Divergent drivers of the microbial methane sink in temperate forest and grassland soils
Divergent drivers of the microbial methane sink in temperate forest and grassland soils
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DOI：
10.1111/gcb.15430
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发表时间：
2020-11
影响因子：
11.6
通讯作者：
Jana Täumer;S. Kolb;Runa S. Boeddinghaus;Haitao Wang;I. Schöning;M. Schrumpf;T. Urich;S. Marhan-
中科院分区：
文献类型：
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作者：
Jana Täumer;S. Kolb;Runa S. Boeddinghaus;Haitao Wang;I. Schöning;M. Schrumpf;T. Urich;S. Marhan-
通气表土是通过CH4氧化细菌（MOB）氧化大气甲烷（CH4）的重要汇。然而，加强草地和森林的管理可能会降低土壤的CH4汇容量。我们调查了草地土地利用强度（150个站点）和森林管理类型（149个站点）对德国三个温带地区表层土壤中潜在大气CH4氧化速率（PMORs）和MOB丰度和多样性（qPCR）的影响。PMORs测量在限定的条件下产生约两倍的CH4氧化在森林中比在草原土壤。在几乎所有地区，草地的高土地利用强度对PMOR（-40%）产生了负面影响，施肥是草地土地利用强度的主要因素，导致PMOR降低了20%。与此相反，森林管理并没有影响PMORs在森林土壤中。高地土壤团簇（USC）-α是森林中MOB的优势类群。相比之下，USC-γ在一半以上的森林土壤中不存在，但在几乎所有的草原土壤中存在。在森林中，USC-α丰度对PMOR有直接的正效应，而在草原中，USC-α和USC-γ丰度对PMOR有正效应，USC-γ的贡献比USC-α更明显。土壤容重对森林和草地的PMOR都有负面影响。研究还发现，温带森林和草原土壤PMORs对pH、土壤质地、土壤持水力和有机碳、氮含量的响应存在差异。pH对PMOR没有直接影响，但通过MOB丰度间接影响，对USC-α有负面影响，对USC-γ丰度有正面影响。我们的结论是，减少草地土地利用强度和植树造林有可能增加土壤的CH4汇功能，不同的参数决定了森林和草地土壤中微生物甲烷汇。
Aerated topsoils are important sinks for atmospheric methane (CH4) via oxidation by CH4‐oxidizing bacteria (MOB). However, intensified management of grasslands and forests may reduce the CH4 sink capacity of soils. We investigated the influence of grassland land‐use intensity (150 sites) and forest management type (149 sites) on potential atmospheric CH4 oxidation rates (PMORs) and the abundance and diversity of MOB (with qPCR) in topsoils of three temperate regions in Germany. PMORs measurements in microcosms under defined conditions yielded approximately twice as much CH4 oxidation in forest than in grassland soils. High land‐use intensity of grasslands had a negative effect on PMORs (−40%) in almost all regions and fertilization was the predominant factor of grassland land‐use intensity leading to PMOR reduction by 20%. In contrast, forest management did not affect PMORs in forest soils. Upland soil cluster (USC)‐α was the dominant group of MOBs in the forests. In contrast, USC‐γ was absent in more than half of the forest soils but present in almost all grassland soils. USC‐α abundance had a direct positive effect on PMOR in forest, while in grasslands USC‐α and USC‐γ abundance affected PMOR positively with a more pronounced contribution of USC‐γ than USC‐α. Soil bulk density negatively influenced PMOR in both forests and grasslands. We further found that the response of the PMORs to pH, soil texture, soil water holding capacity and organic carbon and nitrogen content differ between temperate forest and grassland soils. pH had no direct effects on PMOR, but indirect ones via the MOB abundances, showing a negative effect on USC‐α, and a positive on USC‐γ abundance. We conclude that reduction in grassland land‐use intensity and afforestation has the potential to increase the CH4 sink function of soils and that different parameters determine the microbial methane sink in forest and grassland soils.