ABSTRACT

A diverse array of fungi take part in decomposition, but the variability of their decomposing ability is not fully understood. A total of 49 isolates of Ascomycota and Basidiomycota were obtained from bleached areas of leaf litter in a subtropical forest in southern Japan, and their ability to decompose leaves and recalcitrant compounds was quantified in pure culture. Mass loss of leaves of Castanopsis sieboldii (Fagaceae) and Schima wallichii (Theaceae) was evaluated at 20 C for 12 wk in vitro. Fungi caused a loss of −0.4% to 34.3% of the original leaf mass. The greatest mass loss was caused by four isolates of Mycena (Tricholomataceae). Isolates of Lachnocladiaceae caused greater mass loss of recalcitrant compounds, registered as acid-unhydrolyzable residue (AUR), which includes lignin, relative to Xylariaceae. Isolates of Rhytismataceae, Lachnocladiaceae, Marasmiaceae, and Omphalotaceae exhibited selective decomposition of AUR, Mycena exhibited simultaneous decomposition of AUR and components other than AUR, and Xylariaceae exhibited selective decomposition of components other than AUR. Mass losses of leaves and AUR caused by each fungal isolate were similar for C. sieboldii and S. wallichii. The Mycena isolates obtained from C. sieboldii caused greater mass losses of leaves and AUR than those obtained from the other tree species, suggesting a “home-field advantage” of decomposing potentialities, with implications for natural interactions beyond the in vitro system evaluated here.

摘要

各种各样的真菌参与分解，但它们分解能力的可变性尚不完全清楚。从日本南部亚热带森林的枯叶落叶漂白区共分离出 49 株子囊菌和担子菌，并在纯培养中量化了它们分解叶子和顽固化合物的能力。在 20°C 下在体外评估了栲( Castanopsis sieboldii) (壳斗科) 和Schima wallichii (Theaceae)叶片的质量损失12 周。真菌导致原始叶质量损失 -0.4% 至 34.3%。最大的质量损失是由四个迈锡纳分离株引起的（口蘑科）。Lachnocladiaceae 的分离株导致顽固化合物的质量损失更大，登记为酸不可水解残留物 (AUR)，其中包括相对于木香科的木质素。Rhytismataceae、Lachnocladiaceae、Marasmiaceae 和 Omphalotaceae 的分离株表现出 AUR 的选择性分解，Mycena表现出 AUR 和 AUR 以外的成分的同时分解，木香科表现出 AUR 以外的成分的选择性分解。对于C. sieboldii和S. wallichii 而言，由每种真菌分离物引起的叶子和 AUR 的质量损失相似。从C. sieboldii获得的迈锡尼分离物 导致叶子和 AUR 的质量损失比从其他树种获得的损失更大，表明分解潜力的“主场优势”，对此处评估的体外系统之外的自然相互作用产生影响。