Vascular Plant Species Composition Research Articles

Plant dispersal strategies in primary succession on the Tolbachinsky Dol volcanic Plateau (Russia)

AbstractQuestionsDispersal strategies are crucial in the colonization of disturbed landscapes. This influences species expansion in early‐successional areas, determines dispersal distances, and affects the structure of communities. Volcanic eruptions destroy vegetation over vast areas and trigger community assembly processes in hostile environments. The questions are (a) Which dispersal strategies are advantageous during the colonization of primary areas? (b) Which environmental constraints drive species distributions according to their dispersal strategies? (c) Which dispersal or establishment traits are beneficial in the filtering processes during the community assembly?LocationThe study area was located in a primary volcanic habitat formed by the volcanic eruption in 1975–1976 in Tolbachinskii Dol Plateau, Kamchatka, Russia.MethodsThe composition of vascular plant species along environmental gradients was recorded. The proportion of species with different dispersal strategies was analysed under various conditions to determine the most successful dispersal mode. Logistic regressions were used to investigate the relationship between dispersal modes and environmental variables. Filtering processes acting on dispersal or establishment traits were revealed using linear modelling.ResultsSpecies without appendages for wind dispersal predominated in remote exposed sites, while species with seeds adapted for effective wind dispersal were common in more vegetated habitats, which support trapping and facilitation. Endozoochorous seeds occurred in woody communities and predominated in mature forests. The results show that the determinants of species composition according to dispersal mode are woody debris, shrub layer coverage and microrelief. Dispersal modes and life‐forms converged in the most severe habitats.ConclusionsOn the tephra plain, species without special adaptations for wind dispersal benefitted through the colonization of primary habitats, whereas anemochorous seeds were blown into natural traps. The aerodynamic characteristics of seeds and the turbulent features of habitats were important in primary succession, as well as biotic facilitation and environmental conditions. Both dispersal and environmental filters interactively shaped the community structure in early succession.

Microtopography driven plant species composition in alpine region: a fine-scale study from Southern Norway

This study explores the relationship between the species composition of lichen and vascular plant species with microtopography at fine scale. We conducted our study in Hardengervidda National Park, Norway. Specifically, we aim to test whether the species richness of different plant life-forms peaks at middle of the microtopography gradient, and then explain the observed patterns with an aid of snow cover gradient along microtopography and snow cover. We sampled 69 species of vascular plants and lichens in 151 plots of 4 m2 along 23 transects during summer on Tronsbu, Sandhaug and Besso. Detrended correspondence analysis (DCA) was performed to explore how microtopographical gradient was related to the variation in the species composition. One-way ANOVA was performed to test the microtopographic variability in species richness. Afterwards, generalized linear model (GLM) was used to reveal species richness patterns along the snow cover gradient. The first axis in DCA represents the complex gradient from snow free ridge to wet snowbed habitats and the second axis represents a gradient from acidic to calcareous sites. Lichens species richness is greater in ridge than in snowbeds, while all other life forms follow the opposite trend. Species richness for total plant species, vascular plant species and herbaceous plant species increased with increase in weighted average snow indicator value (WASI), whilst species richness for lichen species declined substantially towards the maximum WASI value. In contrast, species richness for dwarf shrub species showed a unimodal relationship with WASI. This study shows that liquid water availability provides a good potential explanation for species composition and richness in mountains, which is controlled by snow cover and prevalent wind direction.

Nature-oriented park use of satoyama ecosystems can enhance biodiversity conservation in urbanized landscapes

Satoyama is one of the semi-natural ecosystems in Japan. Traditional agricultural practices in satoyama provide preferable habitats for many species, thus, enhancing biodiversity. However, many satoyama ecosystems have been altered by agricultural intensification and rapid urbanization. Meanwhile, ageing and shrinking population has led to the abandonment of remaining satoyama ecosystems, resulting in their potential degradation. We argue that counteracting the abandonment of satoyama is particularly essential in urbanized landscapes because conserving its biodiversity would have a payoff for urban communities. We focused on nature-oriented park use of satoyama ecosystems, utilizing their original scenery, topography, water features, and vegetation. To evaluate the potential of nature-oriented park use for biodiversity conservation, we examined the differences in diversity and species composition of vascular plants and butterflies among three land-use types (agricultural-use, park-use, and abandoned sites) of satoyama ecosystems. Diversity of native plants and butterflies did not significantly differ between agricultural-use and park-use sites and that of native plants was significantly lower at abandoned sites than at agricultural-use sites. Although species composition of native plants at agricultural-use sites and park-use sites significantly differ, that of native butterflies did not. The efficacy of park use for biodiversity conservation, thus, depended on the taxa. Nonetheless, for striking a balance between the difficulty in maintaining agricultural use and accelerating satoyama abandonment, our study highlights the utility of park use as an alternative usage, contributing to biodiversity conservation. Balancing the wise use of satoyama in urbanized landscapes is a fundamental step toward the conservation of its biodiversity and human–nature interactions.

Primary Successions of Vegetation on the Young Moraines in the Severo-Chuiskiy Center of Glaciation (Central Altai)

The primary successions of vegetation have been investigated in the continental conditions of the Severo-Chuiskiy center of present-day glaciation (Central Altai) from the colonization of deglaciated terrains by the first plants to the formation of simple plant groups to the primary plant communities. The observations were carried out for 15 years on the young moraines of the valley glaciers of Malyi Aktru (2200–2250 m a.s.l.) and Bolshoi–Levyi Aktru (2370–2500 m a.s.l.) in chrono-sequences from the ends of glaciers to the moraines of the mid-19th century. Three stages and four sub-stages of the primary succession of vegetation are identified. The species composition of vascular plants, mosses, and ground lichens is identified; the dominant species and the peculiarities of primary vegetation are characterized. Ideas about the course of successions and their peculiarities at different altitudes in the upper part of the forest and subchalet altitudinal zones are obtained. It has been found that, in the 150 year period, a young forest community has been formed on new moraines in the upper part of the forest altitudinal zone, and a combination of microcenoses similar to tundra communities have been formed in the alpine altitudinal zone. The primary succession of vegetation on both glacier forelands has some similarities, especially in early stages of ecosystem development (pioneer species composition and three-stage structure of successions). Strong differences appear during the late stages of succession. The primary succession of vegetation on the foreland of the Malyi Aktru glacier involves 146 species of vascular plants, 44 species of mosses, and 6 species of lichens. On the foreland of Bolshoi Levyi Aktru, 128 species of vascular plants, 26 species of mosses, and 8 ground lichens have been recorded.

СОСУДИСТЫЕ РАСТЕНИЯ СКВЕРА «САД СОЛОВЬЕВ» (Г. ПЕРМЬ)

Since 2009, the territory of the Cook log No. 3 (Motovilikhinsky district of Perm), called the "Garden of Solovyov Square", has been improved and landscaped by local enthusiasts. Its total area is about 10 ha, but only the southern part, which is about 1.5 ha, is actually developed. It’s used for planting ornamental species of woody and herbaceous plants. The work is carried out in accordance with the concept devel-oped by the invited specialists. Within its framework, landings are carried out on the so-called "experi-mental sites". These are a kind of introduction spots where cultivars of a certain orientation are planted. In the summer of 2020, we conducted a survey of the species composition of vascular plants in the “Garden of Soloviev Square”. A total of 290 species of vascular plants were found. Of these, 120 are wild-growing, 170 are cultivated, including 20 species – an old crop that has been preserved on the slopes since the existence of the "Michurinsky gardens". 9 species are invasive; 6 are listed in the Appendix to the Red book of the Perm region (2018), and one species, Geranium sanguineum, is listed in the Red book with status III. The square is intensively used for environmental education and enlightenment.

Anthropogenic fire, vegetation structure and ethnobotanical uses in an alpine shrubland of Nepal’s Himalaya

Alpine vegetation of the Himalaya is used as food, medicine or fodder, and is commonly managed with fire by agropastoralists. Prescribed fire can have positive effects on rangeland biodiversity, but studies evaluating its effects in alpine shrublands are scarce. Our objective was to examine the effects of anthropogenic fire on biophysical characteristics, species richness, abundance and composition in an alpine shrubland with socioeconomic value to local peoples in Langtang National Park in central Nepal. We surveyed biophysical variables, vascular plant species richness and composition along three transects at ascending elevations, and conducted interviews with local people and park officials on the use of fire in the region. We found 69 species of vascular plants in 89 plots; species richness was greater in burned plots and with increasing elevation, with 13 species unique to burned plots. We identified 14 indicator species in both burned and unburned plots; eight of them were Himalayan endemics. In burned plots, the indicator species were predominantly grasses and perennial forbs with ethnobotanical uses. This is the first detailed study on alpine shrubland anthropogenic fire in the Nepalese Himalaya. Burning may, at least temporarily, replace woody with more palatable herbaceous species, and weaken the elevational gradient of the shrubland.

ВИДОВОЙ СОСТАВ СОСУДИСТЫХ РАСТЕНИЙ БОЛОТ СРЕДНЕРУССКОЙ ВОЗВЫШЕННОСТИ

ВИДОВОЙ СОСТАВ СОСУДИСТЫХ РАСТЕНИЙ БОЛОТ СРЕДНЕРУССКОЙ ВОЗВЫШЕННОСТИ

The ratio between bryophyte functional groups impacts vascular plants in rich fens

AbstractQuestionFens have a well‐developed bryophyte layer covering most of the ground. Non‐sphagnaceous bryophytes, especially the group of so‐called brown mosses, prevail over sphagna under alkaline conditions. In sub‐alkaline conditions, rich fens allow the co‐occurrence of both these functional groups, but sphagna are competitively superior over non‐sphagnaceous bryophytes and seedlings of vascular plants, and they are currently expanding in some regions. We test whether the ratio between the two major bryophyte functional groups (bryo‐ratio) accounts for the species composition of vascular plants in fens.LocationCentral and Eastern Europe.MethodsAnalysis of two existing regional‐ and continental‐scale data sets of the vegetation‐ plot records and measured local factors by Canonical Correspondence Analysis with variation partitioning (community‐level analysis) and Structural Equation Modelling (species‐level analysis).ResultsAt the community level, the bryo‐ratio accounted significantly for species composition of fen‐specialized vascular plants, more obviously in the regional‐scale data set. At the species level, more fen species (50–67% according to the data set) were significantly directly affected (adjusted p < 0.05) by the bryo‐ratio than by water pH (14–17%) and by measured water table depth (WTD) in the regional data set (12.5%). In the continental data set, the comparable proportions of species were directly affected by the bryo‐ratio and WTD inferred by soil moisture indicator values (50% vs 58%). Most of the species affected significantly by the bryo‐ratio preferred the fens rich in non‐sphagnaceous bryophytes. They were largely those with a low capability of vegetative reproduction.ConclusionsThe group of species preferring brown moss patches includes mostly rare and endangered species with a great need for generative reproduction (e.g., Primula farinosa, Triglochin palustris, Pedicularis palustris, Saxifraga hirculus). Our findings demonstrate the important role of the bryophyte layer in the structuring of vascular plant communities in fens and highlight urgent conservation needs for brown moss patches.

Grazing as a conservation management approach leads to a reduction in spider species richness and abundance in acidophilous steppic grasslands on andesite bedrock

Recent decades have seen increased awareness of the double-edged effects of grazing. Grazing is necessary for the long-term maintenance of relict steppic grasslands but is associated with adverse effects on arthropods. Data on spiders are conflicting, and data from steppic grasslands on igneous rocks are lacking. We performed a case study on the effects of sheep grazing on spiders that inhabit small acidophilous steppic grasslands on andesite bedrock. These rare and disappearing grasslands are present in central Europe on upper parts of andesite hills due to the presence of extreme geophysical conditions combined with the pressure of herbivores. Spiders were sampled using pitfall traps and sweeping, and the plant cover as well as vascular plant species composition were analyzed. We captured a total of 689 individuals of 79 spider species. The Chao-1-estimated species richness reached 46.5 ± 11.6 species at grazed sites and 93.7 ± 9.9 species at control sites; the abundance was also lower at grazed sites. The species composition differed in response to grazing (Sorensen similarity index 0.528). Most threatened species were present in lower abundance or completely absent at the grazed grassland, which was true for all vegetation-dwelling threatened spider species. In contrast to the negative response of spiders, all threatened plant species except Veronica prostrata were more abundant at the grazed grassland. It is likely that grazing as a conservation management led to a reduction in spider species richness and abundance at the examined central European acidophilous steppic grassland on andesite bedrock.

Changes in vascular plant species composition, top-soil and seed-bank along coppice rotation in an Ostrya carpinifolia forest

Ostrya carpinifolia forests are formations traditionally managed as coppice, with a high biodiversity that characterizes much of the Italian and Balkan low mountain and hill landscapes. Here, we analyze changes in vegetation, seed-bank, soil and litter at six different stages during the coppicing rotation and after 10 years of abandonment of an Ostrya carpinifolia forest located in the central Apennines. Data show that the dynamism characterizing this coenose during traditional coppice rotation alters after cessation of the management practices. Although from the phytosociological point of view all the forest stands belonged to the same association, the highest biodiversity was achieved in the early stages after cutting. This was ascribed to the canopy removal, which creates favourable conditions for the germination of pre-mantels and mantels species stored in the soil seed-bank, while suitable conditions for the nemoral flora are maintained around the tree stumps. In later years, a reduction of non-strictly forest species and an increase in the relative thicknesses of the more superficial top-soil horizons occurred, reaching the maximum around 18 years after cutting. With the abandonment, simplification of the top-soil morphology, total loss of seed bank viability and increase of open-environments species were observed.

Assessing the potential of routine stand variables from multi-taxon data as habitat surrogates in European temperate forests

To encourage forest managers to use biodiversity indicators in their work, providing environmental variables that depict species habitats, have well-calibrated and strong relationships with biodiversity and are easy to routinely record would be a step forward. The Index of Biodiversity Potential (IBP) is a rapid habitat assessment method widely used in France. It uses ten variables that indicate potential habitat for forest-dwelling species and is easy for forest managers to implement during their day-to-day activities. The objective of this paper is to evaluate the indicator power of these IBP variables at the stand scale, i.e. their capacity to co-vary with empirical species richness and composition data for nine taxa. The data were obtained from 487 plots set up in 19 forested areas in France. Taxonomic data focused on corticolous lichens, corticolous and saproxylic bryophytes, polypores, saproxylic beetles, ground beetles, hoverflies, birds, bats and vascular plants. For the latter five taxa, we built subgroups of forest-specialist species. The IBP variables were recorded on 1-ha circular plots centered on the sampling point used to record taxonomic data. We explored the relationships between the IBP variables and species composition/richness of nine taxa at the stand scale. Furthermore, we searched for threshold values for all the significant relationships found between species richness and the IBP variables. Variations in the species composition of vascular plants and saproxylic beetles, and to a lesser extent, polypores, bats and lichens, were significantly related to habitat variations (ranked according to the Procrustes significance level). The contribution of the IBP variables to the total inertia of species composition was about 18.7% on average. The IBP variables had a lower number of significant relationships with species richness than with species composition. Unexpectedly, the forest subgroups mainly showed fewer significant relationships with habitat variables than did the full-groups, both for species richness and composition. We highlighted seven significant thresholds in the habitat variables above which species richness was significantly higher. Finally, we recommend that forest managers (i) routinely use a rapid habitat assessment such as the IBP, (ii) orient silvicultural practices to ensure conservation of autochtonous tree species, large logs and different types of aquatic habitats above the thresholds highlighted in this study, and (iii) periodically complete a biodiversity assessment at the forest scale by recording taxonomic data.

Vegetation changes in the Hasbruch forest nature reserve (NW Germany) depend on management and habitat type

AimsWe carried out vegetation studies in the ancient Hasbruch forest, which provided the unique conditions of unmanaged (UM) and managed (M) stands in two vegetation types Stellario-Carpinetum loniceretosum (POOR) and stachyetosum (RICH) stands in one closed forest allowing us to study (1) the changes in species composition and richness over 20 years considering the entire forest as well as (2) group-specific changes. LocationHasbruch forest in the lowlands of Lower Saxony, Germany. MethodsIn 2016 we resurveyed the vascular plant species composition of 79 semi-permanent plots analysed in 1996. General and group-specific trends as well as drivers of changes were analysed using DCA, PCA, LM, t-test, U test, ANOVA. ResultsTree and shrub layer coverage increased significantly in the entire forest. Herb layer species richness decreased significantly only in group RICH_UM. While the pH-value increased significantly in group POOR, it decreased significantly in group B. EIV F increased significantly in group POOR_M and decreased significantly in group RICH_UM. EIV L increased significantly in both of the managed groups, while it decreased significantly in group RICH_UM. An increase was found for EIV N in group POOR_M, whereas a decrease was found in group RICH_M. Strongly increasing species were Ilex aquifolium, Rubus fruticosus agg. and Hedera helix; strongly decreasing species Geum urbanum and Primula elatior. The change in species richness was positively affected by ΔpH and negatively affected by ΔT1cov in the entire forest. ConclusionsThe main drivers for changes in species richness and composition in the Hasbruch forest were light and water availability. The effects of the drivers strongly depended on the vegetation type. Changes in species composition were more pronounced in nutrient-rich forests than on nutrient-poor sites. In nutrient-rich forests, decreased groundwater influence led to decreased soil pH which especially affected typical woodland plants in a negative way. Management positively affected light-demanding species as well as some N-demanding species. Thus, unmanaged, nutrient-rich stands displayed the highest losses in species diversity. In the nutrient-poor stands, changes in species composition were not significantly related to changes in soil and management. However, increasing pH as well as increased Ellenberg L, F, and N values suggest a tendency towards eutrophication. This is possibly a consequence of N deposition and recovery from soil acidification.

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.

Flora and vegetation of the Minusinsk town and its vicinity

The article demonstrates the results of studies about species composition of lichens, fungi, mosses and higher vascular plants found in the ribbon pine forests in the Minusinsk town and its vicinity. The article based on the original authors’ herbaria. 62 basidial macromycetes, 80 lichens and 210 species of the higher vascular plants were found in the studied area. The plant communities and their dominant species were studied.

Ground vegetation diversity and geobotanical analysis in dune pine forests in southwest Estonia

Abstract To investigate the ecosystems on dunes, five typical dunes were selected in the coastal area of the Baltic Sea in southwest Estonia. To study ground vegetation species richness, species composition and horizontal structure, 251 quadrats of 1 m2 in size were established and descriptions of vascular plants, bryophytes and lichen species were provided. Topographical factors, soil horizons, soil pH and electrical conductivity, soil nutrients, soil moisture conditions and light conditions were determined. In total, 42 vascular plant, 43 bryophyte and 48 lichen species were recorded on five dunes. Vascular plant species richness and composition on forested dunes was dependent on the absolute dune height, zone and aspect of the slope, soil nitrogen, potassium and phosphorus content, soil pH and moisture, the cover of the bryophyte-lichen layer and light conditions. Regarding bryophyte and lichen layer species composition, important factors were the aspect of the dune, vascular plant species cover, light conditions, the thickness of the moderately decomposed organic soil horizon, soil pH, electrical conductivity and volumetric water content. Lichen species richness was highest on the slopes of the dunes, while bryophyte species richness was higher at the bottoms and decreased towards the tops of the dunes. Ground vegetation species richness and species’ horizontal and vertical structure on forested dunes were highly dependent on topography-induced differences, aspect, height and zone of the dunes. The most important factors controlling the complex of ground vegetation were light conditions, soil water content, thickness of the moderately decomposed litter layer and soil potassium and calcium content.

Сhanges in the ground cover structure in the “forest –forest edge – cutover” ecotone in a bilberry spruce stand ten years after logging

Data of the vascular plant species composition in the ecotone “forest – forest edge – cutover” ten years after logging of a bilberry spruce stand in the north-taiga subzone of the Arkhangelsk Region are reported. Differences among zones of the ecotone complex regarding species percent covers and frequency of occurrence were revealed. Changes in the ground cover species abundance compared to earlier reforestation stages (2–5 years after logging) are discussed. Plant species were grouped according to their response to logging and subsequent tree layer restoration. The first group consists of typically forest-dwelling species whose phytosociological optimum corresponds to bilberry spruce forest conditions ( Goodyera repens , Listera cordata , Vaccinium vitis-idaea , V. myrtillus, Hylocomium splendens ). The second group includes the forest species that have demonstrated a negative response to logging and have been actively recovering their abundance since the time of tree layer formation in the cutover site ( Carex globularis , Chamaepericlymenum suecicum, Equisetum sylvaticum , Gymnocarpium dryopteris , Luzula pilosa , Maianthemum bifolium , Melampyrum pratense , Oxalis acetosella , Pleurozium schreberi , Rubus arcticus , Trientalis europaea ). The third group is made up of forest edge species ( Empetrum nigrum and Orthilia secunda ). The forth group comprised typically forest-dwelling apophytes, which responded positively to logging, but declined in abundance as the tree layer was forming ( Avenella flexuosa, Chamaenerion angustifolium , Polytrichum commune ). A separate group consists of the species whose response to logging and subsequent tree layer formation could not be detected by geobotanical, and has no statistic proof. It is shown that 10 years after logging, although the tree layer has formed, each zone of the ecotone complex has preserved their specific traits of the ground cover structure.

La Sal Daisy,Erigeron mancus,Density and Associated Species from Treeline Ecotone and Alpine Habitats

The La Sal daisy, Erigeron mancus, is endemic to treeline ecotone and alpine meadow habitats of the La Sal Mountains in Utah, an insular, laccolithic mountain range on the Colorado Plateau in southeastern Utah. From 2009 to 2011 we established elevational transects through upper spruce-fir forest, treeline ecotone, and alpine meadow habitats on Laurel Ridge in the Middle Mountain group of the La Sal Mountains to measure (1) periodic changes in E. mancus population density, (2) changes in the elevation of the E. mancus population centroid, (3) changes in patch size occupied by E. mancus, and (4) changes in frequency of occurrence in herbaceous plant species associated with E. mancus along these transects. We measured both E. mancus density and vascular plant species composition within 1-m × 1-m square frames in mid-July, near peak alpine plant flowering time. The E. mancus population density on Mt. Laurel ridge did not significantly change from 2009 to 2015, but the species was most abundant in alpine meadow habitat for both years. Changes in patch width, centroid elevation, and frequency of occurrence of 30 associated plant species were also not statistically significant. Like E. mancus, most species show changes in frequency of occurrence between upper spruce-fir forest, treeline ecotone, and alpine meadow habitats. Individual plants of E. mancus are probably long-lived perennials, so changes in population density and distribution due to global warming are expected to be gradual and/or have an unknown lag time. Although there is no evidence of ongoing change in the Laurel Ridge population of E. mancus, having this information will provide a solid statistical basis for determining significant future changes.

Vascular Plant Species Composition, Relative Abundance, Distribution, and Threats in Arsi Mountains National Park, Ethiopia

A study of vascular plant species composition, relative abundance, distribution, and anthropogenic threats to these species' survival was carried out in the Galama Mountains in Arsi Mountains National Park, Ethiopia. An Intensive Modified Whitaker nested plot design was used to sample vegetation in disturbed and undisturbed habitats across the landscape. A total of 191 plant species (including 5 identified only to the genus level) in 56 families were recorded. The dominant family was Asteraceae, followed by Poaceae. Twenty species (about one-tenth of all species recorded) are endemic to Ethiopia. The highest overall species richness was recorded in the dry evergreen Afromontane vegetation in the undisturbed plots and in the Erica (heath) habitat in the disturbed plots. Rare plant species were less frequent in the disturbed plots than in the undisturbed ones. Regression analysis indicated a significant decrease in total species richness with increase in elevation. It also indicated a significant decrease in species richness and average plant species ground cover with increasing amounts of fresh livestock dung. The rate of tree removal exceeds the rate of regeneration in the dry evergreen Afromontane vegetation. Myrsine melanophloeos, Schefflera abyssinica, and Juniperus procera were the dominant tree species in the lower elevations (2843 to 3200 m above sea level) and have been found to be overharvested. Based on the current anthropogenic pressures in the study area, we expect species diversity and frequency of occurrence to diminish over time. Urgent conservation measures including control of tree harvesting and livestock encroachment should be prioritized in Arsi Mountains National Park.

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.

The Euro-Siberian geographical element flora structure of the Middle Siberia forest-steppes

The structure of geographical (arealogical) elements is one of the most important flora characteristics, because genetic composite groups are established on the basics of generic and species areas analysis and regularities of flora formation are determined. The object of the research is a complete species composition of vascular plants, revealed within the boundaries of the researched forest-steppes - Krasnoyarsk, Kansk and Achinsk (Krasnoyarsk Region). The North forest-steppes flora was detected by the specific flora method established by A.I. Tolmachev. The aim of this work is to summarize materials of the Euro-Siberian geographical element flora structure in the North forest-steppes ecosystems of the Middle Siberia with the characteristics of geographical elements selected on the basis of the fitohorions concept. It is based on the accordance principle of species distribution to natural (Botanical-geographical) zoning of the Earth. To determine the areas we used modern planetary floristic zoning established by A.L. Takhtajan with some amendments: floristic zoning by L.I. Malysheva was taken into account to Siberia, etc., the Russian Far East - by R.V. Camelina. As a result of the work geographical elements of the boreal group were assigned: Circumboreal (133 species, 9,6% of the whole flora), Eurosiberian (384 species, 27,7%), Pontic-South Siberian (81 species, 5,85%), Siberian (154 species, 11,12%).