Phylogenetic biogeography and taxonomy of disjunctly distributed bryophytes

More than 200 research papers on the molecular phylogeny and phylogenetic biogeography ofbryophytes have been published since the beginning of this millenium. These papers corroborated assumptions of a complex genetic structure of morphologically circumscribed bryophytes, and raised reservations against many morphologically justified species concepts, especially within the mosses. However, many molecular studies allowed for corrections and modifications of morphological classification schemes. Several studies reported that the phylogenetic structure of disjunctly distributed bryophyte species reflects their geographical ranges rather than morphological disparities. Molecular data led to new appraisals of distribution ranges and allowed for the reconstruction of refugia and migration routes. Intercontinental ranges of bryophytes are often caused by dispersal rather than geographical vicariance. Many distribution patterns of disjunct bryophytes are likely formed by processes such as short distance dispersal, rare long distance dispersal events, extinction, recolonization and diversification.

Study on Bryophytes in Sygara Mountain

In order to identify the species of bryophytes in Sygara Mountain in Tibet,2390 samples in the area were collected,identified and analyzed. The results show that bryophytes of Sygara Mountain have 26 families,70 genera and 134 species; among them,25 families,69 genera and 133 species are mosses,and only one is liverwort,namely Conocephalum conicum( L.) Dum. 4 dominant families are in the descending order of Bryaceae,Dicranaceae,Pottiaceae,Polytrichaceae respectively,and the dominant genera are Hypnum,Brachythecium,Plagiomnium,Racomitrium and Dicranodontium.

Literature Analysis of Bryophytes in China during 2005-2015

In order to study China's bryophyte,this paper uses bibliometrics for statistical analysis of literature about China's bryophyte during 2005-2015.The results show that in terms of published article distribution of different journals,there are 13 kinds of journals with more than 5 papers about bryophyte,accounting for 32.5%; in terms of the number of papers published in different years,it was smallest in 2005,only 16,while it reached the largest number of 33 in 2008; in terms of the number of papers published for different first authors,there are most authors publishing less than 9 papers,accounting for 87.5%,there is only one author publishing 9 papers,and there are 5 people publishing more than 9 papers; in terms of author unit distribution,in the 278 articles collected,there are 12 units publishing papers of less than 6,accounting for 30%,the unit publishing the most papers(36) is Guizhou Normal University,5 units publish 6 papers,accounting for 12.5%,and the units publishing papers of less than 6 account for 57.5%; in terms of literature research level,there are most papers about basic and applied basic research(natural science),accounting for 91.2%,the papers about engineering and technology(natural science) account for 5.5%,and other papers account for 3.3%.

An enumeration of bryophytes collected from North Korea

Bases on studies of bryophytes collecled by Cao Tong in August 1997 from North Kolea, 81 species belonging to 52 genera, 26 families of mosses and 16 species belonging to 12 genera, 10 families of hepatics are recorded. Among these, 6 rpeciec and 1 form are new to bryoflora of the Korean Peninsula. These are : Campylopus gracilis (Mitt.) Jaeg.,Grimmia leavigata (Brid.) Brid., Okamura hakoniensis f. mutiflagellifera (Okam.) Nog., Orthotrchum erubescens C. Muell.,Scapania verrucosa Heeg., Schistidum strictum (Turn.) Loeske ex O. Maort. and Schistidium subconfertum (Broth.)Deguchi.

Responses of terrestrial bryophytes to simulated climate change in a secondary evergreen broad-leaved forest in southern China

Tropical regions are biodiversity hotspots and are well-suited to explore the potential influence of global climate change on forest ecosystems. Bryophytes have essential ecological functions in tropical forest ecosystems, but knowledge of the potential impact of global warming and possible changes in water availability patterns on terrestrial bryophytes is limited. We transplanted eight terres- trial moss species from two elevations (900 and 500 m) to warmer and drier elevations (500 and 100 m) during a halfyear observation period on Tai Mo Shan, southern China. The simulated climate change resulted in severely declined health status and marked decrease in growth of the trans- planted species when compared with their performance at the original elevations. Five of the eight selected species survived for six months after being transplanted to the warmer and drier lowlands, though their health status deteriorated severely. Sematophyllum subhumile , Pseudotaxiphyllum pohliaecarpum and Brachythecium buchananii were highly susceptible to changes in temperature and rainfall patterns and might be used as suitable bioindicators. As the tropics are expected to become hotter and drier, terrestrial mosses might be negatively affected or even be at risk of extinction. Bryophytes in the tropics could represent one of the best biological communities to reflect the direct adverse impact of climate change and provide early warning of the biological outcomes induced by ongoing climate crisis.

Modeling and Mapping Forest Floor Distributions of Common Bryophytes Using a LiDAR-Derived Depth-to-Water Index

This article describes how the cartographic depth-to-water (DTW) index in combination with other variables can be used to quantify, model and map the distribution of common forest floor bryophytes, at 1 m resolution. This was done by way of a case study, using 12 terrain and climate representative locations across New Brunswick, Canada. The presence/absence by moss species was determined at each location along upland-to-wetland transects within >10-m spaced 1-m2 forest floor plots. It was found that Bazzania trilobata, Dicranum polysetum, Polytrichum commune, Hylocomium splendens, and Pleurozium schreberi had greater probabilities of occurrence in well-drained forested areas, whereas Sphagnum fuscum and Sphagnum girgensohnii dominated in low-lying wet areas. The presence/absence of each species was quantified by way of logistic regression analyses, using DTW, slope, canopy closure, forest litter depth, ecosite type (8 classes), nutrient regime (4 classes, poor to rich);vegetation type (deciduous, coniferous, mixed, and shrubs), and macro- and micro-topography (upland, wetland;mounds, pits) as predictor variables. Among these, log10DTW and forest litter depth were the most consistent predictor variables, followed by mound versus pit. For the mapping purpose, only log10DTW and already mapped classifications for upland versus wetland and vegetation type were used to predict the probability of occurrences for the most frequent moss species, namely, D. polysetum, P. schreberi and Sphagnum spp. The overall accuracy for doing this ranged from 67% to 83%, with false positives and negatives amounting to 18% to 42%. The overall classification accuracy exceeded the probability by chance alone at 76.8%, with the significance level reached at 75.3%. The average level of probability by chance alone was 60.3%.

Bryophyte mass to stem length ratio: A potential metric for eco-physiological response to land use

Methods of analysis are needed that quantitatively characterize the response of organisms to anthropogenic disturbance. Herein a method is presented that characterizes bryophyte morphological variability in response to timber harvest treatments (clearcut and partial cut). Samples (n = 6196) of the semi-aquatic bryophyte Brachythecium frigidum were collected from clearcut, partial cut and full forest stream reaches between August 2003 and October 2005 and analyzed to obtain mass to stem length ratios (M:SL). Results show that relative to a full forest (i.e. full canopy cover condition), average M:SL ratios were reduced approximately 18% in the partial cut and 37% in the clearcut, indicating a decrease in biomass per unit stem length with increasing harvest intensities. Increased light intensities and higher air temperatures resulting from decreased canopy cover in the harvest treatments corresponded to lower M:SL ratios (0.31 and 0.24 for the partial cut and clearcut, respectively). Results quantify the morphological response of B. frigidum to habitat perturbation, thereby validating the method as a useful assessment of anthropogenic disturbance in post-timber harvest environments. Additional work should be conducted to test the method in other physiographic regions and to isolate bryophyte response to alterations of distinct environmental variables.

<i>Rhynchostegium megapolitanum</i>(Web. et Mohr) B.S.G.—A Rare Bryophyte in Dune Ecosystems of Zealand, Denmark

Rhynchostegium megapolitanum was observed during a study of the effects of the invasive nonnative Rosa rugosa in a sand dune. The vascular as well as the epiphytic and epigeic cryptogam vegetation was recorded., and soil properties were measured. Epihytic lichens were abundant on dead or dying branches of Rosa rugosa scrubs, under which the stable substrate and high light exposure provided growth conditions for an epigeic community dominated by lichens and bryophytes. The occurrence of the rare bryophyte Rhynchostegium megapolitanum is discussed.

Study on the Bryophytes Cultivation and Breeding Based on Mosses Garden

Slow growth is a bottleneck for the large-scale application of bryophytes in landscaping.The article reviewed the progress of artificial breeding researches,summarized several effective means of collecting germplasm resources and cultivating and breeding,discussed the feasibility of specialized mosses garden,and proposed the approaches of scale breeding such as stereo-cultivation and optimization of cultivation media.

Approaches and Prospects of Developing Tourism Value of Natural Bryophyte Resources in West Sichuan

Abundant bryophytes with high ecological and ornamental value are distributed in natural forests in west Sichuan. Through exploring the practices and forecasting the application of bryophytes from 2 aspects(using bryophytes in the natural world and building artificial moss garden), this paper proposed that the large-scale application of bryophytes could be realized via the development of bryophyte tourism products and commodities on the basis of ecological restoration and artificial cultivation experiment.

Diversity Characteristics of Bryophytes on the Eastern and Western Slopes of Sejila Mountain

[Objectives]To study the characteristics of bryophytes in subalpine cold zone and related transition zone.[Methods]The study was divided into scale A and scale B.On the scale of A,specimens were collected from Tongmai-Pailong-Dongjiu-Lulang-Sejila Pass-Nyingchi Town-Bagi Village along the national Highway 318.A sample plot was set for each 100 m altitude increase,and samples were collected between each two sample plots as well.On the scale of B,bryophyte specimens were collected and studied in the fixed sample plot of the Tibetan Nyingchi Alpine forest Ecosystem Research Observatory.[Results]Through the sampling and collection of bryophytes in Sejila Mountain,more than 3000 specimens were identified with the classical classification method.There were 216 species of bryophytes belonging to 82 genera and 24 families.The bryophytes in the study area differed obviously in different vegetation types and slopes.The species richness of Sabina saltuaria-Abiesgeorgei var.smithii forest was the highest.Theαdiversity of Abiesgeorgei var.smithii forest was the highest,followed by Sabina saltuaria-Rhododendron forest,and that of alpine shrub was the lowest.Diversity studies showed that theβdiversity of Sabina saltuaria-Rhododendron forest and Rhododendron forest on the eastern slope was the largest,and those of alpine shrub and Sabina saltuaria-Abiesgeorgei var.smithii forest were the lowest.However,theβdiversity of Abiesgeorgei var.smithii forest on the western slope was the highest,and those of alpine shrub and Abiesgeorgei var.smithii forest were the lowest.[Conclusions]There are obvious differences in the distribution of bryophytes on the eastern and western slopes of Sejila Mountain of Tibet.

Composition and Function of Bacterial Communities of Bryophytes and Their Underlying Sediments in the Dajiuhu Peatland, Central China

Symbiotic microbiomes of Sphagnum have been confirmed to play a fundamental role in carbon and nitrogen cycles, however, little is known about microbiomes associated with other bryophytes in subtropical peatland ecosystems. To explore the differences in community structure, metabolic potential and interaction relationship of bacterial microbiomes associated with different bryophytes species, the gametophytes of three bryophyte species(Sphagnum palustre, Aulacomnium androgynum, and Polytrichum commune) and their underlying peat sediments were collected from the subtropical Dajiuhu Peatland and subjected to Illumina high-throughout sequencing of 16S r RNA gene. Results showed that bacterial diversity was lowest in S. palustre, the dominant moss species, among the three moss species investigated in Dajiuhu Peatland. Bacterial communities from bryophytes clearly separated with those from sediments as indicated by both phylogenetic and taxonomical approaches. Linear discriminant analysis effect size(LEf Se) identified 30 and 36 indicator taxa in mosses and peat sediments. Bacteroidetes, Verrucomicrobia and Thermoleophilia significantly enriched in S. palustre, A. androgynum and P. commune, Chloroflexi, Proteobacteria and Acidobacteria subgroup 6 was indicator taxa for corresponding underlying sediments, respectively. Despite of these differences in compositions, bacterial functional structures were similar among all bryophytes, such as abundant aerobic heterotrophs, rare nitrifiers and denitrifiers. This phenomenon was also observed among the underlying sediments. Network analysis indicated that Proteobacteria and Acidobacteria located in the center of network and exerted strong interactions to other taxa. The sub-network of bacterial communities in sediments was more connected and microbial groups were more competitive than those in bryophytes subnetwork. Our results offer new insight into the community structure, ecological function and interaction pattern of bacterial microbiomes in the Dajiuhu Peatland across different habitats.

川西冷杉林下地表苔藓固氮速率及林窗的影响

苔藓与蓝细菌的共生固氮作用为许多生态系统贡献了高达50%氮输入,是“新增”氮素的重要来源。然而,苔藓与蓝细菌共生固氮速率如何受林窗等生态系统动态影响仍然未知。本文研究了四川西部典型藓类冷杉林地表苔藓与蓝细菌的固氮速率在生长季内的动态变化,及其在林窗和林冠覆盖两种生境下的差异,并评估了苔藓含水量、气温和光照条件等因素对固氮速率的驱动作用。研究结果发现,锦丝藓(Actinothuidium hookeri)和塔藓(Hylocomium splendens)生长季平均固氮速率分别为77.49和129.69 nmol·(g·d)^(−1)。地表苔藓固氮速率在生长季不同月份的变化极大,固氮速率高峰出现在生长季早期的5月、7月、8月,基本与植物生长高峰期相符;6月苔藓含水量较低,导致苔藓几乎没有固氮活性;生长季末期的10月苔藓固氮速率较低,不及7月的1/7。相比于林冠覆盖生境,林窗提高了地表气温、光照和苔藓含水量,但从整个生长季来看,林窗对苔藓固氮速率仅表现出微弱的促进作用。综上,苔藓与蓝细菌共生体固氮速率和林窗的影响效应可以为深入认识生态系统氮循环提供依据。

金马河沿岸次生林苔藓植物群落对人为干扰的响应

为探索人为干扰对四川金马河沿岸次生林苔藓植物群落的影响,通过分析比较不同干扰程度(轻度、中度、重度)区域苔藓植物的生态位、多样性、生活型、生长附着基质,研究苔藓植物群落特征和物种分布规律。结果表明,在金马河沿岸次生林地12块样地中共调查到苔藓植物15科23属34种,其中,苔类植物3科4属4种,藓类植物12科19属30种。优势科主要为青藓科和羽藓科,其中,细叶小羽藓具有最大的重要值和生态优势度,其重要值、生态位宽度和生态优势度分别为0.5368、2.4648、0.1169,占据重要生态位,台湾青藓次之。耐旱性强的丛集型苔藓植物种类随着人为干扰程度的增强而增加,占比从30.43%逐渐增至40.91%,且其重要值在重度干扰区位于前列。重度干扰区苔藓植物群落的物种丰富度指数和Shannon-Wiener多样性指数均显著低于轻、中度干扰区(P<0.05),中度干扰区苔藓植物群落的Pielou均匀度指数显著高于其他两个干扰区(P<0.05)。重度干扰区苔藓植物附着在腐(枯)木的数量显著少于轻度干扰区(P<0.05),附着在树干的数量显著少于中度干扰区(P<0.05),且主要附着在土壤和岩石上,附着基质逐渐倾向于单一类型。金马河沿岸次生林重度干扰区的苔藓植物物种丰富度指数、Shannon-Wiener多样性指数显著降低(P<0.05),过度干扰会导致林地内生态环境和苔藓植物群落结构遭受破坏。

Strong evidence for latitudinal diversity gradient in mosses across the world

Species richness generally decreases with increasing latitude,a biodiversity gradient that has long been considered as one of the few laws in ecology.This latitudinal diversity gradient has been observed in many major groups of organisms.In plants,the latitudinal diversity gradient has been observed in vascular plants,angiosperms,ferns,and liverworts.However,a conspicuous latitudinal diversity gradient in mosses at a global or continental scale has not been observed until now.Here,we analyze a comprehensive data set including moss species in each band of 20° in latitude worldwide.Our results show that moss species richness decreases strongly with increasing latitude,regardless of whether the globe is considered as a whole or different longitudinal segments(e.g.,Old World versus New World) are considered separately.This result holds when variation in area size among latitudinal bands is taken into account.Pearson's correlation coefficient between latitude and species richness is-0.99 for both the Northern and Southern Hemispheres.Because bryophytes are an extant lineage of early land plants and because mosses not only include most of extant species of bryophytes but also are important constituents of most terrestrial ecosystems,understanding geographic patterns of mosses is particularly important The finding of our study fills a critical knowledge gap.

3种苔藓植物对模拟大气氮沉降的生理响应

苔藓植物是地表生态系统的重要组分,研究苔藓植物对氮沉降的生理响应可以在机理机制上探讨如何科学合理利用苔藓指示大气氮沉降。以西北地区3种苔藓植物——齿肋赤藓(Syntrichia caninervis),真藓(Bryum argenteum)和尖叶匐灯藓(Plagiomnium acutum)为研究对象,设置0、2、4、6 g·m^(-2)4个不同氮素处理梯度(分别计为N_(0)、N_(2)、N_(4)、N_(6)),研究氮素增加对不同苔藓植物叶绿素、渗透调节物质含量和抗氧化酶活性的影响。结果表明(:1)4个氮素处理水平均能促进尖叶匐灯藓的叶绿素a和叶绿素b合成,尤以N_(4)处理的促进作用最佳,而N_(2)处理对齿肋赤藓和真藓的叶绿素a和叶绿素b具有明显的抑制作用(对齿肋赤藓的抑制作用更强)。(2)苔藓体内可以产生脯氨酸(Pro),可溶性糖(SS)和可溶性蛋白(SP)来调节细胞渗透平衡。不同氮素处理均促进了真藓和尖叶匐灯藓Pro,SS和SP的含量,但N_(2)处理下齿肋赤藓的3种物质含量开始下降,说明其对氮较为敏感。(3)在设定的氮素添加处理下,低浓度氮素促进3种苔藓植物的抗氧化酶活性,但高浓度氮素抑制苔藓植物的抗氧化酶活性。(4)齿肋赤藓的抗氧化系统调节中起主要作用的是超氧化物歧化酶(SOD),而真藓和尖叶匐灯藓的抗氧化系统调节中起主要作用的是过氧化氢酶(CAT)。综上所述,3种苔藓植物中,齿肋赤藓对氮素增加最为敏感,其次是真藓和尖叶匐灯藓,据此可将齿肋赤藓作为大气氮沉降的指示植物。

湿地公园苔藓植物群落特征及其与环境因子的关系——以贵阳市为例

苔藓植物作为湿地公园的植物组成成分之一,开展其群落构建的研究,可为湿地生态系统管理和生物多样性维持机制提供重要理论依据。贵阳湿地和苔藓植物资源丰富,以贵阳市3个典型湿地公园为对象,研究苔藓植物的物种分布特征和环境因子,采用双向指示种分析(TWINSPAN)和典范对应分析(CCA)方法对苔藓植物群丛进行数量分类和排序。结果表明,贵阳市3个典型湿地公园有苔藓植物17科28属66种,其中,丛藓科(Pottiaceae)、灰藓科(Hypnaceae)、青藓科(Brachytheciaceae)为优势科;3个湿地公园苔藓植物β多样性差异较小,物种相似度高,丰富度低。苔藓植物分布的生境类型主要为石生与树生;生活型以交织型和丛集型为主。苔藓植物群丛类型可以分为13类,均有各自的特征,其物种组成和群落特征能较好的反映群丛类型与环境之间的关系,3个湿地公园的生境具有相似性。CCA分析结果表明,影响湿地公园中苔藓植物群丛分布的首要环境因子是海拔,其次是空气湿度,再次是郁闭度,光照也有一定影响。

滇西北地区典型苔藓植物的引燃特性研究

为研究地表苔藓植物的引燃特性,以滇西北地区广泛分布的多蒴曲尾藓、锦丝藓为试验对象,以香烟和柱香作为引火源,在森林防火紧要期,研究了2种苔藓植物在不同试验条件下的引燃率。利用SPSS Statistics 27.0建立多元线性回归方程,并对该回归方程进行了检验。分析结果表明,各影响因素对多蒴曲尾藓引燃率影响程度大小排序为热释放速率>火源燃烧速率>苔藓含水率>火源直径>气温>相对湿度,对锦丝藓引燃率影响程度大小排序为苔藓含水率>气温>火源燃烧速率>火源直径>相对湿度>热释放速率。多蒴曲尾藓、锦丝藓模型拟合优度分别为0.820、0.893。通过残差分析得知,多蒴曲尾藓、锦丝藓引燃率预测结果误差分布为±8.895%、±5.845%。研究结果可以为滇西北地区地表可燃物的管理、火险预警等提供依据,为深入开展苔藓植物的火灾风险辨识与评价奠定基础。

川西亚高山森林苔藓与枯落物持水特征

森林苔藓和枯落物在水土保持、水分涵养方面具备重要作用,但现有研究多单一关注苔藓或枯落物,对苔藓-枯落物层的整体效应的认识较少,尤其针对高海拔西南森林林下的苔藓-枯落物层,更为鲜见。本文以川西贡嘎山针叶林和阔叶林地被层(苔藓、枯落物)为研究对象,通过野外调查、采样瓶取样浸水试验,分析了单一苔藓、单一枯落物及苔藓-枯落物整体的持水特征。结果表明:(1)贡嘎山苔藓和枯落物最大持水率为327.9%~432.6%,最大持水量为16.6~79.4 t/hm^(2),有效拦蓄量为7.1~34.2 t/hm^(2)。针叶林比阔叶林具有更大的持水能力和水分拦蓄能力。(2)不同地被组分中,苔藓-枯落物层持水率、有效拦蓄率、持水量和拦蓄量最大,苔藓显著提高了针叶林地被层的水源涵养能力;(3)地被层持水量与时间呈对数关系,吸水速率与时间呈幂函数关系,不同组分持水量和持水率均在0~2 h内迅速增长,2~12 h内缓慢增长,12 h时几乎达到饱和状态。(4)与单一苔藓或枯落物层相比,苔藓-枯落物整体的吸水速率更快,具有更高效的短期降水拦蓄能力。本研究结果可为亚高山森林水源涵养和生态水文研究与保护提供参考和理论基础。

弹丝的水湿运动释疑

为理解水湿运动对植物孢子的传播作用,本文从来源、结构和着生方式三方面对苔类植物和蕨类植物木贼属中弹丝的情况进行了介绍,并对水湿运动在不同类群植物孢子释放中的作用及意义进行了讨论,以期为中学生物学中与“结构与功能相适应”相关的教学内容提供拓展信息。