关键词: Poisson回归模型, 红松林, 一级枝条分布, 二级枝条分布, 负二项回归模型

Abstract: Wood-decaying fungi are an important group in the forest ecosystem. They can improve the material cycling by decomposing cellulose, semi-cellulose and lignin of wood into nutrition that can be absorbed easily by themselves and other organisms. An investigation about the distribution characters of wood-decaying fungi was carried in three forest types in the Fenglin Nature Reserve. Nine hundred and sixty-six specimens were collected and identified to 122 species, belonging to 49 genera, 17 families and 7 orders. The majority of the polypores in Fenglin are north temperate element and cosmopolitan element, showing a distinct north temperate character. By comparing the fungal community composition of the three forest types, we found that the number of brown rotting fungi in the broad leaved-Korean pine mixed forest was greater than that of the poplarbirch forest and fir forest, accounting for 29.9% of the whole individuals. The white rotting fungi were the major group in the other two forests with 93.6% and 90.6% of the whole individuals, respectively. The fungal biodiversity in the broad leavedKorean pine mixed forest was the highest, with Shannon diversity index 4.60, Simpson index 0.99 and Pielou evenness index 0.99. Most of the wood-decaying fungi of Fenglin Nature Reserve preferred growing on the fallen wood with decaying degrees 2 and 3. Forest type, decaying degree and diameters of host wood were the main reasons affecting fungal community. Even growing on the same species of host, the fungal species were different in the different forest types.

Key words: first-order branch distribution, Pinus koraiensis, Poisson regression model, negative binomial regression model., second-order branch distribution