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Summary The sexual reproductive organs of bryophytes – in which gametes necessary for fertilization are produced, namely, male antheridia and female archegonia – are formed from vegetative haploid gametophytes. In dioicous bryophytes such as Marchantia polymorpha, the genes within the sex‐determining regions in distinct sexual strains have been identified. However, in monoicous bryophytes such as Physcomitrium patens, how the two sex fates are specified on the same gametophyte remained unknown. Here, we identified an RWP‐RK domain‐containing transcription factor in P. patens, PpRKD, as a factor required for the development of female organs, based on the absence of archegonia in loss‐of‐function Pprkd mutants and the specific expression of PpRKD in archegonia. When ectopically induced, the expression of PpRKD resulted in the repression of antheridial development and the emergence of archegonium‐like organs. Furthermore, the young primordia inside the antheridial bundle displayed typical archegonial division patterns, suggesting that PpRKD confer female fate to antheridium primordia. This study represents the first instance where the function of sex determination has been identified among RKD orthologs in land plants. This finding should provide a new framework for the molecular evolutionary context of the genes in the RKD family, considering the recent elucidation of their roles in algae. [ABSTRACT FROM AUTHOR]

Vitamin B12, also known as cobalamin, is an essential organic cofactor for methionine synthase (METH), and is only synthesized by a subset of bacteria. Plants and fungi have an alternative methionine synthase (METE) that does not need B12 and are typically considered not to utilize it. Some algae facultatively utilize B12 because they encode both METE and METH, while other algae are dependent on B12 as they encode METH only. We performed phylogenomic analyses of METE, METH and 11 further proteins involved in B12 metabolism across more than 1600 plant and algal genomes and transcriptomes (e.g. from OneKp), demonstrating the presence of B12-associated metabolism deep into the streptophytes. METH and five further accessory proteins (MTRR, CblB, CblC, CblD and CblJ) were detected in the hornworts (Anthocerotophyta), and two (CblB and CblJ) were identified in liverworts (Marchantiophyta) in the bryophytes, suggesting a retention of B12-metabolism in the last common land plant ancestor. Our data further show more limited distributions for other B12-related proteins (MCM and RNR-II) and B12 dependency in several algal orders. Finally, considering the collection sites of algae that have lost B12 metabolism, we propose freshwater-to-land transitions and symbiotic associations to have been constraining factors for B12 availability in early plant evolution. This article is part of the theme issue 'The evolution of plant metabolism'. [ABSTRACT FROM AUTHOR]

Agricultural intensification has led to the loss of most natural wetlands from human‐dominated landscapes but, in recent decades, wetland restoration has gained traction worldwide. Restoration of suitable habitat conditions is hampered by nutrient residues from decades of high‐input farming, by continued input of nutrients from surrounding farmland and by incomplete restoration of natural hydrology. We assessed the effect of wetland restoration and disturbance (grazing) on vascular plant and bryophyte diversity in restored wetlands in Denmark at plot and landscape scales. Compared to near‐natural wetlands, we found a lower species richness and community uniqueness in restored wetlands, but we also found that grazing had a positive effect on vascular plant richness in restored wetlands. The size of the local species pool, presence of near‐natural habitat prior to restoration and near‐natural restored hydrology all had positive effects on plant diversity, whereas high soil iron and nitrogen had negative effects. Synthesis and applications: Restoration of plant diversity in wetlands is challenging, but our results point to potential remedies: plan restoration areas near colonisation sources of the target biota, restore hydrology to near‐natural conditions, discontinue nutrient loads from surrounding arable land and restore near‐natural grazing regimes. Bryophytes may be particularly useful as indicators for successful restoration of wetlands. [ABSTRACT FROM AUTHOR]

Remote sensing (RS) can be an efficient monitoring method to assess the ecological impacts of restoration. Yet, it has been used relatively little to monitor post‐restoration changes in boreal forestry‐drained peatlands, and particularly the linkages between changes in RS and plant species remain vague. To understand this gap, we utilize data from the Finnish peatland restoration monitoring network spanning 150 sites and a 10‐year post‐restoration monitoring period. We employ Bayesian joint species distribution models (Hierarchical Modeling of Species Communities) to study (1) the changes in optical Sentinel‐2 and Landsat satellite spectral signatures, (2) whether the RS variables improve predictions of vascular plant and moss species and functional type occurrence and cover, and (3) what kinds of associations exist between RS variables and plant species or functional types. Our results show that peatland restoration increases the reflectance of red and near‐infrared (NIR) bands in sparsely treed pine mire forests and open mires but not in densely treed spruce mire forests. Impacts on other tested RS variables consisting of moisture and greenness indices are less clear. Additionally, RS variables increase species‐ or functional type‐specific predictive power only modestly, and there are few clear links between the changes in RS variables and species or functional‐type occurrence and cover. We suggest that red and NIR reflectance can be used as satellite‐based indicators for peatland restoration success and further studies are required to develop usable methods for detecting species‐specific changes with RS. [ABSTRACT FROM AUTHOR]

The bryophyte genus Ulota has its main diversification area in Patagonia, with 18 currently accepted species, all of which are endemic to the area. Despite this richness, ongoing studies indicate the existence of hitherto unknown species in this territory. However, the strong resemblance between species often complicates the discrimination of new taxa, making the use of integrative taxonomy approaches compulsory. During surveys conducted in past decades, a morphotype of a Ulota , closely resembling Ulota macrodontia , was discovered coexisting with this species. Ulota macrodontia is characterized by unique peristomial features within the genus, and the variant morphotype shares these characteristics while displaying some distinct gametophytic and sporophytic features. Biometric analyses demonstrate that the differences are stable, and without intermediate states. The results obtained from the analyses of one nuclear and four plastid loci reveal a close relationship between both morphotypes, with the samples of U. macrodontia forming a well-supported monophyletic group. We propose to treat the new morphotype at species level (Ulota brachypoda sp. nov.), discussing why this is the most appropriate taxonomic rank, and we provide a detailed and illustrated description. Additionally, a distribution map of the two endemics is included. [ABSTRACT FROM AUTHOR]

The Hypnodendrales form the sister group to all other pleurcarpous mosses in the superorder Hypnanae. Many species are closely associated with the cool temperate rainforests of Australasia, while others are widespread in higher altitude wet forests across tropical South-East Asia. Several of the Malesian entities are taxonomically ambiguous, having been variously treated as species complexes or as single very variable species. Here we use dated phylogenies to examine the timing of diversification of major clades within the Hypnodendrales, test the hypothesis that widespread, taxonomically problematic species have diversified relatively recently in South-East Asia from within clades of southern temperate origin, and address taxonomic questions within Hypnodendron. A chronogram with broad taxonomic sampling is constructed, followed by a second dated phylogeny with dense sampling from Hypnodendron vitiense , a representative morphologically variable species found throughout Eastern Australia and South-East Asia. The crown group Hypnodendrales are found to have originated in the mid-Cretaceous, although they share a Most Recent Common Ancestor (MRCA) with the other Hypnanae in the late Jurassic. Extant members of Hypnodendron share a MRCA ±28 Mya, a little before the start of the collision of Australia with the Sunda plate that initiated the Australasian–Malesian floristic interchange. Within H. vitiense , there is strong phylogenetic structure consistent with the diversification and isolation of populations in South-East Asia within the last 10 Mya. The New Zealand endemic H. marginatum is found to be derived from within an Australasian clade of H. vitiense , this in turn being distinct from a South-East Asian/tropical Australian H. vitiense clade. Our results suggest that the phylogeography of this prominent group of mosses closely mirrors that of the rainforest ecosystems of which they are a part. [ABSTRACT FROM AUTHOR]

Weed control in container-grown ornamentals can be improved by careful herbicide selection. Four studies were conducted in greenhouses at Oregon State University to improve the understanding of how differences in the mode of action and formulation of herbicides can affect bryophyte control efficacy and crop safety. Granular (G) formulations of pendimethalin and indaziflam were compared with sprayable liquid (L) formulations of pendimethalin, indaziflam, and dimethenamid-p as well as with a nontreated control on four perennial container-grown ornamentals. Indaziflam in the L formulation performed better than that in the G formulations for controlling hairy bittercress up to 20 weeks after the initial treatment. Dimethenamid-p was more effective than indaziflam for liverwort and moss control. Pendimethalin in the G formulation less effectively controlled hairy bittercress than the L formulation did, but it performed better against moss during a second study. The L formulation of indaziflam injured Japanese pachysandra and boxwood and reduced root and shoot growth by 10% to 29%. Dimethenamid-p provided excellent control of the weed species tested and was safe for the crops, indicating its potential use as an alternative to hand-weeding in greenhouses. [ABSTRACT FROM AUTHOR]

Despite their ecological significance, non‐vascular photoautotrophs (NVPs) are frequently excluded from ecological experimental studies, leading to a limited comprehension of how their communities are affected by the ecosystem dynamics and an underestimation of their role in ecosystem functioning. We studied the impact of vascular plant taxonomic and functional diversity on three groups of ground NVPs (lichens, bryophytes, and cyanobacteria) within one of the longest‐running plant biodiversity experiments (Biodiversity and Ecosystem Function at Cedar Creek Ecosystem Science Reserve). Utilizing the permanent plot framework of this experiment, we analyzed the effects of almost 30 years of treatment across various levels of vascular plant taxonomic and functional diversity on NVPs. For each diversity level we documented NVP cover and richness. Using generalized linear models we evaluated the effect of vascular plant taxonomic and functional diversity, as well as environmental factors affected by vascular diversity (such as vascular plant cover, light penetration, soil nutrient content, and microtopography) on NVP richness and cover. Using these models, we conducted structural equation modeling analyses (SEM) that allowed us to differentiate the direct and indirect impacts of vascular plant taxonomic and functional diversity on NVPs. Our results showed that both lichen and bryophyte richness and cover decreased with higher vascular plant taxonomic and functional diversity, while cyanobacteria cover increased as a function of the same parameters. We also showed that microtopography serves as better predictor for lichens and bryophytes, while nutrient‐related factors perform better as predictors for cyanobacteria. Additionally, our findings indicate that NVP cover ranged from 0.001% to 100% (mean 15%) in the surveyed plots, representing a major, still ignored, component of the experimental plots. This study shows that vascular plant diversity directly and indirectly affects NVP communities, but the consequences of these effects at community and ecosystem levels are still to be explored. [ABSTRACT FROM AUTHOR]

In vitro culture experiments are crucial for studying chemically-mediated interactions in plants. However, the difficulty in distinguishing spores and sporelings of different bryophyte species hinders research on early developmental stages. Here we propose a modification of the sandwich technique, a standard method for studying plant allelopathic, and present a case study using two common mosses. As in the standard sandwich method, we have created a physical barrier using gelled medium, and inoculated spores of Tortula muralis and Syntrichia ruralis in two layers. To assess their intra- and interspecific interactions, we measured the green coverage of the protonemata using image analysis, and the degree of sporeling development using a categorical index. We successfully obtained physically separated sporelings of target and emitters from spores of these two species. The green coverage analysis showed no differences in any of the comparisons. However, the developmental index showed a negative effect of T. muralis on S. ruralis, whereas S. ruralis appeared to promote the development of T. muralis. The method proposed here is successful for culturing moss spores. The two inocula (the emitter and the receiver) are physically separated but the set-up allows the diffusion of water-soluble and volatile substances. For testing interactions at these early stages of the gametophyte, we recommend measuring the degree of development of moss sporelings rather than their coverage. Our results revealed both positive and negative interspecific interactions between T. muralis and S. ruralis sporelings. This supports that positive interactions in bryophytes may be more common than previously thought. [ABSTRACT FROM AUTHOR]

Knowing the centers of richness and endemism is crucial for prioritizing biodiversity conservation efforts, particularly in taxa susceptible to environmental changes and in regions of significant biological importance. We used species occurrence data from species lists, online information sources, and herbarium records to identify the centers of endemism of liverworts in Colombia. Sampling biases were assessed using the 'sampbias' package. Geospatial analyses were applied to identify species richness and endemism centers, with the latter identified using the NDM/VNDM algorithm. Species conservation status was evaluated based on IUCN Red List criterion B using the 'ConR' package. Despite low sampling efforts across all regions, the collection bias model revealed disparities in sampling, with fewer expected records in the Orinoco, Caribbean, and Amazon regions, highlighting the need for new inventories in these priority areas. The Andean (567 total species, 16 endemic species and subspecies) and Pacific (301 total species, 7 endemic species) regions stood out with higher richness. Two centers of endemism were identified: the Pacific and the Andean regions, emerging as priorities for conservation investments. Only 4% of the total area of the centers of endemism in Colombia was found within protected areas (PAs), and 40% of species were classified as threatened. Despite the challenges, 22.7% of the endemic species are found within PAs, underscoring the urgent need for efficient PA management, especially those located along the central Andes Mountain range. [ABSTRACT FROM AUTHOR]

Restoration efforts to maintain oak-dominated habitats and enhance biodiversity often employ selective thinning, but its long-term effect on multiple taxa remains unclear. This study examines the effects of halo thinning around pedunculate oak on epiphytic and tree-related microhabitat (TreM) diversity in the boreal–nemoral forest zone. We revisited nine sites in Latvia with 150–331-year-old oaks, where thinning was conducted in 2003–2004. Epiphyte species composition and cover were assessed, and TreMs were evaluated using standardised methods. Diversity indices (Hill numbers, q = 0; 1; 2; 3) and statistical models (LMMs, Poisson GLMMs) were used to analyse the effects of thinning on species richness and TreM occurrence. Halo thinning over the past 20 years has not caused significant differences in epiphyte or TreM diversity, though managed trees exhibited a higher occurrence of the most common microhabitats. These findings suggest halo thinning may enhance specific TreM features but do not substantially promote epiphyte and TreM diversity. Future research should implement systematic monitoring, deriving the relationships between the conditions after the thinning and their effects, thus serving as the basis for adaptive habitat management strategies. Expanding the scope of such studies is essential for developing evidence-based forest management strategies. [ABSTRACT FROM AUTHOR]

New forests on former agricultural land originate either from natural regeneration or active restoration. Previous research has compared biodiversity of naturally regenerated stands (NR) and plantations (PL), however, whether understory succession towards natural forests depends on stand type remains unknown. In this study, we used data from two monitorings on permanent plots (2011 and 2019) in PL (n = 11) and NR (n = 11) birch stands in Estonia to highlight successional changes in herb and bryophyte communities together with environmental changes. We further evaluated whether stand type influenced the recovery of forest specialists. We found an increase in tree growth characteristics, soil phosphorus and nitrogen content, no change in light conditions and a decrease in soil pH in both stand types. The amount of litter and deadwood was higher in NR in 2011. Herb richness increased from 123 to 130 and the number of bryophytes from 43 to 62. Stand types shared 50% of herb species in 2011 and 2019, while the fraction of shared bryophytes increased from 37.2 to 56.5%. We observed an increase of forest specialists and a decrease in light-demanding species (based on indicator value for light) in both stand types. Bryophyte cover and richness increased and species compositions of stand types converged. However, the number of bryophytes was significantly higher in NR plots indicating the significance of deadwood as growth substrate. We conclude that the recovery of forest understory followed similar successional pathways in PL and NR. [ABSTRACT FROM AUTHOR]

The moss Physcomitrium patens is a model system for the evolutionary study of land plants, and as such, it may contain as yet unannotated genes with functions related to the adaptation to water deficiency that was required during the water-to-land transition. In this study, we identified a novel gene, Bryophyte Co-retained Gene 1 (BCG1), in P. patens that is responsive to dehydration and rehydration. Under de- and rehydration treatments, BCG1 was significantly co-expressed with DHNA , which encodes a dehydrin (DHN). Examination of previous microarray data revealed that BCG1 is highly expressed in spores, archegonia (female reproductive organ), and mature sporophytes. In addition, the bcg1 mutant showed reduced dehydration tolerance, and this was accompanied by a relatively low level of chlorophyll content during recovery. Comprehensive transcriptomics uncovered a detailed set of regulatory processes that were affected by the disruption to BCG1. Experimental evidence showed that BCG1 might function in antioxidant activity, the abscisic acid pathway, and in intracellular Ca2+ homeostasis to resist desiccation. Overall, our results provide insights into the role of a bryophyte co-retained gene in desiccation tolerance. [ABSTRACT FROM AUTHOR]

The recovery rates and assembly processes of stream bryophyte communities after severe disturbances are not well known. Breaking of an ice dam caused an extreme flood that completely removed bryophyte cover along several hundreds of metres of a boreal stream (Stream Uopajanpuro, Koillismaa, NE Finland). We monitored recolonization rates and successional processes of stream bryophytes in the disturbed stream section over 8 years. In the first two summers after the disturbance, the disturbed section remained largely unvegetated. The initial recovery of the bryophyte community resulted mainly from colonization of vegetative moss fragments of the dominant, perennial species present in the undisturbed upstream section, whereas typical early successional colonist species remained scarce. The recovery of total cover, richness and community composition of stream bryophytes took 5–6 years after the disturbance event, even though bryophyte vegetation supplying fragments was located in the immediate vicinity upstream of the disturbance site. Bryophyte species showed differences in the colonization–recovery rates. Mean spatial segregation among species showed no trend during recovery, whereas several species pairs showed both segregation and aggregation trends. Our results indicate that extreme flooding can have devastating effects on bryophyte cover, and the recovery of bryophytes is slow compared to other stream organisms, with full recovery taking up to several years. This recovery time estimate may only apply if there is an immediate upstream source of vegetative propagules from undisturbed populations. Where such populations are absent, recovery of bryophyte communities can take decades. [ABSTRACT FROM AUTHOR]

Summary Large‐scale gene duplications (LSGDs) are crucial for evolutionary adaptation and recurrent in vascular plants. However, the role of ancient LSGDs in the terrestrialization and diversification of bryophytes, the second most species‐rich group of land plants, remains largely elusive due to limited sampling in bryophytes. Employing the most extensive nuclear gene dataset in bryophytes to date, we reconstructed a time‐calibrated phylogenetic tree from 209 species, covering virtually all key bryophyte lineages, for phylogenomic analyses of LSGDs and diversification. We newly identified two ancient LSGDs: one in the most recent common ancestor (MRCA) of extant bryophytes and another in the MRCA of the majority of Jungermanniales s. lato. Duplicated genes from these two LSGDs show significant enrichment in photosynthesis‐related processes and structures. Rhizoid‐responsive ROOTHAIR DEFECTIVE SIX‐LIKE (RSL) genes from ancient LSGDs are present in rhizoidless bryophytes, challenging assumptions about rhizoid absence mechanisms. We highlighted four major diversification rate upshifts, two of which slightly postdated LSGDs, potentially linked to the flourishing of gymnosperms and angiosperms and explaining over 80% of bryophyte diversity. Our findings, supported by extensive bryophyte sampling, highlight the significance of LSGDs in the early terrestrialization and diversification of bryophytes, offering new insights into land plant evolution. [ABSTRACT FROM AUTHOR]

The article explores the ancient role of flavonoids in land plants' adaptability to environmental stresses, highlighting their antioxidant properties and multifunctionality. Flavonoids have evolved to serve as defense mechanisms against stressors, modulate plant growth and development, and potentially emerged in response to biotic pressures and UV protection. They also act as signaling molecules, influencing auxin movement and belowground organ growth in angiosperms, while regulating human cell growth and metabolism through protein activities. The document further discusses flavonoids' interactions with hormone signaling pathways, stress responses, and their contribution to plant adaptation in changing environments, shedding light on their diverse roles in plant biology and specialized metabolism. [Extracted from the article]

Rho/Rac of plant (ROP) GTPases are plant-specific proteins that function as molecular switches, activated by guanine nucleotide exchange factors (GEFs) and inactivated by GTPase-activating proteins (GAPs). The bryophyte Marchantia polymorpha contains single copies of ROP (MpROP), GEFs [ROPGEF and SPIKE (SPK)] and GAPs [ROPGAP and ROP ENHANCER (REN)]. MpROP regulates the development of various tissues and organs, such as rhizoids, gemmae and air chambers. The ROPGEF KARAPPO (MpKAR) is essential for gemma initiation, but the functions of other ROP regulatory factors are less understood. This study focused on two GAPs: MpROPGAP and MpREN. Mpren single mutants showed defects in thallus growth, rhizoid tip growth, gemma development, and air-chamber formation, whereas Mpropgap mutants showed no visible abnormalities. However, Mpropgap Mpren double mutants had more severe phenotypes than the Mpren single mutants, suggesting backup roles of MpROPGAP in processes involving MpREN. Overexpression of MpROPGAP and MpREN resulted in similar gametophyte defects, highlighting the importance of MpROP activation/inactivation cycling (or balancing). Thus, MpREN predominantly, and MpROPGAP as a backup, regulate gametophyte development, likely by controlling MpROP activation in M. polymorpha. [ABSTRACT FROM AUTHOR]

The tailings dump of Barraxiutta (Sardinia, Italy) contains considerable concentrations of heavy metals and, consequently, is scarcely colonized by plants. However, wild populations of the liverwort Lunularia cruciata (L.) Dum. form dense and healthy‐looking carpets on this tailing dump.L. cruciata colonizing the tailing dump was compared with a control population growing in a pristine environment in terms of: (i) pollutant content, (ii) photochemical efficiency, and (iii) volatile secondary metabolites in thalli extracts.L. cruciata maintained optimal photosynthesis despite containing considerable amounts of soil pollutants in its thalli and had higher sesquiterpene content compared to control plants.Sesquiterpenes have a role in plant stress resistance and adaptation to adverse environments. In the present study, we propose enhanced sesquiterpenes featuring Contaminated L. cruciata as a defence strategy implemented in the post‐mining environment. [ABSTRACT FROM AUTHOR]

This paper describes a range of Paleozoic and Mesozoic mosses and assesses how far they can be referred to extant taxa at the family, ordinal, or class levels. The present study provides new data on Paleozoic mosses of the order Protosphagnales, re-evaluating affinities of some groups previously thought to be unrelated. The leaf areolation pattern, combined with the leaf costa anatomy, results in the subdivision of Protosphagnales into five separate families: Protosphagnaceae (at least six genera), Polyssaieviaceae (at least three genera), and three monogeneric families: Rhizonigeritaceae, Palaeosphagnaceae, and Servicktiaceae. We urge caution in referring Paleozoic and Early Mesozoic fossil mosses as members of Dicranidae and Bryidae, as they may belong to the extinct moss order Protosphagnales. Additional evidence supports the relation of the Permian genus Arvildia to extant Andreaeopsida. We segregate Late Palaeozoic and Early Mesozoic mosses that are superficially similar to extant members of either Dicranales or Polytrichales, into the artificial informal group of Archaeodicranids, distinguishing them from ecostate Paleozoic and Mesozoic mosses, which are combined here into another artificial informal group, Bryokhutuliinids. The latter includes the genus Bryokhutuliinia, widespread in contemporary Asia, from the Middle Jurassic to the Lower Cretaceous, as well as other superficially similar ecostate plants from different regions worldwide, ranging from the Upper Palaeozoic to the Lower Cretaceous. A list of Paleozoic, Mesozoic, and Eocene moss fossils suitable for age calibration in phylogenetic trees is provided. [ABSTRACT FROM AUTHOR]

Aquatic bryophytes are frequently used as bioindicators of water quality in rivers. Poor water quality increases physiological stress in moss, and stress levels can be estimated by measuring the concentrations of photosynthetic pigments and by calculating pigmentary indices. However, studies collecting many samples in a short time may need to store them until analysis. In the meantime, the pigments may suffer some degradation. Given the lack of studies on this problem for aquatic bryophytes, this one investigates the effect of three storage methods (refrigerated at 6 °C, frozen at − 20 °C and dried at room temperature) on the concentrations of chlorophyll a, chlorophyll b, pheophytin a and the following ratios: chlorophyll a/chlorophyll b, D430/D410, D665/D665a, D430/D665 and D480/D665 (where Dx is the absorbance at x nm) in the aquatic moss Fontinalis antipyretica. The results showed that refrigeration was the most suitable method, freezing might be suitable for some parameters, and drying was inadequate for this purpose. We recommend that all studies on photosynthetic pigments detail the time elapsed from collection to sample analysis, as well as the storage method used. [ABSTRACT FROM AUTHOR]

Funaria hygrometrica, a cosmopolitan moss species known for its remarkable dispersal capacity, was selected as the focal organism to investigate the relationship between landscape features and genetic diversity. Our study encompassed samples collected from two distinct regions: the Spanish Sierra Nevada Mountains (SN), characterized by a diverse landscape with an altitudinal difference of nearly 3500 m within a short distance, and the Murcia Region (MU) in Southeast Spain, characterized by a uniform landscape akin to the lowlands of Sierra Nevada. Genotyping analysis targeted three genetic regions: the nuclear ribosomal internal transcribed spacer (nrITS), the chloroplast rps3-rpl16 region, and the mitochondrial rpl5-rpl16 spacer. Through this analysis, we aimed to assess genetic variability and population structure across these environmentally contrasting regions. The Sierra Nevada populations exhibited significantly higher haplotype diversity (Hd = 0.78 in the highlands and 0.67 overall) and nucleotide diversity (π% = 0.51 for ITS1) compared to the Murcia populations (Hd = 0.35, π% = 0.14). Further investigation unveiled that samples from the lowlands of Sierra Nevada showed a closer genetic affinity to Murcia than to the highlands of Sierra Nevada. Furthermore, the genetic differentiation between highland and lowland populations was significant (ΦST = 0.55), with partial Mantel tests and ResistanceGA analysis revealing a strong correlation between ITS1-based genetic diversity and landscape features, including altitude and bioclimatic variables. Our study elucidated potential explanations for the observed genetic structuring within F. hygrometrica samples' populations. These included factors such as a high selfing rate within restricted habitats, a limited average dispersal distance of spores, hybrid depression affecting partially incompatible genetic lineages, and recent migration facilitated via human activities into formerly unoccupied areas of the dry zones of Southeast Spain. [ABSTRACT FROM AUTHOR]

Treating peat with nutrient-rich ash significantly increases the content of different nutrients in the substrate. Such ash treatment promotes the revegetation of abandoned extracted peatlands. The aim of this study is to analyze the effect of wood ash (WA15 = 15 t ha−1 and WA10 = 10 t ha−1), oil shale ash (OSA8 = 8 t ha−1), and a mixture of wood ash and oil shale ash (WA10 + OSA8) on the revegetation (vascular plants and bryophytes) of the Puhatu abandoned extracted peatland in NE Estonia. The following results were obtained: (1) The MRPP tests indicate that there are compositional differences between the treatments. (2) Altogether, 23 vascular plant and 3 bryophyte species were recorded in the treatment areas. (3) Nine years after these ash treatments, the highest mean vascular plant species richness was recorded for WA15 (3.8 ± 0.3) and the lowest for OSA8 (2.0 ± 0.3). (4) A greater number of vascular plant species was observed in the WA15 area. (5) Mixed ash and wood ash had a significant effect on the amount of biomass in vascular plants. Treating with either wood ash or a mixture of ash ensured the rapid formation of vascular plants and bryophyte layers, contributing to the restoration of the abandoned peatland ecosystem. [ABSTRACT FROM AUTHOR]

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]

IntroductionMethodsKey resultsConclusionsBased on previous analyses of Syntrichia norvegica and S. ruralis, the idea of panmictic populations in Scandinavia can be rejected, despite the high dispersal capacities of wind-dispersed spores. We tested, using comprehensive European datasets, whether intraspecific phylogeographical structure reflects glacial and post-glacial history. We expected different entities to indicate immigration from known Late Glacial Maximum refugial areas, and habitat differentiation.Using plastid markers (atpB–rbcL and rpl16), we investigated 45 and 190 Scandinavian and 17 and 15 non-Scandinavian specimens of Syntrichia norvegica and S. ruralis, respectively.We revealed four intraspecific entities in Syntrichia norvegica. Two were from the Scandinavian mountains and the Alps, and one from the Scandinavian mountains only. The fourth was widespread across the Scandinavian mountains, the northern lowlands, and the Baltic Sea islands Öland and Gotland. For S. ruralis, we recovered five entities, of which three were from both Scandinavia and the Alps. One of these occurred in strongly calcareous habitats in southern Scandinavia and the Alps and dominated on Öland and Gotland. One entity was widely distributed only in Scandinavia. One was restricted to the border between boreo-nemoral and southern-boreal Scandinavia.The plastid haplotype distribution patterns suggest glacial survival of Syntrichia norvegica and S. ruralis in refugia south, east and possibly within ice-covered areas of Scandinavia. We hypothesise that one S. ruralis entity evolved adaptations to strongly calcareous habitats. The dominance or prevalence of specific haplotypes of both species on Öland and Gotland contributes to the unique biodiversity of these islands. [ABSTRACT FROM AUTHOR]

The phenylpropanoid pathway is one of the plant metabolic pathways most prominently linked to the transition to terrestrial life, but its evolution and early functions remain elusive. Here, we show that activity of the t -cinnamic acid 4-hydroxylase (C4H), the first plant-specific step in the pathway, emerged concomitantly with the CYP73 gene family in a common ancestor of embryophytes. Through structural studies, we identify conserved CYP73 residues, including a crucial arginine, that have supported C4H activity since the early stages of its evolution. We further demonstrate that impairing C4H function via CYP73 gene inactivation or inhibitor treatment in three bryophyte species—the moss Physcomitrium patens, the liverwort Marchantia polymorpha and the hornwort Anthoceros agrestis —consistently resulted in a shortage of phenylpropanoids and abnormal plant development. The latter could be rescued in the moss by exogenous supply of p -coumaric acid, the product of C4H. Our findings establish the emergence of the CYP73 gene family as a foundational event in the development of the plant phenylpropanoid pathway, and underscore the deep-rooted function of the C4H enzyme in embryophyte biology. Synopsis: The phenylpropanoid pathway is assumed to represent a key plant metabolic adaptation associated with terrestrial life, and processes about 30% of all photosynthetic carbon on Earth. This study highlights the importance of the evolutionary co-emergence of the CYP73 gene family, which encodes t -cinnamic acid 4-hydroxylase (C4H) enzymes, in establishing this pathway in a land plant's ancestor. The CYP73 gene family emerged in an ancestor of land plants and has subsequently been conserved. The CYP73 gene family encodes C4H, the first plant-specific enzyme in the phenylpropanoid pathway, from the earliest stages of its evolution. Alteration of C4H function via CYP73 gene inactivation or inhibitor treatment consistently disrupts phenylpropanoid synthesis and development in land plants. This paper shows that the t -cinnamic acid 4-hydroxylase activity emerged with the CYP73 gene family in a common ancestor of all land plants. [ABSTRACT FROM AUTHOR]

Forests cover one-third of the global land and are important components of carbon and nitrogen cycling. Anthropogenic disturbances, such as forest road systems or skid trails for timber harvesting, can dramatically change the nutrient cycling in these ecosystems. Skid trails increase soil erosion and thus the displacement of soil organic carbon (SOC) and total nitrogen (Nt). Additionally, runoff transports high amounts of dissolved organic carbon (DOC), which can have a negative impact on aquatic ecosystems. One of the most important countermeasures against soil erosion is the quick recolonization of vegetation. To date, the extent to which natural vegetation succession influences the relocation of SOC and Nt, and in particular the role of mosses in this context, has not been well investigated. This study investigates the influence of natural vegetation succession and in particular of mosses on the displacement process of SOC and Nt as well as DOC caused by soil erosion. To this end, we combine the results of a field study using in-situ rainfall simulations with small-scale runoff plots in skid trails of the Schönbuch Nature Park in southwestern Germany with the results of ex-situ rainfall simulation experiments with infiltration boxes containing the substrate from the respective skid trails. The eroded sediments of skid trails were on average enriched in SOC by 16% and in Nt by 35% compared to the original soil, which lead to a decrease of the C/N ratio in sediments. As vegetation succession progressed, the displacement of SOC and Nt was reduced, confirmed by a negative correlation between the enrichment ratios of SOC (ERSOC), Nt and total vegetation cover. However, mosses tended to reduce ERSOC more than vascular plants. Additionally, mosses significantly decreased DOC concentration in surface runoff compared to bare soils, while no difference in DOC concentration in percolated water could be observed. Future research should explore the role of mosses in the storage of SOC and Nt in the soil and their impact on soil stability. Thus, utilizing mosses could potentially minimize environmental impacts from soil disturbances in forests. [ABSTRACT FROM AUTHOR]

The sporophytes of moss plants are dependent on the gametophytes for both photosynthesis and water, which makes conducting cells (hydroids and leptoids) an important part of the sporophyte anatomy. A previous study found that Physcomitrium pyriforme, which has shorter sporophytes, had higher rates of water transport than Funaria hygrometrica, which has taller sporophytes. The aim of this study is to test for differences in the conducting cell anatomy between these two moss species, which could be responsible for differences in water transport rates. We used histology methods to fix, embed, and section sporophyte seta and then quantified the numbers and sizes of the conducting cells. The results revealed that leptoids comprise a higher proportion of the conducting cell area in P. pyriforme, while hydroids comprise more of the conducting cell area in F. hygrometrica. These results point toward the leptoids playing a role in water transport in the moss sporophyte. [ABSTRACT FROM AUTHOR]

Anacolia menziesii sensu lato (Bartramiaceae) is a common and widespread moss in western North America that has been treated as either a single variable species or two distinct taxa, A. menziesii s.s. and A. baueri, with the two variously interpreted as species or subspecies. Interpretation has been hampered historically because the primary character used to separate the two entities, capsule shape, is absent on most specimens of this dioicous moss, and gametophytes have not yielded characters that can be used to separate the two putative entities with confidence. Here, we quantified previously categorical traits to test whether morphological characters are continuous across the geographic range or whether discrete morphological groups exist within A. menziesii s.l. We found that quantitative sporophyte characters replacing analogous categorical characters support the recognition of two entities, and that quantitative gametophyte characters also support the recognition of two entities. Furthermore, the two morphologically defined entities are overlapping geographically but have distinctive ecological niches. This provides strong evidence supporting the recognition of two species and provides new tools for separating sterile material. [ABSTRACT FROM AUTHOR]

Past efforts to identify and characterize minimally monophyletic groups (microgenera) by deconstructing larger bryophyte genera successfully determined 10 microgenera comprising the moss family Streptotrichaceae. Thirty other microgenera have also been found in the moss family Pottiaceae. A microgenus consists of one ancestral species and, optimally, four immediate descendant species, each of which shares exactly the same ancestral traits. To determine if microgenera were common, evidence of these in larger genera was garnered from published estimates of species per genus in other groups and from molecular cladograms in the moss family Pottiaceae. Both classical mesogenera and cladistically enlarged macrogenera exhibited an internal granularity of one to five species, either as multiple species below the inflection point in the hollow curve of logarithmic graphs of species per genus or as small groups of molecular cladogram branches. Microgenera are basic units of evolution. The constancy of size and monothecy of traits in microgenera give them properties that larger taxonomic groups lack. Sequences of microgenera monophyletic are easily concatenated, adaptational changes may be directly determined, self-similarity across scale allows extended scientific inferences, and traits can be associated with survival across millions of years of environmental perturbation. [ABSTRACT FROM AUTHOR]

This review summarizes recent progress in our current understanding of the mechanisms underlying the cell death pathways in bryophytes, focusing on conserved pathways and particularities in comparison to angiosperms. Regulated cell death (RCD) plays key roles during essential processes along the plant life cycle. It is part of specific developmental programmes and maintains homeostasis of the organism in response to unfavourable environments. Bryophytes could provide valuable models to study developmental RCD processes as well as those triggered by biotic and abiotic stresses. Some pathways analogous to those present in angiosperms occur in the gametophytic haploid generation of bryophytes, allowing direct genetic studies. In this review, we focus on such RCD programmes, identifying core conserved mechanisms and raising new key questions to analyse RCD from an evolutionary perspective. [ABSTRACT FROM AUTHOR]

Background and Aims Latitudinal diversity gradients have been intimately linked to the tropical niche conservatism hypothesis, which posits that there has been a strong filter due to the challenges faced by ancestral tropical lineages to adapt to low temperatures and colonize extra-tropical regions. In liverworts, species richness is higher towards the tropics, but the centres of diversity of the basal lineages are distributed across extra-tropical regions, pointing to the colonization of tropical regions by phylogenetically clustered assemblages of species of temperate origin. Here, we test this hypothesis through analyses of the relationship between macroclimatic variation and phylogenetic diversity in Chinese liverworts. Methods Phylogenetic diversity metrics and their standardized effect sizes for liverworts in each of the 28 regional floras at the province level in China were related to latitude and six climate variables using regression analysis. We conducted variation partitioning analyses to determine the relative importance of each group of climatic variables. Key Results We find that the number of species decreases with latitude, whereas phylogenetic diversity shows the reverse pattern, and that phylogenetic diversity is more strongly correlated with temperature-related variables compared with precipitation-related variables. Conclusions We interpret the opposite patterns observed in phylogenetic diversity and species richness in terms of a more recent origin of tropical diversity coupled with higher extinctions in temperate regions. [ABSTRACT FROM AUTHOR]

Ptychostomum pseudotriquetrum (Hedw.) J.R.Spence & H.P.Ramsay (Bryaceae) is a bipolar and one of the most widespread species within Antarctica, exhibiting a ubiquitous presence along the Antarctic Peninsula. This study analyzed its chloroplast genome, which is 123,172 bp in length, and consists of 82 protein-coding genes, four ribosomal RNA genes, and 31 transfer RNA genes. A phylogenetic tree, constructed using 58 conserved orthologous protein-coding genes from 19 complete chloroplast genomes of the class Bryopsida, confirmed that P. pseudotriquetrum belongs to clade Bryaceae. Within this clade, P. pseudotriquetrum diverged from the clade containing Anomobryum gemmigerum and Bryum argenteum. This study contributes to enriching chloroplast genome resources for the family Bryaceae and the genus Ptychostomum. Such advancement could facilitate future genetic investigations aimed at conserving and exploiting Antarctic bryophytes. [ABSTRACT FROM AUTHOR]

The dry forests of southern Ecuador are characterized by a great floristic variety and high endemism rates in different taxonomic groups; however, these forests are disappearing at an alarming rate due to anthropogenic disturbances. Epiphytic cryptogams (bryophytes and lichens) are important in seasonally dry tropical forests (SDTFs) and, due to their physiology (poikilohydric species), are sensitive to the changes associated with specific human disturbances. We examined the response of epiphytic cryptogams to habitat disturbance in SDTFs (natural and semi-natural forests) by registering the frequency and coverage of epiphytic cryptogams on 182 trees. We recorded a total of 53 epiphytic cryptogams (47 lichens and 6 bryophytes). A greater number of species was found in the natural forest, with 51 species, than the semi-natural forests (DFs), which had 45 species. We found that total richness tended to decrease with increased intensity of disturbance. The impoverishment was particularly related to the reduction in tree density and diversity (e.g., selective logging) in semi-natural compared to natural forests. However, the epiphytic composition showed little relationship with forests disturbance. We conclude that anthropic disturbance, particularly selective logging, are the main factors affecting the diversity of epiphytic cryptogams in the SDTFs from southern Ecuador. [ABSTRACT FROM AUTHOR]

Background: Systematic studies on the biodiversity of bryophytes along elevational gradients have been conductuted within the native vegetation of the Azores, using the MOVECLIM framework. The primary objective of this study was to inventory the bryophytes present within preserved areas of native vegetation in Terceira Island (Azores). From 25 to 28 September 2012, an inventory of the bryoflora was carried out along an elevational gradient, starting near Serreta lighthouse (38.76658 Latitude; -27.37539 Longitude; 40 m a.s.l.) and culminating on the top of Santa Bárbara Mountain (38.73064 Latitude; -27.32164 Longitude; 1000 m a.s.l.). The study followed the adapted MOVECLIM standardised protocol, as follows: i) six sites were selected along an elevational transect, each site spaced at 200 m elevation intervals; ii) within each site, two 10 m x 10 m plots were established in close proximity from each other (10-15 m); iii) within these plots, three 2 m x 2 m quadrats were randomly selected and sampled for bryophytes. The following substrates were surveyed in each quadrat: rock, soil, humus, organic matter, tree bark at three different heights and leaves/fronds. For each available and bryophyte-colonised substrate, three replicate microplots of 10 cm x 5 cm were collected, resulting in a maximum of 24 microplots per quadrat. New information: Nearly three-quarters of the maximum expected number of microplots (636 out of 864; eventID) were found across the six sites on Terceira Island, resulting in a total of 3677 records (occurrenceID). A high proportion of the specimens could be identified to the species rank (n = 3661; 99.6%), representing 38 families, 60 genera and 92 species, including 58 species of liverworts (Marchantiophyta) and 34 species of mosses (Bryophyta). The inventory included several endemic species: two liverwort species endemic to the Azores, five species endemic to Macaronesia (three mosses and two liverworts) and 11 European endemic species (three mosses and eight liverworts). The elevations with the highest species richness, the highest number of endemic species and the highest number of conservation concern species, spanned between 600 and 1000 m a.s.l. above sea level, coinciding with the best preserved forest vegetation. Overall, tree-dwelling and ground-dwelling substrates showed similar levels of bryophyte occupation (75% vs. 72%). However, the 636 events were unevenly distributed across substrates: leaves and rocks had the fewest replicates (n = 54; 50.0%), while humus and the lowest tree height had the highest values (n = 106; 98.1% and n = 98; 90.7%, respectively). The study contributed to expanding knowledge about the diversity and distribution of the Azorean Bryoflora, both on a local and a regional scale. [ABSTRACT FROM AUTHOR]

Over the last decade, access to global data has become increasingly critical for research, allowing insights into diverse biological, environmental and societal questions at a macro scale. Digitisation has greatly enhanced the use of herbarium data in the analysis of species distributions and ecological niche modelling. Yet, sources on modelling and mapping methodology using open-source software is greatly lacking for beginners. We have created a replicable and thorough tutorial to visualise species occurrence data and exploratory analysis that was developed by undergraduates with broad backgrounds and levels of experience. This tutorial integrates the open-source programmes QGIS, MaxEnt and R to develop distribution maps, using bryophytes as a case study, to promote the accessibility of open-source software and remote access learning. This tutorial has already set the foundation for further research into distribution modelling of rare Illinois bryophytes to better understand the potential impact of climate change.

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.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.

Three moss species are recorded for the first time in the Republic of North Macedonia. These are Brachytheciastrum dieckei, Kiaeria starkei and Orthotrichum schimperi. Details on records are given including distribution, georeferences and ecology. [ABSTRACT FROM AUTHOR]

Abstract Climate change significantly impacts the distribution of woody plants, indirectly influencing the dynamics of entire ecosystems. Understanding species' varied responses to the environment and their reliance on biotic interactions is crucial for predicting the global changes' impact on woodland biodiversity. Our study focusses on Dicranum viride, a moss of conservation priority, and its dependence on specific phorophytes (host trees). Using species distribution modelling (SDM) techniques, we initially modelled its distribution using climate-only variables. As a novel approach, we also modelled the distribution of the main phorophyte species and incorporated them into D. viride SDM alongside climate data. Finally, we analysed the overlap of climatic and geographic niches between the epiphyte and the phorophytes. Inclusion of biotic interactions significantly improved model performance, with phorophyte availability emerging as the primary predictor. This underscores the significance of epiphyte-phorophyte interactions, supported by substantial niche overlap. Predictions indicate a potential decline in the suitability of most of the current areas for D. viride, with noticeable shifts towards the northern regions of Europe. Our study underscores the importance of incorporating biotic interactions into SDMs, especially for dependent organisms. Understanding such connections is essential to implement successful conservation strategies and adapt forest management practices to environmental changes.

Plant communities are complex systems shaped by a combination of deterministic and stochastic ecological processes. Bryophytes are an essential component of plant diversity in natural ecosystems, yet our understanding of their community ecology needs to catch up to that of other organisms. The unique geological history, alpine climatic conditions, and high habitat heterogeneity of Tibet provide suitable areas for bryophytes to survive in the alpine regions. Therefore, field surveys were conducted across 184 plots in forest, thicket, and herbaceous vegetation of Tibet to investigate the role of deterministic processes such as biological interactions and abiotic effects, along with stochastic processes, in shaping the distribution of bryophyte assemblages. We employed various analytical methods, including mixed effects models, partial least squares path modeling, null model analysis, and neutral community models. The study showed that bryophyte richness was highest in forests. Bryophyte assemblages showed greater segregation in forest and thicket environments compared to herbaceous vegetation. As the influence of stochastic processes increased, that of deterministic processes decreased from forests through thickets to herbaceous vegetation. Deterministic processes were the main driving forces for the bryophyte assemblage pattern. Soil properties and climatic factors, particularly pH played a key role in determining bryophyte patterns in Tibet. This study has deepened our comprehension of how deterministic and stochastic ecological processes interplay and shape bryophyte distribution patterns in Tibet. [ABSTRACT FROM AUTHOR]

Climate change significantly impacts the distribution of woody plants, indirectly influencing the dynamics of entire ecosystems. Understanding species' varied responses to the environment and their reliance on biotic interactions is crucial for predicting the global changes' impact on woodland biodiversity. Our study focusses on Dicranum viride, a moss of conservation priority, and its dependence on specific phorophytes (host trees). Using species distribution modelling (SDM) techniques, we initially modelled its distribution using climate-only variables. As a novel approach, we also modelled the distribution of the main phorophyte species and incorporated them into D. viride SDM alongside climate data. Finally, we analysed the overlap of climatic and geographic niches between the epiphyte and the phorophytes. Inclusion of biotic interactions significantly improved model performance, with phorophyte availability emerging as the primary predictor. This underscores the significance of epiphyte-phorophyte interactions, supported by substantial niche overlap. Predictions indicate a potential decline in the suitability of most of the current areas for D. viride, with noticeable shifts towards the northern regions of Europe. Our study underscores the importance of incorporating biotic interactions into SDMs, especially for dependent organisms. Understanding such connections is essential to implement successful conservation strategies and adapt forest management practices to environmental changes. [ABSTRACT FROM AUTHOR]

The authors studied the content of photosynthetic pigments and their ratio during the warm period of the year (May–October) and during the period with stable snow cover (April) in sphagnum moss Sphagnum papillosum Lindb. on an oligotrophic bog in Arkhangelsk oblast. The content of photosynthetic pigments decreased from May to July, reaching a minimum, and then increased again by autumn. The content of pigments in moss tissues under the snow was comparable to the July minimum. Based on the results of factor and cluster analyses, it was suggested that the S. papillosum pigment complex in the first half of the growing season is adapted to high insolation and a long photoperiod, which is reflected by such indicators as the chlorophyll a/b ratio and the proportion of chlorophylls in the light-harvesting complex. In addition, during the growing season, the pigment complex apparently adapts to moisture conditions that depend on precipitation, especially during the period of summer decrease in the bog water level, which reflects the Chl/Car ratio. [ABSTRACT FROM AUTHOR]

Summary: Water scarcity, resulting from climate change, poses a significant threat to ecosystems. Syntrichia ruralis, a dryland desiccation‐tolerant moss, provides valuable insights into survival of water‐limited conditions.We sequenced the genome of S. ruralis, conducted transcriptomic analyses, and performed comparative genomic and transcriptomic analyses with existing genomes and transcriptomes, including with the close relative S. caninervis. We took a genetic approach to characterize the role of an S. ruralis transcription factor, identified in transcriptomic analyses, in Arabidopsis thaliana.The genome was assembled into 12 chromosomes encompassing 21 169 protein‐coding genes. Comparative analysis revealed copy number and transcript abundance differences in known desiccation‐associated gene families, and highlighted genome‐level variation among species that may reflect adaptation to different habitats. A significant number of abscisic acid (ABA)‐responsive genes were found to be negatively regulated by a MYB transcription factor (MYB55) that was upstream of the S. ruralis ortholog of ABA‐insensitive 3 (ABI3). We determined that this conserved MYB transcription factor, uncharacterized in Arabidopsis, acts as a negative regulator of an ABA‐dependent stress response in Arabidopsis.The new genomic resources from this emerging model moss offer novel insights into how plants regulate their responses to water deprivation. See also the Commentary on this article by Marks, 243: 828–829. [ABSTRACT FROM AUTHOR]

A foundational concept in ecology is the positive relationship between habitat heterogeneity and species diversity. Epiphytes demonstrate microhabitat specialization to particular areas within a tree; thus, epiphyte communities are potentially influenced by the structural heterogeneity of host trees. We evaluated the relationship between structural features of Acer macrophyllum and epiphyte distributions and abundance in a temperate rainforest in Washington, USA. Epiphytes and structural features of three Acer macrophyllum trees were systematically surveyed using the point-intercept method from the base to the crown and on three branches for each tree. Rarefied species richness increased with structural richness. Species richness along the trunk differed significantly among types of structural features (i.e., broken branches, burls, holes, rivets, branches, and trunks); broken branches had the highest species richness and branches had the lowest, followed by trunks. Rarefied species richness increased with height and peaked at 12 m, but the relationship between structural diversity and height was not significant. The species that occurred on branches were different to those that occurred on trunks, and species composition varied significantly among trunk features. The high structural diversity in northern temperate rainforest trees influenced the fine-scale distribution of nonvascular epiphytes and may explain their coexistence in tree crowns. [ABSTRACT FROM AUTHOR]

Biological nitrogen fixation (BNF) by bryophytes is an essential source of new nitrogen in nitrogen-limited boreal ecosystems. This assessment is, however, primarily based on reports from northern Europe and, to a lesser extent, Western North America. A more systematic and extensive evaluation of nitrogen fixation by moss is required to close current gaps in records of moss BNF and better assess the importance of bryophytes on N input in boreal ecosystems. Here, we evaluated nitrogen fixation activity and contribution to N input of dominant bryophyte species in black spruce forests from Eastern Canada. We assessed the relative abundance, BNF activity, and relative contribution to nitrogen input on five sites along a 600 km transect. We report that several moss species contribute to nitrogen input but that Ptilium crista-castrensis is the main contributor. Estimated nitrogen input by mosses (≪ 1 kg·ha−1·year−1) is in the low range of N inputs reported in the literature and is consistent with activities reported elsewhere for similar species, N deposition, and forest age. Results show that atmospheric deposition, while low, remains a more significant source of exogenous N to mature black spruce forests than bryophytes. [ABSTRACT FROM AUTHOR]

Background and Aims Desiccation tolerance (DT) is crucial for survival in arid environments, where organisms develop strategies in reproduction, maintenance and defence to cope with water scarcity. Therefore, investigating the relationship between reproduction and DT is essential to understand the ecology and adaptive strategies of species. This study explores the connection between the development of male and female gametangia in the moss Bryum argenteum and the decrease in DT during the progression of phenological phases in gametangia and protonema. Methods Samples collected from a dry tropical forest in Brazil were cultivated, cloned and subjected to desiccation. Subsequently, the physiological parameters of shoots and protonemata were analysed. Shoot and protonema regeneration were monitored for 28 d after the physiological analyses. Both phases were subjected to control and desiccation treatments. Key Results Significant effects of desiccation and sex on the physiological parameters and regeneration capacity of shoots and protonemata were found. Male shoots generally exhibited lower values of Fv/Fm (quantum efficiency of photosystem II) and ϕPSII (effective quantum yield of photosystem II), while females demonstrated higher values and better recovery after desiccation. Protonemata also showed variation in Fv/Fm over time and with sex, with no significant differences in ϕPSII between them. Desiccated male shoots had higher mortality rates and produced fewer new shoots. For females, the regeneration patterns varied between the desiccation-exposed groups and the control, with decreased shoot production, and some protonemata growing into filaments without forming shoots. Conclusion These findings improve our understanding of the ecological responses of bryophytes to desiccation stress and provide insights into their adaptive strategies in challenging environments, such as the possible rarity of males in dioicous moss populations. [ABSTRACT FROM AUTHOR]

In accordance with the 92/43/EEC "Habitats" Directive, Mediterranean temporary ponds are identified as a priority natural habitat within the European context. They are a very interesting and unique habitat type, as ecological conditions can vary greatly in a short period of time. Due to their small size, many Mediterranean hydrophytic bryophytes typical of this habitat are often overlooked or misinterpreted. Their distribution, habitats, ecology, and strategies are generally poorly understood. Several of them are currently considered rare or endangered in the Mediterranean. As these ponds are particularly sensitive to human activities and natural changes, such bryophytes and associated vegetation communities may be at risk. This study is focused on their floristic variability in different environmental conditions in two sites of particular phytogeographic interest in the Mediterranean area. In the Sardinian Pauli of Giara, 56 taxa (50 Bryophyta and 6 Marchantiophyta) were found, and in the Umbria Piana di Ferretto, 54 taxa (34 Bryophyta and 20 Marchantiophyta) were documented. The taxa from the two areas were analysed and compared. Life strategies, life macroforms, light and moisture preferences, chorological elements, and moisture belts were considered. The data are presented here together with information on the phytogeography and ecology of the species recorded. The findings indicate that a bespoke monitoring strategy and dedicated conservation measures are essential for the effective protection of bryophytes, ensuring the achievement of meaningful and sustainable conservation outcomes. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are widespread globally, primarily due to long-term anthropogenic pollution sources. Since PAHs tend to accumulate in soil sediments, liverwort plants, such as Lunularia cruciata, are susceptible to their adverse effects, making them good models for bioindicators. The aim of this study was to probe the impact of anthracene, a three-ring linear PAH, on the growth parameters of L. cruciata and the relationship established with the internalization of the pollutant throughout the phenology of the plant. Intrinsic plant responses, isolated from external factors, were assessed in vitro. L. cruciata absorbed anthracene from the culture medium, and its bioaccumulation was monitored throughout the entire process, from the gemma germination stage to the development of the adult plant, over a total period of 60 days. Consequently, plants exposed to concentrations higher than 50 μM anthracene, decreased the growth area of the thallus, the biomass and number of tips. Moreover, anthracene also impinged on plant symmetry. This concentration represented the maximum limit of bioaccumulation in the tissues. This study provides the first evidence that architectural variables in liverwort plants are suitable parameters for their use as bioindicators of PAHs. [ABSTRACT FROM AUTHOR]

Mosses are an early lineage of the plant kingdom, with around 13,000 species. Although an important part of biodiversity, providing crucial ecosystem services, many species are threatened with extinction. However, only circa 300 species have so far had their extinction risk evaluated globally for the IUCN Red List. Functional traits are known to help predict the extinction risk of species in other plant groups. In this study, a matrix of 15 functional traits was produced for 723 moss species from around the world to evaluate the potential of such predictability. Binary generalized linear models showed that monoicous species were more likely to be threatened than dioicous species, and the presence of a sporophyte (sexual reproduction), vegetative reproduction and an erect (straight) capsule instead of a pendent (immersed) one lowers the risk of species extinction. A longer capsule, seta and stem length, as well as broader substrate breadth, are indicative of species with a lower risk of extinction. The best-performing models fitted with few traits were able to predict extinction risks of species with good accuracy. These models applied to Data Deficient (DD) species proved how useful they may be to speed up the IUCN Red List assessment process while reducing the number of listed DD species, by selecting species most in need of a full, detailed assessment. Some traits tested in this study are a novelty in conservation research on mosses, opening new possibilities for future studies. The traits studied and the models presented here are a significant contribution to the knowledge of mosses at risk of extinction and will help to improve conservation efforts. [ABSTRACT FROM AUTHOR]

Environmental factors mediating community change over time have been well documented for vascular plants, but not for their non‐vascular relatives, bryophytes. Elevation is one variable that has been explored regarding bryophyte community change wherein as elevation increases, bryophyte communities increase in diversity and abundance, whereas diversity and abundance decline for vascular plant communities. This begs the question, how might other environmental variables such as slope and aspect influence bryophyte communities, and how might these variables drive community changes over time? Our study focused on bryophyte communities in high elevation, spruce‐fir zones in the Great Smoky Mountains National Park (GSMNP), located in the Southeastern United States to answer this question. Plots established in 2007 were revisited and reinventoried in 2020. Comparisons were drawn to determine whether changes in bryophyte coverage corresponded to canopy cover change and environmental factors including elevation, slope, and aspect. Diversity and abundance at the two timepoints were analyzed. Alpha diversity and turnover across orders of q were compared for different elevation zones. Bryophyte alpha diversity at q = 0 significantly declined over time in association with elevation, but at q = 2, changes in alpha diversity varied according to changes in gap fraction, a measure of canopy cover, and slope. Bryophyte coverage remained stable except in the highest elevation zone dominated by fir trees where there was a decline in coverage predicted by aspect. There were high rates of turnover across all elevation zones regardless of Hill number. In contrast with other studies which examine how environmental variables mediate community changes at q = 0, the species richness of a community, our study shows that the environmental drivers of bryophyte community change vary depending on how abundance is weighted. [ABSTRACT FROM AUTHOR]

The mutualistic arbuscular mycorrhizal (AM) symbiosis arose in land plants more than 450 million years ago and is still widely found in all major land plant lineages. Despite its broad taxonomic distribution, little is known about the molecular components underpinning symbiosis outside of flowering plants. The ARBUSCULAR RECEPTOR-LIKE KINASE (ARK) is required for sustaining AM symbiosis in distantly related angio-sperms. Here, we demonstrate that ARK has an equivalent role in symbiosis maintenance in the bryophyte Marchantia paleacea and is part of a broad AM genetic program conserved among land plants. In addition, our comparative transcriptome analysis identified evolutionarily conserved expression patterns for several genes in the core symbiotic program required for presymbiotic signaling, intracellular colonization, and nutrient exchange. This study provides insights into the molecular pathways that consistently associate with AM symbiosis across land plants and identifies an ancestral role for ARK in governing symbiotic balance. [ABSTRACT FROM AUTHOR]