Bryophyte Conservation Research Articles

Causes of the large variation in bryophyte species richness and composition among boreal streamside forests

Abstract:Questions: Boreal forests along small streams are bryophyte diversity hotspots because they are moist, productive and relatively high pH. Do these factors also explain the large differences in species richness and species composition found among streamside sites? Do the species of species‐poor sites represent nested subsets of the species of more species‐rich sites? How do the results apply to conservation?Location: Forests along small streams in mid‐boreal Sweden.Methods: Survey of the flora of liverworts and mosses and habitat properties, including calculation of a pH‐index based on species indicator values, in 37 sites (1000‐m2 plots).Results: The number of bryophyte species per plot ranged from 34 to 125. Neither soil moisture nor basal area of trees (a proxy for productivity) correlated significantly with species richness and composition, whereas pH‐index and cover of boulders did. Species richness and composition were more strongly correlated with pH‐index for mosses than for liverworts. The richness and composition of bryophyte species most frequently found on moist ground, stream channel margins and, most unexpected, woody debris were all more strongly associated with the pH‐index than with other habitat properties. Although species composition was significantly nested, there was still some turnover of species along the first ordination axis.Conclusions To attain high numbers of species, streamside forests need to have boulders and at least pockets with higher soil and stream‐water pH. The number of Red list species was weakly correlated with total species richness and the most species‐rich sites contained many species found more in non‐forest habitats. Hence, bryophyte conservation in streamside forests should not focus on species‐rich sites but on the quality and quantity of substrate available for assemblages of forest species that are strongly disfavoured by forestry.

Causes of the large variation in bryophyte species richness and composition among boreal streamside forests

Questions: Boreal forests along small streams are bryophyte diversity hotspots because they are moist, productive and relatively high pH. Do these factors also explain the large differences in species richness and species composition found among streamside sites? Do the species of species-poor sites represent nested subsets of the species of more species-rich sites? How do the results apply to conservation? Location: Forests along small streams in mid-boreal Sweden. Methods: Survey of the flora of liverworts and mosses and habitat properties, including calculation of a pH-index based on species indicator values, in 37 sites (1000-m2 plots). Results: The number of bryophyte species per plot ranged from 34 to 125. Neither soil moisture nor basal area of trees (a proxy for productivity) correlated significantly with species richness and composition, whereas pH-index and cover of boulders did. Species richness and composition were more strongly correlated with pH-index for mosses than for liverworts. The richness and composition of bryophyte species most frequently found on moist ground, stream channel margins and, most unexpected, woody debris were all more strongly associated with the pH-index than with other habitat properties. Although species composition was significantly nested, there was still some turnover of species along the first ordination axis. Conclusions To attain high numbers of species, streamside forests need to have boulders and at least pockets with higher soil and stream-water pH. The number of Red list species was weakly correlated with total species richness and the most species-rich sites contained many species found more in non-forest habitats. Hence, bryophyte conservation in streamside forests should not focus on species-rich sites but on the quality and quantity of substrate available for assemblages of forest species that are strongly disfavoured by forestry. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Progress Towards a Species Inventory for Conservation of Bryophytes in Ireland

Ireland has one of the richest bryofloras in Europe, with a wealth of Atlantic species that is shared only with western Scotland. Until recently knowledge of Irish bryophyte distribution has nevertheless been insufficient to inform conservation priorities. Intensive field surveys of rare and threatened bryophytes in Ireland were therefore carried out during 1999-2005 and are continuing. The draft Red List of Irish bryophytes from 1998 has already been greatly altered by this work, with deletion of 53 taxa that were under-recorded, whereas 24 taxa have been newly discovered in Ireland and several others that had been lost for more than a century have been rediscovered. The result should eventually be a more reliable Red List that provides an effective tool for conservation of threatened bryophytes, by recognising which taxa are really threatened and which populations are of greatest importance in a European context. Action to protect bryophytes in Ireland can then be developed more effectively. It has been realised that certain habitats are especially threatened, most notably the montane 'Northern Hepatic Mat', but also some coastal sites and intermediate fens.

Patterns, Hypotheses and Processes in the Biology of Rare Bryophytes

Dominant patterns and processes in rare bryophyte ecology are presented within the framework of current rarity theory. Available evidence suggests that bryophyte conservation should primarily consider the importance of establishment and habitat requirements for rare species. Preservation of rare and high quality habitats is essential. Future understanding of causes of rarity in bryophytes will benefit most by exploring the ecological drivers that allow species to expand their ranges. Comparisons of rare-common congeners, rare species throughout their range (not only where they are rare) and species currently experiencing range expansions or contractions are likely to yield the most robust and relevant data sets.

Ex situconservation of bryophytes: progress and potential of a pilot project

A pilot project was set up to investigate the potential use of ex situ techniques for the conservation of bryophytes by the Royal Botanic Gardens, Kew and the U.K. statutory conservation agencies (English Nature, Scottish Natural Heritage and Countryside Council for Wales) in August 2000. Successful protocols have been established for the initiation of plants collected from their natural habitats into axenic culture from sporophytes, gemmae and leafy gametophores. Methods have also been established for the long-term storage of explants in liquid nitrogen (cryopreservation). The existing collection incorporates a number of British Red List species, and includes some European Red List taxa. Current work focuses on expanding the number of species in the collection, both in culture and in cryo-storage. Protocols for the weaning and introduction of bryophytes into their natural habitats after cryopreservation are under development and a priority of the project.

Predicting bryophyte diversity in grassland and eucalypt‐dominated remnants in subhumid Tasmania

AbstractAim To determine the environmental factors associated with bryophyte diversity in remnants in a fragmented, agricultural landscape.Location Eighty‐two remnants of tussock grassland, eucalypt woodland and eucalypt forest in the subhumid Midlands region of Tasmania, Australia.Methods Remnants were surveyed for bryophytes and predictor variables, such as vascular plant cover, climate, and topography. Management histories for each remnant were compiled using both site observation and landowner surveys. Bryophyte cover, richness, and composition were related to the independent variables using simple correlation and general linear models.Results We found weak relationships between the dependent variables and the fragmentation variables (remnant area, remnant perimeter to area ratio, distance to nearest remnant, distance to nearest larger remnant, and remnant age). Instead, climatic variables were important in predicting bryophytes, in particular those affecting humidity (minimum temperature of the coldest month, precipitation). Despite extensive sheep grazing in this landscape, grazing was not correlated with bryophyte diversity. Bryophyte diversity was not explained by vascular plant richness and was only weakly explained by composition, but was predicted by the cover of vascular plants. There was greater bryophyte cover and richness and different composition where the cover of native vascular plants was lower.Main conclusions The implications of our results are that all remnants, regardless of area, age and isolation, appear to be valuable for bryophyte conservation in this highly altered landscape. Our results also suggest that the cover of the vascular plant community, rather than its diversity, holds promise as a guide to bryophyte diversity. Bryophyte composition was similar between sites and a focus on the most species‐rich sites may be the best conservation strategy in this ecosystem.

Cryptogam communities on decaying deciduous wood – does tree species diversity matter?

Bryophyte and fungal communities were investigated on fallen trees representing seven deciduous tree species in a mixed near natural nemoral forest. Bryophytes were represented by 41 taxa, including several very frequent species. Of the 296 fungal species, most were recorded with very low frequency and the share of high frequent species was much lower than among the bryophytes. Species turnover was bigger in the fungal communities, compared to the bryophyte communities, and related to a higher extent to measured differences in environmental conditions. Tree species diversity was found to be an important factor for fungal species composition, while only small differences in bryophyte species composition were found between the different tree species. On the other hand bryophyte species richness showed distinct relations to tree species and microclimatic variables, a tendency which was not evident for fungal diversity. It is concluded that the two organism groups to some extent differ in their conservation demands. Thus, conservation of wood-inhabiting bryophytes requires prioritising of large, coherent forest stands in which a stable humid microclimate and a reasonable supply of dead wood is secured. Successful conservation of fungi requires that substantial amounts of dead wood are left for natural decay in a variety of natural forest environments representing different tree species, so that heterogeneity in dead wood types is secured.

SUBSTRATE FORM DETERMINES THE FATE OF BRYOPHYTES IN RIPARIAN BUFFER STRIPS

Studies on the effectiveness of forest buffer strips left along streams after logging have long overlooked the biota of the buffers themselves, despite their high species richness. We investigated mosses and liverworts (bryophytes), abundant and species‐rich groups in boreal forests, before and 2.5 years after logging along 15 small streams. In each site, two 1000‐m2 (20 × 50 m) plots along the stream were inventoried; one plot in an area subjected to clear‐cutting, and another in a buffer strip (10 m wide on each side of the stream). Ten plots along small streams in forest reserves in the same region were used as references. We found that less than half as many bryophyte species per plot disappeared after logging in the buffer strips compared to the clearcuts. The changes in bryophyte cover and in species composition were smaller in the buffer strips, and the species that were negatively affected in the clearcuts were less affected in the buffer strips. However, there was a significant change in species composition in the buffer strips compared to the references. Substrate form and taxonomic group were important factors in understanding this turnover. Many species growing on substrates with a convex form (e.g., logs, tree bases, and mesic ground) decreased or disappeared, while species on concave substrates were rather unaffected. This held for both mosses and liverworts, although liverworts were generally more sensitive than mosses. The difference in response of assemblages on convex vs. concave substrates makes changes in microclimate due to logging a likely explanation. The species in most need of protection (i.e., the red‐listed species) were among the ones with strongest declines in the 20 m wide buffer strips. In order to function optimally for bryophyte conservation, forests along small streams need to be protected from high windthrow frequency and strong edge effects. Increasing the width of buffer strips at sites with known or potential values (e.g., large amounts of woody debris or boulders) should be considered a better strategy than using narrow buffer strips with a fixed width.

Bryophyte (moss and liverwort) conservation under remnant canopy in managed forests

Management of forest for timber values presents potential threats for forest floor bryophytes, as localized disturbances are applied across landscapes. Dispersal limitation may exacerbate local extirpation, by preventing recolonization within a cut-block rotation period. Populations of forest floor bryophytes that persist under those patches of tree canopy remaining after clear-cutting could reduce dispersal distances and thereby contribute to conservation of species across the landscape. We examined bryophyte guilds (liverworts, forest-habitat mosses and colonist–pioneer mosses) and community composition in relation to habitat quality (microclimate and substrate) in five treatment classes in New Brunswick Acadian forest, 4 years after harvest. Four potential refugium classes with intact substrate were examined: three were characterized by remnant canopy height, one was treeless. These were compared to clear-cut areas with substrate disturbance. Microclimate (temperature, total daily photosynthetically active radiation and vapour pressure deficit) differed significantly between areas with and without remnant canopy, but differed little among refugium classes. This suggests that any remnant canopy moderates microhabitat relative to treeless areas. Liverworts and forest-habitat mosses were more frequent under remnant canopy than in open and clear-cut areas, with 25 species present only under remnant canopy. Environmental variation explained approximately 24% of bryophyte pattern, highlighting the potential influence of the pre-harvest community, which we could not document. In the absence of substrate disturbance, patches of remnant canopy provide potential refugia for some forest-habitat bryophytes. Characteristics of effective refugia (size and shape) should be determined by assessments of their impacts on: (i) change in bryophyte communities in refugia relative to natural dynamics and (ii) recolonization of adjacent areas.

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

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

A GIS-based survey for the conservation of bryophytes at the landscape scale

Geographical information system (GIS) data on landscape features and land use were collected to predict bryophyte diversity and conservation value in order to determine the factors that favour bryophytes at a large geographical scale and propose the relevant conservation measures. Total species diversity and diversity in species of high conservation value were highly correlated, and the landscape features promoting them were the proportion of military lands, steep slopes, and broadleaf woodland. Military lands seemed to be especially important for the conservation of endangered species highly specialized to open habitats maintained by the appropriate level of disturbance. Woodland cover was also as a key factor for bryophyte diversity but landscape heterogeneity, such as steep slopes with a range of contrasting ecological conditions, was required to reach the highest species numbers. The GIS-based approach presented here may help focusing the attention on sites exhibiting the appropriate landscape features in terms of conservation, which is especially relevant in the context of the European network `Natura 2000' for designating, conserving, and managing the sites of high biological value.

Bryophyte conservation in Scotland

Summary Scotland has an internationally important bryophyte flora. The oceanic element in our flora is the most important, with the bryophyte communities of broadleaf woodland and montane heath being of particular significance. Until recently, all management for bryophyte conservation has been incidental; with bryophytes possibly benefiting from measures for the protection of the habitats in which they occur. Conservation interest in bryophytes as a result of wildlife legislation and the production of action plans has given an impetus to species conservation. So far this has been limited to baseline surveys, necessary because of the lack of knowledge of the status of most of the species involved. The small size and critical nature of the plants means that even basic survey work is problematic, the problems differing from species to species. Implementation of the action plans will need more autecological studies of some species and possibly some direct action for a small number with critical populations. L...

Relationships between productivity, number of shoots and number of species in bryophytes and vascular plants

Summary 1 We measured species density, biomass and shoot density for both bryophytes and vascular plants in 90 small plots in 18 calcareous fens. In addition, we recorded leaf area index and litter mass of vascular plants. Our goals were: (a) to compare the relationship between biomass and species density for the two taxonomic groups, (b) to test whether biomass and species density of bryophytes and vascular plants are related to their shoot density, and (c) to assess the degree to which biomass, shoot and species density of bryophytes are correlated with characteristics of the vascular plant layer. 2 For bryophytes there was a positive linear relationship between biomass and species density. Vascular plant species density was not related to biomass. Furthermore, bryophyte biomass and species density were linearly and positively related to bryophyte shoot density. For vascular plants, only biomass but not species density was related to shoot density. 3 We concluded that a bryophyte favourability gradient existed along which biomass and shoot and species density increased. This gradient was attributed to positive interactions within dense bryophyte stands, high clonal fragmentation, absence of competitive hierarchies and to the limited ability of larger bryophyte species to replace small species along this favourability gradient. 4 Since species density for vascular plants varied independently from biomass and shoot density, there was no such favourability gradient as for bryophytes. Large size variation, predominantly negative interactions between species, and clonal integration of species (e.g. tussock-forming grasses and sedges) may be responsible for the different behaviour of the two taxonomic groups. 5 Bryophyte favourability decreased with increasing vascular plant biomass. Concerning light availability, we found highest bryophyte favourability at intermediate levels where the combination of radiation and moisture seems to be optimal for bryophytes. No relationship was found between bryophyte favourability and vascular plant shoot density and litter mass. 6 The negative relationship between bryophyte favourability and vascular plant biomass is important for bryophyte conservation. Stands of low vascular plant production are those with the potential for highest species richness, and should therefore receive conservation priority.

Bryology and bryophyte protection in south-eastern Europe

This paper reports on the state of knowledge of bryophytes in south-eastern European countries and the level of protection of bryophytes there. The study also suggests actions to be taken in order to reach an acceptable level of bryophyte conservation in this region. The difficulties and peculiarities involved in protection of bryophytes in south-eastern Europe are also discussed, in general and by country. The aim of this study is to encourage bryological investigations in SE Europe and to revive interest in bryophytes and bryophyte protection in this region.

Integrating bryophytes into a forest management plan: lessons from grid-mapping in the forest of Soignes (Belgium)

Abstract 258 bryophyte species were recorded in the 4 380 ha of the forest of Soignes (Belgium). The specific richness is artificially increased by many bryophytes not characteristic of forests such as epilithic species and weeds. In addition, certain species characteristic of ancient woodlands, like Anomodon viticulosus, Brachythecium plumosum, Homalia trichomanoides, Homalothecium sericeum, Rhizomnium punctatum, Taxiphyllum wissgrillii and Thamnobryum alopecurum were found on the concrete of the drainage network. Thus, the richness of the forest of Soignes is partly due to the ability of the bryophytes to colonize habitats of substitution. This ability suggests that the use of bryophytes as indicators of ancient woodlands must be properly tested. Two species, Ephemerum stellatum and Orthotrichum consimile , belong to the European Red List of Bryophytes, while 20 other species are considered as rare or threatened in Belgium. In addition, the forest of Soignes represents a remarkable disjunct area of distribution in Belgium for a number of other species. The distribution of species richness is patchy, ranging from 37 species·km −2 to 122 species·km −2, with an average of 70.5 species·km −2 . The effects of current management practices on the bryoflora are documented, and suggestions for integrating bryophyte conservation with logging and recreation are made.

Bryophyte conservation in the UK

Bryophyte conservation in the UK

Conservation of Bryophytes in Europe. Means and Measures

Conservation of Bryophytes in Europe. Means and Measures

Effects on the flora in Norway spruce forests following clearcutting and shelterwood cutting

Clearcutting and shelterwood cutting of mature Norway spruce peatland forests were compared regarding the effects on the forest flora. Repeated observations of the field and bottom layer vegetation were made before and until 7 or 8 years after harvesting at four sites located along a gradient from southern to northern Sweden. Clearcutting resulted in a greater change of species composition compared with shelterwood cutting. Diversity, measured as Simpson's index, and species number per subplot were lower in the clearcut than in the shelterwood after 7 or 8 years. By applying Ellenberg's indicator values, it was concluded that shelterwood regimes may preserve species preferring shaded and moist conditions, whereas those species decreased after clearcutting. Species preferring high levels of nitrogen increased in the clearcut. According to both multivariate and univariate analyses, the vegetation changed in a similar direction at all sites, although the level of response differed considerably. Despite these similarities, there was a marked site effect, which was not surprising considering the large geographic variation between sites. It is concluded that shelterwood cutting might be a better alternative than clearcutting for forests on fertile peatland sites, with respect to conservation of vascular plants and bryophytes.

<strong>Conservation Status of Bryophytes in Eastern Australia</strong>

No bryophyte conservation programs are in place in Australia as the knowledge of bryophytes is poor, especially of their habitat preferences and distribution. The conservation of species against habitats is discussed and it is maintained on present evidence that areas conserved for vascular plants and/or animal habitats, as national parks and forest reserves, in most cases would adequately conserve bryophytes.

Protection of bryophytes in the Murmansk Region (Russia)

This paper reports on some basic trends in the conservation of bryophytes in the Murmansk Region (Russia). They are: (1) the recognition of rare bryophytes and the publication of the Regional Red Data Book (the first edition, including nine liverworts and 21 mosses was published in 1979, the second edition in 1990, including 108 species of bryophytes); (2) the investigation of the bryoflora in existing nature reserves, the majority of these territories being unexplored; (3) the description and organization of new nature reserves, where many rare and interesting species of bryophytes are concentrated. The difficulties and peculiarities in the protection of bryophytes in the Murmansk Region are also discussed.