The effect of resource history on the functioning of soil microbial communities is maintained across time
The effect of resource history on the functioning of soil microbial communities is maintained across time
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DOI：
10.5194/bg-8-1477-2011
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发表时间：
2011-01-01
期刊：
影响因子：
4.9
通讯作者：
Bradford, M. A.
中科院分区：
文献类型：
--
作者：
Keiser, A. D.;Strickland, M. S.;Bradford, M. A.
历史资源条件似乎影响微生物群落功能。随着时间的推移，历史影响可能会随着人口对当代环境的反应而减弱。或者，由于适应新环境的遗传潜力不同等因素，它们可能会持续存在。使用实验微观世界，我们测试竞争的假设，不同的土壤微生物群落在共同的环境（H1（a））收敛或（H1（B））保持不同的功能随着时间的推移。使用6 × 2（土壤群落接种物×凋落物环境）的全因子设计，我们比较了分解率在实验中的缩影，包含草或硬木凋落物环境。100天后，将发育的群落接种到新鲜的凋落物中，然后再分解100天。我们在第三个100天的时期重复这一做法。在每个连续的100天内，我们发现更高的分解率（即功能），这表明当社区拥有当代环境的实验历史时，它们的功能会更好。尽管这些功能的收益，最初不同的社区之间的分解率的差异持续存在，支持的假设，不同的是保持跨时间。与功能相反，社区组成更相似，遵循共同的实验历史。我们还发现，“专业化”的一个实验环境中产生的成本，在替代环境中的功能丧失。例如，实验历史的草凋落物环境减少分解时，社区接种到硬木凋落物环境。我们的工作通过实验证明，尽管预期快速生长速率，生理灵活性和快速进化，但微生物群落之间的初始功能差异会随着时间的推移而保持。这些研究结果质疑，如果我们要可靠地预测全球变化对地球化学循环的影响，微生物动力学是否可以从生态系统过程模型中省略。
Historical resource conditions appear to influence microbial community function. With time, historical influences might diminish as populations respond to the contemporary environment. Alternatively, they may persist given factors such as contrasting genetic potentials for adaptation to a new environment. Using experimental microcosms, we test competing hypotheses that function of distinct soil microbial communities in common environments (H1(a)) converge or (H1(b)) remain dissimilar over time. Using a 6 x 2 (soil community inoculum x litter environment) full-factorial design, we compare decomposition rates in experimental microcosms containing grass or hardwood litter environments. After 100 days, communities that develop are inoculated into fresh litters and decomposition followed for another 100 days. We repeat this for a third, 100-day period. In each successive, 100-day period, we find higher decomposition rates (i.e. functioning) suggesting communities function better when they have an experimental history of the contemporary environment. Despite these functional gains, differences in decomposition rates among initially distinct communities persist, supporting the hypothesis that dissimilarity is maintained across time. In contrast to function, community composition is more similar following a common, experimental history. We also find that "specialization" on one experimental environment incurs a cost, with loss of function in the alternate environment. For example, experimental history of a grass-litter environment reduced decomposition when communities were inoculated into a hardwood-litter environment. Our work demonstrates experimentally that despite expectations of fast growth rates, physiological flexibility and rapid evolution, initial functional differences between microbial communities are maintained across time. These findings question whether microbial dynamics can be omitted from models of ecosystem processes if we are to predict reliably global change effects on biogeochemical cycles.