Early chemical changes during wood decomposition are controlled by fungal communities inhabiting stems at treefall in a tropical dry forest
Early chemical changes during wood decomposition are controlled by fungal communities inhabiting stems at treefall in a tropical dry forest
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DOI：
10.1007/s11104-021-05048-y
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发表时间：
2021-07
期刊：
影响因子：
4.9
通讯作者：
François Maillard;E. Andrews;Molly K. Moran;Dan V. Du;P. Kennedy;J. Powers;Skip J. Van Bloem;J. Schilling
中科院分区：
文献类型：
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作者：
François Maillard;E. Andrews;Molly K. Moran;Dan V. Du;P. Kennedy;J. Powers;Skip J. Van Bloem;J. Schilling
目的更好地了解枯木如何分解对于准确描述森林中的碳和养分循环至关重要。真菌主导了这一分解过程，但我们对真菌群落结构的了解仍然有限，真菌群落结构最终控制了木材分解的命运。在热带生态系统中尤其如此。为了解决这一知识差距，我们的研究利用了一次极端风暴事件，该事件导致大量同步的枯木进入森林地面。在这里，我们报告了波多黎各干燥森林中树木第一年的木材分解数据，这些树木是在2017年被飓风玛丽亚摧毁的九种树种。我们测量了木材分解12个月后的性能和相关真菌群落，并将其与初始木材性能和茎上真菌群落进行了比较，以确定木材分解速率和化学变化的最佳预测指标。结果木材化学变化的主要原因是木聚糖的快速损失，木聚糖是研究树种的主要半纤维素成分。真菌群落以腐养真菌和植物病原真菌为主，随时间变化不大。不同真菌功能群落的初始相对丰度和比值是木聚糖和葡聚糖损失的显著预测因子，与腐生菌相比，植物病原真菌加速了纤维素和半纤维素的分解速率。结论树木砍伐时存在的真菌是木材分解的强大驱动力，表明植物病原真菌可能是干燥热带森林中半纤维素的有效早期分解者。
PurposeA better knowledge of how deadwood decomposes is critical for accurately characterizing carbon and nutrient cycling in forests. Fungi dominate this decomposition process, but we still have limited understanding of fungal community structuring that ultimately controls the fate of wood decomposition. This is particularly true in tropical ecosystems. To address this knowledge gap, our study capitalized on an extreme storm event that caused a large and synchronized input of deadwood to the forest floor.MethodsHere we report data for the first year of wood decomposition of trees in a Puerto Rican dry forest for nine tree species that were snapped by Hurricane Maria in 2017. We measured wood properties and the associated fungal communities after 12 months of decomposition and compared them with initial wood properties and stem-inhabiting fungal communities to identify the best predictors of wood decomposition rates and chemical changes.ResultsChanges in wood chemistry were primarily explained by rapid xylan losses, the main hemicellulose component for the studied tree species. Fungal communities were dominated by saprotrophic and plant pathogenic fungi and showed moderate changes over time. The initial relative abundances and ratios of different fungal functional guilds were significant predictors of both xylan and glucan losses, with plant pathogenic fungi accelerating cellulose and hemicellulose decomposition rates compared to saprotrophs.ConclusionOur results confirm that fungi present at the time of treefall are strong drivers of wood decomposition and suggest that plant pathogenic fungi might act as efficient early decomposers of hemicellulose in dry tropical forests.