Epiphytic Bryophytes Research Articles

Vertical variation in epiphytic cryptogam species richness and composition in a primeval Fagus sylvatica forest

AbstractQuestionBiodiversity surveys of epiphytic bryophytes and lichens on standing trees are mostly restricted to the lowermost 2 m, since sampling above this level is time‐consuming and therefore expensive. However, sampling only the stem base is likely to result in underestimation of forest epiphyte diversity, because microclimate and physico‐chemical site conditions, both of which vary with height above the ground, play important roles for poikilohydric organisms. We investigate variation in epiphyte diversity and composition along the vertical gradient in forests and discuss factors that may potentially account for height‐dependent distribution patterns.LocationMontane primeval beech forest Havešová in the Carpathians, eastern Slovakia.MethodsTen circular plots, each 500 m2, were selected randomly in an area severely affected by windfall. Epiphytes were sampled along the stems of recently uprooted trees, from base to the canopy. Mean Ellenberg indicator values (EIV) for light, moisture, acidity and nitrogen availability were used as surrogate variables for environmental interpretation of compositional patterns for sampling segments of 2 m along the stem.ResultsBy sampling only the lowest 2 m, 10% of the total bryophyte and 48% of the lichen species would have been missed. We detected systematic patterns of compositional variation for both groups along the vertical gradient. While pleurocarpous mosses and liverworts were mostly restricted to the stem base, acrocarpous mosses and crustose lichens occurred along the stem almost to the top. Foliose and fruticose lichens were concentrated at intermediate heights and in the upper canopy. Patterns of variation in EIVs suggested that increasing light availability, decreasing moisture and increasing inputs of acidic and nitrous substances are responsible for the compositional shifts along the vertical gradient.ConclusionsSampling only the stem base implies severe underestimation of the epiphyte diversity in temperate broad‐leaved forests. The middle and the upper parts of tree stems have distinctive compositions of epiphytic cryptogams, because microclimate and physico‐chemical site factors vary with height above the ground.

The epiphytic bryophyte vegetation of Kamilet Valley (Artvin, Turkey)

In this study, the vegetation of epiphytic bryophytes in the Kamilet Valley and its surroundings (Arhavi, Artvin) was investigated. The study area is located within the borders of the Eastern Black Sea Mountains and is one of the 122 important plant areas in Turkey. The investigation of epiphytic bryophyte communities was carried out in 2016 during different vegetation periods according to Braun-Blanquet?s phytosociological methodology. Phytosociological data obtained from 65 relevés were ordinated using detrended correspondence analysis (DECORANA) and classified using two-way indicator species analysis (TWINSPAN). Consequently, six epiphytic bryophyte communities new to Turkey were determined with TWINSPAN and DECORANA: Leucobryo-Tetraphidetum pellucidae, Anomodonto attenuati-Neckeretum crispae, Frullanio tamarisci-Exsertothecetum crispae, Ulotetum crispae, Anomodonto attenuati-Neckeretum crispae-leucodontetosum sciuroidis, and Ulotetum crispae-isothecietosum alopecuroidis. All syntaxa are presented by analyzing them in terms of their ecological and floristic classifications.

Distribution of epiphytic bryophytes in Wroclaw in relation to urban-use complexes

Abstract Studies on epiphytic bryophyte species richness and diversity in various urban-use complexes in Wroclaw (excluding urban forests) were conducted in 2013-2016 to check the research hypothesis that, in spite of the observed phenomenon of return of bryophytic epiphytes to cities, urban parks still favor species richness and the diversity of bryophytic epiphytes in built-up areas. Epiphytes (38 species) were recorded in all distinguished urban-use complexes but with strongly differentiated frequency, and 64% of all the trees colonized with epiphytes were situated either along streets or inside urban green areas (32% in each). It was shown that the highest species richness (89% of all the species found), bryophyte total coverage and values of the diversity indices referred to the latter complex. 20 species revealed preferences to occur mostly or exclusively on trees situated in urban parks. The second urban-use complex, which visibly affected the distribution of epiphytes, was the complex of streets; Tortula muralis occurred only on trees along streets and six other species occurred more frequently in these complexes than in others: Orthotrichum diaphanum, O. pumilum, O. pallens, Ceratodon purpureus, Syntrichia virescens, Bryum argenteum. In general, epiphytes – which were recorded on more than 20 trees – colonized a large number of phorophytes, from 12 to 33. They also showed some tendencies to occupy trunks of some host tree species more frequently than others. Detailed data are provided.

Variation in Acer saccharum Marshall (Sugar Maple) Bark and Stemflow Characteristics: Implications for Epiphytic Bryophyte Communities

Past studies have demonstrated successions of epiphyte communities on trees of progressively larger diameters, suggesting the existence of temporal resource-gradients associated with aging/growing phorophyte hosts. The objective of this study was to identify possible resource gradients associated with the diameter/age of Acer saccharum (Sugar Maple) in northern New York. We determined epiphytic bryophyte cover by species on 102 Sugar Maples (min–max = 11–84 cm diameter at breast height) from 12 Adirondack northern hardwood forest stands. We extracted a 12.6-cm2 bark sample from each tree to analyze in the laboratory for moisture-holding capacity, surface-moisture availability, drying rates, and leachate cation and nitrogen concentrations. We collected throughfall and stemflow from 15 trees (19–79 cm dbh) at a separate site over the course of a growing season and analyzed samples for cation and nitrogen concentrations. Bark mass per unit surface area (g cm-2) was positively correlated with tree diameter, reflecting increasing bark thickness with age. Bark moisture-holding capacity (H2O as % dry mass) was independent of tree diameter, but bark surface-moisture availability (g H2O cm-2 bark) increased with diameter as a result of thickening bark. Bark drying rates were negatively correlated with bark mass (thickness). Cation (Ca2+, Mg2+, K+) concentrations in bark leachate were all positively correlated with tree diameter, but NH4+ and DON concentrations varied independently of tree diameter, and NO3- concentrations were typically below detection limits. Stemflow became enriched 10- to 20-fold with dissolved cations but not with dissolved nitrogen. Percent cover of several mesophytic and calciphilic epiphytes (e.g., Anomodon rugelii, Brachythecium laetum, Neckera pennata, and Porella platyphylla) were positively correlated with cation concentration in bark leachate, bark thickness, and moisture availability, and negatively correlated with bark drying rate. The results of this study are consistent with hypotheses that increased moisture and nutrient availability and slower drying rates of bark on large-diameter trees may account for increasing total cover and species richness of bryophtyes and increasing dominance of mesophytic and calciphilic bryophytes on larger trees. We extend McCune's similar gradient hypothesis with an analogous set of nutrient-based gradients, and offer an alternative mechanism for McCune's original time-based moisture gradient.

Early responses of vascular plant and bryophyte communities to uniform shelterwood cutting in hemiboreal Scots pine forests

Shelterwood (SW) cutting is considered a sustainable harvest method but its impact on understorey diversity of Scots pine (Pinus sylvestris) forests has not been thoroughly studied. Our aim was to clarify how uniform SW cutting in interactions with soil scarification, deposition of logging residues and altered light conditions affects the species richness and composition of vascular plants and bryophytes and how different species groups and individual species vary in their responses to SW practices. We monitored permanent vegetation plots in nine mature pine forests of hemiboreal Estonia before, shortly after and 3–4 years after SW harvesting. The results indicated that the effect of uniform SW harvesting was species group specific as the majority of vascular plant species groups as well as mosses and epigeic bryophytes increased in richness, however, the species richness of epiphytic and epixylic bryophytes decreased. Late-successional species showed two types of responses to SW harvesting: either reduction of cover or reduction followed by a recovery. Soil scarification favoured early-successional bryophyte species as well as the richness of tree seedlings and dwarf-shrubs but diminished the cover of Vaccinium myrtillus, Vaccinium vitis-idaea and Hylocomium splendens. The harvest-induced changes in the species composition were more pronounced for bryophyte communities than for vascular plants. Retention of green trees and dead-wood is important in SW harvesting for sustaining the vulnerable epixylic and epiphytic bryophyte species. To summarise, uniform SW harvesting increases the species richness of vascular plant and bryophyte communities in pine forests - at least in the short term.

Epiphytic bryophytes in urban forests of Wrocław (SW Poland)

Abstract Data documenting the occurrence of epiphytic bryophytes in the urban forests of the Wroclaw city were collected and reported for the first time. Research was carried out in 2015-2016, in forest areas situated within the city administrative boundaries, to find whether some epiphytic species reported from the Wroclaw environs in the 19th century and presently considered to be primeval forest relicts occur in urban forests. The survey was carried out using the established network of 50 study plots randomly scattered within the urban forested areas. In total 42 species (4 liverworts and 38 mosses) were recorded on 467 trees; three of them are primeval forest relicts. In this paper, the host-tree preferences, distribution in the individual forests, relative frequency, abundance and exposure to compass directions of the studied taxa are analysed. Of the species described, only 17 are obligatory epiphytes, while 22 of them are character forest species. However, 82% of the latter were noted on a small number of tree trunks. Two moss taxa, Hypnum cupressiforme and Platygyrium repens, were most frequently found (on 76 and 50% of the trees, respectively). Among the species recorded in the studied area, there are five that have been showing some expansive tendencies in Europe in recent decades. The potential ability of these species to spread in urban areas is discussed in relation to their general ecological requirements.

Bryophyte stable isotope composition, diversity and biomass define tropical montane cloud forest extent.

Liverworts and mosses are a major component of the epiphyte flora of tropical montane forest ecosystems. Canopy access was used to analyse the distribution and vertical stratification of bryophyte epiphytes within tree crowns at nine forest sites across a 3400 m elevational gradient in Peru, from the Amazonian basin to the high Andes. The stable isotope compositions of bryophyte organic material (13C/12C and 18O/16O) are associated with surface water diffusive limitations and, along with C/N content, provide a generic index for the extent of cloud immersion. From lowland to cloud forest δ13C increased from -33‰ to -27‰, while δ18O increased from 16.3‰ to 18.0‰. Epiphytic bryophyte and associated canopy soil biomass in the cloud immersion zone was estimated at up to 45 t dry mass ha-1, and overall water holding capacity was equivalent to a 20 mm precipitation event. The study emphasizes the importance of diverse bryophyte communities in sequestering carbon in threatened habitats, with stable isotope analysis allowing future elevational shifts in the cloud base associated with changes in climate to be tracked.

Floristic composition and vertical zonation of epiphytic bryophytes in Dense Montane Ombrophilous Forest in southern Brazil

Dense High-montane Ombrophilous Forest possesses environmental characteristics that give it unique structure and floristic composition. Assuming that elevation and associated variables act as filters for bryophyte communities, the purpose of this study was to analyze the distribution of bryophytes in relation to vertical phorophyte zonation within the nebular forest, a type of rainforest in a high altitude environment, characterized by the occurrence of constant cloud, in Parque Estadual Pico do Marumbi, Parana, Brazil. All bryophytes occurring on twenty-eight trees in the elevation range of 1000 to 1500 m were sampled and analyzed in six predefined vertical zones. Samples were identified using standard methods and references for bryophytes, and their coverage and abundance was characterized for each tree. Comparisons among zones were done using cluster analysis and diversity. A total of 96 species and 31 families were recorded, with Lejeuneaceae being the richest family followed by Frullaniaceae. Some species were common to all areas, and eight new occurrences for the state of Parana are reported. This study found high diversity (ranging from H′ = 2.6 to H′ = 4.1) and abundance (0.01 to 0.07) of bryophytes, with a predominance of liverworts. Among the areas analyzed, the floristic compositions of only two differed by more than 50%. This study represents the first evaluation of bryophytes in this elevation range, and the results confirm the importance of conserving high montane regions.

Climate Warming Effects on Epiphytes in Spruce Forests of the Alps

Nascimbene J., Nimis P.L., Mair P. & Spitale D. 2018: Climate warming effects on epiphytes in spruce forests of the Alps. – Herzogia 31: 374–384.Climate warming in the Alps is setting major challenges to biodiversity conservation, potentially threatening epiphytic bryophytes and lichens, whose poikilohydric nature makes their eco-physiology strongly dependent on ambient temperature. In this work, we used species occurrence data along steep elevational-temperature gradients within the range of Alpine spruce-dominated forests for modelling the response of epiphytes to temperature shifts. Results provide evidence for species-specific and differently shaped species-temperature relationships, indicating that the sensitiveness of single species to climate warming is likely to influence community composition. Many epiphytes that currently occur in Alpine forests are vulnerable to warming, and may soon experience local extinction. The local assessment of the current altitudinal range of species may provide a tool to monitor the effects of warming by identifying the most critical species and the locations where their conservation is expected to be more effective.

The bryophyte flora of Fethiye Babadağ (Muğla/Turkey)

In this study was investigated the bryophyte diversity of Fethiye Babadağ (Muğla), was investigated. After identification of approximately 850 bryophyte samples collected from the research area, a total of 171 moss taxa belonging to 24 families and 68 genera, 19 liverwort taxa belonging to 15 families and 15 genera and one hornwort species were reported from the study area. Weissia armata (Thér. & Trab.) Fedosov and Fissidens arnoldii R. Ruthe were collected from the area as a second record for Turkey among the others. Additionally, Syntrichia minor (Bizot) M. T. Gallego, Pottiopsis caespitosa (Brid.) Blockeel & A.J.E. Sm., Weissia breutelii Müll. Hal, Lewinskya tortidontia (F.Lara, Garilleti & Mazimpaka) F.Lara, Garilleti & Goffinet and Orthotrichum vittii F. Lara, Garilleti & Mazimpaka which were recorded after 2000 and in very limited known localities in Turkey, were recorded from the study area. Moreover, epiphytic bryophytes of the mountain were also evaluated in this study. At the end, a total of 51 bryophyte taxa (4 liverworts and 47 mosses) were found on 17 different trees.

The Life Forms, Life Strategies and Ecological Characteristics of Epiphytic Bryophytes in Kamilet Valley (Artvin-Türkiye) and Surroundings

Bu çalışmada, Türkiye’deki 122 Önemli Bitki Alanından biri olan Doğu Karadeniz Dağları’nın sınırları içerisinde yer alan Kamilet Vadisi (Arhavi-Artvin) ve çevresinin epifitik briyofit florası ve briyofitlerin ağaç türlerine göre dağılımları araştırılmıştır. 2015 ve 2016 yıllarının farklı vejetasyon dönemlerinde ağaç gövdelerinden alınan toplam 428 briyofit örneğinin teşhis çalışmaları sonucunda, 51 takson (8 ciğerotu, 43 karayosunu) belirlenmiştir. Ekolojik ve floristik yönden incelenen taksonların hayat formu ve yaşam stratejisi analizleri de yapılmıştır. Hayat formlarından saçak ve yastık, yaşam stratejilerinden ise perennial kalıcıların baskın olduğu görülmüştür. Epifitik taksonlar tarafından en çok tercih edilen ağaç Alnus glutinosa olurken en az tercih edilen ağaç Pinus sylvestris olmuştur. Ayrıca, floristik listedeki taksonların çoğunun; mezofitik, sciofit ve subnötrofit karakterde olduğu görülmüştür.

Effects of natural forest dynamics on vascular plant, bryophyte, and lichen diversity in primevalFagus sylvaticaforests and comparison with production forests

AbstractStand structure, mean tree age, deadwood amount and microclimate all change markedly in the course of natural forest dynamics. The last remaining primeval forests of the temperate forest biome are valuable study objects to investigate the effects of forest dynamics and management on forest structure and function as well as phytodiversity, which is not sufficiently understood.Three pairs ofFagus sylvaticaprimeval and production forests in eastern Slovakia were selected for studying the effects of natural forest development stages on vascular plant, bryophyte, and lichen species richness and composition. We further compared the diversity patterns in the initial, optimal and terminal stages of forest development with those of nearby production forests.The plot‐level species richness of epiphytic bryophytes and lichens increased from the initial to the terminal stage, but only lichens exhibited a significantly higher cumulative species richness (γ diversity) in the later (optimal and terminal) stages. No increase in species richness from the initial to the terminal stage was found for deadwood‐inhabiting epiphytes and the ground‐layer vascular plants. Canonical correspondence analyses identified characteristic bryophyte and lichen species for the different development stages, while the bulk of vascular ground layer species occurred across all stages with no stage preference.Stem diameter was an even more important driver of epiphyte diversity and species composition than the development stage. All stages of the primeval forests (including the initial) were more species‐rich in epiphytes and, when investigating larger plot numbers, also in vascular plants than the production forests.Synthesis. In primeval forests of European beech, plant species richness did not differ significantly between the consecutive forest development stages, while species composition did. This is attributable to the small‐scale mosaic structure of the forest, rapid gap closure by beech, and the continuity of deadwood across the stages, which reduces spatio‐temporal differences in microhabitat availability in the forest. Bryophytes and lichens are species‐richer, and vascular plants at least similarly rich, in the primeval as compared to the production forests, if the study area is sufficiently large.

ПИГМЕНТНЫЙ СОСТАВ ФОНОВЫХ ЭПИФИТНЫХ ВИДОВ БРИО- И ЛИХЕНОБИОТЫ КРУПНЫХ ГОРОДОВ КАК БИОИНДИКАЦИОННЫЙ ПРИЗНАК

Выявлены биохимические показатели общего состояния воздуха в городах – содержание фотосинтетического пигмента в биомассе лишайников и зелёных мхов. Установлена валовая концентрация фотосинтетических пигментов (хлорофиллов а и b) и на их основе выделены 2 зоны: с высоким и низким содержанием пигментов для города Брянска и Орла.Оптимальное соотношение хлорофиллов а и b (5 : 3) не определено ни для одной пробы биомасс, в среднем для г. Брянска – 2,2 : 4,3, для г. Орла – 2,5 : 3,4. Малые значения концентрации хлорофилла а определены для экотопов эпифитных мхов и лишайников в центральных районах и для зон воздействия передвижных источников загрязнения. Для биомасс лишайников в пробах Орла максимальное значение концентрации хлорофилла а превышает минимальную концентрацию в 7,2 раза, для хлорофилла b – в 20,1 раза. Для биомасс мхов в пробах города Орла максимальное значение концентрации хлорофилла а превышает минимальную концентрацию в 8,3 раза, хлорофилла b – в 17,9 раз. Для биомасс эпифитных бриофитов в Брянске наибольшие значения валового содержания хлорофилла а выше минимальных в 5,2 раза, хлорофилла b – в 19,6 раз. Вариабельность показателей пигментов для гаметофитов фоновых видов зелёных мхов низкая, что подтверждает достоверность данных. Вариабельность признаков для Orthotrichum spesiosum по хлорофиллу а составила 12 %, хлорофиллу b – 17%, у Pylaisia polyantha по хлорофиллу а – 14 %, хлорофиллу b – 15%, у Amblystegium serpens по хлорофиллу а – 12 %, хлорофиллу b – 14%. Вариабельность концентрации пигментов для талломов лишайников низкая, находится в пределах нормы. Вариабельность признака для Xanthoria parietina рассчитана по хлорофиллу а – 11%, хлорофиллу b – 15%, для Phiscia ciliata по хлорофиллу а – 12%, хлорофиллу b – 17%, для Phiscia pulverulenta по хлорофиллу а – 13%, хлорофиллу b – 15%, для Melanelia olivacea по хлорофиллу а – 14%, хлорофиллу b – 12%. Для биохимической индикации общего состояния воздуха можно использовать содержание показательного пигмента – хлорофилла b. Для экотопов двух крупных городов староосвоенного региона создана база данных для биохимического мониторинга с использования распространённых видов биоиндикаторов.

Effects of gap and growth substrate on nitrogen and phosphorus contents of bryophytes in an alpine forest

Bryophyte plays an important role in nutrient enrichment and cycling in the forest ecosystems. The role of bryophyte in nitrogen (N) and phosphorus (P) cycles might be affected by forest regeneration and growth substrate. To understand the role of bryophyte in N and P cycling in the forest ecosystem, we measured the contents of N and P in the bryophytes that grew on different positions (gap center, gap edge, and closed canopy) and growth substrates (standing tree, fallen log, snag, large dead branch, stump and forest floor) in an alpine forest ecosystem. The results showed that the N content in the bryophyte on the forest floor was 3.12 mg·g-1, which was significantly lower than those on other growth substrates. Although N content in the bryophyte on the snag reached up to 17.41 mg·g-1, no significant differences of N contents in the bryophytes were observed among standing tree, fallen log, large dead branch and snag. The highest and lowest P contents was 1.09 mg·g-1 in the bryophyte on the forest floor and 0.61 mg·g-1 in the bryophytes on the snag, respectively. Furthermore, P content in the bryophyte on the forest floor was significantly higher than that on other growth substrates, but no significant differences of P contents in the bryophytes were detected among standing tree, fallen log, large dead branch and stump. The gap position significantly affected N and P contents in the bryophytes, with the N and P contents in the bryophytes on fallen log and large dead branch at gap center being significantly higher than those at the gap edge. The effects of coarse woody debris (CWD) on the N and P contents in the bryophyte depended on its types and decay classes, with their interaction having much stronger effects on N and P contents in the bryophytes. The N contents in the epiphytic bryophytes on fallen logs with V decay class were significantly higher than those with other decay classes. Similarly, the N contents in the epiphytic bryophytes on large dead branches with III decay class were significantly higher than those with other decay classes. Meanwhile, the P contents in the bryophytes on fallen logs with 2 decay class were significantly higher than those with other decay classes. Moreover, the P contents in the epiphytic bryophytes on the snags with 4 decay class were significantly higher than those with other decay classes. In conclusion, both forest gap regeneration and CWD decay process can affect the N and P contents in the bryophytes, and thereafter manipulate the nutrient cycles in the forest ecosystems.

Shifts in the importance of the species pool and environmental controls of epiphytic bryophyte richness across multiple scales.

Species richness is influenced by a nested set of environmental factors, but how do these factors interact across several scales? Our main aim is to disentangle the relative importance of environmental filters and the species pool on the richness of epiphytic bryophytes across spatial scales. To do so, we sampled epiphytic bryophytes in 43 oak forests across the northwest of the Iberian Peninsula. As predictorswe used climate, descriptors of forest structure and micro-environment. We applied structural equation modeling to relate these variables with richness and cover at three scales: locality (forest), stand (three stands per forest), and sample (a quadrate in a tree). We assumed top-down relationships, so that large-scale variables influenced lower scale variables, and in which cover directly influenced richness. Richness at the next larger scale (locality to stand and stand to sample) is considered a surrogate of the species pool and included as a predictor of richness at the next smaller scale. Environmental variables explain locality richness, but as we decrease the spatial scale, its importance decreases and the dependence on species pool increases. In addition, we found unexpected bottom-up relationships (between micro-scale environment to locality richness). Our results point to the scale dependence of niche vs. neutral processes: niche processes are important at the locality (forest) scale, while neutral processes are significant at the small (sample) scale. We propose a modified conceptualization of the factors influencing biodiversity at different spatial scales by adding links across different scales (between micro-environment and locality-scale richness in our study).

Orthotrichum patens Bruch & Brid. (Bryophyta, Orthotrichaceae) in Suffolk and Derbyshire, another epiphytic moss new to Britain

Orthotrichum patens is reported new to Britain from two sites in the counties of Suffolk and Derbyshire. Previous reports of this species in Britain are thought to be based on O. affine; they date from the nineteenth century at a time when the structure of the stomata was not recognised as significant. Orthotrichum patens is described and illustrated, and its diagnostic characters are discussed. Some comments are included on changes in the epiphytic bryophyte flora in Britain in recent decades.

Structural Complexity and Ecosystem Functions in a Natural Mixed Forest under a Single-Tree Selection Silviculture

The objective of forest management has become broader, and it is essential to harmonize timber production with conservation of the forest ecosystem. Selection cutting is recognized as a major alternative of clear-cutting, because it can maintain the complexity and heterogeneity of a natural forest; however, its long-term evaluations are limited. This study compared various attributes of stand structures, which are indicators of biodiversity and ecosystem carbon stock between managed and unmanaged blocks (12.6 ha area in total) in a natural mixed forest in Hokkaido, the northernmost island of Japan. We found that 30 years’ implementation of single-tree selection did not affect the volume, size structure, species diversity nor spatial distribution of overstory trees in the managed stands. Also, the total carbon stock in the managed stands was almost equal to that of the unmanaged stands. In contrast, several structural attributes and indicator elements that are significant for biodiversity (such as large-diameter live trees, dead trees, cavities, epiphytic bryophytes, and some avian guilds) showed marked decrease in the managed stands. We conclude that it is required to leave these structures and elements to some extent for deriving the merit of the management as an alternative silvicultural regime in the region.

Species richness and composition of epiphytic bryophytes in flooded forests of Caxiuanã National Forest, Eastern Amazon, Brazil.

This study aimed to compare the richness and composition of the epiphytic bryoflora between várzea and igapó forests in Caxiuanã National Forest, Brazilian Amazon. Bryophytes were collected on 502 phorophytes of Virola surinamensis. Average richness per phorophyte and composition between forests and between dry and rainy periods was tested by two-way analysis and by cluster analysis, respectively. In total, 54 species of 13 families were identified. Richness was greater in igapó forest (44 species) compared to várzea forest (38 species). There was no significant difference in the number of species between the studied periods. Cluster analysis showed the bryoflora composition was different between várzea and igapó, but not between dry and rainy periods. Results did not corroborate the hypothesis that várzea forests harbor higher species richness than igapó forests.

Environmental drivers of vascular and non‐vascular epiphyte abundance in tropical pre‐montane cloud forests in Northern Peru

AbstractQuestionsWhat is the role of microclimate relative to easily obtainable measures of forest structure in explaining epiphyte abundance? Do these roles differ between epiphytic plant groups?LocationTropical pre‐montane cloud forests, Alto Mayo watershed, northern Peru.MethodsWe recorded vascular epiphyte abundance, epiphytic bryophyte cover and forest structural features in 36 plots (20 m × 20 m), and measured air temperature and humidity in a subset of 17 plots. We modelled bryophyte cover, total vascular epiphyte abundance and the abundances of the main vascular epiphyte groups separately (bromeliads, aroids, ferns), as a function of forest structure and microclimate using spatial autoregressive models. Three forest structural variables (basal area, tree height and canopy openness) and two microclimatic variables (minimum humidity and maximum temperature) were considered. We constructed all possible combinations of maximum two‐variable models from the five explanatory variables and carried out AIC‐based model selection and variable importance tests with these as input models.ResultsCanopy openness was the most important variable explaining the abundance of the main epiphytic plant groups. It was also strongly correlated with stand microclimate. Therefore, predictions of epiphyte abundance did not improve with the inclusion of microclimatic data in the models. There were some differences among the epiphytic plant groups in their response to microclimate and forest structural features.ConclusionsForest stand microclimate, reflected through canopy openness in particular, was a main determinant of the distributions of all epiphytic plant groups. This implies that easily measurable forest structural variables alone can be used as good predictors of epiphyte abundance. Taxon‐specific differences in responses to microclimate imply that these taxa may also differ in their sensitivity to predicted future changes in temperature and rainfall.

Intensive forest management affects bryophyte diversity in the western Pyrenean silver fir-beech forests

Understanding how bryophytes respond to management gradients in temperate forests is an important issue for their conservation and has major implications for forest management. This is especially true for western Pyrenean silver fir-beech forests, where high bryophyte turnover, as well as species loss, has been reported in the last 30years. This study is the first to explore bryophyte diversity patterns across western Pyrenean silver fir-beech forests with different management intensities. Our specific aims were to determine the main drivers of bryophyte richness and turnover and explore which bryophyte species can be used as indicators of management intensity. The effect of management was assessed on the overall bryophyte diversity as well as on the bryophyte groups based on taxonomy, life cycle strategy, sensitivity to forest management intensity and habitat preference. Bryophyte diversity was analyzed by generalized linear mixed models and multiple regression analysis on distance matrices. The results suggest that bryophyte richness in the Pyrenean forests is decreasing with intensive forest management. The bryophyte richness decrease on highly disturbed stands can be attributed to a loss of suitable microhabitats, such as large trees. Elevational gradient, as a proxy of climatic factors, is also an important driver of bryophyte species richness in the studied area. Long-lived and epiphytic bryophytes decreased on steep slopes. Turnover was driven by elevation and percentage of large gaps, which might be linked with forest management. The results also suggest that Dierssen's classification of bryophytes regarding sensitivity to forest management is not suitable for the evaluation of the effects of forest management in the studied region. Our main recommendation for bryophyte conservation is to avoid intensive forest management and to minimize the forest practices in steep slopes which are prone to soil erosion.