Bryophyte Species Richness Research Articles

Bryophytes and Their Distribution Pattern in the Nagliai Strict Nature Reserve (Curonian Spit, Lithuania)

Jukonienė, I. & Subkaitė, M. 2017. Bryophytes and their distribution pattern in the Nagliai Strict Nature Reserve (Curonian Spit, Lithuania). — Herzogia 30: 16–35.Data on bryophyte species diversity in the Nagliai Strict Nature Reserve (Curonian Spit, Lithuania) are presented. Bryophyte diversity and their patterns of distribution across different habitats were analysed. Species richness, biotal dispersity, Shannon's diversity and evenness indices were used for the evaluation of bryophyte diversity in various habitats, and the Jaccard and Bray-Curtis coefficients employed for comparisons of similarity. A total of 75 species were recorded for the territory (32 in grasslands and 62 in forests). Two species and three varieties were new to Lithuania, and four species and one variety were new to the Curonian Spit. Variations in bryophyte species richness and relative abundance of the most frequently encountered species were observed for fore-dune grassland, sand plain and dune ridges.Distinct species composition was ascertained for various substrata located in both dry and wet forests. The most frequent species occurring throughout the territory were those that favoured dry conditions and grow on different substrata, whereas obligate epixyles and epiphytes were rare. Species preferring full light were the most frequently encountered taxa in grassland habitats.

Habitat heterogeneity and diversity of bryophytes in campos rupestres

Campos rupestres (rupestrian grasslands) are characterized by the presence of rock outcrops associated with an herbaceous-shrub physiognomy typically growing on quartzitic soils; they occur a wide variety of habitats. Bryophytes respond rapidly and efficiently to variation in microclimate. The present work aimed to study bryophyte species richness, diversity and composition, their life forms, and the substrates they colonize in exposed and shaded habitats in campos rupestres of Chapada Diamantina. Collections were made in 25 x 25 m sampling plots. One hundred and nine species were recorded and included a predominance of mosses (78 spp.) over liverworts (31 spp.). Most species (79 %) were restricted to one of the two types of habitat (exposed versus shaded). While the genera Campylopus, Polytrichum, Schlotheimia, Macromitrium and Syrrhopodon were prevalent in exposed habitats, Sphagnum, Lepidozia, Micropterygium, Bazzania and Odontoschisma prevailed in shaded habitats. The rupicolous community was more prominent than the other communities in both types of habitat. “Weft” was the most frequent life form in shaded areas, while “turf” predominated in exposed sites. The high number of rare, and exclusive, species illustrates the high degree of heterogeneity among bryophyte communities in campos rupestres, and demonstrates the importance of habitat heterogeneity for the high diversity.

Tree hollows can affect epiphyte species composition

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

Variations in Bryophyte Communities in a Short Elevational Gradient in Atlantic Forest of Southeastern Brazil

In order to better understand the influence of short elevational gradient on the attributes of bryophyte communities, we examined the bryophyte flora within six elevational belts (10, 50, 400, 800, 950, and 1170 m a.s.l.) on a mountain in the Atlantic Forest in southeastern Brazil. Ten subplots (10 × 10 m) distributed randomly in 1 ha forest plot of forest at each elevation were surveyed. A total of 253 species were encountered and the richness did not vary depending significantly on elevation. The floristic similarities of the elevational belts were high > 50%, with the exception of the Mountaintop forest (< 35%), and the classification analyses indicated groups defined by Atlantic Forest vegetation types. Endemism demonstrated a positive correlation with elevation, while the amplitudes of the phytogeographical patterns of the species diminished with increasing elevation. The dioicous condition predominated in all of the elevational belts, and the dioicous/monoicous ratio showed an inverted-parabolic pattern along the gradient. Data concerning bryophyte species richness and distributions will be useful in future projects monitoring the effects of climate change on tropical forests.

No detrimental effects of delayed mowing or uncut grass refuges on plant and bryophyte community structure and phytomass production in low-intensity hay meadows

To maintain European semi-natural grasslands, agri-environment schemes (AES) have been established in many countries but their biodiversity benefits have remained limited. We tested the effects of three new mowing regimes designed to benefit biodiversity in extensively managed meadows across the Swiss lowlands. Our experimental treatments mimicked easily implementable farming practices. We previously showed that invertebrates benefit from delayed mowing and leaving an uncut grass refuge. Here we focus on the effects on plant and bryophyte communities.We compared the standard AES practice (earliest mowing on June 15, no fertilizer input, but no restriction on number of cuts) to three alternative mowing regimes: (i) earliest mowing delayed by one month, (ii) maximum of two cuts per year with at least eight weeks in between, and (iii) leaving an uncut refuge on 10–20% of the meadow area in 12 study areas in the Swiss lowlands. We also tested for the interactive effects of ambient temperature, precipitation, elevation, meadow size, local forest cover, time since AES registration, and phytomass production.After five years of application, we found no difference in the effects of mowing regimes on vascular plant or bryophyte species richness, community composition, phytomass, flowering phenology or average plant height (the latter two indices were derived from the literature). However, cutting frequency and hay nutritional quality (C:N and Ca:P ratios) were lower under delayed mowing. Vascular plant and bryophyte species richness as well as forage quality were negatively related to phytomass, while the latter was positively related to mean summer temperature and negatively to time since AES registration.We conclude that supporting invertebrate biodiversity with alternative mowing regimes has no detrimental effects on the vascular plants and mosses, while the reduced forage quality calls for additional financial compensation of the farmers adopting these agri-environment schemes.

Solitary trees increase the diversity of vascular plants and bryophytes in pastures

Wooded pastures are semi-natural ecosystems that are often considered biodiversity hotspots and are valuable for nature conservation. Ongoing land-use changes, such as management intensification, threaten these ecosystems. Several studies have assessed the effect of tree density and cover on plant species richness, but the individual effects of single trees have not been addressed previously. We studied the effects of single sycamore maple trees (Acer pseudoplatanus) in sycamore maple wooded pastures on vascular plant and ground bryophyte species richness at six sites in the northern European Alps. In total, we found 346 vascular plant species and 264 bryophyte species. Alpha- and beta-diversity were positively influenced by the trees and positively related to tree size- and tree age-related variables. The positive effect of the trees on the species richness of epigeic bryophytes was reduced at high levels of management intensity, possibly due to severe disturbance by cattle trampling under the trees. However, our data showed that the diversity of the ground vegetation increased when trees were present, even in intensively managed pastures. Our findings highlight the high species richness present in sycamore maple wooded pastures at different spatial scales. The trees in sycamore maple wooded pastures can thus be considered keystone structures providing a range of important functions and conservation policies should particularly emphasize the conservation of large and old trees as well as the planting of young trees in these ecosystems.

Forest and substrate type drive bryophyte distribution in the Alps

Understanding the main factors driving bryophyte communities in forests is a worthwhile research area as it provides a framework within which to evaluate effective management options. Previous studies elucidated the role of forest structure, substrate, and climate, but their effect in a wide environmental context encompassing several types of forests is still unclear. The aim of this study was to assess the effect of climate, stand structure, substrates (tree trunks, deadwood, forest floor), and different forest types for species richness, species composition, and cover of bryophytes. Seven different types of Alpine forests dominated by spruce, larch-stone pine, silver-fir, Scots pine, oak, beech, and alder were selected. Bryophytes were sampled on tree trunks, deadwood, and forest floor. The importance of forest type, substrate, climate, and forest structure was determined by variance partitioning. Species richness and species composition were best explained by substrate (respectively 13% and 11%) and by forest type (respectively 13% and 11%). The bryophyte cover was primarily explained by the forest type (24%), and to a lesser extent by the climatic factors and stand structure. Overall, these results suggest that in this region ecologically based forest management might focus their efforts in protecting all the forest types and associated substrates. This means that forests of less economic value should also be preserved, and that acceptable silvicultural options should pay attention to the naturally available substrates. Too often, deadwood availability was a limiting substrate for bryophytes.

Comparing the responses of bryophytes and short‐statured vascular plants to climate shifts and eutrophication

Summary Few experimental studies have tested how abundance and diversity of grassland bryophytes respond to global environmental changes such as climate shifts and eutrophication. Because bryophytes in grasslands are low‐statured, and because plant height is a key functional trait governing plant responses to resource gradients, their responses to these factors could resemble those of better‐studied small vascular plants. Alternatively, traits unique to bryophytes could lead to qualitatively different responses than those of small vascular plants. In a semi‐arid Californian grassland system, where bryophytes are at relatively low abundance and their ecology has been little studied, we compared changes in cover and species richness of bryophytes and short‐statured vascular plants in response to 5 years of experimental fertilization, springtime watering and fertilization + watering, which produced strong gradients in vascular plant biomass. Supporting our hypotheses, the cover and richness of both bryophytes and short vascular plants were negatively related to total community biomass and tall vascular plant cover, and declined in response to the fertilization + watering treatment, in which the cover of tall vascular plants most strongly increased. Two divergent responses were also observed as follows: watering alone increased the cover of bryophytes but not short vascular plants, while fertilization alone reduced the cover of short vascular plants but not bryophytes. Bryophytes and short‐statured vascular plants in grasslands both may be expected to decline under projected global changes in climate and nutrient deposition that enhance total community biomass and competitive pressure. However, shifts in either precipitation or eutrophication regimes alone may have differential effects on bryophytes and short vascular plants in grasslands, and organism‐specific plant functional traits must also be considered. A lay summary is available for this article.

Tropical bryophyte floras: a homogeneous assemblage of highly mobile species? Insights from their spatial patterns of beta diversity

The impact of Pleistocene climate changes substantially varied between tropical regions, resulting in striking differences in angiosperm species richness caused by post-glacial recolonization delays. Tropical bryophytes, which have been perceived as extremely good dispersers due to biased rates of monoecy and hence spore production, differ strikingly from angiosperms in their similar patterns of species richness among tropical regions. Here, we analyse the patterns of beta diversity of tropical bryophytes to determine whether their high dispersal capacities have balanced patterns of species richness and erased any difference of post-glacial recolonization patterns between tropical regions. The partitioning of beta diversity for 7485 tropical moss species among 164 operational geographical units (OGUs) and 3276 liverwort and hornwort species in 154 OGUs revealed a slight, but significantly higher beta diversity among than within tropical regions. The nestedness component of beta diversity did not significantly differ between tropical regions. This indicates that, although regional migration rates were sufficient to erase differences of the impact of Pleistocene climate changes between tropical regions, the similar bryophyte species richness of tropical regions cannot be interpreted in terms of unrestricted migrations and that oceans act as a barrier to routine dispersal, which is sufficient to shape large-scale floristic patterns.

Grazers increase β‐diversity of vascular plants and bryophytes in wood‐pastures

AbstractQuestionsHow does the presence of grazers impact plant diversity at various spatial scales? What are the effects on plant β‐diversity and its two components, species turnover and nestedness? Are the effects caused by defoliation, trampling or defecating?LocationTwenty‐four currently grazed and 24 abandoned wood‐pasture sites in Central Finland.MethodsThe species richness of vascular plants and bryophytes was studied at four spatial scales: within 4‐m2 subplots (α1), within 100‐m2 plots (α2), within sites (α3) and within the landscape (γ). β‐Diversity was studied between subplots within plots (β1), between plots within sites (β2) and between sites within the landscape (β3).ResultsCurrently grazed sites had higher species richness at all of the spatial scales (α1, α2, α3, γ) and higher within‐plot and within‐site β ‐diversities (β1 and β2). At the within‐plot scale (β1) plant β‐diversity was increased primarily by variation in defoliation. At this scale both turnover and nestedness were increased by grazers. At the larger within‐site scale (β2) only turnover was increased, and it was mostly caused by variation in trampling intensities. Within the landscape (β3) currently grazed sites had higher between‐site turnover and lower nestedness than abandoned sites.ConclusionsGrazing creates and maintains high species richness and β‐diversity of vascular plants and bryophytes, mostly due to high species turnover between patches. Defoliation, dunging and trampling are all important turnover agents, although their relative importance varies with spatial scale. At the landscape scale the currently grazed sites had high species turnover between them, and thus the conservation of all grazing‐dependent species requires continued management at various sites, while high nestedness between abandoned sites implies that their biodiversity can be efficiently conserved through protecting the most species‐rich sites.

Change in the bryophyte diversity and species composition of Central European temperate broad-leaved forests since the late nineteenth century

The diversity and species composition of the bryophyte flora colonizing the forest floor, live trees and deadwood in semi-natural broad-leaved forests of northern Germany was compared between a recent survey in 2013 and historical records from around 1900. The survey was based on the comparison of presence/absence data and their interpretation with help of ecological indicator values. Total species richness has declined in bryophytes growing on the forest floor but not in the other guilds, whereas a dramatic species turnover was found for all three guilds. This turnover was apparently primarily driven by the increased atmospheric load of reactive nitrogen from anthropogenic emissions. Sensitive species were replaced by more eutrophication-tolerant bryophytes; liverworts are overrepresented among the sensitive and thus declining species. Promotion of the competitive strength of vascular plants due to increased nitrogen levels is the likely cause of the reduction of bryophyte species richness on the forest floor. Former acidification by high atmospheric sulfur dioxide loads has left an imprint in the bryophyte vegetation by having favored acidophytic species and discriminating against basiphytic species. An increase in the mean indicator value for temperature suggests a beginning effect of climate warming on the bryophyte vegetation. Change in forest structure had an apparently smaller imprint on the bryophyte diversity of the studied semi-natural forests than atmospheric chemistry and climate. In this respect, bryophytes differ from the ecologically similar lichens, where published studies from the same region showed a dramatic decline of species richness and a stronger susceptibility to forest management.

Impact of biotic interactions on biodiversity varies across a landscape

AbstractAimBiotic interactions have a central role in defining species assemblages, realized both through negative and positive impacts. However, forecasts of how these interactions affect biodiversity across landscapes are challenging (and lacking) because the outcome of interactions depends not only on the identity of the interacting species but also on local environmental conditions. Thus, we study how biotic interactions manifest across a landscape.LocationHigh‐latitude northern Finland and Norway (69° N, 21° E).MethodsWe modelled the influence of a dominant shrub, Empetrum hermaphroditum, on spatial patterns of species richness of vascular plants, bryophytes and lichens (using cover of the shrub as a proxy for the frequency and intensity of interaction with other species) across a topographically variable landscape.ResultsThe relationship between the cover of the dominant shrub and species richness differed between guilds, being strongest for vascular plant richness, and varied considerably along environmental gradients. The dominant shrub showed stronger negative impact on vascular plant richness under less abiotically extreme conditions. For lichens, the relationship was the opposite: under mild conditions, species richness increased with the cover of the shrub. Incorporating specific leaf area (SLA) data into analyses revealed that the dominant shrub affected species with high SLA (typically competitive species of resource‐rich environments) most negatively.Main conclusionsOur findings show how the impact of a dominant species varies across a landscape, with distinctly different effects on competitive and stress‐tolerant vascular plants, and on bryophytes and lichens. Spatial predictions of biodiversity trends under global environmental change could, therefore, critically benefit from accounting for context‐dependent impacts of biotic interactions.

How do ditches contribute to bryophyte diversity in managed forests in East-Central Europe?

The study focuses on identifying and assessing the effect of the presence of drainage and roadside ditches on the diversity of bryophytes in managed forests. We compared the composition of moss and liverwort species, their richness and abundance in plots that are located in ditches as well as corresponding control plots in the surrounding forests with regard to the forest type (coniferous, mixed and deciduous). ANOVA demonstrated the pronounced impact that the presence of ditches in managed forests has on an increase in bryophyte species richness. A comparison of forest and ditch types using DCA pointed to a correlation between the number of deciduous trees in the stands and an increased dissimilarity of ditch bryophytes when compared to the bryophytes of the corresponding control plots. Using the ecological indicator values, CCA confirmed the special significance of ditch settlements for hygrophilous species, which at present cannot otherwise find favorable conditions in managed forests. The study proves that ditches, and especially those with intermittent pools of stagnant water, may become a significant source of microhabitat diversity. Their presence may provide a welcome preserve for rare and protected species that cannot find suitable substrates in managed forests.

Microhabitat determines how grazing affects bryophytes in wood-pastures

Wood-pastures are biodiverse biotopes where livestock graze among trees. The diversity of several species groups is related to the structural diversity created by herbivores and by trees, decaying wood and rocks. One of the greatest threats to wood-pastures is abandonment that results in decreased heterogeneity of soil microhabitats as well as encroachment by young trees. We studied the diversity of bryophytes on different microhabitat types (soil, rocks, trees and decaying wood) in grazed and abandoned boreal wood-pastures (48 sites). Most species grew on soil, rocks or both. For both soil and rocks currently grazed sites had higher bryophyte species richness and several individual species also preferred grazed sites over abandoned sites. The grazers increase biodiversity by creating patches of bare soil and exposed rock surfaces. Currently grazed and abandoned sites did not differ significantly in bryophyte species richness on decaying wood or trees, and the overall bryophyte richness on these substrates was quite low due to the scarcity of dead wood and large living deciduous trees with suitable bark conditions. Rare species were observed on all microhabitats, most abundantly on soil and decaying wood. Especially our result on higher richness on rock surfaces shows the complexity of grazing effects on biodiversity. Grazers may affect the biodiversity of a species group that is not consumed by them, on a surface which is not attractive to them. These unobvious interactions should be recalled when planning wood-pasture management and conservation.

Survey of bryophytes in Serra da Canastra National Park, Minas Gerais, Brazil

Serra da Canastra National Park is located in southwestern Minas Gerais State and contains several phytophysiognomies of the Brazilian Cerrado. To date, no study on bryophytes has been conducted in this area and the present study is the first to be carried out in this major biological reserve of Cerrado located on the Brazilian Plateau. This study found 289 species of bryophytes, including mosses, liverworts, and one species of hornwort, representing fourty-one Brazilian endemic species and 56 new records for Minas Gerais State. Most species are widely distributed in Brazil, with only 16% having restricted distributions. Regarding worldwide distribution, 31% are Neotropical. Lejeuneaceae had the highest species richness among liverwort families with 53 species, whereas Sphagnaceae had the highest richness among moss families with 26 species. Phaeoceros laevis was the only hornwort species found in the park. This study contributes to the understanding of bryophyte species richness and distribution, and provides the worldwide and Brazilian distribution of the bryophyte flora of Serra da Canastra National Park, an important center for biodiversity conservation.

Human-sensitive bryophytes retreat into the depth of forest fragments in central European landscape

An importance of the edge effect and other environmental factors on bryophyte communities has been repeatedly evaluated in boreal forests whereas only rarely in forest remnants in traditionally inhabited landscape of central Europe. Adopting the design of a previous study dealing with vascular plants, we examined whether species richness and composition of bryophyte communities in 23 forest fragments (0.1–255 ha) in a representative upland agricultural landscape in central Bohemia coincides with the same environmental factors as vascular plants and if so, whether congruently or not. According to generalized additive models, bryophyte species richness and composition were significantly related to forest vegetation type, stand basal area and soil pH, analogous to vascular plants. Distribution of human-sensitive bryophyte species was further associated with slope aspect and an unlimited long-range edge effect, shown by increased occurrence of human-sensitive bryophytes along the entire distance gradient from the forest edge (0–477 m). Communities of bryophytes and vascular plants were highly congruent in species richness, species turnover and even in number of species with similar colonization ability. We conclude that requirements of human-sensitive bryophytes are fulfilled only in the core areas of large forest fragments. The small size of most current forest fragments and the range of the edge effect suggest that spatial patterns of bryophyte species composition within forest fragments have been substantially altered in the entire region of central Europe.

Reinvestigation on species richness and environmental correlates of bryophytes at a regional scale in China

Reinvestigation on species richness and environmental correlates of bryophytes at a regional scale in China

Genera as surrogates of bryophyte species richness and composition

Surrogates offer quick and cost-efficient solutions to assess and monitor biodiversity. In this study we have tested higher taxa surrogates, particularly genera richness and composition as surrogates for bryophyte species richness and composition, in two different habitats (exposed rock outcrops and watercourses), across two spatial scales (local and micro scale), in central and northern Portugal. Furthermore, we have also tested the influence of environmental variables on the richness and composition of species and genera. Our results showed significant and positive relationships between species and genera richness and composition for the habitats and scales studied. Also, concerning the analyzed scales analyzed, correlations between species and genera richness, as well as species and genera composition, were found to be positive and significant. Moreover, the environmental variables tested influenced species and genera richness and composition in the same way. In conclusion, the higher taxa approach could be an effective method for a rapid assessment and monitoring of bryophytes in the studied area, for the habitats and scales considered.

Latitudinal diversity gradients in bryophytes and woody plants: Roles of temperature and water availability

AbstractIt remains unclear whether the latitudinal diversity gradients of micro‐ and macro‐organisms are driven by the same macro‐environmental variables. We used the newly completed species catalog and distribution information of bryophytes in China to explore their spatial species richness patterns, and to investigate the underlying roles of energy availability, climatic seasonality, and environmental heterogeneity in shaping these patterns. We then compared these patterns to those found for woody plants. We found that, unlike woody plants, mosses and liverworts showed only weakly negative latitudinal trends in species richness. The spatial patterns of liverwort richness and moss richness were overwhelmingly explained by contemporary environmental variables, although explained variation was lower than that for woody plants. Similar to woody plants, energy and climatic seasonality hypotheses dominate as explanatory variables but show high redundancy in shaping the distribution of bryophytes. Water variables, that is, the annual availability, intra‐annual variability and spatial heterogeneity in precipitation, played a predominant role in explaining spatial variation of species richness of bryophytes, especially for liverworts, whereas woody plant richness was affected most by temperature variables. We suggest that further research on spatial patterns of bryophytes should incorporate the knowledge on their ecophysiology and evolution.

Weak response of bryophyte assemblages to second commercial thinning in boreal spruce forest of south-central Sweden

Forest management regimes dictate the composition and structure of large parts of the Fennoscandian boreal forest region. The understanding of thinning impacts on understorey plant communities is considerably lower compared to the effects of final felling. We studied the response of bryophyte assemblages to second commercial thinning in spruce-dominated stands sampled to be representative of the dominant forest type of south-central Sweden. Eighteen stands were analysed 6–12 years after second commercial thinning, and were compared with six stands commercially thinned only once, at two spatial scales (0.1 and 0.01 ha), with stand ages varying between 52 and 66 years. We found few strong differences in bryophyte species richness and no differences in bryophyte species composition between stands thinned once or twice. More pioneer species were found in stands thinned only once, a result that needs further study. Species richness declined significantly with time since thinning on both investigated spatial scales. Canopy cover significantly affected the composition of forest floor species. Thinning effects over longer time periods need further study, and also effects in different forest types along productivity gradients. For nature conservation, studies targeted towards thinning response of uncommon species connected to specific habitats and substrates will be essential.