q₁₀ suggests that stable SOC is more susceptible to loss under warming compared to active SOC.

Conclusions

Consequently, MAP-driven changes in D_SOC significantly influence the soil C cycle feedback to climate warming in riparian zone ecosystems. Specifically, locations with greater MAP are likely to experience stronger positive feedback from SOC loss in response to warming.

中文翻译：

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河岸生态系统土壤有机碳分解的热敏性

 目标

河岸生态系统的土壤含有大量的有机碳 （C），容易受到人为干扰。然而，河岸生态系统中土壤有机碳 （SOC） 分解的变暖响应受到的关注有限。

 方法

在这项研究中，我们量化了三峡水库河岸带 1270 至 1416 mm 的平均年降水量 （MAP） 梯度中 SOC 分解的热敏感性 （Q₁₀）。

 结果

我们的研究结果表明，Q₁₀ 的范围为 1.1 到 2.1。值得注意的是，MAP 通过对 SOC （D_SOC） 和土壤 pH 值的分解性产生积极影响，对 Q₁₀ 产生负面影响，共同解释了 Q₁₀ 中 52.5% 的变化。在研究的因素中，D_SOC 成为 Q₁₀ 变化的最关键决定因素。观察到的 D_SOC 和 Q₁₀ 之间的负相关表明，与活性 SOC 相比，稳定的 SOC 在变暖下更容易损失。

 结论

因此，MAP 驱动的 D_SOC 变化显着影响了河岸带生态系统中土壤 C 循环对气候变暖的反馈。具体来说，MAP 较大的位置可能会因变暖而从 SOC 损失中获得更强的正反馈。