丰林国家级自然保护区木腐真菌多样性与寄主倒木的关系

木腐真菌是一类以木材为生长基质的大型真菌, 通过分泌各种水解酶全部或部分降解木材中的木质素、纤维素和半纤维素, 促进森林生态系统的物质循环, 具有重要的生态功能。本研究调查了丰林国家级自然保护区固定样地中木腐真菌的多样性和倒木特征, 并进行了木腐真菌的物种多样性和数量与倒木的种类、数量、腐朽程度、直径大小等的相关性分析。结果显示: 在样地内共采集木腐真菌标本295份, 经鉴定为93种, Shannon多样性指数为3.86, Simpson指数为0.96。相关性分析发现木腐真菌的数量和种类与直径为2-5 cm和5-10 cm的倒木、2级腐烂的倒木和红松倒木均显著相关。样地中优势倒木寄主分别为槭属(Acer)、榛属(Corylus)、云杉属(Picea)和松属(Pinus), 这4类倒木上生长的木腐真菌种类组成具有明显的差异, 槭属和榛属倒木上的共有优势种主要是三色拟迷孔菌(Daedaleopsis tricolor)、云芝(Trametes versicolor)和桦附毛孔菌(Trichaptum pargamenum), 而松属和云杉属的共有优势种主要有白囊耙齿菌(Irpex lacteus)、云芝、冷杉附毛孔菌(Trichaptum abietinum)和褐紫附毛孔菌(T. fuscoviolaceum)。倒木产生真菌子实体的概率研究表明, 同一类寄主倒木上发生木腐真菌子实体的概率在调查面积增加到0.36 ha后趋于一个定值, 松属倒木中仅有10.2%产生真菌子实体, 槭属和云杉属分别是12.9%和13.4%, 榛属最高, 达到53.7%。本研究结果对于预测森林生态系统中木腐真菌的发生具有重要理论意义。     

大小兴安岭针叶树倒木上木腐真菌的物种多样性

木腐真菌在森林生态系统中具有丰富的物种多样性, 并在倒木的降解过程中发挥重要的生态功能。针叶树是大小兴安岭森林生态系统的优势树种, 因此研究针叶树倒木木腐真菌物种多样性和影响其物种分布的相关环境因子有助于揭示大小兴安岭森林生态系统物质循环的机理。本研究收集了近16年对大小兴安岭地区冷杉属(Abies)、落叶松属(Larix)、云杉属(Picea)和松属(Pinus) 4类针叶树倒木上1,561份木腐真菌标本的采集信息, 统计了物种种类及其腐朽类型, 并选取具有代表性的地点开展木腐真菌群落多样性及其与环境因子的相关性分析。结果显示, 大小兴安岭针叶树倒木木腐真菌有166种, 隶属于70属, 其中白腐真菌有111种, 占所有种类的66.9%, 褐腐真菌为55种, 占所有种类的33.1%。在4类针叶树倒木上均能生长的真菌种类有19种, 占所有种类的11.5%, 其中柔丝干酪孔菌(Oligoporus sericeomollis)是各类倒木上木腐真菌群落中的优势种。大兴安岭地区落叶松属为优势寄主, 其倒木上生长的木腐真菌种类数和个体数在4类倒木中均为最高; 而小兴安岭地区松属倒木上木腐真菌种类数和个体数比其他3类倒木高, 是该地区的优势寄主。对6个代表性地区木腐真菌群落的研究显示, 有11种真菌在6个地区均有分布, 小兴安岭地区木腐真菌多样性普遍高于大兴安岭地区; 聚类分析显示树种比地理位置对木腐真菌物种分布的影响更大。     

长白山阔叶红松林优势树种的木腐真菌群落结构特征

木腐真菌是森林生态系统中非常重要的组成部分,能够降解倒木,实现生态系统中的物质循环。长白山阔叶红松林林分结构复杂,林内植物种类多样,倒木数量极多,为木腐真菌的生长提供了丰富的基质。为了解该林分中不同树种对木腐真菌的影响,本研究选取了长白山自然保护区25 hm2永久性大样地中325块20 m×20 m的样方,对样方中的木腐真菌进行了调查和记录,并对其中4类优势树种槭属、椴属、栎属和松属倒木上的降解真菌分别进行了统计和分析,结果发现:阔叶红松林中这4种优势寄主上的木腐真菌占所调查真菌总数的86.6%,物种数占总数95.3%,囊括了该林分中木腐真菌的绝大多数。但不同树种上的真菌种类有很大差别,4种树种上木腐真菌的种类韦恩图显示,这4类优势树种共有种类仅为7种,而各自独特种至少占本类树种倒木上真菌种类的25%,尤其松属上的独特种类数占松属真菌总数的45.7%。倒木的腐烂程度和径级对木腐真菌也有着极为重要的影响。不论哪个树种,腐烂程度为2级的倒木均生长有种类最多、数量最大的真菌;而径级大于10 cm的倒木也是木腐真菌的优先选择。     

辽东次生林木腐菌的物种多样性及其分布特征

2013年7—9月,以清原林场、老秃顶子国家级自然保护区和宽甸白石砬子自然保护区为研究区域,对辽东次生林中木腐菌的物种多样性及其分布特征进行了研究.经过野外调查,共采集和记录木腐菌1062份,经鉴定为92种,隶属于48个属;其中白石砬子国家级自然保护区木腐真菌物种最丰富,Shannon多样性指数为4.04.从物种的地理成分来看,辽东地区的木腐菌以世界性广布和北温带分布为主,具有明显的北温带特征.白腐真菌是该地区倒木的主要分解者;该地区的木腐菌主要生长在腐烂等级为2、3的倒木上,主要优势寄主为槭属倒木,有243份真菌采集于槭属倒木,占总数的23.2%.     

北京东灵山木腐菌主要种类的区系组成及分布特征

于2013年9月中旬和2014年9月下旬,对北京东灵山自然保护区的木材腐朽真菌进行调查和分析。结果表明:在15种树属上共采集1007份标本,经鉴定为128种,隶属于11目24科;其中优势科为多孔菌科、锈革孔菌科和皱皮菌科,分别占该地总种数的27.34%、17.96%和12.5%;优势种为14种,个体数量占全部数量的48.76%,而且绝大部分为白腐菌;通过绘制稀疏曲线,发现在倒木腐烂阶段的中后期,寄主直径为0~5 cm和10 cm,寄主树种为栎属和杨属,基质树皮存在状态下木腐菌数量和物种多样性较高;生长个体数量少的基质含有较多的木腐菌物种;发挥主要降解作用的功能类群中,后续降解者的数量最多,先锋物种和终极分解者数量较少;该地褐腐菌比例较低与缺少针叶树种有关;为了提高该地木腐菌的多样性,可以从保护基质多元化着手。     

色季拉山不同腐解等级华山松倒木上的苔藓植物组合

倒木是森林生态系统维持健康和更新的重要组成部分, 在倒木不同腐解阶段, 倒木上定植的苔藓植物组合的差异尚不清楚。为深入探讨倒木上苔藓植物组合变化规律及其影响因素, 该文对西藏色季拉山同一地点不同腐解程度的4株华山松(Pinus armandii)倒木上的苔藓植物进行了样方调查和数据分析。结果表明: 4株倒木上40个样方共有苔藓植物22科52种, 其中藓类13科38种, 苔类9科14种; 以恒有优势种为特征进行划分, 共得到14个物种组合。随着倒木腐解程度加大以及周围环境的不断改变, 生长其上的苔藓植物物种多样性逐渐增加, 但组合数量和苔藓总盖度却呈现先增大后减小的趋势。苔藓物种由耐旱性强的丛生型藓类, 如木灵藓科、白发藓科, 逐渐演替为喜阴湿环境、快速生长的垫状或毯状藓类, 如提灯藓科、羽藓科和青藓科。倒木苔藓植物组合空间结构复杂程度逐渐增大。倒木是多种苔藓植物选择的重要生长基质, 其上苔藓植物受倒木的腐解程度、水分和光照等条件的影响而发生相应的物种组合变化。     

Bryophyte societies on the fallen logs of Pinus armandii with different decay classes in Sygera Mountains

倒木是森林生态系统维持健康和更新的重要组成部分, 在倒木不同腐解阶段, 倒木上定植的苔藓植物组合的差异尚不清楚。为深入探讨倒木上苔藓植物组合变化规律及其影响因素, 该文对西藏色季拉山同一地点不同腐解程度的4株华山松(Pinus armandii)倒木上的苔藓植物进行了样方调查和数据分析。结果表明: 4株倒木上40个样方共有苔藓植物22科52种, 其中藓类13科38种, 苔类9科14种; 以恒有优势种为特征进行划分, 共得到14个物种组合。随着倒木腐解程度加大以及周围环境的不断改变, 生长其上的苔藓植物物种多样性逐渐增加, 但组合数量和苔藓总盖度却呈现先增大后减小的趋势。苔藓物种由耐旱性强的丛生型藓类, 如木灵藓科、白发藓科, 逐渐演替为喜阴湿环境、快速生长的垫状或毯状藓类, 如提灯藓科、羽藓科和青藓科。倒木苔藓植物组合空间结构复杂程度逐渐增大。倒木是多种苔藓植物选择的重要生长基质, 其上苔藓植物受倒木的腐解程度、水分和光照等条件的影响而发生相应的物种组合变化。     

中国主要天然落叶松林的多孔菌多样性

落叶松是我国北方重要的针叶树种,天然落叶松倒木上生长有种类繁多的多孔菌,它们能够分解倒木中的纤维素、半纤维素和木质素,促进森林生态系统的物质循环,同时维持生态系统中的碳平衡,在森林生态系统中发挥重要的生态功能.本文针对我国5种主要落叶松树种上的多孔菌种类,综合分析了该类群的物种组成和分布特征,并对不同树种上的多孔菌种群进行对比分析.结果表明： 落叶松上共有多孔菌107种,分属11科43属,其中褐腐真菌种类49种,占到总数的45.4%,是中国已报道褐腐真菌种类的50%.91.7%的多孔菌生长在刚开始腐烂的倒木上.兴安落叶松上的多孔菌不论是种类还是数量均比其他4种落叶松多.兴安落叶松和长白落叶松以及新疆落叶松和西藏落叶松上的多孔菌种群相似度高,这与其林分的天然分布相一致.     

丽江老君山国家公园木腐真菌区系组成与分布特征

木腐真菌是自然界中以木材为主要生长基质的一类大型真菌,通过分解倒死木的木质素、纤维素和半纤维素实现森林生态系统的物质循环,是森林生态系统的重要组成部分。研究木腐真菌的生态分布及其与环境因子的关系对分析其在森林生态系统中的生态功能有重要作用。本文在野外调查的基础上对云南省丽江老君山国家公园的木腐真菌物种组成和生态习性进行了分析,共采集标本196份,经鉴定为68种,隶属于8目21科40属,优势科为多孔菌科、拟层孔菌科和锈革孔菌科,优势属为异担子菌属,其区系组成以北温带成分为最多(38.2%),其次是世界广布成分,表现出明显的北温带特征。从生态习性来看,63种为腐生菌,其中51种造成白色腐朽,12种造成褐色腐朽;5种为外生菌根菌。木腐真菌的物种组成在不同林分中存在明显差异,落叶阔叶林中种类最多,共34种;其次为针阔混交林,有26种;暗针叶林有22种。脆波斯特孔菌与粗毛韧革菌在3种林分类型中均有分布且多度较高,是该地区的优势种。     

丰林自然保护区木材腐朽真菌发生规律及其物种多样性

木材腐朽真菌是森林生态系统中的一个重要类群,通过将木材中的纤维素、半纤维素和木质素分解成为可被自身和其他生物利用的营养物质,能够促进森林生态系统中的物质循环。通过对丰林自然保护区3个不同林分内木材腐朽真菌的分布特征开展野外调查,共得到标本966份,经鉴定为122种,隶属于7目17科49属,多孔菌科为该地区优势科。物种区系地理成分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区系特征。通过比较3个林分内木材腐朽真菌群落组成结构,发现阔叶红松混交林内褐腐菌数量较多,占总体的29.9%,杨桦林和云冷杉林内木材腐朽真菌主要为白腐菌,分别占总体的93.6%和90.6%。阔叶红松混交林中木材腐朽真菌物种多样性指数最高,Shannon指数4.60,Simpson指数0.99,Pielou均匀度指数0.99。该保护区中木材腐朽真菌多数生长在腐朽等级为2、3级的倒木上。通过比较3个林分内主要树种上木材腐朽真菌的分布特点,发现林分类型、寄主腐烂程度和直径大小是影响该地区木材腐朽真菌分布的主要因素,同样的树种在不同林分中所生长的木材腐朽真菌种类不同。     

Increased CO<Subscript>2</Subscript> evolution caused by heat treatment in wood-decaying fungi

Wood-decaying fungi are regarded as the main decomposers of woody debris in boreal forests. Given that fungal respiration makes a significant contribution to terrestrial carbon flows, it is important to understand how the wood-decaying fungal metabolism is regulated in relation to different environmental conditions and disturbances. In the present study, we investigated the effect of temperature stress on wood decomposition rate in 18 species of wood-decaying fungi, representing a broad range of species–habitat associations. Heat shock duration and temperature were calibrated to match the conditions of a forest fire. We found a general increase in fungal decay rate after heat shock; the response was more pronounced in species associated with fire-prone forests. The underlying mechanism is unclear, but possibly relates to an up-regulation at the cellular level in response to heat shock. Our results show that the decomposition rate of dead wood can be strongly affected by environmental triggers.     

Saproxylic moths reveal complex within-group and group-environment patterns

We investigated saproxylic moths of the family Tineidae, a neglected group inhabiting wood-decaying fungi and dead wood, within the Bia?owie?a Primeval Forest in Poland. Study data were obtained from the collection of 280 fruiting bodies of wood-decaying fungi and the subsequent rearing of adults. Spatial and statistical distribution of saproxylic moths, relationship among species and the influence of environment reflected by interaction with tree and fungal species together with tree and stand level characteristics were studied. Fifteen species and 533 individuals of saproxylic moths were reared. The fungal species, number of fruiting bodies and standing position of a tree influenced species richness. Moth abundance was influenced by fungal species, coniferous trees, increasing tree diameter, number of fruiting bodies and brown rot. Moth abundance was also enhanced by standing dead trees located in managed forests with higher canopy closure. Analyses indicate that several moth species favor a particular rot type and that some fungi host a richer fauna than others. Furthermore, our results indicate mutually independent fungal colonization events by saproxylic moth species, and thus a possible mechanism exists for competition avoidance with other saproxylic moths. Saproxylic moths revealed complex within-group patterns that responded differently to environmental variables. Thus, potential conservation of these organisms requires various approaches including ecosystem management, especially in the context of addressing their diverse habitat requirements.     

Fungal wood decomposer activities influence community structures of myxomycetes and bryophytes on coarse woody debris

Dead wood is an important habitat for forest organisms, and wood decay fungi are the principal agents determining the dead wood properties that influence the communities of organisms inhabiting dead wood. In this study, we investigated the effects of wood decomposer fungi on the communities of myxomycetes and bryophytes inhabiting decayed logs. On 196 pine logs, 72 species of fungi, 34 species and seven varieties of myxomycetes, and 16 species of bryophytes were identified. Although white rot was the dominant decay type in sapwood and heartwood, brown and soft rots were also prevalent, particularly in sapwood. Moreover, white rot and soft rot were positively and brown rot negatively correlated with wood pH. Ordination analyses clearly showed a succession of cryptogam species during log decomposition and showed significant correlations of communities with the pH, water content, and decay type of wood. These analyses indicate that fungal wood decomposer activities strongly influence the cryptogam communities on dead wood.     

Detection and Identification of Decay Fungi in Spruce Wood by Restriction Fragment Length Polymorphism Analysis of Amplified Genes Encoding rRNA

We have developed a DNA-based assay to reliably detect brown rot and white rot fungi in wood at different stages of decay. DNA, isolated by a series of CTAB (cetyltrimethylammonium bromide) and organic extractions, was amplified by the PCR using published universal primers and basidiomycete-specific primers derived from ribosomal DNA sequences. We surveyed 14 species of wood-decaying basidiomycetes (brown-rot and white-rot fungi), as well as 25 species of wood-inhabiting ascomycetes (pathogens, endophytes, and saprophytes). DNA was isolated from pure cultures of these fungi and also from spruce wood blocks colonized by individual isolates of wood decay basidiomycetes or wood-inhabiting ascomycetes. The primer pair ITS1-F (specific for higher fungi) and ITS4 (universal primer) amplified the internal transcribed spacer region from both ascomycetes and basidiomycetes from both pure culture and wood, as expected. The primer pair ITS1-F (specific for higher fungi) and ITS4-B (specific for basidiomycetes) was shown to reliably detect the presence of wood decay basidiomycetes in both pure culture and wood; ascomycetes were not detected by this primer pair. We detected the presence of decay fungi in wood by PCR before measurable weight loss had occurred to the wood. Basidiomycetes were identified to the species level by restriction fragment length polymorphisms of the internal transcribed spacer region.     

Detection and identification of decay fungi in spruce wood by restriction fragment length polymorphism analysis of amplified genes encoding rRNA

We have developed a DNA-based assay to reliably detect brown rot and white rot fungi in wood at different stages of decay. DNA, isolated by a series of CTAB (cetyltrimethylammonium bromide) and organic extractions, was amplified by the PCR using published universal primers and basidiomycete-specific primers derived from ribosomal DNA sequences. We surveyed 14 species of wood-decaying basidiomycetes (brown-rot and white-rot fungi), as well as 25 species of wood-inhabiting ascomycetes (pathogens, endophytes, and saprophytes). DNA was isolated from pure cultures of these fungi and also from spruce wood blocks colonized by individual isolates of wood decay basidiomycetes or wood-inhabiting ascomycetes. The primer pair ITS1-F (specific for higher fungi) and ITS4 (universal primer) amplified the internal transcribed spacer region from both ascomycetes and basidiomycetes from both pure culture and wood, as expected. The primer pair ITS1-F (specific for higher fungi) and ITS4-B (specific for basidiomycetes) was shown to reliably detect the presence of wood decay basidiomycetes in both pure culture and wood; ascomycetes were not detected by this primer pair. We detected the presence of decay fungi in wood by PCR before measurable weight loss had occurred to the wood. Basidiomycetes were identified to the species level by restriction fragment length polymorphisms of the internal transcribed spacer region.     

森林生态系统中木腐真菌群落形成机理及生态功能

在森林生态系统中,枯死木是一个重要的组成部分,为很多生物提供栖息地,有助于养分循环以及碳和水的储存.木材分解是森林生态系统养分循环、土壤形成和碳收支的决定性过程,越来越受到森林生态学家、病理学家和管理者的重视.在此过程中,木腐真菌通过分泌多种酶降解木材主要成分,实现生态系统中的物质循环,具有极为关键和重要的作用.木腐真...     

Wood-decay type and fungal guild dominance across a North American log transplant experiment

We incubated 196 large-diameter aspen (Populus tremuloides), birch (Betula papyrifera), and pine (Pinus taeda) logs on the FACE Wood Decomposition Experiment encompassing eight climatically-distinct forest sites in the United States. We sampled dead wood from these large-diameter logs after 2 to 6 y of decomposition and determined wood rot type as a continuous variable using the lignin loss/density loss ratio (L/D) and assessed wood-rotting fungal guilds using high-throughput amplicon sequencing (HTAS) of the ITS-2 marker. We found L/D values in line with a white rot dominance in all three tree species, with pine having lower L/D values than aspen and birch. Based on HTAS data, white rot fungi were the most abundant and diverse wood-rotting fungal guild, and soft rot fungi were more abundant and diverse than brown rot fungi in logs with low L/D values. For aspen and birch logs, decay type was related to the wood density at sampling. For the pine logs, decay type was associated with the balance between white and brown/soft rot fungi abundance and OTU richness. Our results demonstrate that decay type is governed by biotic and abiotic factors, which vary by tree species.     

Survey of subterranean termites (Isoptera: Rhinotermitidae) in a managed silvicultural plantation in Portugal, using a line-intersection method (LIS)

Subterranean termites (Reticulitermes grassei) were surveyed over successive seasons in a managed eucalyptus plantation in southeastern Portugal for 26 months. Termite activity in seven diameter categories of lying dead wood was investigated by a modified line intersection method (LIS). Each item sampled was inspected and assessed for termite attack and for general (i.e. fungal) decay status using standard protocols. Line intersection is quantitative to the extent that it can link foraging and decay parameters to woody biovolume. It was found that termites selected items with larger diameter, the observed trend showing an exponential character with greater termite attack as diameter increased. Attack by termites was positively associated with prior decay by fungi. A clear positive relationship was shown between rainfall and total woody biovolume containing live termites, underlining the importance of moisture for termite activity. Subterranean termites appeared to be important wood decomposers in the woodland studied, with an average of 30% of lying dead wood branches showing signs of termite attack.