Minerals limit the deep soil respiration response to warming in a tropical Andisol
Minerals limit the deep soil respiration response to warming in a tropical Andisol
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DOI：
10.1007/s10533-022-00965-1
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发表时间：
2022-09
期刊：
影响因子：
4
通讯作者：
Casey R. McGrath;C. H. Hicks Pries;N. Nguyen;B. Glazer;Stanley Lio;S. Crow
中科院分区：
文献类型：
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作者：
Casey R. McGrath;C. H. Hicks Pries;N. Nguyen;B. Glazer;Stanley Lio;S. Crow
热带地区拥有世界上三分之一的土壤有机碳，但很少有实验能使热带土壤原位变暖。这些土壤对气候变化引起的损失的脆弱性是不确定的，许多人假设这些土壤对气候变化不太敏感，因为热带系统中已经很高的温度可能会限制微生物的敏感性，或者由于高度风化的热带土壤中有机碳的矿物保护增加。在这里，我们提出了一个深土壤（0-100厘米）变暖实验在热带Andisol的结果。土壤可以储存大量的、持久的土壤碳，这些碳被不好的和非结晶的矿物（PNCM）保护而不被分解。在20厘米深的间隔，我们测量了关键的土壤特性，包括碳，氮，pH值，PNCM，细菌和真菌丰富度沿着与温度，水分和CO2的生产。在一年的土壤变暖，CO2的生产显着增加了50-300%，每升温度，但只有在顶部40厘米的土壤剖面相比，其他深层土壤变暖实验的结果。多模态分析支持我们的假设，即高浓度的PNCM是缺乏CO2响应的主要驱动因素，其次是高相对土壤水分和低细菌丰富度，这可能是有机碳可用性的代理。缺乏升高的CO2生产响应变暖表明有限的积极反馈，气候变化的Andisols驱动的有机物质的强大的矿物保护。因此，在考虑将土壤碳储存管理作为气候行动的一部分时，应将安迪索尔视为高度优先的恢复或保护区。
Tropical regions hold one third of the world’s soil organic carbon, but few experiments have warmed tropical soils in situ. The vulnerability of these soils to climate change-induced losses is uncertain with many hypothesizing these soils would be less sensitive to climate change because already-high temperatures in tropical systems might limit microbial sensitivity or due to increased mineral protection of organic carbon in highly weathered tropical soils. Here we present the results of a deep soil (0–100 cm) warming experiment in a tropical Andisol. Andisols can store large, persistent pools of soil carbon that are protected from decomposition by poorly and non-crystalline minerals (PNCM). In 20 cm depth intervals, we measured key soil properties including carbon, nitrogen, pH, PNCM, bacterial and fungal richness along with temperature, moisture, and CO2production. Over a year of soil warming, CO2production significantly increased by 50–300% per degree of warming, but only in the top 40 cm of the soil profile in contrast to the results of other deep soil warming experiments. Multimodal analysis supported our hypothesis that high concentrations of PNCM was the primary driver of the lack of CO2response, followed by high relative soil moisture and low bacterial richness, which may be a proxy for organic carbon availability. The lack of elevated CO2production in response to warming suggests a limited positive feedback to climate change in Andisols driven by their strong mineral protection of organic matter. Therefore, Andisols should be considered high priority restoration or protection areas when considering the management of soil carbon stocks as part of climate action.