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Background: According to the Species Catalogue of China, Tibet, China, has more than 1,000 species of bryophytes, showing its remarkably high biodiversity. Amongst them, the Polytrichaceae is one of the largest family, with six genera and 25 species, one subspecies and two varieties reported previously. New information: Based on a field survey and specimen identification, the following species have been newly recorded in the bryoflora of Tibet, namely Oligotrichum obtusatum Broth., Pogonatum contortum (Menzies ex Brid.) Lesq. and Polytrichum sphaerothecium (Besch.) Müll. Hal. [ABSTRACT FROM AUTHOR]

Subtropical moss peatlands have important ecological functions, and their protection and restoration are urgent. The lack of understanding of the biogeochemical changes in subtropical moss peatlands after human disturbance, particularly regarding their underground ecological changes, limits the efforts towards their protection and restoration. In this study, typical subtropical moss peatlands and the Cryptomeria swamp forest (CSF) formed by long-term (more than 20 years) drainage and afforestation in the Yunnan–Guizhou Plateau of China were selected as the research sites. Moreover, 16S rRNA high-throughput sequencing technology was used to study the differences in soil bacterial community diversity and composition among a natural Sphagnum fen (SF), Polytrichum bog (PB), and CSF to explore the effects of drainage and afforestation on different types of moss peatlands and its mechanism combined with soil physicochemical properties. Results showed that (1) drainage and afforestation significantly reduced the α diversity of soil bacterial communities in SF while significantly increasing the α diversity of soil bacterial communities in PB. Soil bacterial communities of SF had the highest α diversity and had many unique species or groups at different taxonomic levels. (2) The impact of drainage and afforestation on the soil bacterial community composition in SF was significantly higher than that in PB. Drainage and afforestation caused significant changes in the composition and relative abundance of dominant groups of soil bacteria in SF at different taxonomic levels, such as significantly reducing the relative abundance of Proteobacteria, significantly increasing the relative abundance of Acidobacteria, and significantly reducing the ratio of Proteobacteria to Acidobacteria, but did not have a significant impact on the corresponding indicators of PB. The changes in the ratio of Proteobacteria to Acidobacteria may reflect changes in the trophic conditions of peatlands. (3) Soil moisture content, available phosphorus content, and pH were key driving factors for changes in soil bacterial community composition and diversity, which should be paid attention to in the restoration of moss peatlands. This study provides insights into the protection and restoration of subtropical moss peatlands. [ABSTRACT FROM AUTHOR]

Introduction: Leptoids, the food-conducting cells of polytrichaceous mosses, share key structural features with sieve elements in tracheophytes, including an elongated shape with oblique end walls containing modified plasmodesmata or pores. In tracheophytes, callose is instrumental in developing the pores in sieve elements that enable efficient photoassimilate transport. Aside from a few studies using aniline blue fluorescence that yielded confusing results, little is known about callose in moss leptoids. Methods: Callose location and abundance during the development of leptoid cell walls was investigated in the moss Polytrichum commune using aniline blue fluorescence and quantitative immunogold labeling (label density) in the transmission electron microscope. To evaluate changes during abiotic stress, callose abundance in leptoids of hydrated plants was compared to plants dried for 14 days under field conditions. A bioinformatic study to assess the evolution of callose within and across bryophytes was conducted using callose synthase (CalS) genes from 46 bryophytes (24 mosses, 15 liverworts, and 7 hornworts) and one representative each of five tracheophyte groups. Results: Callose abundance increases around plasmodesmata from meristematic cells to end walls in mature leptoids. Controlled drying resulted in a significant increase in label density around plasmodesmata and pores over counts in hydrated plants. Phylogenetic analysis of the CalS protein family recovered main clades (A, B, and C). Different from tracheophytes, where the greatest diversity of homologs is found in clade A, the majority of gene duplication in bryophytes is in clade B. Discussion: This work identifies callose as a crucial cell wall polymer around plasmodesmata from their inception to functioning in leptoids, and during water stress similar to sieve elements of tracheophytes. Among bryophytes, mosses exhibit the greatest number of multiple duplication events, while only two duplications are revealed in hornwort and none in liverworts. The absence in bryophytes of the CalS 7 gene that is essential for sieve pore development in angiosperms, reveals that a different gene is responsible for synthesizing the callose associated with leptoids in mosses. [ABSTRACT FROM AUTHOR]

Northern peatlands are globally important carbon stores. With increasing fire frequency, the re-establishment of bryophytes becomes crucial for their carbon sequestration. Smoke-responsive germination is a common trait of seeds in fire-prone ecosystems but has not been demonstrated in bryophytes. To investigate the potential role of smoke in post-fire peatland recovery, we tested the germination of spores of 15 bryophyte species after treatment with smoke-water. The smoke responsiveness of spores with different laboratory storage times and burial depths/age (3–200 years) was subsequently tested. Smoke increased the germination percentage for 10 of the species and the germination speed for four of these. Smoke responsiveness increased along the fire frequency gradient from open expanse to forest margin, consistent with the theory that this selects for the maintenance of fire-adapted traits. Smoke enhanced the germinability of 1-year but not 4-year laboratory-stored spores, and considerably increased the germinability of spores naturally buried in peat for up to ~ 200 years. The effect of fire may be overlooked in non-fire-prone ecosystems, such as those in which wetland bryophytes dominate. Our study reveals a mechanism by which an increase in fire frequency may lead to shifts in species dominance, which may affect long-term carbon sequestration in peatlands. [ABSTRACT FROM AUTHOR]

The aim of this study is to analyze the volatile composition and antimicrobial and antioxidant activities of the essential oils of Polytrichum commune and Antitrichia curtipendula. The essential oils obtained by hydrodistillation (HD) from each species were identified by GC-MS/FID. The main components were biformene (13.06%), α-pinene (6.53%), and bornyl acetate (8.10%) in P. commune. Nonanal and tetradecanal as major compounds were 19.96% and 20.23% in A. curtipendula essential oils, respectively. Antioxidant activity of obtained essential oils was evaluated using in-vitro antioxidant models. There was no significant difference within the groups according to DPPH activity. Also, the essential oil from P. commune showed higher metal-ion chelating activities than that of the essential oil of A. curtipendula. Metal-ion chelating activities varied between 4.1% and 67.4% at the 800 μg/mL concentration, respectively. The antimicrobial activity was tested by a minimal inhibition concentration test. Each moss species showed good antimicrobial activity against microorganisms according to the results of minimal inhibition concentration experiments. [ABSTRACT FROM AUTHOR]

The name Polytrichum commune, validated in Hedwig's Species muscorum frondosorum of 1801, was based on earlier entities that can be traced back to the pre‐Linnaean literature of the early 16th century. More than 200 years after its valid publication it remains to be typified. The single herbarium sheet for P. commune in the Hedwig‐Schwägrichen Herbarium in G contains nine specimens from different continents that represent four different species (P. commune, P. juniperinum, P. perigoniale, P. subpilosum). After careful study of the origins and taxonomic affinities of the specimens on this sheet, a lectotype is designated. [ABSTRACT FROM AUTHOR]

Consistent with a role in sporophyte maturation and desiccation, a function that is antithetic to that of tracheophyte stomata, hornwort and moss stomata including those of I Funaria i (Fig. In tracheophytes, stomata are found on the surface of leaves; in mosses, stomata, when present, are confined to the solitary spore capsule in the unbranched sporophyte (Paton and Pearce, 1957). This argument is somewhat problematic considering that the bryophyte ancestor likely emerged before the appearance of vascular plants (Wellman et al., 2003) (although there are no fossils of bryophytes in the Rhynie Chert, one of the oldest known macrofossil land plant assemblages), yet did not evolve to fill the ecological niche rapidly occupied by early vascular plants. Keywords: bryophytes; evolution; Polytrichum; PAP; 3'-phosphoadenosine 5'-phosphate; plant height; Sphagnum; stomata EN bryophytes evolution Polytrichum PAP 3'-phosphoadenosine 5'-phosphate plant height Sphagnum stomata 366 371 6 04/02/21 20210301 NES 210301 The greatest cost associated with terrestrial photosynthesis is maintaining hydration in the presence of phenomenal evaporative forces from the atmosphere (Wong et al., 1979). [Extracted from the article]

Two chlorophyll fluorescence (ChlF) methods were used to study the effects of high light (photoinhibition) and dehydration, common stressors of the alpine environment, on primary photosynthetic processes in the moss Polytrichum commune from the Czech Republic, the Jeseníky Mountains. Photoinhibition (PI) was studied in fully hydrated thalli of P. commune and during the period of spontaneous desiccation. Time courses of Kautsky kinetics (KK) of ChlF and derived parameters: maximum quantum yield (FV/FM), effective quantum yeld (ΦPSII), and non-photochemical quenching parameters, were measured before and after the samples were treated with high light (1500 μmol m-2 s-1 PAR) for 60 min. Dehydration effects were tested in two sets of experiments with a Pulse-Amplitude-Modulation fluorometry (PAM) and Fast Chlorophyll Fluorescence induction curve (OJIP) techniques. In PAM tests, the desiccating samples were exposed to saturating light pulses every 10 min. in order to obtain ΦPSII and non-photochemical quenching (NPQ). In the second dehydration experiment, OJIP transients of ChlF were repeatedly recorded, OJIP-derived ChlF parameters were plotted against relative water content (RWC) monitored during desiccation. Combined ChF techniques provided insights into the mechanisms activated during P. commune desiccation, such as dissipation of excess absorbed energy through heat dissipation, and conformational changes or destructions of the light harvesting complexes. Combination of stressors resulted in amplified interference with the photosynthetic machinery, even when the added stressor (dehydration) was applied in low dose. [ABSTRACT FROM AUTHOR]

Lichens and mosses are among the first organisms to colonize the open bedrock of eastern Georgian Bay, Ontario making them essential for primary soil formation and ecosystem succession, while also providing nesting habitat for turtle species‐at‐risk. However, the slow growing nature of lichen and moss makes them vulnerable to ecohydrological stresses caused by climate and land‐use change. In order to better understand how lichen and moss will respond to stressors, we examined which ecohydrological factors (e.g., near‐surface soil moisture and temperature) control the CO2 exchange of lichen (Cladonia spp.) and moss (Polytrichum spp.) on rock barrens, and the time of year growth primarily occurs. Net ecosystem productivity (NEP) was significantly greater in the wet period of the growing season than the dry, with an estimated difference of 0.7 μmol m−2 s−1 for lichen, 2.9 μmol m−2 s−1 for moss, and 2.5 μmol m−2 s−1 for a moss and lichen mix. These findings indicate that the wet portions of the growing season are critical for growth, while lichen and moss have little to no productivity during the dry period. Our results indicate that near‐surface soil moisture is an indicator of the CO2 exchange of lichen and moss, and this relationship varies among cover types. For the geographical regions where warm, dry conditions are expected to increase in duration and frequency with climate change, lichen and moss NEP will likely decrease, thus limiting the long‐term availability of nesting habitat for turtle species‐at‐risk. [ABSTRACT FROM AUTHOR]

Summary: Primary succession models focus on aboveground vascular plants. However, the prevalence of mosses and lichens, that is cryptogams, suggests they play a role in soil successions. Here, we explore whether effects of cryptogams on belowground microbes can facilitate progressive shifts in sand dune succession.We linked aboveground vegetation, belowground bacterial and fungal communities, and soil chemical properties in six successional stages in Arctic inland sand dunes: bare sand, grass, moss, lichen, ericoid heath and mountain birch forest.Compared with the bare sand and grass stages, microbial biomass and the proportion of fungi increased in the moss stage, and later stage microbial groups appeared despite the absence of their host plants. Microbial communities of the lichen stage resembled the communities in the vascular plant stages. Bacterial communities correlated better with soil chemical variables than with vegetation and vice versa for fungal communities. The correlation of fungi with vegetation increased with vascular vegetation.Distinct bacterial and fungal patterns of biomass, richness and plant–microbe interactions showed that the aboveground vegetation change structured the bacterial and fungal community differently. The asynchrony of aboveground vs belowground changes suggests that cryptogams can drive succession towards vascular plant dominance through microbially mediated facilitation in eroded Arctic soil. [ABSTRACT FROM AUTHOR]

This paper presents data on the content and ratio of pigments, photosynthesis rate, and assimilation number throughout the annual cycle of Polytrichum commune in the forest belt of the Khibiny Mountains. It is shown that the activity of the pigment complex in the photosynthetic organs of P. commune is preserved and maintained over 2 years. The highest content of plastid pigments in this year's shoots was recorded in fall, in the past year's shoots in the summer. In winter, the content of chlorophylls in the photosynthetic organs of this year's shoots decreased in 1.5 times relative to the summer maximum, and carotenoids - in 1.4 times. In the past year's shoots, no significant changes in the content of the pigments were noted. During the active vegetation period, the photosynthetic intensity in this year's shoots is in 1.5 times as high as that in the past year's shoots. At the end of the growing season in the past year's shoots the value of LHC (76%) due to their immersion deep into the moss clumps and shading them with this year's shoots. Chlorophyll's efficiency (assimilation number) in P. commune shoots of different ages in early spring (April) is in 2 times as high as that in fall (October). [ABSTRACT FROM AUTHOR]

Mosses, classified as bryophytes, are of economic importance in the horticulture industry where they are used for decoration and gifts. Polytrichum commune (common haircap moss) is a popular moss species used in TerraLiving's terrariums. However, moss growth is slow, taking up to 12 months for complete growth which limits its economic value. Moss is conventionally grown on peat soil but its prolonged use under the slow moss growth is uneconomical. Therefore, synthetic soil has been proposed as an alternative growth media. Hence, the aims of this study are to investigate the physicochemical characteristics of both peat and synthetic soils which affect the growth of common haircap moss (in terms of increase in horizontal length and number of shoots). Soil pH and cation exchange capacity (CEC) to study the rationale behind. Polytrichum commune was grown in both peat and synthetic soils over a course of 6 weeks (after an acclimatization period of 2 weeks) to determine their rate of growth in different soil types, measured in terms of horizontal length increment (in mm) and number of new shoots. It was observed that the moss grown in peat soil exhibited greater horizontal growth (9.280 ± 2.756 mm) than synthetic soil. This is heavily linked to the significantly lower pH and higher CEC of peat soil. The number of shoots formed was similar in both peat and synthetic soil (8.267 ± 1.535 and 7.8 ± 0.803 respectively), possibly due to similar levels of phytohormone production. In conclusion, peat soil is a better media for the growth and cultivation of P. commune. [ABSTRACT FROM AUTHOR]

Two new benzophenones (1 and 2), were isolated from the endohydric moss Polytrichum commune. Their structures were elucidated by spectroscopic methods including extensive 2 D NMR techniques. Compound 2 is the first example of benzophenone with a rare cyclopropylacetamide from the natural resources. Compounds 1 and 2 were screened their cytotoxicity against five cancer cell lines (HCT-116, A-549, MCF-7, HepG2, A-375,), and no cytotoxic activities were observed (IC50 > 100 μM). [ABSTRACT FROM AUTHOR]

Moss-dominated vegetation type is considered one of the the most productive community type in treeless alpine environments in European mountains. In this study, net carbon exchange rate (NCER) of alpine moss Polytrichum commune was measured by automatic CO2 exchange station unit. Samples of mosses were collected in a mountains from the site located above tree line (1420 m a.s.l.), and transferred to Brno, Czech Republic. Then the cluster of moss (23 cm in diameter, 30 cm in depth) including dead parts was placed into open measuring chamber end exposed to local climate for two weeks in autumn 2019. The chamber closed by a transparent lid repeatedly each 20 min and NCER measured by the system. Data on photosynthetically active radiation (PAR), relative air humidity (RH), and moss temperature (T) were recorded as well. Maximum/minimum dark respiration reached 1.0 and 0.2 µmol (CO2) m-2 s-1. The highest NCER was found - 0.6 µmol (CO2) m-2 s-1 was caused by photosynthesis of moss clump at the temperature within the range of 14.5-17.5°C and 100% of relative air humidity. [ABSTRACT FROM AUTHOR]

A moss from the alpine environment of the Jeseníky mountains, Polytrichum commune, was studied under lab-induced light stress to analyse photoinhibition (PI) stress response; three PI doses were used: PAR 1500 µmol m-2 s-1 for 60 min., 1200 µmol m-2 s-1 for 60 min. and 1200 µmol m-2 s-1 for 30 min.; in the last one the added component of slight desiccation stress was added. Chlorophyll fluorescence parameters were plotted as time series, immediately before and after the PI treatments, then every 20 minutes for three hours (recovery period). FV/FM, ΦPSII and NPQ parameters and quenching components were analysed. Decreasing courses and final values of FV/FM and ΦPSII parameters along with increased values of NPQ clearly indicated PI stress response, although not very severe. Quenching parameters analysis showed a dominant role played by xanthophyll pigments along with changes in PS II in the non-photochemical energy quenching. Dehydration contributed additional value to NPQ. All these factors are consistent with the adaptation of the species to harsh conditions of alpine environments. [ABSTRACT FROM AUTHOR]

Plants in the high Arctic are exposed to a 24-h photoperiod for several months. These conditions can be damaging for plants at lower latitudes. When common crops are artificially maintained under continuous light (CL), photosynthetic processes maintain endogenous circadian rhythms, but it is unclear whether plants naturally acclimated to CL also maintain such rhythmicity. Alternatively, Arctic plants have to utilise the favourable conditions during the short Arctic summers. In this study, we evaluate the existence of daily cycles in pigment composition in three Arctic plants in a tundra ecosystem at 78 °N that display examples of different growth forms: the bryophyte Polytrichum hyperboreum, the herb Bistorta vivipara and the dwarf shrub Salix polaris. Changes in pigment composition are excellent indicators of the restructuring of the light-harvesting apparatus. Most pigment parameters analysed did not show any consistent pattern of variation between subjective noon and midnight. P. hyperboreum had the highest level of rhythmicity, while S. polaris was the most stable. Despite these subtle changes, the primary effects observed were induced by light and its effect on the de-epoxidation state of the xanthophyll cycle pigments (AZ/VAZ). Both short- and long-term adjustments of the AZ/VAZ correlated with changes in photochemical efficiency (ΦPSII). When the plants were artificially darkened during the night, it became evident that the midnight sun prevents the complete relaxation of the xanthophyll cycle. These results indicate that light is the primary driver of photochemical efficiency in Arctic plants, and consequently, photosynthesis is not completely interrupted at night. [ABSTRACT FROM AUTHOR]

There is a growing appreciation that much of the trait variation within plant species is represented within individuals, for example, occurring among leaves within a plant. Subindividual variation is predicted to have key ecological consequences, but empirical understanding of how subindividual variation relates to species interactions, such as herbivory, is limited. We measured two physical defenses and herbivore damage on multiple leaves within individual plants of Piper polytrichum C.DC. (Piperaceae), a tropical understory shrub. We partitioned variance among- and within-plants and quantified patterns of trait and damage variation vis-à-vis leaf size and architectural position. We found that variance was considerably higher within plants than among plants for toughness (97%) and trichome density (57%), and that herbivore damage also varied most within plants (74%). Surprisingly, leaf position and size explained only small amounts of variance in traits (2.5%–16.5%) and herbivory (≤4%), indicating subindividual variability had low spatial predictability. The data suggest that individual P. polytrichum plants represent heterogeneous and spatially unpredictable landscapes of physical traits, and that interactions with herbivores are similarly variable. Our results are consistent with the hypothesis that subindividual variability defends plants against herbivores by increasing the difficulty of foraging for high-quality tissue. [ABSTRACT FROM AUTHOR]

The paper provides a list of 54 species of bryophytes (48 mosses and six liverworts) collected from Spitsbergen, the largest island of the Arctic Svalbard archipelago (Norwegian Arctic), in 2016. They were collected mainly from its southeastern coast (Sørkapp Land and Torell Land), which has been rapidly abandoned by glaciers in the last few decades and is heavily under-investigated bryologically. The most interesting and phytogeographically important findings are the mosses Bryum salinum, Campylium longicuspis, Coscinodon cribrosus, Orthogrimmia sessitana, Pogonatum dentatum, Polytrichum juniperinum, Sanionia georgicouncinata, Schistidium frigidum, and S. pulchrum, and the liverwort Cephalozia bicuspidata. For each species, a short taxonomic and phytogeographical comment is provided, and the distribution of 12 rare or otherwise phytogeographically interesting species in Svalbard is shown on maps. [ABSTRACT FROM AUTHOR]

An early-branched moss Polytrichum commune is a widely accepted model object for ecological, environmental, physiological, and genetic studies. Its mitochondrial genome has been sequenced and annotated. The genome contains 67 genes in total and has a length equal to 114,831 bp, which exceeds the length of most known mitochondrial genomes for mosses. A phylogenetic tree based on 33 coding sequences of mitochondrial genome was constructed, and the pairwise identity of whole mitogenome sequences was estimated for 44 Bryophyta species. Based on the analysis of pairwise identity, it was shown that mitogenomes of Tetraphis pellucida and Buxbaumia aphylla sufficiently differ from those of other Bryophyta species. The first known Bryophyta mitogenome rearrangement was identified in Pogonatum inflexum within Polytrichopsida. Based on the intergenic repeats occurrence in 44 bryophyte mitochondrial genomes and available data on repetitive elements content in other Viridiplantae groups, it was noted for the first time that greater stability of the moss’s mitogenomes is probably associated mainly with the absence of long (>1 kb) repeats. The phenomenon of absence of the intergenic repetitive elements in the terminal clades species was discovered.

The relationship between the small‐scale distribution pattern of bryophyte biomass on restored milled peatlands and substrate properties (e.g. moisture, pH, nutrients, and their ratios) was studied. Substrate properties may determine the species composition of bryophyte communities that have developed in such areas. Two experimental sites were established in northern Estonia where the moss‐layer‐transfer technique had been used for the revegetation of abandoned peatfields for almost a decade before sampling. Diaspores of Sphagnum species common on bogs were distributed in these sites. After 7 years one site was mainly dominated by Sphagnum whereas true mosses (Polytrichum strictum, Aulacomnium palustre, and Pleurozium schreberi) were abundant in the other site. Three moss groups were distinguished: Sphagnum, P. strictum, and other mosses based on cluster analysis. The biomass of Sphagnum was related to peat moisture and potassium content. For P. strictum the N/K ratio was important, and the production of A. palustre grew with the increase in the N/P ratio of peat. It was concluded that peat properties played an important role in the formation and development of bryophyte communities on revegetated peatfields on a small scale (<0.1 ha). [ABSTRACT FROM AUTHOR]

In the present paper, we compare how the kelp gull, Larus dominicanus, utilizes various nest building materials, particularly vascular plants, bryophytes, lichens and other components, in the Fildes Peninsula area (King George Island) and on the Argentine Islands area. In both areas, nest material primarily consisted of the Antarctic hairgrass (Deschampsia antarctica), bryophytes, lichens, feathers, limpets, and algae. Our study reveals area-specific differences in the utilization of plants for nest building related to local conditions during the nesting season. In the Fildes area, vegetation emerges from under the winter snow cover earlier in the spring, giving the gulls greater choice locally, meaning that the gulls need not resort to long distance material transfer. Here, mosses and lichens dominate in the nest material, likely collected from the nearby vegetation formations. The Antarctic hairgrass in these conditions is mostly found in nests located directly within hairgrass formations. However, on the more southern Argentine Islands, kelp gulls routinely use D. antarctica and some mosses, transferring them from coastal hill tops where snow generally disappears earlier. Here, the gulls appear to be selective still, as they rarely use some mosses, such as Polytrichum strictum, that are abundant near the nesting locations. In the Argentine Islands area, we documented long-range transfer of the Antarctic hairgrass and some other vegetation materials from places of abundance to bare rocks of low islands lacking developed vegetation. This demonstrates the potential of the gulls to serve as dispersal and gene pool exchange agents for the local terrestrial biota in the maritime Antarctic, especially between highly isolated populations from small islands and ice-free areas. [ABSTRACT FROM AUTHOR]

The western Antarctic Peninsula experienced rapid warming in the second half of the 20th century, which has increased vascular plant abundance and moss productivity. To better understand long-term ecological responses, we used paleoecological and microclimate data to investigate dynamics of late-Holocene peatbank development and landscape influences. In peatbank cores from three locations on Litchfield Island (64°46′S; 64°06′W) high-resolution plant macrofossil and geochemical analysis show contrasting ecological and environmental changes. Two peatbanks on the southwest- and west-facing slopes of two separate hills are about 500 years old in contrast to a north-facing peatbank that is 2700 years old. The period from 1350 to 450 calibrated years before present (cal yr BP) at the north-facing peatbank had low accumulation (0.25 mm yr −1 , 36 g OM m −2 yr −1 ), which we interpret as a period of low temperature and increased snow cover. Microclimate differences were amplified by this regional climate cooling, causing the delayed peat initiation on non-equator-facing slopes. Over the last 500 years, the north-facing peatbank had an accumulation rate (0.7 mm yr −1 , 76 g OM m −2 yr −1 ) that was lower than the southwest- and west-facing peatbanks (1–1.4 mm yr −1 , 97–110 g OM m −2 yr −1 ). Microclimate data suggest that slope aspect on Litchfield Island influences soil temperature, snow cover, and water availability that in turn affect growing-season lengths and peat accumulation. Plant macrofossils preserved in the north- and west-facing peatbanks show a centennial-scale pattern of fluctuation in relative abundance of dry-adapted Polytrichum strictum and wetter Chorisodontium aciphyllum mosses. Our results suggest that moss communities responded to external environmental influence, particularly those affecting moisture conditions, while topography and resultant microclimate differences had a strong influence on peat accumulation. [ABSTRACT FROM AUTHOR]

La découverte d' Oreoweisia torquescens (Hornsch. ex Brid.) Wijk & Margad., de Polytrichum pallidisetum Funck, de Scapania apiculata Spruce et de Scopelophila ligulata (Spruce) Spruce dans le massif de la Vanoise est présentée. Celle d' Oreoweisia torquescens confirme sa présence en France. Les affinités écologiques et les nouvelles localités sont brièvement décrites. Leurs répartitions sont discutées. The discovery of four species of bryophytes, Oreoweisia torquescens (Hornsch. ex Brid.) Wijk & Margad., Polytrichum pallidisetum Funck, Scapania apiculata Spruce and Scopelophila ligulata (Spruce) Spruce in the Vanoise Massif is presented. The presence of Oreoweisia torquescens in France is confirmed. Its ecological requirements and the news localities are briefly described. Their distributions are discussed. [ABSTRACT FROM AUTHOR]

The bryophyte diversity in northern British Columbia is insufficiently studied. We conducted a bryophyte survey in a 2.2-km2 proposed ecological reserve at the summit of Pink Mountain in the Peace River District of northern British Columbia. Pink Mountain is at the southern periphery of the ranges of several arctic flora species as well as the northernmost reaches of other temperate flora species. The south summit of Pink Mountain has a high floristic diversity coincident with its limestone geology, which provides a more alkaline condition for plant growth than the north summit does. We documented 65 species, including 2 new provincial records for British Columbia (Polytrichum hyperboreum and Tayloria hornschuchii), one red-listed (threatened) species (Tortula systylia), and one blue-listed (at-risk) species (Mnium arizonicum). Polytrichum hyperboreum and T. hornschuchii have affinities to habitats more typical of polar regions. The presence of P. hyperboreum at Pink Mountain represents a southward range extension from 61°33'N in western North America. Because isolated populations at species distribution limits are likely to be vulnerable to climate change, the establishment of an ecological reserve on the south end of the summit of Pink Mountain is important for the preservation of bryophyte habitat. [ABSTRACT FROM AUTHOR]

Questions Spontaneous revegetation from indigenous soil was used as a restoration method for peatlands degraded during road construction in northern Norway. We examined how plant community properties responded to the restoration, and which environmental factors affected the restoration success. Location Restored peatlands along roadsides at E10, mainland connection to the Lofoten islands, northern Norway. Methods The restored area originally consisted of poor to intermediate Sphagnum-dominated natural peatlands. Restoration consisted of stripping and stockpiling the topmost (30 cm) peat. The peat was stored for 1-2 yr before redistribution, with no further hydrological management. We conducted first time analyses of plant community properties 8 and 9 yr after restoration. We recorded vegetation and environmental variables in 108 plots distributed between 18 transects running from the road edge over the restored area to the undisturbed peatland. Undisturbed peatland was used as target for successful restoration. We used CCA and ANOVA to test the effect of restoration on species composition and richness. Results The ordination showed that species composition still differed significantly between restored and undisturbed plots, indicating incomplete restoration after 8 and 9 yr. Soil moisture, pH, slope and microtopography were the most important environmental factors for species composition. Polytrichum mosses had a high percentage cover in restored (30%) compared to undisturbed control plots (1%). Linear regression showed that peatland species decreased in abundance with increasing depth of Polytrichum cushions. Conclusion The low soil moisture level in the restored areas is most likely limiting the establishment of Sphagnum mosses, considered as key species of the typical peatland environment. Thus, the restoration method studied here must be improved to increase the soil moisture by raising the water table or reducing drainage. This should be done through reducing storage time of the peat before redistribution, and minimizing slopes and heterogeneity of the microtopography of the restored area. [ABSTRACT FROM AUTHOR]

Testate amoebae are widely used in ecological and palaeoecological studies of peatlands, particularly as indicators of surface wetness. To ensure data are robust and comparable it is important to consider methodological factors which may affect results. One significant question which has not been directly addressed in previous studies is how sample size (expressed here as number of Sphagnum stems) affects data quality. In three contrasting locations in a Russian peatland we extracted samples of differing size, analysed testate amoebae and calculated a number of widely-used indices: species richness, Simpson diversity, compositional dissimilarity from the largest sample and transfer function predictions of water table depth. We found that there was a trend for larger samples to contain more species across the range of commonly-used sample sizes in ecological studies. Smaller samples sometimes failed to produce counts of testate amoebae often considered minimally adequate. It seems likely that analyses based on samples of different sizes may not produce consistent data. Decisions about sample size need to reflect trade-offs between logistics, data quality, spatial resolution and the disturbance involved in sample extraction. For most common ecological applications we suggest that samples of more than eight Sphagnum stems are likely to be desirable. [ABSTRACT FROM AUTHOR]

We collected snow blight of moss, Polytrichum juniperinum on King George Island, maritime Antarctica. Host died in a circle of about 10-30 cm after snow melts. Clamp connected hyphae and no sclerotia were observed on tip of host leaves. DNA sequence of ITS region from moss symptoms were perfectly matched with fruit bodies of Typhula sp. on Macquarie Island in the maritime Antarctica and high homology with Typhula cf. subvariabilis from Iran. Therefore, we suggested that T. cf. subvariabilis caused snow blight on moss in Antarctica, and this is first record of Typhula snow blight in Southern Hemisphere. These results also suggested that fungi in same genera gained similar ecological niche in both Polar Regions. [ABSTRACT FROM AUTHOR]

The moss Polytrichum juniperinum was widely used by native North Americans and in traditional Chinese medicine to treat several illnesses including burns, wounds, bleeding, fever, kidney stones, and gallstones. This paper reports the efficient establishment of a protonema suspension culture of this moss and evaluation of key factors such as culture medium, trophic condition, initial pH, and inoculum size for increasing biomass production, which has scarcely been studied in this type of biological system. No significant differences were found for the maximum specific growth rate (μ~0.09 d) and the total phenolic content between MS, Knop, and PPNH media, although an effect on tissue differentiation was observed. Growth rate in a mixotrophic condition was (μ 0.27 d) three times greater than in autotrophic and heterotrophic conditions, reaching high cell densities (~11 g DW L). Moreover, simple sugars were secreted into the medium during the growth phase. P. juniperinum protonema cultures tolerated a wide initial medium pH range (4.5-8). The tissue growth index significantly decreased from ~7.7 to 1.9 with increased inoculum size (45-300 mg DW L) under photoautotrophic conditions. Similar responses were obtained under mixotrophic conditions with different sucrose concentrations (15-45 g L), but no responses to sucrose concentration and inoculum sizes were seen under heterotrophic growth conditions. Finally, this high cell density culture of P. juniperinum is suitable for further studies aimed at exploring and establishing a production platform for high-value secondary metabolites. [ABSTRACT FROM AUTHOR]

Metals deposited into ecosystems are non-degradable and become one of the major toxic agents which accumulate in habitats. Thus, their concentration requires precise monitoring. To evaluate pollution around a chlor-alkali plant, a glass smelter, two power plants and a ceramic and porcelain factory, we selected terrestrial mosses with different life forms: the orthotropic and endohydric Polytrichum commune and plagiotropic and ectohydric Pleurozium schreberi. Metal concentrations were determined in both species growing together at sites situated at various distances approximately 0.75, 1.5, 3 and 6 km from polluters. MARS analysis evaluated different tendencies of both species for Cd, Co and Pb accumulation depending on the distance from the emitter. In P. schreberi, the concentration of these metals diminished relatively rapidly with an increasing distance from the emitter up to 3000 m and then stabilised. For P. commune, a steady decrease could be observed with increasing the distance up to 6000 m. PCCA ordination explained that both species from the vicinity of the chlor-alkali plant were correlated with the highest Co, Cr, Cu, Fe and Pb as well as Mn and Ni concentrations in their tissues. The mosses from sites closest to both power plants were correlated with the highest Cd and Zn concentrations. P. commune contained significantly higher Cd, Cr, Ni, Pb and Zn concentrations compared to P. schreberi. This may be caused by the lamellae found in the leaves of P. commune which increase the surface area of the possible aerial absorption of contaminants. Soil may also be an additional source of metals, and it affects the uptake in endohydric P. commune more than in ectohydric P. schreberi. However, the precise explanation of these relations needs further investigation. [ABSTRACT FROM AUTHOR]

* Background and Aims Following the consensus view for unitary origin and conserved function of stomata across over 400 million years of land plant evolution, stomatal abundance has been widely used to reconstruct palaeoatmospheric environments. However, the responsiveness of stomata in mosses and hornworts, the most basal stomate lineages of extant land plants, has received relatively little attention. This study aimed to redress this imbal ance and provide the first direct evidence of bryophyte stomatal responsiveness to atmospheric CO2. * Methods A selection of hornwort (Anthoceros punctatus, Phaeoceros laevis) and moss (Polytrichumjuniperinum, Mnium hornum, Funaria hygrometrica) sporophytes with contrasting stomatal morphologies were grown under different atmospheric CO2 concentrations ([CO2]) representing both modern (440p.p.m. CO2) and ancient (1500p.p.m. CO2) atmospheres. Upon sporophyte maturation, stomata from each bryophyte species were imaged, measured and quantified. * Key Results Densities and dimensions were unaffected by changes in [CO2], other than a slight increase in stoma tal density in Funaria and abnormalities in Polytrichum stomata under elevated [CO2]. * Conclusions The changes to stomata in Funaria and Polytrichum are attributed to differential growth of the sporophytes rather than stomata-specific responses. The absence of responses to changes in [CO2] in bryophytes is in line with findings previously reported in other early lineages of vascular plants. These findings strengthen the hypothesis of an incremental acquisition of stomatal regulatory processes through land plant evolution and urge considerable caution in using stomatal densities as proxies for paleo-atmospheric CO2 concentrations. [ABSTRACT FROM AUTHOR]

Bryophilous ascomycetes are an overlooked and poorly known fungal group. In this study, the extreme and small-sized niche of Polytrichum piliferum hyaline leaf tips was screened for the presence of these fungi in Finland. Three closely related species were found. Bryochiton perpusillus and Bryochiton monascus were identified from several samples, and DNA isolations revealed a third closely related species, Bryochiton sp. In addition, melanised hyphae, typical to the Bryochiton species, were present in all the samples. According to phylogenetic analyses consisting of combined small subunit (SSU), large subunit (LSU), and 5.8S rDNA sequences, and internal transcribed spacer (ITS) rDNA sequences, the species showed affinity with Teratosphaeriaceae within Capnodiales , and especially with black, meristematic species often inhabiting rock substrate in extreme environments. The connection was supported by meristematic growth of the Bryochiton species in culture. Bryochiton is the second sexual genus associated within the family Teratosphaeriaceae , and B. perpusillus , and B. monascus constitute examples of teleomorphs within a group of meristematic anamorphs. These findings emphasize the multiform diversity underlying poorly researched fungal groups, such as the bryophilous fungi. [ABSTRACT FROM AUTHOR]

Because of its high mobility in ecosystems, mercury is one of the main toxic threats to the environment, and its concentration must be carefully controlled. To fulfill this need, we selected terrestrial mosses with different characteristic life forms: orthotropic and endohydric Polytrichum commune and plagiotropic and ectohydric Pleurozium schreberi . The concentrations of mercury were determined in both species growing together at sites situated approximately 0.75, 1.5, 3 and 6 km to the north, south, east and west, respectively of five known mercury polluters. The mercury concentrations reflected the emissions produced by the surrounding industry, reaching values of 0.44 mg kg−1 in P. schreberi and 0.79 mg kg−1 in P. commune in the vicinity of the chlor-alkali industry. To determine how long a load of Hg would remain in the mosses after mercury emitters restricted releases of Hg to the atmosphere, accumulation and desorption experiments were performed. We compared the two moss species collected from clean and moderately and heavily mercury-polluted sites. After eight days of exposure to mercury, P. schreberi accumulated up to 25 mg kg−1 of Hg, and P. commune accumulated up to 31 mg kg−1. Both in the field and in the experiment, P. commune accumulated significantly higher concentrations of Hg than did P. schreberi , most likely because of its surface morphology, which is likely to enhance the capture of metal from the atmosphere. After sixteen days of exposure, mercury changed the structure of the plasma membrane and affected organelles such as the nuclei and chloroplasts, leading to cell disintegration and death. The negative effects of mercury on the functioning of living cells appeared first in the older leaves of P. schreberi . After 64 days growing in the absence of Hg, P. schreberi clearly retained only 10–14% of the initially accumulated Hg, while P. commune retained 10–21%. [ABSTRACT FROM AUTHOR]

Facilitation between species could be used to increase the number of plant species that can survive on an extensive green roof. Green roofs are associated with high substrate temperatures and water loss which can lead to plant death. Therefore, species that are known to cool substrate temperatures and reduce water loss may be able to act as facilitators. Three drought tolerant, mat-forming species native to Nova Scotia were tested. Species included Cladonia spp. (lichen), Polytrichum commune (acrocarpous moss), and Danthonia spicata (bunchgrass). The target species was the forb Solidago bicolor . Additional neighbour treatments included an artificial plant, conspecific neighbours ( S. bicolor surrounded by 8 S. bicolor ), and a no-neighbour control. This study was conducted over a two year period in green roof modules. Overall, none of the neighbour treatments appeared to facilitate the growth of S. bicolor species. However, the S. bicolor in both the moss and lichen treatments had similar growth measurements to the control, likely due to a mulching effect, an indication that these species can successfully co-exist. Additionally, the substrate temperature in the lichen and moss treatments was significantly cooler than the control. The bunchgrass treatment had a net competitive interaction with S. bicolor . However since no S. bicolor died in this treatment the smaller stature of the S. bicolor in these treatments may improve drought tolerance. Overall, the incorporation of functional diversity, especially varied growth forms, increases the diversity of green roofs potentially improving the resilience and performance of green roof systems over the long term. [ABSTRACT FROM AUTHOR]

The Boreal black spruce forest is highly susceptible to wildfire, and postfire changes in soil temperature and substrates have the potential to shift large areas of such an ecosystem from a net sink to a net source of carbon. In this paper, we examine CO2 exchange rates (e.g., NPP and Re) in juniper haircap moss (Polytrichum juniperinum) and microbial respiration in no-vegetation conditions using an automated chamber system in a five-year burned black spruce forest in interior Alaska during the fall season of 2009. Mean ± standard deviation microbial respiration and NEP (net ecosystem productivity) of juniper haircap moss were 0.27 ± 0.13 and 0.28 ± 0.38 gCO2/m2/hr, respectively. CO2 exchange rates and microbial respiration showed temporal variations following fluctuation in air temperature during the fall season, suggesting the temperature sensitivity of juniper haircap moss and soil microbes after fire. During the 45-day fall period, mean NEP of P. juniperinum moss was 0.49 ± 0.28 MgC/ha following the five-year-old forest fire. On the other hand, simulated microbial respiration normalized to a 10 °C temperature might be stimulated by as much as 0.40 ± 0.23 MgC/ha. These findings demonstrate that the fire-pioneer species juniper haircap moss is a net C sink in the burned black spruce forest of interior Alaska. [ABSTRACT FROM AUTHOR]