Hoppe Björn, Krger Krüger, Kahl Tiemo, Arnstadt Tobias, Buscot François, Bauhus Jürgen, Wubet Tesfaye
1] Department of Soil Ecology, UFZ - Helmholtz Centre for Environmental Research, Halle (Saale), Germany [2] Chair of Silviculture, Faculty of Environment and Natural Resources, University of Freiburg, Freiburg i. Brsg., Germany.
Department of Soil Ecology, UFZ - Helmholtz Centre for Environmental Research, Halle (Saale), Germany.
Sci Rep. 2015 Apr 8;5:9456. doi: 10.1038/srep09456.
Deadwood is an important biodiversity hotspot in forest ecosystems. While saproxylic insects and wood-inhabiting fungi have been studied extensively, little is known about deadwood-inhabiting bacteria. The study we present is among the first to compare bacterial diversity and community structure of deadwood under field conditions. We therefore compared deadwood logs of two temperate forest tree species Fagus sylvatica and Picea abies using 16S rDNA pyrosequencing to identify changes in bacterial diversity and community structure at different stages of decay in forest plots under different management regimes. Alphaproteobacteria, Acidobacteria and Actinobacteria were the dominant taxonomic groups in both tree species. There were no differences in bacterial OTU richness between deadwood of Fagus sylvatica and Picea abies. Bacteria from the order Rhizobiales became more abundant during the intermediate and advanced stages of decay, accounting for up to 25% of the entire bacterial community in such logs. The most dominant OTU was taxonomically assigned to the genus Methylovirgula, which was recently described in a woodblock experiment of Fagus sylvatica. Besides tree species we were able to demonstrate that deadwood physico-chemical properties, in particular remaining mass, relative wood moisture, pH, and C/N ratio serve as drivers of community composition of deadwood-inhabiting bacteria.
朽木是森林生态系统中一个重要的生物多样性热点。虽然对食腐木昆虫和木生真菌已经进行了广泛研究，但对于栖息在朽木中的细菌却知之甚少。我们目前开展的这项研究是首批在野外条件下比较朽木细菌多样性和群落结构的研究之一。因此，我们利用16S rDNA焦磷酸测序技术，比较了两种温带森林树种欧洲山毛榉（Fagus sylvatica）和欧洲云杉（Picea abies）的朽木原木，以确定在不同管理模式下森林地块中朽木在不同腐烂阶段细菌多样性和群落结构的变化。变形菌门α亚纲、酸杆菌门和放线菌门是这两种树种中占主导地位的分类群。欧洲山毛榉和欧洲云杉朽木之间的细菌OTU丰富度没有差异。在腐烂的中期和后期，根瘤菌目的细菌变得更加丰富，在这类原木中占整个细菌群落的比例高达25%。最主要的OTU在分类学上被归为甲基弯曲菌属（Methylovirgula），该属最近在欧洲山毛榉的木块实验中被描述过。除了树种之外，我们还能够证明，朽木的物理化学性质，特别是剩余质量、相对木材含水量、pH值和碳氮比，是栖息在朽木中的细菌群落组成的驱动因素。
