UFZ-Helmholtz Centre for Environmental Research, Department of Soil Ecology, Theodor-Lieser-Str. 4, 06120, Halle (Saale), Germany.
Faculty of Environment and Natural Resources, Chair of Silviculture, University of Freiburg, Tennenbacherstr. 4, 79085, Freiburg i. Brsg., Germany.
Microb Ecol. 2019 Oct;78(3):725-736. doi: 10.1007/s00248-019-01334-6. Epub 2019 Feb 13.
The home-field advantage (HFA) hypothesis has been used intensively to study leaf litter decomposition in various ecosystems. However, the HFA in woody substrates is still unexplored. Here, we reanalyzed and integrated existing datasets on various groups of microorganisms collected from natural deadwood of two temperate trees, Fagus sylvatica and Picea abies, from forests in which one or other of these species dominates but where both are present. Our aims were (i) to test the HFA hypothesis on wood decomposition rates of these two temperate tree species, and (ii) to investigate if HFA hypothesis can be explained by diversity and community composition of bacteria and in detail N-fixing bacteria (as determined by molecular 16S rRNA and nifH gene amplification) and fungi (as determined by molecular ITS rRNA amplification and sporocarp surveys). Our results showed that wood decomposition rates were accelerated at "home" versus "away" by 38.19% ± 20.04% (mean ± SE). We detected strong changes in fungal richness (increase 36-50%) and community composition (R = 0.52-0.60, P < 0.05) according to HFA hypothesis. The changes of fungi were much stronger than for total bacteria and nitrogen fixing for both at richness and community composition levels. In conclusion, our results support the HFA hypothesis in deadwood: decomposition rate is accelerated at home due to specialization of fungal communities produced by the plant community above them. Furthermore, the higher richness of fungal sporocarps and nitrogen-fixing bacteria (nifH) may stimulate or at least stabilize wood decomposition rates at "home" versus "away."
主场优势假说已被广泛用于研究各种生态系统中的落叶分解。然而，木质基质中的主场优势仍未得到探索。在这里，我们重新分析和整合了从两种温带树种（欧洲山毛榉和挪威云杉）的天然枯木中收集的各种微生物群的数据，这些树木生长在一种或另一种树种占主导地位但两种树种都存在的森林中。我们的目的是：（i）检验这两个温带树种的木质分解速率的主场优势假说；（ii）研究主场优势假说是否可以用细菌和固氮细菌（通过分子 16S rRNA 和 nifH 基因扩增来确定）以及真菌（通过分子 ITS rRNA 扩增和孢子体调查来确定）的多样性和群落组成来解释。我们的结果表明，木质分解速率在家的情况下比在客场情况下加速了 38.19%±20.04%（平均值±SE）。根据主场优势假说，我们检测到真菌丰富度（增加 36-50%）和群落组成（R=0.52-0.60，P<0.05）发生了强烈变化。与总细菌和固氮细菌相比，真菌的变化在丰富度和群落组成水平上都要强得多。总之，我们的结果支持了枯木中的主场优势假说：由于植物群落上方产生的真菌群落的专业化，分解速率在家中加快。此外，较高的真菌孢子体和固氮细菌（nifH）丰富度可能会刺激或至少稳定木质在家与客场之间的分解速率。
