Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin 53706, USA.
Nat Commun. 2012;3:1222. doi: 10.1038/ncomms2224.
Microorganisms have a role as gatekeepers for terrestrial carbon fluxes, either causing its release to the atmosphere through their decomposition activities or preventing its release by stabilizing the carbon in a form that cannot be easily decomposed. Although research has focused on microbial sources of greenhouse gas production, somewhat limited attention has been paid to the microbial role in carbon sequestration. However, increasing numbers of reports indicate the importance of incorporating microbial-derived carbon into soil stable carbon pools. Here we investigate microbial residues in a California annual grassland after a continuous 9-year manipulation of three environmental factors (elevated CO(2), warming and nitrogen deposition), singly and in combination. Our results indicate that warming and nitrogen deposition can both alter the fraction of carbon derived from microbes in soils, though for two very different reasons. A reduction in microbial carbon contribution to stable carbon pools may have implications for our predictions of global change impacts on soil stored carbon.
微生物在陆地碳通量中扮演着“守门员”的角色，它们通过分解活动导致碳释放到大气中，或者通过将碳稳定在不易分解的形式来防止其释放。虽然研究集中在微生物产生温室气体的来源上，但对微生物在碳固存中的作用关注较少。然而，越来越多的报告表明，将微生物衍生的碳纳入土壤稳定碳库中是很重要的。在这里，我们研究了加利福尼亚一年生草原在连续 9 年的三种环境因素（升高的 CO₂、升温以及氮沉降）的单一和综合处理后，微生物残留物的情况。我们的结果表明，升温和氮沉降都可以改变土壤中微生物衍生碳的比例，尽管原因非常不同。微生物碳对稳定碳库的贡献减少可能会影响我们对全球变化对土壤储存碳影响的预测。
