Intercollege Graduate Program in Ecology, 103 Tyson Building, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Ecology. 2012 Jan;93(1):24-8. doi: 10.1890/11-1346.1.
Ectomycorrhizal fungal tissues comprise a significant forest-litter pool. Ectomycorrhizal (EM) fungi may also influence the decomposition of other forest-litter components via competitive interactions with decomposer fungi and by ensheathing fine roots. Because of these direct and indirect effects of ectomycorrhizal fungi, the factors that control the decomposition of EM fungi will strongly control forest-litter decomposition as a whole and, thus, ecosystem nutrient and carbon cycling. Some have suggested that chitin, a component of fungal cell walls, reduces fungal tissue decomposition because it is relatively recalcitrant. We therefore examined the change in chitin concentrations of EM fungal tissues during decomposition. Our results show that chitin is not recalcitrant relative to other compounds in fungal tissues and that its concentration is positively related to the decomposition of fungal tissues. Variation existing among EM fungal isolates in chitin concentration suggests that EM fungal community structure influences C and nutrient cycling.
外生菌根真菌组织构成了显著的森林凋落物库。外生菌根（EM）真菌还可能通过与分解真菌的竞争相互作用以及包裹细根来影响其他森林凋落物成分的分解。由于外生菌根真菌的这些直接和间接影响，控制外生菌根真菌分解的因素将强烈控制整个森林凋落物分解，从而控制生态系统养分和碳循环。有人认为真菌细胞壁的成分几丁质由于相对难以降解而降低了真菌组织的分解。因此，我们研究了外生菌根真菌组织在分解过程中几丁质浓度的变化。研究结果表明，与真菌组织中的其他化合物相比，几丁质并不具有抗降解性，其浓度与真菌组织的分解呈正相关。外生菌根真菌分离物中几丁质浓度的差异表明，外生菌根真菌群落结构影响碳和养分循环。
