大兴安岭林区多孔菌的区系组成与种群结构

Fungal flora and population structure of polypores in the Great Xingan Mountains

在过去10 a野外调查和室内鉴定及分析研究的基础上,对大兴安岭林区多孔菌的区系组成和种群结构进行了分析,发现大兴安岭林区的多孔菌具有较高的多样性,共有5目11科56属129种,占中国多孔菌区系的21.36%,优势科是多孔菌科。种的区系地理成分分为7类,以北温带成分和世界广布成分为主,具有明显的北温带成分的区系特征。大兴安岭的多孔菌常见种较多,种群结构中共生菌3种,寄生菌27种,腐生菌占大多数,有99种。在能够引起木材腐朽的126种真菌中,白腐菌93种,占多数,褐腐菌33种,占少数,但该地区褐腐菌所占比例明显高于全国范围内褐腐菌在多孔菌中的比例。通过对大兴安岭主要树种上的种群结构进行比较,表明阔叶树上的木材腐朽菌绝大部分是白色腐朽菌,而针叶树上的白腐菌与褐腐菌数量相差不大,褐腐菌对于针叶林特别是落叶松的更新具有非常重要的作用。

Polypores are important components of forest biodiversity;most of them are wood-decaying fungi and are critical for the decomposition of coarse woody materials,playing key roles in nutrient cycling and energy flows.The poroid wood-inhabiting fungi of the Great Xingan Mountains,China,have been little studied.Difficulties include species identification and lack of relevant information.Our analyses of polypore diversity and population structure in the Great Xingan Mountains are based on 10 years of field investigation and laboratory analyses.Species diversity in this area is rather high,accounting for 21.36 % of all Chinese polypore species,and including 129 species belonging to five orders,11 families and 56 genera of Basidiomycota.The dominant family is the Polyporaceae,including 21 genera and 58 species,and another major family is the Fomitopsidaceae,which including 11 genera and 24 species.The majority of polypores in the Great Xingan Mountains are in these two families.The dominant genera are Postia,Polyporus,Trametes and Phellinus,and nine,nine,eight and seven species were respectively found in these genera.Biogeographically,these polypores can be divided into three groups at family level： cosmopolitan（Hydnodontaceae,Hymenochaetaceae,Meripilaceae,Meruliaceae,Phanerochaetaceae,Polyporaceae and Schizoporaceae）,north temperate（Albatrellaceae,Fomitopsidaceae and Gloeophyllaceae）,pantropical（Ganodermataceae）;three groups at genus level： cosmopolitan（33 genera）,north temperate（21 genera）,pantropical（2 genera）;seven groups at species level： north temperate（52.71 %）,cosmopolitan（34.88 %）,Asian-European（4.65 %）,East Asian（3.1 %）,East Asian-North American（2.33 %）,pantropical（1.55 %）,and endemic（0.78 %）.The dominant element is clearly north temperate but with a strong cosmopolitan influence.According to the occurring frequency in the studied forest,these polypores can be divided into four groups： common species（65）,occasional species（34）,rare species（24） and threatened species（6）,and the common species are dominant.Ecologically these polypores can be divided into three types： saprophytic（99 species）,parasitic（27 species）,and symbiotic（3 species）;saprophytes are clearly dominant.Among the 126 wood-rotting species,93 species cause white rot,and 33 species cause brown rot.The percentage of brown rot fungi was found to be significantly higher in Great Xingan Mountains than in other part of China.The main trees in the Great Xingan Mountains are in genera of Betula,Larix,Populus and Quercus.Population structure was compared on the main angiosperms and gymnosperms,60 species were found on Larix,among these polypores,and 30 of them cause brown rot and the other 30 species cause white rot;46 species grow on Betula,and 8 species cause brown rot and 38 species cause white rot;24 species occur on Populus,and 2 species cause brown rot,while 22 species cause white rot;19 species live on Quercus,among them 3 species cause brown rot and 16 species cause white rot.White rot fungi were mostly found on angiosperm wood,while white and brown rot fungi were found with equal frequency on gymnosperm wood.It seems that the brown rot polypores are very important for the regeneration of larch forest.Most polypores grow on fallen trunks or rotten woods in natural forest,the species diversity of polypores in forest plantation is very low,according to the ecological habits of polypores,the reserve of fallen trunks or rotten woods in forest is very important to preserve the polypores.