古田山国家级自然保护区木腐真菌物种多样性及分布

Species diversity and distribution of wood-decaying fungi in Gutianshan National Nature Reserve

木腐真菌是微生物的一个重要类群,主要以倒木为生长基质,通过产生各种水解酶将倒木的纤维素、木质素和半纤维素分解为小分子物质,对促进森林生态系统中的营养物质循环发挥着重要的生态功能。于2016年8月在浙江古田山国家级自然保护区开展的木腐真菌野外调查,利用形态学和DNA序列分析对采集的标本进行了物种鉴定,并分析了木腐真菌的物种组成和地理成分。在采集的158份标本中鉴定木腐真菌45属92种,其中白腐真菌78种,褐腐真菌14种。古田山的木腐真菌物种区系组成中,热带–亚热带成分比例最高。在158份木腐真菌标本中, 97份标本采自直径大于10cm的倒木或树桩上,分属于76个种,是木腐真菌生长的主要基质大小类型;48份标本采自直径为2–10 cm的枝干上,分属38个种; 13份标本采自直径小于2 cm的枝干上,分属12种。不同腐烂等级倒木上生长的真菌数量和种类差异明显,其中一级腐烂倒木上采集到9份标本(7种),二级腐烂倒木上采集到86份标本(45种),三级腐烂倒木上49份标本(29种),四级腐烂倒木上14份标本(14种)。结果表明,林分中倒木直径大小和腐烂程度是影响木腐真菌生长与分布的重要因子。

Wood-decaying fungi decompose the cellulose,hemicellulose and lignin of wood by producing various hydrolytic enzymes,and therefore play a key ecological role in the nutrient cycle of forest ecosystems.In August 2016,a survey of wood-decaying fungi was carried out in Gutianshan National Nature Reserve,Zhejiang Province.Fungal species were identified using morphological characters and DNA sequence analysis.Both the species composition and biogeography were also analyzed.A total of 92 fungal species,78 white rot species and 14 brown rot species,representing 45 genera were identified from the 158 samples collected.Among these fungi,tropically-contained families are better represented than cosmopolitan families.Of the 158 specimens,97(76 species)were collected from woody substrates with a diameter larger than 10 cm,48(38 species)from a dead branch with a diameter ranging from 2 cm to 10 cm,and 13(12 species)from a dead twig with a diameter smaller than 2 cm.The abundance of fungal species differed conspicuously in different decaying classes of dead wood as well.Of 92 fungal species,seven species(nine specimens)were collected from woody substrate of decay class 1,45 species(86 specimens)from wood of decay class 2,29 species(49 specimens)from wood of decay class 3,and 14 species(14 specimens)from wood of decay class 4.This study indicates that the diameter and decay class of dead wood are important factors influencing the growth and species distribution of wood-decaying fungi.