Vertical patterns in plant diversity and their relations with environmental factors on the southern slope of the Tianshan Mountains (middle section) in Xinjiang (China)

The investigation of distribution patterns of species diversity is significant for successful biodiversity conservation. The spatial patterns of vegetation and different life-forms species diversity along an elevation gradient in the middle section of the southern slope of the Tianshan Mountains in Xinjiang, China were explored, using the detrended canonical correspondence analysis(DCCA) and the generalized additive model(GAM) methods based on a field survey of 53 sampling plots. In this work 158 species of seed plants were recorded, including 141 herbaceous, 14 shrub, and 2 tree species, in which the woody plants are very limited. 53 sampling plots were classified into 9 major plant communities. The results indicate that the herb communities were the most sensitive to changes in elevation gradient. The diversity indices of the community as a whole presented bimodal patterns. The peak values for the species diversities were found in the transition region between mountain steppe desert and mountain desert steppe(2,200–2,300m), and in the alpine grassland region(2,900–3,100m), while maximum species diversities were in the areas of intermediate environmental gradient. The main environmental factors on the distribution patterns in plant diversity were the elevation, soil water, total nitrogen, available nitrogen, organic matter, and total salt. The response tendency of the four diversity indices for the whole community to the soil environment was the same as that of the herb layers.     

Effect of climate and altitude on plant community composition and richness in Brazilian inselbergs

Plant communities are shaped by multiple factors along environmental gradients;however,studies are limited on how environmental filtering drives community composition and species richness on tropical inselbergs.We evaluate the influence of altitude and climatic variables related to temperature and precipitation on plant community composition and species richness on Brazilian inselbergs.We assume as a premise that both climate and altitude would induce changes on plant community composition and species richness at the local level.We used plant inventory data from 370 sampling units across four inselberg sites in the Atlantic Forest of Espírito Santo State,south-eastern Brazil.We tested the univariate and multivariate effects of altitude and climate variables on community composition and species richness with multiple models.Differences in species richness between inselbergs were evaluated using sample-based data to estimate rarefaction and extrapolation curves.In addition,differences in species composition and taxonomic beta diversity were examined via novel frequency-based metrics.A contrasting climate pattern was observed between the inselberg sites,with south sites being wet compared to the dry conditions found in northern sites.Species richness by rarefaction showed a similar pattern within regional sites;however,there were marked differences between regions.Species richness and beta diversity showed significant differences among sites,with higher values in southern sites than in northern sites.In a multi-model comparison between inselberg sites,altitude significantly influenced community composition and species richness and explained more variance than climate models.This finding suggested that climate could act to some extent on these tropical inselbergs;however,altitude was a better predictor of plant community composition and species richness at the local level.     

Higher species diversity occurs in more fertile habitats without fertilizer disturbance in an alpine natural grassland community

Are there some relationships among species diversity and soil chemical properties of high altitude natural grasslands？ Plant community composition and chemical properties of soil samples were compared to investigate the relationship between soil and species diversity, and the richness in Tibetan alpine grasslands. Results showed that species diversity was significantly positively related to soil organic matter （SOM）, total nitrogen （TN）, available nitrogen （AN）, total phosphorus （TP）, available phosphorus （AP）, and available potassium （AK） in the high alpine grasslands. Margalefs species richness index was also significantly positively related to SOM, TN, AN, and TP. Most soil chemical properties showed significantly positive correlation with species diversity and Margalef＇s richness index. Our results suggested that higher plant species richness index and diversity occurred in more fertile soil habitats in high altitude natural grassland community. In practice, fertilization management for the restoration of degraded grassland should be conducted with reference to the nutrient levels ofnatural grassland without the additional artificial fertilizer and with higher species-diversity and richness index.     

Species richness and biodiversity significance of alpine micro-waterbody systems in Gaoligong Mountain,Northwest Yunnan,China

Water quality, size, connectivity and other physical properties of hydrological systems might have different functions in the formation and maintenance of biodiversity, but this remains mostly unclear due to the lack of undisturbed sites for experimental modelling. Alpine freshwater habitats such as micro-waterbodies(MWB) represent a kind of natural system suitable for biodiversity research. In order to assess potential linkages between environmental factors, connectivity of MWBs and aquatic species richness, we conducted a pilot study in two separated MWB systems located in Gaoligong Mountain, northwest Yunnan province, China. A total of 27 MWBs have been analyzed, including 22 connected and 5 isolated bodies. 13 conventional environmental factors were tested while all kinds of aquatic macro-organisms were collected and classified. Results showed a high environmental heterogeneity among MWBs and significant differences between the two systems but only a few environmental variables such as the depth of soil bottom, total Nitrogen and altitude were related to species richness and the formation of the community structure. As a benefit from the high environmental heterogeneity, the cascaded MWB systems provided divergent habitats able to support species richness at a higher level than the same number of randomly selected MWBs. This finding supports the idea that habitat connectivity matters also in extremely small aquatic ecosystems. Moreover, although still a preliminary result, a polarization effect within connected chains where edge MWBs host higher taxa and endemic taxa richness as well as larger populations, was detectable. This study gives interesting insights on the spatial processes driving community structure and a new prospective for biodiversity conservation. Since alpine MWBs have significant effects on the maintenance of watershed biodiversity, further research on such small and crucial ecosystems is encouraged.     

Species-area relationship within and across functional groups at alpine grasslands on the northern Tibetan Plateau,China

The species-area relationship(SAR) is one of the most fundamental concepts in community ecology and is helpful for biodiversity conservation.However,few studies have systematically addressed this topic for different alpine grassland types on the Tibetan Plateau,China.We explored whether the plant composition of different functional groups affects the manner in which species richness increases with increasing area at scales ≤ 1.0 m~2.We also compared species richness(S) within and across forbs,legumes,sedges and grasses,with sampling subplot area(A) increasing from 0.0625 m~2 to 1.0 m~2 between alpine meadow and steppe communities.We applied a logarithmic function(S = b_0 + b_1 ln A) to determine the slope and intercept of SAR curves within and across functional groups.The results showed that the logarithmic relationship holds true between species richness and sampling area at these small scales.Both the intercept and slope of the logarithmic forbs-area curves are significantly higher than those for the three other functional groups(P 0.05).Forb accounts for about 91.9 % of the variation in the intercept and 75.0% of the variation in the slope of the SAR curve when allfunctional groups' data were pooled together.Our results indicated that the different SAR patterns should be linked with species dispersal capabilities,environmental filtering,and life form composition within alpine grassland communities.Further studies on the relationship between species diversity and ecosystem functions should specify the differential responses of different functional groups to variations in climate and anthropogenic disturbances.     

Elevational patterns of warming effects on plant community and topsoil properties: focus on subalpine meadows ecosystem

Climate warming profoundly affects plant biodiversity, community productivity, and soil properties in alpine and subalpine grassland ecosystems. However, these effects are poorly understood across elevational gradients in subalpine meadow ecosystems. To reveal the elevational patterns of warming effects on plant biodiversity, community structure, productivity, and soil properties, we conducted a warming experiment using open-top chambers from August 2019 to August 2022 at high(2764 m a. s. l.), ...     

Altitude as environmental filtering influencing phylogenetic diversity and species richness of plants in tropical mountains

Elucidating how multiple factors affect biodiversity and plant community assembly is a central issue in ecology, especially in vulnerable ecosystems such as tropical mountains. These studies are more relevant in global warming scenarios that induce the upward displacement of plant species towards reduced habitats and hostile environments in tropical mountains. This study aimed to analyze how altitude affects taxonomic and phylogenetic diversity in plant communities of tropical mountains. Thus, w...     

Temporal stability of aboveground net primary production in northern Tibet alpine steppe in response to nitrogen addition

The mechanism that sustains the temporal stability of aboveground net primary production(ANPP) respond to nitrogen deposition is still controversial. Consequently, we investigated the mechanism of temporal stability of ANPP through the effect of N addition on diversity, species asynchrony and portfolio effects in northern Tibet alpine steppe over a period of three years. Our results showed that the community temporal stability did not significantly correlate with the species richness and Shannon–Wiener diversity. Species asynchrony and stability was also not significantly affected by N addition(p 0.05). Furthermore, there was no significant relationship between species asynchrony and temporal stability. Although the value of portfolio effects(z)(z = 1.304, 95% confidence intervals:1.029–1.597) was more than 1, the portfolio effects was not a primary driver of temporal stability due to the biodiversity being unaffected. The above results suggested that the richness, species asynchrony and portfolio effect could not support for mechanism of stability at the alpine steppe. From the results of path analysis, species temporal stability positively supports the community temporal stability in the alpine steppe ecosystem. According to the character of environment and vegetation of alpine steppe at North Tibet, we inferred that dominance species stability is more important than species richness for the community temporal stability.     

Phytogeographic and syntaxonomic diversity of high mountain vegetation in Dinaric Alps (Western Balkan, SE Europe)

The high alpine and subalpine vegetation of Dinaric Alps is very diverse.These are conditional on genuine patterns of development of the geological substrate,climate,soil and terrain on the mountain world,which are interconnected and spatially,and ecologically away.Also,today high mountain vegetation is extremely important indicator of global changes.In this area are many refugia of glacial biodiversity.Very illustrative example for understanding the specific forms of ecological diversity is high alpine vegetation in the area of the Balkan Peninsula.Vegetation of alpine belt of Western Balkans and Bosnia and Herzegovina is differed by extremely high level of biological and ecological diversity.Climatogenous vegetation are alpine and sub-alpine pastures above of timberline,then extra zonal forms of vegetation-glaciers,rock creeps,breaches of rocks,alpine springs,marsh,and tall greenery.This vegetation is dominant determinant of alpine ecosystems that creates their unique physiognomy and also enables prime production of biomass.It is different with extraordinary floral richness,especially in a number of endemic species and glacier relicts that are included in a large number of phytocoenoses,many of which are of endemic.In syntaxonomic sense,alpine vegetation is differentiated into 10 classes:Elyno-Seslerietea,Juncetea trifidi,Salicetea herbaceae,Thalspietea rotundifolii,Asplenietea trichomanis,and Scheuchzerio-Caricetea fuscae,Montio-Cardaminetea,Loiseleurio-Vaccinietea,Mulgedio-Aconitetea and Molinio-Arrhenatheretea.These classes are differentiated into 20 vegetation orders,38 alliances and 190 associations and sub-associations.In total,that is 60 % of communities of total vegetation diversity of Bosnia and Herzegovina,and 12.5% of classes of highest syntaxonomic categories in vegetation diversity of Europe.     

Fish Assemblage Responses to a Low-head Dam Removal in the Lancang River

Dam removal is becoming an effective approach for aquatic biodiversity restoration in damming river in order to balance the aquatic ecosystem conservation with large-scale cascade damming. However, the effects of dam removal on fish communities in Asian mountainous rivers, which are dominated by Cypriniformes fishes, are still not well known. To determine whether dam removal on a mountainous river benefit restoration of fish diversity, we investigated the response of fish assemblage to dam removal using a before-after-control-impact design in two tributaries of the Lancang River(dam removal river: the Jidu River, and control river: the Fengdian River). Fish surveys were conducted one year prior to dam removal(2012) and three years(2013–2015) following dam removal. We observed rapidly and notably spatio-temporal changes in fish biodiversity metrics and assemblage structure, occurring in the Jidu River within the first year after dam removal. Overall, fish species richness, density and Shannon-Wiener diversity all increased immediately in above-and below-dam sites, and maintained a stable level in subsequent years, compared to unchanged situation in the control river. All sites in the Jidu River experienced shifts in fish composition after dam removal, with the greatest temporal changes occurred in sites below-and above-the former dam, resulting in a temporal homogenization tendency in the dam removed river. These findings suggest that dam removal can benefit the recovery of habitat conditions and fish community in Asian mountainous rivers, but the results should be further evaluated when apply to other dammed rivers since the dam age, fluvial geomorphology and situation of source populations could all affect the responses of fish assemblages.     

Current Vegetation Pattern along Glacial Landscape in Central （Garhwal） Himalaya, India

Introduction High mountain ecosystems are comparatively thrilling and sensitive at least at the upper elevation levels, and are determined by abiotic climate related ecological factors. Therefore, the ecosystems at the low temperature limits of plant life are generally considered to be particularly sensitive to climate changes (Koerner 1999). As temperature is a key factor for high mountain plants (Koerner and Larcher 1988, Gottfried et al. 1998), an upward migration of species must be conse…     

Effects of grazing exclusion on plant productivity and soil carbon,nitrogen storage in alpine meadows in northern Tibet,China

Grazing exclusion is widely adopted in restoring degraded alpine grasslands on the Qinghai-Tibetan Plateau. However, its effectiveness remains poorly understood. In this study, we investigated the effects of grazing exclusion on plant productivity, species diversity and soil organic carbon （SOC） and soil total nitrogen （STN） storage along a transect spanning from east to west of alpine meadows in northern Tibet, China. After six years of grazing exclusion, plant cover, aboveground biomass （AGB）, belowground biomass （BGB）, SOC and STN were increased, but species diversity indices declined. The enhancement of AGB and SOC caused by grazing exclusion was correlated positively with mean annual precipitation （MAP）. Grazing exclusion led to remarkable biomass increase of sedge species, especially Kobresia pygmaea, whereas decrease of biomass in forbs and no obvious change in grass, leguminous and noxious species. Root biomass was concentrated in the near surface layer （10 cm） after grazing exclusion. The effects of grazing exclusion on SOC storage were confined to shallow soil layer in sites with lower MAP. It is indicated that grazing exclusion is an effective measure to increase forage production and enhance soil carbon sequestration in the studied region. The effect is more efficient in sites with higher precipitation. However, the results revealed a tradeoff between vegetation restoration and ecological biodiversity. Therefore, carbon pools recover more quickly than plant biodiversity in the alpine meadows. We suggest that grazing exclusion should be combined with other measures to reconcile grassland restoration and biodiversitv conservation.     

Assessment of alpine summit flora in Kashmir Himalaya and its implications for long-term monitoring of climate change impacts

In an era of climate change,the availability of empirical data on alpine summit vegetation in the Himalaya is still scarce.Here we report the assessment of alpine summit flora in Gulmarg Wildlife Sanctuary,Kashmir Himalaya.We employed a globally standardized Multi-Summit Approach and four spatially isolated summits spanning an elevation gradient of 210 m(between 3530-3740 m a.s.l.) from natural treeline to nival zone were studied.Sampling of the summits was carried out in the year 2018 to collect floristic data together with records of soil temperature.A total of 142 vascular plant species were recorded in the sampled summits.Majority of the species were of herbaceous growth form and with perennial life span.Based on Raunkiaer's life form,hemicryptophytes were the most dominant followed by therophytes and phanerophytes.The summit flora showed the predominance of narrow-endemic species,with broad-and non-endemics declining with elevation.A significant relationship between growth form,Raunkiaer's life form,and the degree of endemism with elevation was observed.Both species diversity and soil temperature showed a monotonic decrease with increasing elevation.Interestingly,soil temperature clearly determined the magnitude of species diversity on the summits.Furthermore,based on floristic composition,the lowest summit had the highest dissimilarity with the rest of the summits.The present study employed globally standardized protocol to scientifically assess the patterns of plant diversity on the alpine mountain summits of Kashmir Himalaya,which in turn has wide implications towards long-term monitoring of climate change impact on alpine biodiversity in the rapidly warming Himalaya.     

Understanding how environmental heterogeneity and elevation drives the distribution of woody communities across vegetation types within the campo rupestre in South America

The campo rupestre sensu lato is a vegetation type that occurs in South American mountains, supports a distinctive flora characterized by high rates of endemism, high herbaceous species richness and often-neglected but also species-rich of the arboreal stratum. We aimed to investigate how environmental factors and elevation are associated with the distribution and diversity of woody species in different rupestrian vegetation types across South America. Using a database of 2,049 woody species from 185 sites across four vegetation types within the campo rupestre, we assessed how the vegetation types were grouped according to their floristic composition and number of shared indicator species, as well as by using different beta diversity indices. The most important variables from a set of 27 variables(e.g. altitude, geo-edaphic and climatic) explaining species distribution were identified using redundancy analysis(RDA) and variation partitioning methods. The distribution of vegetation types was related to both environmental and spatial fractions, with a set of 17 variables retained(e.g. rockiness, grass cover and temperature seasonality as the most important variables). There was an association between the floristic composition of each vegetation type and the elevation range. Although the identified vegetation types are floristically related, they are distinguished by exclusive and habitat-specialist woody species. This uniqueness of vegetation types should be considered in terms of complementarity for the conservation of campos rupestres.     

Contrasting patterns of free-living bacterioplankton diversity in macrophyte-dominated versus phytoplankton blooming regimes in Dianchi Lake,a shallow lake in China

Freshwater shallow lakes typically exhibit two alternative stable states under certain nutrient loadings:macrophyte-dominated and phytoplankton-dominated water regimes.An ecosystem regime shift from macrophytes to phytoplankton blooming typically reduces the number of species of invertebrates and fishes and results in the homogenization of communities in freshwater lakes.We investigated how microbial biodiversity has responded to a shift of the ecosystem regime in Dianchi Lake,which was previously fully covered with submerged macrophytes but currently harbors both ecological states.We observed marked divergence in the diversity and community composition of bacterioplankton between the two regimes.Although species richness,estimated as the number of operational taxonomic units and phylogenetic diversity(PD),was higher in the phytoplankton dominated ecosystem after this shift,the dissimilarity of bacterioplankton community across space decreased.This decrease in beta diversity was accompanied by loss of planktonic bacteria unique to the macrophyte-dominated ecosystem.Mantel tests between bacterioplankton community distances and Euclidian distance of environmental parameters indicated that this reduced bacterial community differentiation primarily reflected the loss of environmental niches,particularly in the macrophyte regime.The loss of this small-scale heterogeneity in bacterial communities should be considered when assessing long-term biodiversity changes in response to ecosystem regime conversions in freshwater lakes.     

Biodiversity conservation in the Hindu Kush-Karakoram-Himalayan mountain region of northern Pakistan:Overview of big mammal protection

The high mountains of northern Pakistan comprise the western section of the Hindu KushKarakoram-Himalayas(HKH) region of South and Central Asia. They are home to some rare and endangered species of fauna and flora which form an important link in the biodiversity of the region as a whole. Increasing population and changing life styles in recent decades have brought unprecedented pressures on the biodiversity of this region. Along with the government, the non-governmental organizations(NGOs) and communities have a crucial role to play in conserving biodiversity. In this regard,a number of undertakings to protect depleting species have been initiated by governmental and nongovernmental entities. These efforts are commendable and some have produced positive results, but many exist on a small scale and, with a few exceptions, are not self-sustaining. This paper reports on some of these initiatives of conserving big mammal species like the Astor markhor, Blue sheep,Himalayan brown bear, Himalayan ibex and Snow leopard, with the aim of collating and highlighting them, identifying gaps in conservation and suggesting a way forward so as to promote conservation projects on a larger and more sustainable basis.