Soil carbon and microbes in the warming tropics
Soil carbon and microbes in the warming tropics
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变暖热带地区的土壤碳和微生物
DOI：
10.1111/1365-2435.14050
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发表时间：
2022
影响因子：
5.2
通讯作者：
Nottingham A
中科院分区：
文献类型：
--
作者：
Nottingham A
气候变暖可能会加速土壤有机质的分解，从而破坏地球上最大的陆地活性碳(C)储量。三分之一的碳储存在热带地区。热带土壤固碳或作为额外的二氧化碳来源的潜力将取决于碳输入和输出的平衡，而这种平衡是由土壤微生物群落及其活动对扰动的反应所调节的。本文回顾了气候变暖对湿润热带森林土壤微生物群落和碳储量的影响。最近的原位试验表明，热带森林土壤C矿化对短期变暖具有高度敏感性。然而，这是否会转化为长期的土壤C下降仍不清楚。在年代际时间尺度上，土壤C矿化对变暖的高敏感性与热带陆地表面温度的年际变化与大气二氧化碳增长率之间的相关性，以及使用卡内基-艾姆斯-斯坦福方法生物圈模型的模拟相一致。这种观测到的敏感性可能进一步促进千年时间尺度上的气候变化，河流流域有机物的放射性碳定年表明，在冰川变暖后期，热带土壤C的释放速度加快了两倍。然而，与此证据相反，观测到的随海拔升高的温度梯度的稳定状态土壤C的转换，以及在全新世热极大期和晚冰期变暖期之前热带土壤中C的存在，表明了热带土壤C的长期稳定性。为了使这些最近的实验结果与长期观测结果相一致，我们提出了解释热带土壤C和微生物对多时间尺度变暖反应的机制。迫切需要结合原位实验和监测方法-大规模和跨站点-来解决这些机制在空间和时间尺度上的相互作用，从而更好地理解土壤微生物与热带土壤中碳储存之间的关系。在《华尔街日报》博客上阅读免费的《简明语言摘要》。
Climate warming could destabilise the Earth's largest terrestrial store of reactive carbon (C), by accelerating the decomposition of soil organic matter. A third of that C store resides in the tropics. The potential for tropical soils to sequester C, or to act as an additional source of CO2, will depend on the balance of C inputs and outputs, mediated by the response of soil microbial communities and their activity to perturbation.We review the impact of warming on microbial communities and C storage in humid tropical forest soils over multiple time‐scales.Recent in situ experiments indicate high sensitivity of tropical forest soil C mineralisation to warming in the short term. However, whether this will translate into long‐term soil C decline remains unclear. At decadal time‐scales, high sensitivity of soil C mineralisation to warming is consistent with the correlation between the inter‐annual variation in the tropical land surface temperature and atmospheric CO2growth rate, and with simulations using the Carnegie‐Ames‐Stanford Approach biosphere model. This observed sensitivity may further contribute to climatic change over millennial time‐scales, suggested by radiocarbon dating of organic matter in river basins showing a twofold acceleration in tropical soil C release during the late‐glacial warming period. However, counter to this evidence, long‐term stability of tropical soil C is suggested by observed steady‐state soil C turnover across temperature gradients with elevation, and by the presence of C in tropical soils that pre‐dates the Holocene Thermal Maximum and late‐glacial warming periods.To help reconcile these recent experimental findings and long‐term observations, we propose mechanisms to explain tropical soil C and microbial responses to warming across multiple time‐scales. Combined in situ experimental and monitoring approaches—large‐scale and cross‐site—are urgently needed to resolve the interplay of these mechanisms across spatial and temporal scales, to shape a better understanding of the relationship between soil microbes and C storage in tropical soils.Read the free Plain Language Summary for this article on the Journal blog.