Metagenomic communities inhabiting Phragmites australis litter

In this study, the intermittent lake is taken up as a model for changes in water availability and how they affect the functional microbial communities decomposing Phragmites australis litter. The original material (source material) was exposed to decomposition at a predominately wet site (wet; 45°43'38.30" N, 14°24'16,59" E) or dry site (dry; 45°43'38.29" N, 14°24'16,72" E) for a duration of 45 days.
The overall aim of our study was to evaluate the effect of different conditions due to fluctuating water levels on the decomposition of P. australis litter. To predict litter decomposition dynamics in intermittent lakes, it is critical to understand how the functional microbial communities (present in the decomposing leaves) change under different habitat conditions. First, we hypothesized that functional communities from fresh leaves would change due to the start of the decomposition processes. Second, we hypothesized that the response of communities in different habitats would differ relative to the submergence level, showing differences in the metabolic processes. Our last hypothesis was that changes at the level of functional genes would be more pronounced in bacterial than in fungal functional communities. To evaluate our hypotheses, we analyzed functional microbial communities in fresh P. australis leaves and leaves decomposing in either wet or dry habitats that are characterized by different flooding patterns.

本研究以间歇湖（intermittent lake）为模型系统，探究水分可利用性变化及其对分解芦苇（Phragmites australis）枯落物的功能微生物群落的影响。实验初始材料（源材料）分别在以湿润为主的样地（湿润样地：北纬45°43′38.30″，东经14°24′16.59″）与干燥样地（干燥样地：北纬45°43′38.29″，东经14°24′16.72″）中进行为期45天的分解培养。
本研究的总体目标是评估水位波动所导致的不同生境条件对芦苇枯落物分解过程的影响。若要预测间歇湖中的枯落物分解动态，明确附着于分解叶片中的功能微生物群落在不同生境条件下的变化规律至关重要。其一，我们提出假说：新鲜叶片中的功能群落会因分解过程启动而发生改变；其二，不同生境下的群落响应会随淹水程度的不同而产生差异，进而表现出代谢过程的区别；其三，我们的假说为：相较于真菌功能群落，细菌功能群落在功能基因层面的变化将更为显著。为验证上述假说，我们对新鲜芦苇叶片以及分别在具有不同淹水模式的湿润、干燥生境中进行分解的叶片，开展了功能微生物群落分析。