Chronic Warming and Nitrogen-Addition Alter Soil Organic Matter Molecular Composition Distinctly in Tandem Compared to Individual Stressors
Chronic Warming and Nitrogen-Addition Alter Soil Organic Matter Molecular Composition Distinctly in Tandem Compared to Individual Stressors
复制标题
长期气候变暖和氮素添加对土壤有机质分子组成的影响与个体胁迫相比有显著差异
DOI：
10.1021/acsearthspacechem.2c00380
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发表时间：
2023-02
影响因子：
3.4
通讯作者：
I. Stoica;Maryam Tabatabaei Anaraki;Tom Muratore;M. Knorr;S. Frey;M. Simpson
中科院分区：
文献类型：
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作者：
I. Stoica;Maryam Tabatabaei Anaraki;Tom Muratore;M. Knorr;S. Frey;M. Simpson
森林土壤是碳（C）的主要储存库，但这些储存受到全球气温升高和大气氮（N）沉积的威胁。这些环境胁迫因子通过多种机制改变土壤微生物群落和土壤有机质的生态地球化学。为了研究长期变暖、氮添加以及同时变暖和氮添加（变暖+氮）对森林土壤的影响，14年后对来自哈佛森林土壤变暖和氮添加（SWaN）实验的土壤样品进行了分析。元素分析、气相色谱-质谱法的目标化合物分析和13 C核磁共振（NMR）光谱法用于分析有机和矿物（0 - 10 cm）土层中SOM的变化。总体而言，分子组成和微生物生物量的变化进行了观察，但差异的程度是唯一的变暖，N-添加，变暖+ N处理。具体而言，N-添加减缓SOM分解通过固态13 C NMR测量，而加温和加温+ N加速SOM分解。持续有机质分解后，14年的变暖+ N表示一个显着的变化后，4年和10年的实验治疗观察。这也证明了双因素方法如何导致独特的分子水平反应，而这种反应无法从单独的压力源实验中预测。这项研究强调，需要观察环境压力的串联使用分子水平的方法相结合，以获得一个全面的了解如何持久的人类活动将从根本上改变森林土壤系统。
: Forest soils are major reservoirs of carbon (C), but these stores are threatened by increasing global temperatures and atmospheric nitrogen (N) deposition. These environmental stressors can alter soil microbial communities and soil organic matter (SOM) biogeochemistry through a variety of mechanisms. To investigate the impact of chronic warming, N-addition, and simultaneous warming and N-addition (warming + N) on forest soils, soil samples from the Harvard Forest Soil Warming and Nitrogen Addition (SWaN) experiment were analyzed after 14 years. Elemental analysis, targeted compound analysis by gas chromatography − mass spectrometry, and 13 C nuclear magnetic resonance (NMR) spectroscopy were used to analyze changes in SOM in both the organic and mineral (0 − 10 cm) soil layers. Overall, changes in the molecular composition and microbial biomass were observed, but the extent of differences was unique to warming, N-addition, and warming + N treatments. Specifically, N-addition slowed SOM decomposition as measured via solid-state 13 C NMR, while warming and warming + N accelerated SOM decomposition. Continued SOM decomposition after 14 years with warming + N signified a pronounced change to observations made after 4 and 10 years of experimental treatment. This is also demonstrative of how a two-factor approach leads to a unique molecular-level response that cannot be predicted from experiments with individual stressors alone. This study emphasizes the need to observe environmental stressors in tandem using a combination of molecular-level approaches to obtain a comprehensive understanding of how persistent anthropogenic activity will fundamentally alter forest soil systems.