关键词: 森林生态系统, 木腐真菌, 群落结构, 形成机理, 生态功能

Abstract: Deadwood is an important component of forests that provides habitat and contributes to nutrient cycles as well as carbon and water storage. Given the importance of deadwood decomposition in nutrient cycling, soil formation, and ecosystem carbon budget, it is received increasing attention from ecologists, pathologists and forest managers. Wooddecaying fungal communities play a crucial role in driving ecosystem material cycling by producing various degrading enzymes. The composition of wooddecaying fungal community is affected by many factors, including environmental factors (precipitation, latitude, light, temperature, and humidity) and the characters of host deadwood (chemical composition, physical structure, diameter, volume, and decay degree). They drive the distribution and growth of fungal species and consequently fungal community composition. The fungi could manipulate microbial community in their surroundings. The species forming large networks of mycelial cords can manipulate the bacterial community more effectually. Bacteria have an indirect effect on decomposition rates by consuming the breakdown products of fungal enzymatic activity, thus influencing the dynamics of fungal community. As two main groups of deadwood decomposition, wood-decaying fungi and saprophytic invertebrates interact with each other, showing both inhibitory and facilitative effects. Some soil fungi can colonize deadwood through hyphae growth. The biggest disturbance to the composition of wooddecaying fungi community comes from the deforestation and utilization of forests. The removal of fallen wood directly leads to the loss of the growth substance, which makes many species being endangered and the fungal community composition being simple and the function being relatively simplified. During deadwood decomposition, whiterot fungi degrade lignin by producing peroxidase and laccase, while brown-rot fungi can degrade hemicellulose and cellulose effectively. The activity and type of degrading enzymes affect wood decay rate and nutrient content. Fungal hyphae have an important role in nutrient absorption and transfer. The functional traits of wooddecaying fungi can reflect the adaptation of species to environmental conditions and help to understand the mechanisms underlying the aggregation of fungal communities in different environment. Since wood-decaying fungi have multiple functions in forests, it is necessary to understand the formation of wood-decaying fungal community and its role in decomposition, which provides insights into nutrient cycling and biodiversity conservation.

Key words: forest ecosystem, wood-decaying fungi, community structure, forming mechanism, ecological function.