Soil geochemistry confines microbial abundances across an arctic landscape; implications for net carbon exchange with the atmosphere
Soil geochemistry confines microbial abundances across an arctic landscape; implications for net carbon exchange with the atmosphere
复制标题
DOI：
10.1007/s10533-014-9997-7
复制
发表时间：
2014-08-01
期刊：
影响因子：
4
通讯作者：
Graham, D. W.
中科院分区：
文献类型：
--
作者：
Gray, N. D.;McCann, C. M.;Graham, D. W.
世界陆地有机碳的很大一部分储存在北极永久冻土中。然而，由于永久冻土变暖和释放的碳的原位微生物矿化增加，北极土壤的温室气体排放正在增加，包括甲烷（CH 4（g））。为了确定对这种释放的环境控制，我们在斯瓦尔巴群岛Kongsfjorden收集了13个近地表北极土壤的土壤地球化学和微生物群落条件。碳酸盐矿物含量（即Ca和Mg）和土壤pH值的代理之间存在统计学显著相关性（斯皮尔曼rho = 0.87，p < 0.001）。反过来，pH值与土壤中细菌和I型甲烷氧化菌基因丰度显著负相关（分别为r =-0.71，p = 0.01和r =-0.74，p = 0.006），这也与土壤磷（P）水平共变（分别为r = 0.79，p = 0.01和r = 0.63，p = 0.02）。这些结果表明，土壤磷供应，这是由pH值和其他因素控制，显着影响在这些北极土壤中原位微生物丰度。总的来说，我们得出结论，微生物的反应，以增加“老碳”释放在这个北极地区的限制，在表层土壤中的营养缺乏，从而影响释放到大气中的碳气体的通量和组成。
A large portion of the World's terrestrial organic carbon is stored in Arctic permafrost soils. However, due to permafrost warming and increased in situ microbial mineralisation of released carbon, greenhouse gas releases from Arctic soils are increasing, including methane (CH4(g)). To identify environmental controls on such releases, we characterised soil geochemistry and microbial community conditions in 13 near-surface Arctic soils collected across Kongsfjorden, Svalbard. Statistically significant correlations were found between proxies for carbonate mineral content (i.e. Ca and Mg) and soil pH (Spearman rho = 0.87, p < 0.001). In turn, pH significantly inversely correlated with bacterial and Type I methanotroph gene abundances across the soils (r = -0.71, p = 0.01 and r = -0.74, p = 0.006, respectively), which also co-varied with soil phosphorous (P) level (r = 0.79, p = 0.01 and r = 0.63, p = 0.02, respectively). These results suggest that soil P supply, which is controlled by pH and other factors, significantly influences in situ microbial abundances in these Arctic soils. Overall, we conclude microbial responses to increasing 'old carbon' releases in this Arctic region are constrained by nutrient-deficiency in surface soils, with consequential impacts on the flux and composition of carbon gasses released to the atmosphere.