Greater regulation of permafrost organic matter composition by enzymes and redox than temperature
Greater regulation of permafrost organic matter composition by enzymes and redox than temperature
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酶和氧化还原对永冻土有机质组成的调节作用比温度更大
DOI：
10.1016/j.soilbio.2023.108991
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发表时间：
2023
影响因子：
9.7
通讯作者：
Ernakovich, Jessica
中科院分区：
文献类型：
--
作者：
Lynch, Laurel;Margenot, Andrew;Calderon, Francisco;Ernakovich, Jessica
高纬度生态系统中永久冻土的加速融化增加了土壤微生物的有机质可利用性。永久冻土产生的有机质的化学成分影响微生物代谢效率，这可能决定北极将来是否仍然是一个关键的碳汇，还是转变为温室气体的净来源。在为期90天的模拟解冻实验中，我们测量了来自地表（0-10厘米）和地下（16-25厘米）永久冻土层的土壤和溶解有机质库的化学变化。我们控制温度（1°C和15°C）和氧化还原（排水和饱和）来模拟现场相关条件，并测试OM化学变化是否可以通过催化碳、氮和磷矿化的六种水解酶的活性来解释。通过漫反射红外傅立叶变换（DRIFT）光谱分析发现，冻土深度和酶活性与土壤OM （SOM）官能团化学的变化呈显著相关。氧化还原和ph值驱动溶解的DOM （DOM）化学变化更大。我们的研究结果表明，对永久冻土易受酶解影响的深度解析分析可能有助于解释SOM与DOM循环的不同模式，这些模式可用于约束全球变化期间北极碳储量的模拟预测。
Accelerating permafrost thaw across high-latitude ecosystems increases organic matter (OM) availability to soil microorganisms. The chemical composition of permafrost-derived OM, which influences microbial metabolic efficiency, may determine whether the Arctic remains a critical carbon sink in the future or shifts to net a source of greenhouse gases. During a 90-day, simulated thaw experiment, we measured shifts in the chemistry of soil and dissolved organic matter pools sourced from surface (0–10 cm) and subsurface (16–25 cm) permafrost layers. We manipulated temperature (1 versus 15 °C) and redox (drained versus saturated) to mimic field-relevant conditions and tested whether variability in OM chemistry could be explained by the activities of six hydrolytic enzymes that catalyze carbon, nitrogen, and phosphorus mineralization. We found that permafrost depth and enzyme activities were significantly correlated with shifts in soil OM (SOM) functional group chemistries, as measured by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. Greater variability in dissolved OM (DOM) chemistries were driven by redox and pH. Our results suggest depth-resolved analyses of permafrost vulnerability to enzymatic hydrolysis may help explain distinct patterns in SOM versus DOM cycling that can be used to constrain modeled projections of Arctic carbon storage during global change.
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影响因子：
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作者：
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通讯作者：
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影响因子：
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作者：
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