Fungi are the dominant organisms decomposing leaf litter in streams and mediating energy transfer to other trophic levels. However, less is known about their role in decomposing submerged wood. This study provides the first estimates of fungal production on wood and compares the importance of fungi in the decomposition of submerged wood versus that of leaves at the ecosystem scale. We determined fungal biomass (ergosterol) and activity associated with randomly collected small wood (?2 year?1 in the reference stream; 5.5 and 33.1 g C m?2 year?1 in the enriched stream). However, since the annual input of wood was five times lower than that of leaves, the proportion of organic matter input directly assimilated by fungi was comparable for these substrates (15.4 [wood] and 11.3% [leaves] in the reference stream; 20.0 [wood] and 20.2% [leaves] in the enriched stream). Despite a significantly lower fungal activity on wood than on leaves (per gram of detrital C), fungi can be equally important in processing both leaves and wood in streams.
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机译：真菌是占主导地位的生物，它分解溪流中的凋落物并将能量转移到其他营养级别。然而，关于它们在分解淹没木材中的作用知之甚少。这项研究首次估计了木材上真菌的产量，并比较了在生态系统范围内真菌在淹没的木材分解与叶子分解中的重要性。我们确定了真菌生物量（麦角固醇）和与随机收集的小木材相关的活性（参考流中为？2年？1;浓缩流中为5.5和33.1 g C m？2年？1）。但是，由于木材的年输入量比树叶的年输入量低五倍，因此真菌直接吸收的有机物输入量与这些底物相当（参考流中为15.4 [木材]和11.3％[叶]; 20.0） （木材）和20.2％（叶）在浓缩流中）。尽管木材上的真菌活性明显低于叶片（每克碎屑碳），但真菌在加工河流中的叶片和木材方面同样重要。
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