Fukasawa Yu, Kimura Satsuki, Kominami Yuji, Takagi Masahiro, Matsukura Kimiyo, Makoto Kobayashi, Suzuki Satoshi N, Takemoto Shuhei, Tanaka Nobuaki, Jomura Mayuko, Kadowaki Kohmei, Ushio Masayuki, Kinuura Haruo, Yamashita Satoshi
Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan.
Forestry and Forest Products Research Institute, Tsukuba, Ibaraki, Japan.
Environ Microbiol. 2025 Jan;27(1):e70026. doi: 10.1111/1462-2920.70026.
Oak wilt causes severe dieback of Quercus serrata, a dominant tree species in the lowlands across Japan. This study evaluated the effects of oak wilt on the wood-inhabiting fungal community and the decay rate of deadwood using a field monitoring experiment. We analysed the fungal metabarcoding community from 1200 wood samples obtained from 120 experimental logs from three forest sites at five different time points during the initial 1.5 years of the experiment. Death due to wilt significantly influenced the fungal community composition and reduced fungal diversity, likely due to the dominance of a limited number of species. The operational taxonomic unit richness, occurrence frequency, and DNA copy number of white rot fungi were also enhanced on the logs killed by wilt, depending on the sites. Structural equation modelling suggested that the wilt-initiated changes in the fungal community reduced the decay rate of oak logs. Temperature and wood moisture also affected the fungal community and log decomposition. These results suggest that, in addition to the direct effect of climate, oak wilt indirectly affects log decomposition by structuring the fungal community. Continuous monitoring is essential to evaluate the longer-term effects of oak wilt on the fungal decomposition of wood.
橡树萎蔫病会导致日本低地地区的优势树种——日本枹栎严重枯死。本研究通过一项野外监测实验，评估了橡树萎蔫病对栖息于木材中的真菌群落以及枯木腐朽率的影响。在实验开始的1.5年期间，我们在五个不同时间点，从三个森林地点的120根实验原木上采集了1200份木材样本，分析了真菌代谢条形码群落。萎蔫导致的死亡显著影响了真菌群落组成，并降低了真菌多样性，这可能是由于少数物种占主导地位所致。根据不同地点的情况，在因萎蔫而死亡的原木上，白腐真菌的操作分类单元丰富度、出现频率和DNA拷贝数也有所增加。结构方程模型表明，由萎蔫引发的真菌群落变化降低了橡树木材的腐朽率。温度和木材湿度也影响真菌群落和木材分解。这些结果表明，除了气候的直接影响外，橡树萎蔫病还通过构建真菌群落间接影响木材分解。持续监测对于评估橡树萎蔫病对木材真菌分解的长期影响至关重要。
