树附生苔藓植物多样性及其影响因素

树附生苔藓植物是一类附生在树木上的苔藓植物,是森林生态系统的重要组成部分,在维持生物多样性和生态系统功能等方面发挥着重要的作用。由于树附生苔藓植物结构简单,对环境变化尤为敏感,常在大气污染、气候变化、森林干扰等方面作为指示生物。随着全球变化的加剧,其多样性势必会受到影响。因此,研究树附生苔藓植物多样性分布及其对不同环境因子的响应,对于全球变化背景下树附生苔藓植物的保护和利用具有重要的指导性意义。首先对树附生苔藓植物多样性和空间分布现状进行阐述,然后从附主树木特征、森林群落特征和全球变化等3个方面探讨树附生苔藓植物多样性与影响因素之间的关系,以期从"个体-群落-全球"不同尺度进行分析,为树附生苔藓植物的保护和利用等研究提供借鉴和参考。     

影响广东黑石顶树附生苔藓分布的环境因子

通过对广东省黑石顶自然保护区内5个2500 m2样地内树附生苔藓的调查及有关环境因子的测定,研究了树附生苔藓的分布格局及其与环境因子的关系.树附生苔藓在不同高度的分布存在一定梯度,20 cm高处树附生苔藓的种类数与盖度均大于60 cm及更高处,且其群落优势种的数量组成与后者存在较大差异.不同树种附生苔藓盖度和种数差异较大.基于附生苔藓植物的盖度进行DCA排序及聚类分析将树种分成四组,马尾松(Pinus massoniana)因具有两种特有的网藓(巴西网藓Syrrhopodon prolifer和鞘刺网藓S.armatus)单独一组,福建青冈(Quercus chungii)亦与其余各种的差异均较大,形成一组,其余阔叶树种根据其所处的森林类型分成两组,针阔叶混交林内的阔叶树种和次生阔叶林内的阔叶树种各形成一组.对环境因子及树皮含水量和pH的分析显示,垂直梯度上空气湿度的差异可能是造成附生苔藓在不同高度分布差异的主要影响因子之一,不同树种附生苔藓的差异在一定程度上受树皮pH的影响,而与树皮含水量无关.同一树种上树附生苔藓的分布又在一定程度上受森林类型的影响.     

Epiphytic lichens and bryophytes of forest ecosystems in Tuscany (Central Italy)

The distribution of epiphytic bryophytes and lichens on three species of trees (Quercus ilex, Quercus cerris and Fagus sylvatica, representing the forest ecosystems of central Italy at low, medium and high elevations, respectively) was examined with respect to host specificity and habitat differences. Although most species were host-specific, the results suggested that habitat characteristics are more important than phorophyte properties in determining the distribution of lichens and bryophytes. Factors affecting the diversity of the epiphytic flora were different for lichens and bryophytes. In the case of lichens, climatic parameters and forest monospecificity were important factors, whereas tree cover (i.e. shade) and to a certain extent the number of available trees seemed more important for bryophytes.     

Trends in diversity and abundance of obligate epiphytic bryophytes in a highly managed landscape

Although forest stands represent 47% of the total land area in Europe, alterations to the forest habitat through logging and plantation of exotic trees has led to significant changes in forest biocenoses. Due to their peculiar biology and life history, epiphytic bryophytes, which include a number of species of high conservation value, are especially concerned. Ordinal logit regression was used to test whether trends in diversity and abundance of obligate epiphytic bryophytes are explained by forest cover and spruce plantation and determine specific optima and degree of reliance to these factors at the landscape scale. Spruce plantations had a negative impact on both species diversity and abundance. Although large forest patches were important for a set of species exclusively or more frequently occurring under the forest cover, the abundance of a number of species previously identified as woodland bryophytes decreased or was uncorrelated with increasing forest cover. Furthermore, the species pool adapted to edge-related abiotic conditions was important. The global epiphytic diversity did consequently not decrease with decreasing forest cover at the landscape scale. If large forest patches are important for the conservation of a set of species exclusively or more frequently occurring under the forest cover, the conservation of epiphytic bryophytes thus also involves the conservation of pioneer trees in open landscapes. A series of management measures, which may help maximize the species diversity and probability of occurrence of key-species of high conservation interest, are proposed.     

长白山地区森林生态系统树附生苔藓植物群落分布格局研究

 以苔藓植物盖度为指标,应用双向指示种分析(TWINSPAN)和除趋势对应分析(DCA)对长白山地区不同森林类型36个样地的树附生苔藓植物群落分布格局进行了研究。结果表明,长白山地区树附生苔藓植物的分布格局与森林植被类型相对应,可分成落叶松林、岳桦林、暗针叶林、暗针叶林与红松阔叶林间过渡林、红松阔叶林、白桦林6类树附生苔藓植物群落类型,文章分析了影响树附生苔藓植物群落生态分布的环境因素。     

长白山森林生态系统树附生苔藓植物分布与环境关系研究

应用除趋势典范对应分析（ＤＣＣＡ）、除趋势对应分析（ＤＣＡ）对长白山不同森林类型３６仆样点的树生苔藓植物与环境关系的研究表明,海拔高度、树干离地面的高度、附生树的种类是影响附生苔藓植物分布最重要的环境因子,树干倾斜度与倾斜方向也影响到苔藓在树干不同方向上的分布。     

武汉市城区苔藓植物多样性和分布及与环境因子的关系

对武汉市7个中心城区和部分远郊城区共26个样点73个样地的苔藓群落进行调查,采集苔藓植物样本共431份。经鉴定调查区内共有苔藓植物20科35属91种,其中狭叶小羽藓（Haplocladium angustifolium（Hampe et C.Muell.）Broth.）和钝叶绢藓（Entodon obtusatus Broth.）等为优势种,分布于其中的24个样点。多样性指数分析结果显示,位于青龙山国家森林公园的α多样性Patrick和Shannon-Wiener指数最高,说明该样点苔藓植物群落的复杂程度高,群落所含信息量大。Patrick指数与环境因子的Pearson相关性分析结果显示,土壤含水率和与主要干道距离是显著影响地面生苔藓植物多样性的环境因子,而显著影响树附生苔藓植物多样性的环境因子仅与距主要干道距离相关。用典范对应分析法（CCA）研究26个样点中苔藓植物的盖度与主要环境因子的关系,结果发现人为干扰程度、草本盖度、与城市主要干道的距离等对地面生和树附生苔藓植物的分布都有显著影响。其中地面生苔藓植物的分布受人为干扰和草本盖度影响最为显著;而树附生苔藓植物的分布受附生树干胸径及与主要干道距离影响最为显著。研究结果表明武汉市区苔藓植物的多样性和分布受人为干扰较大,树附生苔藓对汽车尾气等因素更为敏感。     

Response of epiphytic bryophytes to simulated N deposition in a subtropical montane cloud forest in southwestern China

A field manipulation experiment was conducted in a subtropical montane cloud forest in southwestern China to determine the possible responses of epiphytic bryophytes to increasing nitrogen (N) deposition from community to physiology level, and to find sensitive epiphytic bryophytes that may be used as indicators for assessing the degree of N pollution. N addition had significantly negative effects on species richness and cover of the epiphytic bryophyte community. Harmful effects of high N loads were recorded for chlorophyll, growth, and vitality of the species tested. The decline of some epiphytic bryophytes may result from detrimental effects on degradation to photosynthetic pigments. Bazzania himalayana (Mitt.) Schiffn., Bazzania ovistipula (Steph.) Mizut., and Homaliodendron flabellatum (Sm.) Fleisch. are candidates in atmospheric nitrogen monitoring. Epiphytic bryophytes in the montane cloud forest are very sensitive to increasing N deposition and often difficult to recover once they have been destroyed, providing early detection of enhanced N pollution for trees or even the whole forest ecosystem. The inference that increasing N pollution may lead to loss of biodiversity is a concern to the developing economy in western China, and should alert the government to the adverse impacts caused by increased industrial pollution during the process of China’s West Development.     

Bole epiphytic bryophytes on <Emphasis Type="Italic">Lithocarpus xylocarpus</Emphasis> (Kurz) Markgr. in the Ailao Mountains,SW China

Epiphytic bryophytes growing on Lithocarpus xylocarpus (Kurz) Markgr. trunks of different diameter classes in primary (132 plots) and secondary (84 plots) Lithocarpus forests in the Ailao Mountains, SW China, were surveyed and analyzed to determine species composition and richness, and to identify environmental variables that may affect it. Among the 65 species (belonging to 32 genera, 19 families) found, 28 occurred in both forests, with Syrrhopodon gardneri (Hook.) Schwaegr. predominanting. Species richness and total coverage in primary forest were significantly higher than in secondary forest. We suggest that a period of perhaps much more than 110 years is necessary for the recovery of epiphytic bryoflora in montane forest of SW China. Fan, turf, and smooth mat are the most important life forms, with high occurrences in both forests. The life form composition of epiphytic bryophytes is determined mainly by microhabitat and host age. Tree age, the presence of primary forest, bark pH, and plot exposure are the environmental variables that have significantly influenced the composition of epiphytic bryophytes. Tree age explained most variations in epiphytic bryoflora. Bark pH is another important parameter that significantly influenced the epiphytic bryophyte community, but seemed indirectly correlated with tree age. Primary forest is a favorable habitat for epiphytes, due mainly to its diversified canopy structure and the presence of large diameter hosts. Moisture-laden southwest trade winds and forest structure could differentiate microclimate and impel a distinct composition of epiphytes in windward and leeward exposures.     

Assemblages of native bryophytes in secondary forests with introduced Quercus rubra

We have studied the diversity of bryophytes in planted Polish post‐agricultural forests dominated by the native Scots pine Pinus sylvestris and the alien (North American) red oak Quercus rubra. The planted sites would be suitable for a mesic coniferous forest (abbreviation: CFS) or mesic broadleaved forest (abbreviation: BFS). We analysed the structure and composition of the bryophyte assemblages in relation to forest site and substrate availability. Special attention was paid to the introduced Q. rubra as a host species for native bryophytes. A total of 54 bryophyte species (9 liverworts and 45 mosses) were found in the 90 plots ( = phytosociological relevés, 10 × 10 m in area; 45 at each forest site) studied. DCA analysis showed that the bryophyte assemblages of the P. sylvestris–Q. rubra secondary forest community differed significantly between CFS and BFS sites; the similarity of the composition of bryophyte species was 36.8%. The substrate preferences (epigeic, epixylic, epiphytic), as well as the growth form and life form of the recorded bryophytes, also differed between CFS and BFS, while the proportion of bryophytes that had a particular life strategy was very similar. The introduced Q. rubra was inhabited by 28 bryophyte species, including two liverworts. This tree hosted 64% of the CFS and 47% of BFS bryophyte flora and as a host for epiphytes the species successfully fulfilled the functional role of the native oaks (Q. robur and Q. petraea). Thus, the introduction of Q. rubra may contribute to the restoration of post‐agricultural forests and to the conservation of epiphytic bryophyte species. On the other hand, the negative impact of Q. rubra observed on the ground flora (including bryophytes) puts the benefits of Q. rubra for the conservation of native biodiversity in general in question.     

辽东山地古石河冰缘地貌森林生态系统苔藓物种多样性研究

基于9个20 m×30 m森林群落样地的调查数据,采用物种丰富度、α和β多样性指数,对辽东山地古石河冰缘地貌不同林型石生、树生苔藓植物物种多样性进行定量研究,采用皮尔逊相关分析方法对其影响因素进行分析。结果显示,古石河冰缘地貌苔藓植物共有26科46属59种;不同林型石生、树生苔藓植物物种丰富度和α多样性指数均为:暗针叶林针阔混交林落叶阔叶林;石生苔藓植物β多样性指数最高为落叶阔叶林-针阔混交林间(0.44),最低为落叶阔叶林-暗针叶林间(0.33);树生苔藓植物β多样性指数最高为针阔混交林-暗针叶林间(0.40),最低为落叶阔叶林-暗针叶林间(0.25);分析表明,林冠层郁闭度、海拔高度是影响辽东山地古石河冰缘地貌森林生态系统苔藓物种多样性的重要因子。     

Conservation of Portuguese red-listed bryophytes species in Portugal: Promoting a shift in perspective on climate changes

Knowledge of bryophyte diversity can be an important tool for identifying overall biodiversity hotspots. The distribution of red-listed species is an essential data for biodiversity conservation actions, and the assessment of species' response to climate change scenarios is also a key tool in future conservation strategies. In this study, we examine the response of four phytogeographic assemblages of all Portuguese red-listed bryophytes whose distributions are well documented in Portugal. The red-listed species were selected based on their vulnerability as listed in the new Atlas and Red Data book of Portuguese bryophytes according to the IUCN criteria. The main purpose of this study is to develop predictive distributions of threatened bryophytes grouped according to phytogeographic trends aiming to conserve this bryoflora in future. This is achieved by the identification of relationships between specimens' distributions and environmental ecologically meaningful data, which is known to influence different phytogeographic assemblages. Significant differences were found in all distribution models based on future climate scenarios. Several variables play a vital role in the species' distribution models in present and future environmental conditions.     

Tree and stand-scale factors affecting richness and composition of epiphytic bryophytes and lichens in deciduous woodland key habitats

Conservation and sustainable forestry are essential in a multi-functional landscape. In this respect, ecological studies on epiphytes are needed to determine abiotic and biotic factors associated with high diversity. The aim of the present study was to evaluate relative sensitivity of conservation targets (epiphytic bryophytes and lichens) in relation to contrasting environmental variables (tree species, tree diameter at breast height, bark crevice depth, pH, tree inclination, pH, forest stand age, area and type) in boreo-nemoral forests. The study was conducted in Latvian 34 woodland key habitat (WKH) boreo-nemoral forest stands. Generalized linear mixed models and canonical correspondence analysis showed that tree species and tree bark pH were the most important variables explaining epiphytic bryophyte and lichen composition and richness (total, Red-listed, WKH indicator species). Forest stand level factors, such as stand size and habitat type, had only minor influence on epiphytic species composition and richness. The results of the present study indicate a need to maintain the diversity of tree species and large trees, particularly Acer platanoides, Carpinus betulus, Fraxinus excelsior, Populus tremula, Tilia cordata, Ulmus glabra and Ulmus laevis in conservation of epiphytic bryophyte and lichen communities in the future.     

北京东灵山主要森林植被中苔藓植物的物种多样性

通过对北京东灵山地区32个样地植被及苔藓植物的调查,对主要森林植被中苔藓植物物种多样性进行分析。结果表明:东灵山主要森林植被中共有苔藓植物16科33属79种,优势科为青藓科(Brachytheciaceae)和绢藓科(Entodontaceae)等。密叶绢藓(Entodoncompressus)、小牛舌藓(Anomodon minor)等为优势种。地面生苔藓植物物种丰富度以落叶阔叶混交林中最大,白桦林中最小,苔藓植物群落相似性以辽东栎林与落叶阔叶林之间最高,以山杨林与油松林之间最低。树附生苔藓植物物种丰富度以落叶阔叶混交林中最大,油松林中最小;苔藓植物群落相似性以油松林和山杨林之间最高,华北落叶松林与白桦林之间最低。地面生和树附生苔藓植物多样性与林型、树种及其所形成的林内微环境相关。     

Old trees contribute bio-available nitrogen through canopy bryophytes

Symbiotic cyanobacteria??bryophyte associations on the forest floor are shown to contribute significantly to stand-level nitrogen budgets through the process of biological nitrogen fixation (BNF), but few studies have considered the role of canopy bryophytes. Given the high biomass of epiphytic bryophytes in many tree species of the North American temperate rain forest, we suggest that canopy bryophytes may contribute substantially to stand-level N dynamics. We confirm the presence of cyanobacteria and measure rates of BNF at three heights (0, 15 and 30 m) in Sitka spruce trees across three watershed estuaries of Clayoquot Sound, British Columbia, Canada. This study is the first to report BNF by cyanobacteria associated with epiphytic and forest floor bryophytes in the coastal temperate rain forest of North America. Cyanobacteria density was significantly greater in epiphytic bryophytes compared to mosses on the forest floor, and rates of BNF were highest at 30 m in the canopy. The majority of total stand-level BNF (0.76 kg N · ha^-1 · yr^-1) occurs in the canopy, rather than on the forest floor (0.26 kg N · ha^-1 · yr^-1). We suggest that BNF by cyanobacterial-bryophyte associations in the canopy of coastal temperate rain forests is a unique source of ecosystem N, which is dependent on large, old trees with high epiphytic bryophyte biomass.     

西双版纳片段化石灰岩森林附生兰科植物多样性研究

西双版纳石灰岩地区拥有丰富的兰科植物资源,但近年来随着橡胶树的大面积种植,使得该地区很多石灰岩森林呈片段化。为了解片段化石灰岩森林中附生兰科植物多样性状况以及片段化对附生兰科植物的影响,该研究选取了生境片段化的青岩寨和曼纳览,以及连续生境的绿石林和巴卡新寨等4个样地的29个样方进行多样性调查和对比研究。结果表明:4个石灰岩森林样共记录到附生兰科植物34属76种1 528株(丛)。通过对坡向、坡度、海拔、地形、郁闭度和森林类型等6个环境因子与附生兰科植物丰富度进行CCA分析,发现石灰岩地区附生兰科植物的分布主要受海拔和森林类型2个因素的影响,在海拔较高的青岩寨和巴卡新寨附生兰科植物物种丰富度高于低海拔的绿石林和曼纳览,而片段化对附生兰科植物的物种多样性和多度均无显著影响,这可能与片段化的历史较短有关。虽然目前来看生境片段化对石灰岩地区的附生兰科植物多样性无显著影响,但生境脆弱的石灰岩森林植被的保护对于兰科植物多样性保护则更具重要性。     

Tree hollows can affect epiphyte species composition

Tree hollows often harbor animals and microorganisms, thereby storing nutritive resources derived from their biological activities. The outflows from tree hollows can create unique microenvironments, which may affect communities of epiphytic organisms on trunk surfaces below the hollows. In this study, we tested whether the species richness and composition of epiphytic bryophytes (liverworts and mosses) and lichens differ above and below tree hollows of Aria japonica and Cercidiphyllum japonicum in a Japanese temperate forest. The species richness of epiphytic bryophytes and lichens did not differ above and below hollows; however, the species composition of bryophytes differed significantly above and below hollows. Indicator species analyses showed that the moss species Anomodon tristis and the liverwort species Porella vernicosa were significantly more common below than above hollows, while the liverwort species Radula japonica and four lichen species, including Leptogium cyanescens, occurred more frequently above than below hollows. Our results highlight that tree hollows can produce unique microenvironments on trunk surfaces that potentially contribute to the maintenance of epiphytic diversity on a local scale.     

浙江西天目山主要森林类型的苔藓多样性比较

苔藓是森林的重要组分, 是森林保护区的重要保护对象, 在物种资源和生态系统功能维护中有重要作用。该研究以浙江西天目山国家自然保护区内7种主要森林类型(落叶矮林、落叶阔叶林、常绿-落叶阔叶混交林、常绿阔叶林、针阔混交林、针叶林和竹林)内的苔藓植物为对象, 调查了32个10 m × 10 m的样地, 记录地面生苔藓植物盖度和树附生苔藓植物多度, 采用重要值、相似性系数、多样性指数分析了森林类型间的苔藓植物多样性差异。共采集969份标本, 隶属41科84属142种, 其中苔类植物13科18属33种, 藓类植物28科66属109种, 优势科为灰藓科、青藓科和羽藓科。2种混交林(常绿-落叶阔叶混交林和针阔混交林)的物种丰富度和多样性指数均高于其余5种森林, 其中物种丰富度以针阔混交林最高, 苔藓植物多样性则以常绿-落叶阔叶混交林最高, 竹林两者均为最低。海拔等环境因子较为接近的植被类型的苔藓植物多样性相似性较高, 常绿阔叶林与针叶林相似性最高, 而落叶矮林和竹林相似性最小。     

长白山暗针叶林苔藓植物生物量的研究

在长白山北坡暗针叶林对地面和树附生苔藓植物的生物量进行了测定．地面生苔藓采取样带调查取样法测定,树附生苔藓应用McCune方法对树干和树枝的附生苔藓生物量都做了细致的测定．结果表明,长白山暗针叶林中的苔藓植物分布很不均匀,随海拔变化差异很大,海拔1100m最低,仅为543kg·hm^-2;海拔1250m最高,达5097kg·hm^-2．苔藓植物生物量的变化对生境有很好的指示作用,特别是塔藓和拟垂枝藓的生物量随海拔的变化与森林系统的群落学特点有一定的相关性：在海拔1100～1700m,塔藓的生物量与臭冷杉的重要值变化趋势相近,随海拔升高而减少;拟垂枝藓的生物量与鱼鳞云杉重要值的变化趋势相似,随海拔升高而增加．此外,生物量随海拔的变化表明了不同苔藓植物对环境条件要求的差异,拟垂枝藓比塔藓水分条件要求更高．因此,生物量的研究在植物生理上也有一定的指示作用．     

哀牢山湿性常绿阔叶林地生、树干及树枝 附生苔藓生活型组成及其水分特性

为探讨林内不同垂直高度生境下及不同生活型苔藓植物水分特征的差异,该文对哀牢山湿性常绿阔叶林内地生苔藓、林下树干附生和林冠层树枝附生苔藓优势或常见种的生活型组成、持水力、失水特征和水分利用效率进行了研究。结果表明:地生、树干附生和树枝附生苔藓植物类群分别以交织型、扇型、悬垂型苔藓植物占据优势;地生、树干附生、枝条附生苔藓植物的饱和持水率分别为476%DW、210.98%DW、238.95%DW;地生苔藓植物的持水率和失水速率均高于附生苔藓,树干附生苔藓植物持水率低于树枝附生苔藓,而失水速率高于树枝附生苔藓。在不同生活型苔藓的水分特性上,交织型苔藓具有较高的持水率和失水速率,保水性能较弱,其次为悬垂型苔藓,扇型苔藓的持水率最小,失水速率也较快;地生和树干附生苔藓的水分利用效率均显著高于树干附生苔藓,交织型和扇型苔藓的水分利用效率显著高于悬垂型苔藓。在三种生境下,地生苔藓持水力高,水分利用效率较高而保水能力低;枝条附生苔藓持水力低,水分利用效率低而保水能力较高;树干附生苔藓水分利用效率较高而持水力和保水能力均较差。因此,不同生境下苔藓植物生活型组成及其水分变化特性在一定程度上反映了它们对不同生境的适应策略。