在人为沉积下,土壤碳储量的增长在停止后迅速消失
Brooke E Propson1, Donald R Zak2,3, Aimée T Classen3
1Department of Soil and Environmental Sciences, University of Wisconsin, Madison, Wisconsin, USA.
Ecology
|October 14, 2024
概括
沉积量的减少导致森林失去储存的碳,影响北半球的碳汇. 这种损失与土壤微生物活动的变化有关,可能会增加气候变暖.
科学领域:
- 森林生态 森林生态
- 土壤科学 土壤科学
- 生物地质化学生物地质化学
背景情况:
- 人为 (N) 沉积通过抑制土壤有机物分解,历史上增强了陆地碳 (C) 沉积.
- 自20世纪70年代以来,由于减排政策,全球沉积量有所下降.
- 沉积量下降对土壤碳储存和微生物活动的影响在很大程度上是未知的.
研究的目的:
- 评估实验性 (N) 沉积对土壤碳 (C) 储存和微生物活动的长期影响.
- 为了研究土壤C动态的恢复N沉积结束后.
- 了解微生物活动与土壤C变化之间的机制联系.
主要方法:
- 进行了一项为期24年的实验性N沉积研究.
- 随着时间的推移,测量了土壤中的C和N含量.
- 评估了微生物活动,以了解其在C循环中的作用.
- 在处理和恢复阶段 (1994-2022) 进行了对C土壤N沉积的影响大小的比较.
主要成果:
- 经过实验增加的沉积导致在有机地平线上积累了C.
- 在N沉积结束五年后,有机地平线发生了显著的C损失.
- 微生物活动的变化被确定为这些C动态的关键驱动因素.
- 矿物土壤中的土壤C在恢复期间的反应性较低.
结论:
- 沉积量下降会扭转之前缩的碳封存效益.
- 有机地平线碳N后沉积的损失表明北半球碳沉积能力减少.
- 这些发现意味着由于森林土壤C动态的改变,气候变暖的潜在增强.
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