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Patterns of plant communities along vertical gradient in Dhauladhar Mountains in Lesser Himalayas in North-Western India
... The mountain ecosystem is a vital biodiversity center and an ecological function area in arid and semi-arid regions . Mountain ecosystems show apparent ecological vulnerability and are very difficult to recover from disturbances (Ahmad et al., 2020;Arif et al., 2023). Vegetation must be adequately managed and protected to reduce ecosystem vulnerability as species diversity loss may weaken ecosystem stability Li et al., 2021;Arif et al., 2022). ...
... As the study area is in the temperate steppe climate zone of north-western China, it is assumed that the distribution area types of plant families and genera in the region are dominated by temperate components. Unimodal patterns have previously been observed in gradients in the Dhauladhar Mountains in the Lesser Himalayas and the Mount Namjagbarwa region (Ahmad et al., 2020;Sun et al., 2020), while a monotonic response to altitude has been observed in the Swedish mountains and a subarctic mountain tundra Naud et al., 2019). Furthermore, we expect a unimodal or monotonically decreasing diversity with increasing altitude based on empirical observations. ...
... frontiersin.org quadrats of 5 m 2 × 5 m 2 and five quadrats of 1 m 2 × 1 m 2 were marked for recording shrubs and herbs, respectively (Ahmad et al., 2020). Finally, 8 tree quadrats (only seven plots have trees), 115 shrub quadrats, and 115 herb quadrats were deployed, and all vegetation types in the study area were covered along the elevation gradient. ...
The spatial distribution pattern of species diversity and its driving variables are essential to understanding how biodiversity will respond to the threat of future climatic instability. This study examines how the alpha and beta diversity indices vary along the elevation gradient and which factors are more responsible for arid and semi-arid plant diversity and community assembly. There were 121 species from 90 genera and 42 families found at elevations ranging from 1,200 to 2,600 m within the Ningxia Helan Mountain National Nature Reserve in China. These were primarily shrubs and herbs with characteristics adapted to extreme temperatures. The diversity of both the shrub layer and the herb layer was highest at mid-elevation, underscoring the importance of protecting mid-elevation ecosystems. Climatic distance and topographic distance were more influential than spatial distance in driving the species composition change of shrubs and herbs. In the herb layer, climatic, topographic, and spatial factors contributed more to community assembly than shrub communities. In this case, improving the environment in the community or introducing herbs could help the restoration of these places. These findings provide insight into biogeographic patterns, biodiversity growth mechanisms, and community formation processes. Moreover, it can improve projections of climate change within and across ecosystems and provide the scientific basis for the use and management of plant resources in arid and semi-arid regions. (2023), Plant diversity patterns along an elevation gradient: the relative impact of environmental and spatial variation on plant diversity and assembly in arid and semi-arid regions.
... In the western Himalayas, our study area, Ahmad et al. (2020) showed that the richness and composition of local herbaceous plant communities along a gradient of elevation from 2000 to 4000 m were driven by elevation-specific temperature conditions. A subsequent study in the same system found that temperature was also the main driver of phenology in several key species . ...
... We used the twenty-one 20 × 20 m sites established in 2015 and described by Ahmad et al. (2020) at 100 m intervals of elevation from 2000 to 4000 m a.s.l. (Figure 2; Table S1), covering most of the elevation range of subtemperate and alpine vegetation. ...
... The locations of the study sites in India (a) and Himachal Pradesh (b) and the spatial orientation along the elevational gradient (c), adapted from Ahmad et al. (2020). See Table S1 for detailed site characteristics. ...
1. There is a common agreement that, to maximise our understanding of trait-based community assembly, traits related to different organs should be considered as they relate to different ecological niche axes. Floral traits, in particular, have been suggested to play an important role in the plant community assembly along environmental gradients as they determine reproductive success, one of the key functions in plants. However, the role of floral traits in community assembly research remains largely unverified empirically.
2. Using a large and novel dataset on plant traits and plant communities, we analysed the variability of six floral traits of 139 herbaceous species in 21 sites located along an elevation gradient (2,000–4,000 m) in the western Himalaya. The variability of floral traits along the gradient was analysed using community-weighted mean (CWM) trait values and functional diversities (FD) calculated for each study community.
3. The CWMs showed that with increasing elevation, flowering began later, and flowers tended to be larger with decreasing specific flower area (SFA). Along with the convergence in the onset of flowering and SFA (i.e., lower FD at high elevation sites), these patterns suggest that abiotic filtering and plant-pollinator interactions could affect the floral trait composition of the communities. Most likely, increasing low-temperature stress towards high-elevation sites selected for late-flowering species that produce flowers with larger display areas. The low abundance and activity of pollinators at high elevation could also explain why these traits were selected in the communities studied. Delayed flowering with increasing elevation might facilitate the phenological overlap of plants and their pollinators, as pollinator activity at higher elevation peaks in the second half of the vegetation period. The dominance of a species with low SFA and larger display area in high-altitude communities could be attributable to increased flower longevity and attraction of pollinators, respectively, to maximise pollination success under pollinator scarcity.
4. Synthesis. Our study provides empirical support for the recent argument that floral traits contribute considerably to the assembly of plant communities along environmental gradients. Thus, such traits should be included in community assembly research as they represent key ecological functions for reproduction.
... Further, IHR is well known for diversity of forest types across its horizontal and vertical extent with 41.47% of total forest cover of the country (Sati, 2017). The composition of forest community and distribution of plant species in the region is the refection of environmental gradients (Chawla et al., 2008;Chian et al., 2016;Gómez-Díaz et al., 2017;Ahmad et al., 2020). The spatial variation of biodiversity along altitudinal gradients is one of the basic issue and important aspect in biodiversity research in IHR (Rawal et al., 2018). ...
... Among various ecological parameters, plant species diversity has attracted particular attention because of its applicability in assessing current species performance and predicting future community composition (Wang et al., 2008). Especially, assessment of forest community structure and composition in mountain ecosystem is very helpful in conservation and management planning (Körner, 2007;Chawla et al., 2008;Chian et al., 2016;Gómez-Díaz et al., 2017;Lopez-Angulo et al., 2018;Negi et al., 2018b;Ahmad et al., 2020). Majority of the earlier studies focuses on species composition and vegetation distribution in various parts i.e., Dhauldhar mountain in Himachal Pradesh (Ahmad et al., 2020), Bhabha valley (Chawla et al., 2008), Uttarakhand Kumaon Himalaya (Rawal & Pangtey, 1994); Garhwal region (Hussain et al., 2008;Sharma et al., 2018;Negi et al., 2018a,b;Rawal et al., 2018), Khangchendzonga landscape in Sikkim (Sinha et al., 2018), east Nepal (Bhattarai and Vetaas, 2003), and central Nepal (Bhatta et al., 2018) of the Himalayan regions. ...
... Especially, assessment of forest community structure and composition in mountain ecosystem is very helpful in conservation and management planning (Körner, 2007;Chawla et al., 2008;Chian et al., 2016;Gómez-Díaz et al., 2017;Lopez-Angulo et al., 2018;Negi et al., 2018b;Ahmad et al., 2020). Majority of the earlier studies focuses on species composition and vegetation distribution in various parts i.e., Dhauldhar mountain in Himachal Pradesh (Ahmad et al., 2020), Bhabha valley (Chawla et al., 2008), Uttarakhand Kumaon Himalaya (Rawal & Pangtey, 1994); Garhwal region (Hussain et al., 2008;Sharma et al., 2018;Negi et al., 2018a,b;Rawal et al., 2018), Khangchendzonga landscape in Sikkim (Sinha et al., 2018), east Nepal (Bhattarai and Vetaas, 2003), and central Nepal (Bhatta et al., 2018) of the Himalayan regions. However, the patterns of plant diversity across altitudinal gradient in relation to environmental and anthropogenic factors are less known in the Himalayan region (Panda et al., 2017;Rana et al., 2019;Sharma et al., 2019). ...
Understanding patterns in forest communities and its driving factors play a critical role in ecological studies. In view of this, present study attempts to understand the role of environmental and anthropogenic factors towards shaping species diversity and composition along the altitudinal gradient (700–3800 m asl) in Indian western Himalaya. A total of 51 tree species (28 families) were recorded; Pinaceae (5) and Fagaceae (5) were the species rich families. α-diversity indices i.e., Margalef's richness index (R), Shannon index (Hʹ) and Simpson index showed a humped shaped distribution, whereas Evenness index (E) showed an inverted humped shaped distribution along the altitude range. Based on non-metric dimensional scaling (NMDS), four different community types were identified. Redundancy analysis (RDA) revealed a strong relationship of tree species composition with environmental (41.73% variation) and anthropogenic factors (17.35% variation). RDA further indicated that the bulk density (BD), disturbance index (DI), mean diurnal temperature range (Bio2) and solar radiation (SR) are significantly associated with sub-tropical (below 1200 m) and lower temperate forest (1200–1700 m) types. Likewise, soil organic carbon (SOC), precipitation of the driest quarter (Bio17) and pH were significantly associated with upper temperate (1700–2900 m), and subalpine forest composition (>2900 m). Both NMDS classification and RDA ordination clearly demonstrate spatial variability in composition of tree community and environmental properties.
... Elevational gradient provides complex biotic (flora and fauna) and abiotic factors (soil, temperature, precipitation, moisture, etc.), which observe drastic changes with elevation (Körner, 2007). Consequently, the topographic complexity in the mountains increases isolation and encourages speciation, developing a higher degree of turnover with elevation, a higher rate of beta diversity, and species richness (Körner, 2007;Elsen et al., 2018;Ahmad et al., 2020). ...
... Nevertheless, studies pertaining to flowering phenological aspects of trees and shrubs have been undertaken in Eastern Himalayas in Nepal and China (Ranjitkar et al., 2013), Qilian mountains in China (Zhao et al., 2018) and Sikkim (north-east) Himalayas in India (Basnett et al., 2019). However, nothing has been explored in the Lesser Himalayan region of Indian Himalayas, which harbor a wide range of species richness and diversity (Ahmad et al., 2020). The Dhauladhar mountain range in Lesser Himalayas is quite unique and relatively unexplored from the research perspective. ...
... Therefore, it holds within itself immense riches which are yet to be completely uncovered. Recently, we investigated the composition, structure, and patterns of diversity of herbaceous plant species along an elevational gradient in the Dhauladhar Mountains (Ahmad et al., 2020). In the present study, we observed the effect of elevational gradient and temperature on flower phenological events in populations of 24 herbaceous species along 2,000 to 4,000 m elevation in Dhauladhar mountain range of Lesser Himalayas in north-west India. ...
Studying phenology is undeniably one of the most effective ways to monitor and perceive how a particular plant species interact and respond to varying environmental conditions. In this study, the shifts in flowering phenological events of 24 herbaceous species with the changing elevation and temperature were observed in Dhauladhar Mountain range of Lesser Himalaya. Five permanent plots (20 × 20 m2) were established from 2,000 m to 4,000 m elevation at each rising 500 m distance for the documentation of herbaceous flora. Abundance-based documentation of flowering phenological events (onset of flowering duration [OFD] ≥ 10% to 30%, the peak of flowering duration [PFD] > 30% to 80%, the end of flowering duration [EFD] > 80% and total flowering duration [FD] as the difference of end and onset of flowering DOY) was done in each plot. The onset, the peak, and the end of the flowering day of the year (DOY) were recorded at 20%, 55%, and 90% floral abundance, respectively, from 1st of January. Upon analyses, the Linear-mixed effects model depicted significant differences in the flowering phenological events with elevation and soil temperature. The onset of flowering DOY and peak of the flowering DOY varied significantly with soil temperature gradient, while the end of flowering DOY showed non-significant interaction. The linear model of ANOVA demonstrated that OFD, PFD, EFD and FD varied significantly with elevation at p
... The slope of the observational plots varied between 15 • to 30 • . During vegetation sampling, whenever any obstruction (rock covering > 10% area, permanent water body, etc.) was encountered in the establishment of the plots, the distance between each plot was increased by ± 20 m (Mosley et al., 1989;Gómez-Díaz et al., 2017;Bhatta et al., 2018;Ahmad et al., 2020). The observational plots (40 × 40 m 2 ) were placed using ropes and poles. ...
... These observations are corroborated by studies reporting species richness decline along elevation in Kashmir Himalayas (Khuroo et al., 2011) and Nepal Himalayas (Bhattarai et al., 2014). Parallel to our study, a decrease in species richness of non-native species above 1,100 m was observed in Himachal Pradesh (Ahmad et al., 2018), whereas a decrease in total species richness and Simpson diversity was observed at ≥ 3,200 m in Dhauladhar mountain range (Ahmad et al., 2020). Lower elevations showed high species richness, which can be attributed to adequate availability of water, optimal temperature, and congregation of non-native species (Körner et al., 2011;Zhang et al., 2016;Ahmad et al., 2020). ...
... Parallel to our study, a decrease in species richness of non-native species above 1,100 m was observed in Himachal Pradesh (Ahmad et al., 2018), whereas a decrease in total species richness and Simpson diversity was observed at ≥ 3,200 m in Dhauladhar mountain range (Ahmad et al., 2020). Lower elevations showed high species richness, which can be attributed to adequate availability of water, optimal temperature, and congregation of non-native species (Körner et al., 2011;Zhang et al., 2016;Ahmad et al., 2020). Also, high incidences of anthropogenic disturbance led to a high species richness in lower elevation out of which non-native plants form a major portion. ...
High-elevation mountain communities are progressively threatened by habitat fragmentation and climate change resulting in habitat shift and biodiversity loss. Despite it, very few studies have focussed on niche distribution and diversity pattern of non-native and native plant species in high mountain communities, and their role in identifying endemic species with high extinction risk in Himalayas. To determine niche width and diversity pattern of species based on the nativity, and ascertain the role of niche width in conservation prioritization of endemic/native species, four sites were selected in western Himalayas. We analysed diversity indices (based on native, non-native, and total species) such as Species richness, Simpson index, Chao-1 index, Whittaker index (βw), and species niche width across the elevational gradient in study sites. Non-native species were found to thrive in lower elevations. The niche width of non-native species declined with increase in elevation, but a few non-native species had a broad niche width (habitat generalist). Such habitat generalist species may lead to the displacement of endemic or native habitat specialist species (having narrow niche width). Species like Aconitum heterophyllum, Aconitum violaceum, Bergenia stracheyi, Dactylorhiza hatagirea, Jurinea dolomiaea, Sinopodophyllum hexandrum, Morina longifolia, and Roscoea alpina etc. were found to have a narrow niche width. Such species will face an extinction risk due to the upward shift of non-native species. The high elevational plant communities are more susceptible to extinction risk due to the accelerated spread of non-native species influenced by climate change. This study emphasizes the crucial need to implement strategies for the control of non-native species, describing species compositional changes at higher elevations, and aids to efficiently identify and conserve native species under high extinction risk.
... Altogether, 40 woody taxa including 11 trees and 29 shrubs were recorded from the high elevation (2800-4000 m) sampling units. The extent of tree species richness observed in the current study corresponds to other Himalayan timberlines [60][61][62][63][64][65][66][67]. The lowest species richness recorded at site-VII beyond 3800 m could be consequence of effect of eco-physiological constraints, such as very short growing spell, geographical barriers, extremely low temperature [43] and microclimatic conditions in mountainous landscapes [65]. ...
... The extent of tree species richness observed in the current study corresponds to other Himalayan timberlines [60][61][62][63][64][65][66][67]. The lowest species richness recorded at site-VII beyond 3800 m could be consequence of effect of eco-physiological constraints, such as very short growing spell, geographical barriers, extremely low temperature [43] and microclimatic conditions in mountainous landscapes [65]. The woody taxa exhibited hump shaped pattern, a usual condition observed in the Himalayan region [17,25,26,[67][68][69][70][71]. ...
The composition, structure, and patterns of vegetation undergo a noticeable shift along the elevational gradient, and this is regulated by various abiotic variables, primarily the elevation and edaphic characteristics. The present study investigated the change in community characteristics of woody vegetation along a vertical gradient from 2800 m till 4000 m in parts of upper Bani Wildlife Sanctuary in Jammu and Kashmir. In all, 40 woody species were recorded including 11 trees and 29 shrubs with a distinctive hump shaped pattern that becomes steeper with the rising elevation. Quercus semecarpifolia Sm. and Betula utilis D.Don. exhibited a wide elevational range (3000–3500 m asl), eventually forming the climatic climax along southern and northern aspects. The diversity and phytosociological attributes peaked at intermediate elevation with H¯=1.74 recorded for trees and H¯=2.48 observed for shrubs. The average density and basal cover for trees and shrubs ranged between 75.50 Nha⁻¹ & 20.09 m²ha⁻¹ and 69.31 Nha⁻¹ & 4.50 m²ha⁻¹, respectively. The species turnover rate was recorded high in case of trees (0.11–0.77) and low for shrubs (0.17–0.29). A modest density of 114 seedlings ha⁻¹ and 249 saplings ha⁻¹ was recorded across the forest types. The low seedling (0.22) and sapling (0.48) per tree ratio indicated a low regeneration performance anticipating a very slow upslope movement of the tree line. This may result in population decline of a few select species in future, necessitating effective monitoring and management intervention for which these findings will be helpful.
... Overall, the numbers of species and OTUs were higher at low altitudes than high altitudes. The main reason may be that high-altitude organisms were more susceptible to environmental stress than low-altitude plants (Ahmad et al., 2020). ...
... Besides, the highest species evenness and Shannon diversity both appeased at low altitude at 1,170 m and had a decreasing trend at mid-altitude. The reasons for this result may be that compared with high altitude and low altitude, the plant's species replacement rate was less at mid-altitude (Ahmad et al., 2020). At the same time, they are also likely affected by large-scale climate and environment forcing. ...
Arbuscular mycorrhizal fungi (AMFs) play a vital role in ecosystems, especially in ecosystem variability, diversity, and function. Understanding the AMF diversity, distribution, and their driver at different altitudinal gradients is a benefit for understanding the ecological function of AMF in mountain ecosystems. In this study, we explored the AMF molecular diversity and their distribution from 660 to 3,500 m a.s.l. in Mount Taibai of Qinling Mountains based on high-throughput sequencing technology. A total of 702 operational taxonomic units (OTUs) in 103 species of AMF are isolated from soil samples, which belong to 18 identified and 1 unidentified genus in 10 families. The fungi in the genus of Glomus is the most dominant, with the occurrence frequency of 100% and the relative abundance of 42.268% and 33.048% on the species and OTU level, respectively. The AMF colonization in root could be simulated by a cubic function with the change of altitudes with the peak and trough at a.s.l. 1,170 and 2,850 m, respectively. Further, AMF diversity indices including Sob, Shannon diversity, and Pielou evenness also showed the same cubic function change trends with increasing altitude at OTU and species levels. However, the average values of diversity indices at OTU level are always higher than these at the species level. Based on the OTU level, the highest and lowest values of Shannon and Pielou indices are observed at the altitudes of 1,400 and 2,800 m, respectively. The pattern of AMF community distribution in Mt. Taibai is driven by altitude with the characteristics of more abundance in the medium- to low-altitude than high-altitude areas. In general, abundant AMF molecular diversity and species exit in different elevations of Mt. Taibai, which indicate gradient changes with elevations.
... ( Figure 1). The vegetation structure and communities are complicated and much dissected due to the essentially rough and changeable terrain (Ahmad et al., 2020;Ullah et al., 2021). Hence, the region sustained varied biodiverse flora and fauna (Xu et al., 2019). ...
Introduction
Non-native species are globally successful invaders with negative impacts on vegetation communities’ social, economic, and ecological values. Hence, the current research was carried out to assess the spatial distribution patterns and vegetative diversity of the four non-native species in severely invaded areas of the semi-arid parts of northern Pakistan.
Methods
The research was conducted using data from 1065 plots spread across 165 sites. These sites represented habitats throughout Northern Province, such as farm countryside, highlands, and abandoned places in rural and urban areas.
Results and discussion
The communities were floristically diverse, represented by 107 plant species, and dominated mainly by annual and perennial life forms with herbaceous habits. Similarly, the floristic structure shows significant variation tested by the χ2 test (P< 0.05) for plant status, life forms, life cycle, and habitat base distribution. In addition, the diversity indices show significant variation having the highest diversity in C-III ( P. hysterophorus -dominated sites) and lowest in C-IV ( S. marianum -dominated sites, i.e., primarily pure communities), indicating non-native species may increase or decrease site diversity. The diversity communities were further supported by higher quantities of soil nutrients, i.e., organic percentage (2.22 ± 0.04). Altitude, soil nutrients, and texture were shown to be the environmental factors most associated with communities that non-native species had invaded.
Recommendation
It is recommended that relevant, additional soil and climatic parameters be integrated into species distribution models to improve our understanding of the ecological niches of different species and to make a collective approach for preserving and conserving native plant communities.
... Natural terrestrial ecosystems such as conserved areas maintain highly stable physical interactions among living beings, which generate ecosystem services without human intervention (Oguh et al. 2021). Their distribution in topographic regions is largely associated with elevation, as distinct elevations imply particular conditions in temperature, precipitation, and soil properties that change the configuration of organisms in ecological communities (Ahmad et al. 2020;Massaccesi et al. 2020;Ramírez et al. 2023). Those changes in soil bacteria and fungi imply specific taxonomic compositions associated with vegetation and parameters such as pH and available organic carbon (Cui et al. 2019;Ji et al. 2022). ...
The influence of elevation on natural terrestrial ecosystems determines the arrangements of microbial communities in soils to be associated with biotic and abiotic factors. To evaluate changes of fungi and bacteria at the community level along an elevational gradient (between 1000 and 3800 m.a.s.l.), physicochemical measurements of soils, taxonomic identifications of plants, and metabarcoding sequences of the 16S rRNA gene for bacteria and the ITS1 region for fungi were obtained. The bacterial taxonomic composition showed that Acidobacteriota increased in abundance with elevation, while Actinobacteriota and Verrucomicrobiota decreased. Furthermore, Firmicutes and Proteobacteria maintained maximum levels of abundance at intermediate elevations (1200 and 2400 m.a.s.l.). In fungi, Ascomycota was more abundant at higher elevations, Basidi-omycota tended to dominate at lower elevations, and Mortierellomycota had a greater presence at intermediate sites. These results correlated with the edaphic parameters of decreasing pH and increasing organic carbon and available nitrogen with elevation. In addition, the Shannon index found a greater diversity in bacteria than fungi, but both showed a unimodal pattern with maximum values in the Andean Forest at 2400 m.a.s.l. Through the microbial characterization of the ecosystems, the elevational gradient, soil properties, and vegetation were found to exert significant effects on microbial communities and alpha diversity indices. We conclude that the most abundant soil microorganisms at the sampling points differed in abundance and diversity according to the variations in factors influencing ecological communities.
... Most mountains (e.g., Himalayas, Alps, Caucasus) are covered with forests, which are replaced by grasslands at increased altitudes (Bardelli et al., 2017;Ahmad et al., 2020;Ivashchenko et al., 2021). Hence, the distribution patterns of R S change at higher altitudes. ...
The patterns of change in bioclimatic conditions determine the vegetation cover and soil properties along the altitudinal gradient. Together, these factors control the spatial variability of soil respiration ( R S ) in mountainous areas. The underlying mechanisms, which are poorly understood, shape the resulting surface CO 2 flux in these ecosystems. We aimed to investigate the spatial variability of R S and its drivers on the northeastern slope of the Northwest Caucasus Mountains, Russia (1,260–2,480 m a.s.l.), in mixed, fir, and deciduous forests, as well as subalpine and alpine meadows. R S was measured simultaneously in each ecosystem at 12 randomly distributed points using the closed static chamber technique. After the measurements, topsoil samples (0–10 cm) were collected under each chamber ( n = 60). Several soil physicochemical, microbial, and vegetation indices were assessed as potential drivers of R S . We tested two hypotheses: (i) the spatial variability of R S is higher in forests than in grasslands; and (ii) the spatial variability of R S in forests is mainly due to soil microbial activity, whereas in grasslands, it is mainly due to vegetation characteristics. Unexpectedly, R S variability was lower in forests than in grasslands, ranging from 1.3–6.5 versus 3.4–12.7 μmol CO 2 m ⁻¹ s ⁻¹ , respectively. Spatial variability of R S in forests was related to microbial functioning through chitinase activity (50% explained variance), whereas in grasslands it was related to vegetation structure, namely graminoid abundance (27% explained variance). Apparently, the chitinase dependence of R S variability in forests may be related to soil N limitation. This was confirmed by low N content and high C:N ratio compared to grassland soils. The greater sensitivity of grassland R S to vegetation structure may be related to the essential root C allocation for some grasses. Thus, the first hypothesis concerning the higher spatial variability of R S in forests than in grasslands was not confirmed, whereas the second hypothesis concerning the crucial role of soil microorganisms in forests and vegetation in grasslands as drivers of R S spatial variability was confirmed.
... A study on the Loess Plateau of China (Chai et al., 2016) showed that taxonomic beta diversity did not change significantly with succession; however, other studies have found that taxonomic beta diversity decreased with succession (Kavgacı et al., 2010;Purschke et al., 2013). This difference may be related to forest age (Dalmaso et al., 2020), local climate (Keil et al., 2012), topography (Ahmad et al., 2020), research scales (Zhang et al., 2015), and other factors. Most studies of phylogenetic beta diversity showed a downward trend with succession (Purschke et al., 2013;Chai et al., 2016), indicating that deterministic processes gradually dominated the shift of phylogenetic structure in the community. ...
Community vertical stratification drives temporal taxonomic and phylogenetic beta diversity in a mixed broadleaf-conifer forest. Temporal change of beta diversity provides a better understanding of the extent and consequences of species composition in forest communities with the ongoing global climate change. However, relatively little is known about temporal beta diversity changes across vertical stratification in the forest. In this study, we divided more than 5,000 tree individuals from a mixed broadleaf-conifer forest into four vertical strata (i.e., shrub, subcanopy, lower canopy, and upper canopy) to quantify how vertical stratification drives the temporal change of taxonomic and phylogenetic beta diversity. We found that taxonomic beta diversity significantly decreased while phylogenetic beta diversity showed an insignificant increase after 5 years. When considering vertical stratification, taxonomic beta diversity in the subcanopy, lower canopy, and upper canopy significantly changed with inconsistent directions, but phylogenetic beta diversity in the shrub significantly increased. Moreover, the significant decrease in taxonomic beta diversity is mainly driven by changes in species composition in shrub and subcanopy stratification (with 85.89% contributions). The changes in phylogenetic beta diversity are driven by shifts in the shrub and upper canopy (with 96.02% contributions). Our study suggests that taking community vertical stratification into consideration contributes to a better understanding of temporal beta diversity in forest communities. KEYWORDS vertical structure, phylogenetic, taxonomic, temporal beta diversity, mixed broadleaf-conifer forest, Dongbaishan forest plot
... Within each individual habitat, 50 × 50 m plots were randomly demarcated, which were systematically divided into 5 × 5 m and 1 × 1 m quadrats for vegetation documentation and sampling. Measurement of root, shoot, and leaf traits Fifty healthy plants from each population with similar growth stages were collected from each habitat using the systematic quadratic method (Ahmad et al., 2020). Shoot and root length (cm), diameter (mm), dry mass (g), and specific root length (cm/g) were measured. ...
Climate change and anthropogenic pressures have resulted in a significant shift in the invasion susceptibility and frequency of non-native species in mountain ecosystems. Cirsium arvense (L.) Scop. (Family: Asteraceae) is an invasive species that spreads quickly in mountains, especially in the trans-Himalayan region of Ladakh. The current study used a trait-based approach to evaluate the impact of local habitat heterogeneity (soil physico-chemical properties) on C. arvense. Thirteen plant functional traits (root, shoot, leaf, and reproductive traits) of C. arvense were studied in three different habitat types (agricultural, marshy, and roadside). Functional trait variability in C. arvense was higher between, than within habitats (between different populations). All the functional traits interacted with habitat change, except for leaf count and seed mass. Soil properties strongly affect C. arvense's resource-use strategies across habitats. The plant adapted to a resource-poor environment (roadside habitat) by conserving resources and to a resource-rich environment (agricultural and marshy land habitat) by acquiring them. The ability of C. arvense to use resources differently reflects its persistence in introduced habitats. In summary, our study shows that C. arvense invades different habitats in introduced regions through trait adaptations and resource-use strategies in the trans-Himalayan region.
... Forests possess the greatest diversity in terms of species, genetic material, and ecological processes of all ecosystems [16]. The composition and diversity of tree species provide information for better planning and management for the restoration of native species and it is a useful tool in forestry for comparing the composition of different species [17]. Reduction in population sizes may lead to adverse consequences [18]. ...
The objective of this work was to study species composition and diversity of tree species between two vegetation stands, one is a protected vegetation stand and the other is a non-protected vegetation stand. The tree species composition and community structure were analyzed by field visits in Nanta forest region. Random sampling was done by using a standard size of quadrat i.e., 10x10m 2. Results showed that a total of 30 species belonging to 25 genera and 11 families are present in the protected site whereas 8 species belonging to 7 genera and 5 families are present in the unprotected site. Anogeissus pendula (Edgew) and Dichrostachys cinerea (L.) were the most important species in protected and non-protected sites respectively. The Simpson's index is higher in protected vegetation stands showing greater sample diversity. Family Fabaceae is dominant in both the vegetation stand which shows the ecological importance of this family.
... Our result confirms that beta TD and PD diversity prevailed by turnover, while beta FD diversity prevailed by nestedness (Figure 6), suggesting spatial mismatches between beta TD, PD, and FD diversity (Doxa et al., 2020). Habitat heterogeneity is often considered important in promoting turnover rates (Ahmad et al., 2020). Our study areas are large (344.22 km 2 ), span 639.38 km vertically, and have a pronounced physical gradient (Zheng et al., 2021a). ...
Understanding the multifaceted plant diversity and its maintenance mechanisms is crucial for biodiversity conservation. Dam-induced water level fluctuations dramatically alter various aspects of riparian diversity, such as taxonomic (TD), phylogenetic (PD), or functional (FD) diversity. However, few studies simultaneously evaluated plant TD, FD, and PD, especially in the subtropical reservoir riparian zone. Here we sampled plant diversity and environmental drivers along inundation gradients of the Three Gorges Reservoir Region in China. We integrated multifaceted plant diversity to assess how distinct ecological processes affect the plant community assembly and how they respond to inundation gradients, spatial variability, climate, and soils in dam-regulated riparian zones. We found that alpha TD, PD, and FD diversity exhibited decreasing trends with increasing inundation gradients and significant positive correlations with soil organic matter. The number of clustering plant communities increases along the inundation gradients. Beta TD and PD diversity were mainly dominated by species turnover with fewer contributions from nestedness, while beta FD diversity was mainly dominated by nestedness with fewer contributions from species turnover. The explainable rates of different dimensions of beta diversity, turnover, and nestedness ranged from 11% to 61%, with spatial factors explaining the highest beta diversity in different dimensions, followed by inundation gradients, soil properties, and climate variables. Our results suggest dispersal limitations are more important for species turnover in dam-regulated riparian zones at regional scales, while inundation gradients and soil fertility are more critical in shaping plant community assemblages at the local scale. This study emphasizes that environmental and spatial gradients are critical for understanding the assembly mechanisms driving multifaceted plant communities at local and regional scales and reinforces the importance of protecting seed sources and dispersal pathways and maintaining river connectivity when implementing restoration projects. CITATION Zheng J, Arif M, He X, Liu X and Li C (2023) Distinguishing the mechanisms driving multifaceted plant diversity in subtropical reservoir riparian zones.
... All these features have made the Himalayas an interesting candidate for biodiversity studies along the altitudinal gradients. Many researchers have studied patterns of species diversity along altitudinal gradients in the Himalayan region (Rawat et al., 2018;Ahmad et al., 2020;Bhat et al., 2020;Sharma and Kala, 2022). However, due to the remote and difficult-to-reach terrains in high-altitude areas, only a few studies have been conducted on the species composition and diversity in these remote areas of the Himalayas. ...
Elevational gradient, slope, and aspect offer a unique opportunity to explore the response of plant species under changing environmental conditions. The present study aimed to analyze the species diversity and distribution patterns with respect to altitude, aspect, and habitat types in the Kashmir Himalayas. Considering major aspects and habitats, a total of 123 representative sites were selected along the elevational gradients for the present study. The plant species composition of each selected site was studied by organized sampling following the standard ecological methods. During the present study, a total of 361 vascular plant species belonging to 71 families and 214 genera were identified in the study area. At the lower altitudes, the southern aspect and drier habitats showed the highest diversity. Moreover, a significant amount of compositional dissimilarity was observed between the studied aspects, habitats, and elevation belts and was mainly due to species turnover rather than the nestedness component. Further, among the studied variables, altitude was the most important contributing variable, explaining the greatest variation in the species composition. The paired effects of altitude and habitat explained the maximum variation in plant species composition. It may be concluded that floristic diversity should be studied not only with reference to elevational gradients but should also include aspects and habitats. The current study will act as a reference in this direction. A similar study must be replicated in other parts of the Himalayan region in the future to improve our understanding of the distribution and preferences of plant species in mountainous zones. This, in turn, will be immensely helpful in the conservation and sustainable utilization of resources in these ecologically fragile regions.
... All these features have made the Himalayas an interesting candidate for biodiversity studies along the altitudinal gradients. Many researchers have studied patterns of species diversity along altitudinal gradients in the Himalayan region (Rawat et al., 2018;Ahmad et al., 2020;Bhat et al., 2020;Sharma and Kala, 2022). However, due to the remote and difficult-to-reach terrains in high-altitude areas, only a few studies have been conducted on the species composition and diversity in these remote areas of the Himalayas. ...
Elevational gradient, slope, and aspect offer a unique opportunity to explore the response of plant species under changing environmental conditions. The present study aimed to analyze the species diversity and distribution patterns with respect to altitude, aspect, and habitat types in the Kashmir Himalayas. Considering major aspects and habitats, a total of 123 representative sites were selected along the elevational gradients for the present study. The plant species composition of each selected site was studied by organized sampling following the standard ecological methods. During the present study, a total of 361 vascular plant species belonging to 71 families and 214 genera were identified in the study area. At the lower altitudes, the southern aspect and drier habitats showed the highest diversity. Moreover, a significant amount of compositional dissimilarity was observed between the studied aspects, habitats, and elevation belts and was mainly due to species turnover rather than the nestedness component. Further, among the studied variables, altitude was the most important contributing variable, explaining the greatest variation in the species composition. The paired effects of altitude and habitat explained the maximum variation in plant species composition. It may be concluded that floristic diversity should be studied not only with reference to elevational gradients but should also include aspects and habitats. The current study will act as a reference in this direction. A similar study must be replicated in other parts of the Himalayan region in the future to improve our understanding of the distribution and preferences of plant species in mountainous zones. This, in turn, will be immensely helpful in the conservation and sustainable utilization of resources in these ecologically fragile regions.
... All these features have made the Himalayas an interesting candidate for biodiversity studies along the altitudinal gradients. Many researchers have studied patterns of species diversity along altitudinal gradients in the Himalayan region (Rawat et al., 2018;Ahmad et al., 2020;Bhat et al., 2020;Sharma and Kala, 2022). However, due to the remote and difficult-to-reach terrains in high-altitude areas, only a few studies have been conducted on the species composition and diversity in these remote areas of the Himalayas. ...
Elevational gradient, slope, and aspect offer a unique opportunity to explore the response of plant species under changing environmental conditions. The present study aimed to analyze the species diversity and distribution patterns with respect to altitude, aspect, and habitat types in the Kashmir Himalayas. Considering major aspects and habitats, a total of 123 representative sites were selected along the elevational gradients for the present study. The plant species composition of each selected site was studied by organized sampling following the standard ecological methods. During the present study, a total of 361 vascular plant species belonging to 71 families and 214 genera were identified in the study area. At the lower altitudes, the southern aspect and drier habitats showed the highest diversity. Moreover, a significant amount of compositional dissimilarity was observed between the studied aspects, habitats, and elevation belts and was mainly due to species turnover rather than the nestedness component. Further, among the studied variables, altitude was the most important contributing variable, explaining the greatest variation in the species composition. The paired effects of altitude and habitat explained the maximum variation in plant species composition. It may be concluded that floristic diversity should be studied not only with reference to elevational gradients but should also include aspects and habitats. The current study will act as a reference in this direction. A similar study must be replicated in other parts of the Himalayan region in the future to improve our understanding of the distribution and preferences of plant species in mountainous zones. This, in turn, will be immensely helpful in the conservation and sustainable utilization of resources in these ecologically fragile regions.
... The comparatively low predictive validity proposes that a broad range of omitted biotic and abiotic factors could be liable for restricting the allocation of understory vegetation (Saiter et al. 2016). Our results predicted that elevation assumed a significant part in shaping the taxonomic diversity in BP and SA forests which is consistent with the findings of Zhao and Fang (2006), Binkenstein et al. (2018) and Ahmad et al. (2020). Topographic variations determine the solar radiation received and water and nutrients availability, governing the subsistence and growth of vegetation indirectly by establishing microenvironments. ...
The temperate Kashmir Himalaya, regardless of its simple representation as a giant temperate forest, exhibits remarkable vegetation dissimilarity being inadequately perceived. We explored the species diversity and taxonomic composition of herbaceous stratum in 147 plots over 36.75 ha of temperate Kashmir Himalayan landscape, describing three heterogeneous forest types, viz., low-level blue pine (BP), mixed-conifer (MC), and subalpine (SA) forests. Regression and constrained ordination (canonical correspondence analysis) analyses are used to quantify the relevance of environmental variables in governing herbaceous species composition and diversity. Landscape-level richness of 245 species ranging from 113 species in BP forest to 173 species in SA forest is documented. Mixed conifer forest manifested maximal species richness and Whittaker-β score among the forest types. With an aggregate of 42 species, Asteraceae attributed the optimum species richness accompanied by Poaceae (19 spp.), Lamiaceae (16 spp.), and so on, besides 22 monotypic families. Fragaria nubicola proclaims the dominant species, while Trifolium pratens, Pimpinella diversifolia and Impatiens brachycentra represent the most significant indicator species in BP, MC and SA forests. The consequence of elevation gradient on species richness across the landscape proclaims a significant unimodal paradigm (p = 0.005) ascribed to environmental stress at both elevational extremes. Latitude and precipitation proved as influencing ecological gradients underpinning the distribution of species composition in BP forest. However, in MC and SA forests, geographic location and precipitation and elevation and precipitation are highly associated with CCA-1 axis. To optimize biodiversity protection, conservation efforts must take forest scale variations in flora into consideration.
... with a spatial resolution of 250 m. Our subplot setting method was based on the strategy of Ahmad et al. (2020). The sample plots are divided into one tree plot (20 × 20 m), five shrub subplots (5 × 5 m), and five herb subplots (1 × 1 m) (Fig. 1C). ...
Research into species composition and diversity in forest systems with successional stages can provide a scientific basis for optimal allocation and regulation of community structure. However, it is unclear how succession in arid and semi-arid forests changes the composition and diversity of species. The present study analyzed how species composition and diversity within successional gradients in arid and semi-arid areas of China evolved based on a spatially substituted temporal approach and identified the key factors influencing community composition and species diversity. Study findings have shown that species composition and life forms differ greatly between and among successional stages. In contrast, species richness is significantly lower in late-successional stages than in mid-successional stages. In the α-diversity, Shannon-Wiener diversity and Margalef richness reached an apex in the middle of the succession. At the same time, Pielou evenness and Simpson dominance did not change significantly over time. Except for Margalef richness, the α-diversity of different life forms throughout the successional gradient was consistent. The results of the β-diversity analysis indicate that the species turnover process has occurred during succession. It is evident that communities located at adjacent successional stages have high similarities in species composition. However, the loss or renewal of species was more advanced in the early and late stages, and the differences between communities were more evident. The main reasons for this can be attributed to differences in microhabitats (precipitation and temperature) and competition among species in various successional stages. It has been demonstrated that species diversity changes considerably in dry forest ecosystems as the ecosystem progresses through different stages of development. Effective conservation measures are needed to allow new species to establish themselves.
... Intriguingly, we found that the AM fungal richness and diversity followed the pattern that peaked at mid-elevation (i.e., around 800 m) and decreased then (Fig. S5). A similar pattern was also found by Zhang et al. (2021) and the degree of root colonization by AM fungi also followed this trend, where they suggested that this could be resulted from the great difference in the plant's species replacement rate along elevation (Ahmad et al., 2020). ...
Arbuscular mycorrhizal (AM) fungi play an important role in facilitating ecosystem function and stability. Yet, their community response patterns and ecological assembly processes along elevational gradients which cross a range of climates and soil conditions remain elusive. We used Illumina MiSeq sequencing to examine trends in soil AM fungal community along an elevational gradient from 100 m to 2300 m in central Japan. A total of 750 operational taxonomic units (OTUs) affiliated to 12 AM fungal genera were identified from soil samples, and the AM fungal community composition differed strongly with elevation, with variance explained more by climate, followed by soil and plant factors. The AM fungal α-diversity, network connectivity and complexity between AM fungal taxa and also with plant communities all exhibited a maximum at the mid-elevation of 800 m and then declined, principally influenced by soil pH and precipitation. Stochastic processes dominated AM fungal community assembly across the whole elevation gradient, with homogenizing dispersal being the main process. Only when AM fungal communities were contrasted across a relatively broad range of elevations, did variable selection (deterministic process) became significant, and even then in a mixed role with stochasticity. While OTUs of AM fungi are clearly adapted to particular environmental ranges, stochasticity due to rapid dispersal has a major role in determining their occurrence, suggesting that AM fungi may possess generalized and interchangeable niches, and can adjust their distribution rapidly - at least on the scale of a single mountain. This finding emphasizes that the roles of AM fungi in plant ecology may be non-specific and easily substituted, and furthermore that there is rapid local scale dispersal, which may allow plants to maintain effective AM associations under environmental change.
... Species richness recorded during the present study was higher than in earlier reports from the Indian Himalayan region (Singh et al., 2007;Chawla et al., 2008;Dar and Sundarapandian, 2016;Pandey et al., 2018;Haq et al., 2019Haq et al., , 2021Ahmad et al., 2020). Asteraceae, Lamiaceae, Rosaceae, and Ranunculaceae were reported to be dominant contributing maximum species. ...
The present study is an attempt to evaluate the Conservation Priority Index (CPI) of species, habitats, and communities for their conservation and management planning in the Kashmir Himalayas in India. The present study is an attempt to prioritize 361 plant species, 18 plant communities (10 within the forest zone and 08 within the alpine zone), and 07 habitats for conservation planning. Out of the total plant species recorded, 06 species were categorized as critically endangered, 20 endangered, 28 vulnerable, and 98 species to be near threatened. Amongst the forest and alpine communities, Abies pindrow community and Juniperus squamata-Rhododendron anthopogon mixed community showed the maximum CPI values. Amongst the habitats, dry habitats showed the maximum CPI in the sanctuary. The study found that the threatened species positively correlated with the native and endemic species indicating that these species were rigorously affected due to biotic and abiotic stresses. Based on the results of the present study, we propose a practical method for biodiversity conservation and management of protected areas. The approach employs a variety of qualitative and quantitative features to compute CPI in conjunction with phytosociological data. This kind of study will be immensely helpful to forest officials, policy makers, conservators, and researchers for planning better strategies to conserve and manage particular species, communities, and even habitats in protected areas.
... Species richness recorded during the present study was higher than in earlier reports from the Indian Himalayan region (Singh et al., 2007;Chawla et al., 2008;Dar and Sundarapandian, 2016;Pandey et al., 2018;Haq et al., 2019Haq et al., , 2021Ahmad et al., 2020). Asteraceae, Lamiaceae, Rosaceae, and Ranunculaceae were reported to be dominant contributing maximum species. ...
The present study is an attempt to evaluate the Conservation Priority
Index (CPI) of species, habitats, and communities for their conservation and
management planning in the Kashmir Himalayas in India. The present study is
an attempt to prioritize 361 plant species, 18 plant communities (10 within the
forest zone and 08 within the alpine zone), and 07 habitats for conservation
planning. Out of the total plant species recorded, 06 species were categorized
as critically endangered, 20 endangered, 28 vulnerable, and 98 species to
be near threatened. Amongst the forest and alpine communities, Abies
pindrow community and Juniperus squamata-Rhododendron anthopogon
mixed community showed the maximum CPI values. Amongst the habitats,
dry habitats showed the maximum CPI in the sanctuary. The study found
that the threatened species positively correlated with the native and endemic
species indicating that these species were rigorously aected due to biotic
and abiotic stresses. Based on the results of the present study, we propose a
practical method for biodiversity conservation and management of protected
areas. The approach employs a variety of qualitative and quantitative features
to compute CPI in conjunction with phytosociological data. This kind of study
will be immensely helpful to forest o�cials, policy makers, conservators, and
researchers for planning better strategies to conserve and manage particular
species, communities, and even habitats in protected areas.
... Although many studies along the Himalayan altitudinal gradients have been conducted in order to better understand large-scale biogeographical patterns along with what drives them, [31][32][33][34][35][36][37][38][39][40][41][42][43][44] no clear pattern has emerged, as most of these studies attempted to document the pattern of species and composition at lower or higher elevational zones. Therefore, the floristic characteristics and plant diversity patterns in the Himalayan region in general and the Indian Himalayan region in particular are still data-deficient and thus poorly understood [22,45]. Furthermore, the Pir Panjal range, a remote area of the Indian Himalayan region, has remained unexplored owing to its remoteness, inaccessibility and difficult terrains. ...
The structure and distribution patterns of Himalayan vegetation are poorly explored, and research on species composition along the elevation gradient in these mountain ranges is still deficient. The current study was undertaken to analyze the variation and pattern of plant species composition along a vertical gradient in northwestern Himalaya, India. A total of 18 sites were selected along an elevation gradient ranging from 2200 to 3900 m asl positioned at an interval of 100 m. The Renyi diversity profile, non-metric multidimensional scaling based on the Bray–Curtis dissimilarity metric and beta diversity components among the elevation belts were calculated. Furthermore, to study the influence of altitude on species richness and diversity, a generalized additive model was created. Two hundred and ten plant species representing 66 families and 147 genera were recorded. The Renyi diversity profiles show that the lower and mid-altitudes had rich species diversity. The results of the non-metric multidimensional scaling analysis show a considerable variation in the total plant species composition among the studied elevation belts. The observed multiple-site Sorensen dissimilarity index across the studied elevation belts was very high. The contribution of species replacement or the turnover component to the observed dissimilarity was much higher than the nestedness component. Furthermore, the herbaceous and tree richness showed a significant decrease with increase in elevation; however, the richness of shrubs showed a bimodal pattern. The present study increases our understanding of the trends and patterns of species richness along the vertical gradient in the Himalayan region.
... CCA1, the most significant axis in the CCA biplot (Gebrehiwot et al. 2018), indicates a key role of elevation in species distribution. A similar result was also reported in other Himalayan studies by Sharma et al. (2018) in the Bhagirathi catchment area of Garhwal Himalaya, India; Thakur et al. (2021) in the Churdhar Wildlife Sanctuary, India, and Ahmad et al. (2020) in the Dhauladhar Mountains of northwestern India. Other topographical factors, i.e., slope and aspect, were strongly correlated to CCA2, which are known to affect plant physiological growth, diversity, and dispersal. ...
Himalayan ecosystems provide a unique opportunity to analyze the determinants of species richness across large elevation gradients. Understanding forest diversity and structure is fundamental to set conservation priorities. A quantitative assessment of tree species was conducted in Kashmir Himalayan forests to ascertain their composition, stand structure and distribution in 143 plots of 50 × 50 m². Altogether, 13 species were recorded, ranging from five in subalpine (SA) forests to 10 in mixed conifer (MC) forests. There was a compositional dissimilarity among forest types. Pinus wallichiana was the most important species in low-level blue pine (BP) forests, whereas Abies pindrow prevailed in mid-elevation MC and high-elevation SA forests. Pinaceae contributed around 98% of stems and was the most speciose family, followed by Sapindaceae and Betulaceae. Stand density and basal area differed among forest types and were significantly correlated with elevation and slope. The tree diameter class distribution displayed an approximate reverse J-shaped pattern indicating the influence of disturbance. As the first two axes of the canonical correspondence analysis explained more than 93% of the inertia in the species-environment relation, elevation and slope are the main drivers of species distribution. Information about these forest attributes could provide better ecological insights for sustainable forest management.
... In montane ecosystems, the altitudinal effects on plant community composition and diversity pattern have attracted much attention (Costanza et al. 2011;Boscutti et al. 2018;Ahmad et al. 2020;Hamid et al. 2021). According to previous studies, the most commonly spatial patterns reported are monotonic and unimodal changes, which depend on the changes of environmental variables with altitude gradient (Grytnes 2003;Naud et al. 2019;Ahmad et al. 2021). ...
In montane systems, there are normally significant spatial differences in vegetation community structure and ecological processes due to the complex topography. The study of such topographic effect can provide scientific basis for the prediction of vegetation dynamics. In this work, the effects of altitude and slope aspect on species richness and flowering phenology of herbaceous communities were investigated in Qilian Mountains, a typical mountainous region in arid climate zones of China. Our monitoring of 102 plots in 34 sites revealed that there were significant topographic effects on species richness and flowering phenology. Specifically, the results showed a spatial pattern that the average number of species in plots was slightly higher at middle altitudes, and was higher on shady than sunny slopes. In flowering phenology, the flowering onsets of low-altitude and sunny-slope communities are generally earlier than that of high-altitude and shady-slope communities, respectively, while the ending dates of flowering between slope aspects and between altitudes are relatively small. This topographic effect revealed the influences of temperature and soil moisture on community structure and flowering phenology, which is reflected in the inverse responses of species richness to temperature and soil water content, and the high sensitivity of flowering phenology to temperature. It can be inferred that under the conditions of climate warming and wetting in the future, the species diversity of herbaceous community may increase at high altitudes, and the flowering duration is likely to be further prolonged in Qilian Mountains.
... The spatial heterogeneity of diversity indices was apparent across temperate Kashmir Himalayan coniferous forests, and it corresponded to shifts in forest composition and distribution and was associated with ecological processes (Zhang et al., 2015). The wide array of species (245), genera (171), and families (52) recorded via the extensive field survey indicates considerable diversity, similar to other Himalayan forests (Rahman et al., 2017;Ahmad et al., 2020;Dar and Sundarapandian, 2016) and temperate ecosystems elsewhere (Wang et al., 2019;Kutnar et al., 2019). ...
We assessed the understory vegetation types in temperate Kashmir Himalayan coniferous forests, their species composition and what function ecological drivers execute in shaping compositional trends using a multivariate statistical approach. The agglomerative clustering analysis depicted eight discrete plant associations in terms of herb species composition with simple underlying indicator species and ecological drivers. At one extreme, we found alpine and subalpine areas (Tanacetum multicaule Sch.Bip. – Aconitum heterophyllum Wall. ex Royle – Lomatogonium caeruleum (Royle) Harry Sm. ex B.L. Burtt community (TAL)) occupying high elevations (2961.88±205.56m) with notable species richness (6.04), while lower (2459.36±94.07m) areas are inhabited by Thalictrum minus L. – Galium aparine L. – Achillea millefolium L. (TGA) community. The Poa pratensis L.– Senecio chrysanthemoides DC. – Clinopodium umbrosum (M.Bieb.) Kuntze (PSC) community was most diverse, supported higher species diversity (Shannon=2.22±0.07; Simpson=0.84±0.01; Fisher's α=4.51±0.30) and also exhibited a maximum number of trails crossing the plot. Canonical Correspondence analysis (CCA) examined the species-ecological interactions and displayed a significant role of most studied environmental variables in the species distribution patterns. The latter in the decreasing significance order comprised precipitation (F=2.3; p=0.001), latitude (F=2.15; p=0.001), grazing (F=1.56; p=0.01), longitude (F=1.63; p=0.013), slope (F=1.33; p=0.07), elevation (F=1.32; p=0.07), aspect (F=0.1; p=0.47), trails (F=0.78; p=0.85) and mean monthly minimum temperature (F=1.23; p=0.172). The variance partitioning used to evaluate the comparative significance of topographic, climatic and disturbance factors on understory vegetation composition depicted that topography (14.26%) strongly partitioned the vegetation distribution subsequently followed by climatic (11.52%) and disturbance (4.49%) factors.
... Several other meteorological conditions may accompany greater altitudes (Pauchard et al., 2009). These factors may include a reduced supply of resources, shorter growing seasons, lower microbial activity, and a smaller human population density (Ahmad et al., 2020;Ali, 2017). An altitude-based change to a plant species' functional characteristics may significantly affect the species' attributes (Ali et al., 2014;Trunschke & Stöcklin, 2017). ...
Invasive biology acknowledges the concept of better performance by invasive plants in the introduced range. Xanthium strumarium L. is one of the successful invasive species in Khyber Pakhtunkhwa, Pakistan. The phenological pattern, vegetative and reproductive traits plasticity analysis of the species was explored to explain the inva-sive success across the altitudinal gradient in the current invaded habitats. Phenologi-cal patterns and timing (seedling, vegetative growth, flowering and fruiting, drying, and seed bank) were observed during a full year for two seasons. We also examine plant functional traits at altitudes of 500, 1000, and 1500 m a.s.l. to assess traits and biomass variations. The X. strumarium exhibits late vegetative and reproductive phe-nology at higher altitudes, enabling them to occupy an empty niche and benefit from decreased competition for resource acquisition. The lower altitude plants show a higher growth rate (stem size increase, number of leaves, and leaf area) due to the higher nutrient availability. Higher altitude plants have the highest reproductive bio-mass and biomass ratio revealing plant abilities to be reproductively adapted in the higher altitudes. Among climatic variables, mean yearly temperature, mean annual yearly humidity, and mean day length in hours, while in soil variables, organic matter and nitrogen percentage significantly affect the phenological and morphological stages. Therefore, we conclude that X. strumarium can invade higher altitudes with a shift in its phenological and morphological changes making the invasion process successful. K E Y W O R D S elevation gradient, functional traits, invasive success, Pakistan, phenological shift, reproductive performance
... Assessing species composition, diversity, and structure has been a major focus of ecological studies (Bhat et al., 2020). Such an evaluation is helpful in improving our understanding of forest ecosystems to improve conservation and management planning (Ahmad et al., 2020). ...
The forests of the central Himalayan region are characterized by the dominance of some populous and conspicuous tree species across altitudes that are crucial for ecosystem functions and services. An understanding of such forests with relation to species richness, diversity, structural pattern, and distribution is crucial in maintaining ecosystem stability. Considering this, the present study was undertaken on the four most common forest types dominated with Sal (Shorea robusta), Chir-pine (Pinus roxburghii), and Banj-oak (Quercus leucotrichophora), and mixed-oak (Q. lanuginosa and Q. floribunda) between 300 and 2250 m msl. Across the studied forest stands, we recorded a total of 110 plant species, belonging to 53 families. The most dominating life form was herbaceous (52%), followed by trees (27%), and shrubs (21%). Tree density was recorded maximum (884 ind. ha −1) at the mixed oak stand and minimum (652 ind. ha −1) recorded at the chir-pine forest; however, maximum (51.58 m 2 ha −1) total basal area (TBA) was recorded in banj-oak forest and minimum (33.42 m 2 ha −1) at mixed-oak forest stand. Tree density, seedling density, and TBA are significantly varied among the forest stands. The temperate oak forests comprised higher species richness and diversity at tree and shrub stratum. However, subtropical sal and chir-pine stand recorded higher regeneration. All stands exhibited high community dependence on forest resources that may increase the vulnerability of forest with respect to human interference, thus deserve immediate attention. Site-specific management and conservation measures have been suggested to provide opportunities for sustainable management of all forest stands.
... Subedi et al., 2019), and flowering plants(Bhattarai et al., 2004;Wang et al., 2007). Both unimodal and bimodal relationships between species richness and elevation have been commonly observed in various plant taxa(Acharya et al., 2011;Ahmad et al., 2020;Bhattarai et al., 2004;Kluge et al., 2017;Oommen & Shanker, 2005;Sun et al., 2020). Moreover, endemic species richness in the region appears to peak at markedly higher elevations than total species richness(Kluge et al., 2017;Vetaas & Grytnes, 2002), possibly because climate change (especially historical temperature fluctuation) is greater at high elevations; hence, there are more perturbations at these high elevations that in turn drive speciation. ...
Mountain ecosystems support a significant one-third of all terrestrial biodiversity, but our understanding of the spatiotemporal maintenance of this high biodiversity remains poor, or at best controversial. The Himalaya hosts a complex mountain ecosystem with high topographic and climatic heterogeneity and harbors one of the world's richest floras. The high species endemism, together with increasing anthropogenic threats, has qualified the Himalaya as one of the most significant global biodiversity hotspots. The topographic and climatic complexity of the Himalaya makes it an ideal natural laboratory for studying the mechanisms of floral exchange, diversification, and spatiotemporal distributions. Here, we review literature pertaining to the Himalaya in order to generate a concise synthesis of the origin, distribution, and climate change responses of the Himalayan flora. We found that the Himalaya supports a rich biodiversity and that the Hengduan Mountains supplied the majority of the Himalayan floral elements, which subsequently diversified from the late Miocene onward, to create today's relatively high endemicity in the Himalaya. Further, we uncover links between this Miocene diversification and the joint effect of geological and climatic upheavals in the Himalaya. There is marked variance regarding species dispersal, elevational gradients, and impact of climate change among plant species in the Himalaya, and our review highlights some of the general trends and recent advances on these aspects. Finally, we provide some recommendations for conservation planning and future research. Our work could be useful in guiding future research in this important ecosystem and will also provide new insights into the maintenance mechanisms underpinning other mountain systems.
... Elevation is an important indicator of microclimatic variations, which influences plant invasion (Wilson et al., 1992). Apart from harsher climatic conditions, increase in elevation is also characterized with decline in availability of resources, shorter growth seasons, lower microbial activity, and comparatively low human population densities (Pauchard et al., 2009;Ahmad et al., 2020). Thus, elevation based variations can significantly alter functional characteristics of a plant species (Trunschke and Stöcklin, 2017). ...
In invasion ecology, hypothesis of an invasive species exhibiting enhanced performance in the introduced range has been widely acknowledged. Examining the role of phenotypic plasticity in improving plants’ performance is essential to understand adaptive responses of an exotic invasive species to environmental variations. As Parthenium hysterophorus L. (Asteraceae) is one of the most widespread subtropical invader globally, we selected it as a model plant for studying its adaptive responses along the elevation gradient. Sites at an elevation of 700 m, 900 m, 1,100 m and 1,500 m were selected in the lower Himalayas for analysing plant functional traits of the weed and assessing variations in biomass allocation along elevation. Non-reproductive traits, i.e. above-ground plant height (AGPH) and below-ground biomass (BGB), and reproductive traits, i.e. capitula count per plant (CC), seed size, seed thickness and seed mass varied significantly with the elevational gradient. Soil properties also exhibited significant variations along elevation, except pH and total nitrogen (TN). Production of large number of heavier seeds, with smaller size at higher elevations showed enhanced reproductive fitness (adaptation) of P. hysterophorus. The study concluded that alteration in reproductive traits aids the successful invasion and expansion of P. hysterophorus in mountain ecosystems.
The present study was carried out to assess the floristic diversity and community characteristics in the forest and alpine zone of Gulmarg Wildlife Sanctuary (GWLS), Kashmir Himalaya. A total of 123 sites were selected along an elevational gradient (2300–4200 m a.m.s.l) in each and every accessible aspect and habitats from July 2018 to June 2022. The present study recorded 364 species of vascular plants belonging to 227 genera and 74 families. Of the total species, 22 were trees, 34 shrubs, 290 herbs and 14 ferns. A total of 18 communities (10 within forest and 8 within alpine zone) were identified. Within the identified forest communities, species richness ranged from 44 to 198; tree density and total basal area ranged from 185–810 Ind ha−1 and 20.28–159.8 m2 ha−1, respectively. Density of shrubs and herbs in forest zone ranges from 886–2040 Ind ha−1 and 27.79–87.75 Ind m−2, respectively. Within the alpine communities, species richness ranged from 26–93; total density of shrubs and herbs ranged from 1410.0–5540 Ind ha−1 and 31.73–102.2 Ind m−2, respectively. Within the forest zone, diversity of trees, shrubs and herbs ranged from 0.88–1.67, 0.27–1.82 and 3.29–4.81, respectively. Within the alpine communities, species diversity of shrubs and herbs ranged from 0.73–1.33 and 2.21–3.69, respectively. Present study presents a first comprehensive floristic and community assessment of GWLS, and provides a template, which can be replicated in other protected as well as unprotected areas of the Kashmir Himalaya.
Treeline ecotone, though studied the world over because of its sensitivity to changing climate, has received limited attention in the Himalaya. It is in this backdrop that an extensive study in the Daksum-Sinthan Top area of Kashmir Himalaya, India, was carried out to document the taxonomic, life-form and phylogenetic diversity of plant assemblages at the treeline ecotone in relation to elevation and aspect. A total of 235 species belonging to 168 genera and 71 families were recorded in the ecotone. Only 26% of species were common between the north-facing and south-facing aspects, and a decline in the total number of species with elevation was the general trend. Herbs were predominant at all the elevations on both aspects. Sørensen’s dissimilarity across the elevations and aspects was low and the turnover component (βsim) was the major contributor to the overall dissimilarity. Phylogenetic overdispersion was noticed at lower elevations and phylogenetic clustering was prevalent at higher elevations on both aspects. Diffuse-type treeline-form was more common on the north-facing slope and tree-island type on the south-facing slope. The dominant treeline species on the north-facing slope was Betula utilis, and Pinus wallichiana on the south-facing slope.
Environmental filtering (EF) and dispersal filtering (DF) are widely known to shape plant community assembly. Particularly in arid and semi-arid mountainous regions, however, it remains unclear whether EF or DF dominate in the community assembly of different life forms or how they interact along elevational gradients. This research aims to reveal how different ecological processes influence herbaceous and woody community assembly and how they respond to various environmental drivers and elevational gradients. Here we integrated taxonomic diversity (TD), phylogenetic diversity (PD), and ecological drivers across an elevational gradient of 1,420 m in the Helan Mountain Nature Reserve, in typical arid and semi-arid areas of China. This study showed that the TD and PD of herbaceous communities significantly increase linearly with changing elevation gradients, while woody 'TD' showed a unimodal pattern, and there was little relationship between woody 'PD' and elevation. Herbaceous species exhibited significant phylogenetic clustering at low elevations, where they were influenced by climate, aspect, and tree cover. However, woody species exhibited random patterns across elevations. Herbaceous and woody species' taxonomic and phylogenetic beta diversity is governed primarily by spatial turnover rather than nestedness. Spatial turnover is caused primarily by EF and DF's combined influence, but their relative importance differs between herbaceous and woody communities. Therefore, we conclude that the responses of herbaceous and woody plants along elevation gradients in the Helan Frontiers in Plant Science
The present study aimed to assess the spatial distribution and invasion potential of naturalized Datura innoxia Mill., a member of the family Solanaceae, across elevation, edaphic, and climatic gradients in invaded communities of semiarid regions in northern Pakistan. The species’ phytosociological attributes, diversity indices, and biotic and environmental factors were assessed in 21 sites (210 plots) and categorized into three elevation groups separated by Ward’s agglomerative cluster. The vegetation was dominated by annual species, which facilitated the naturalization and invasion of alien species. The groups were dominated by D. innoxia, having different codominant species Parthenium hysterophorus L. in Group I, Medicago denticulata in Group II, and Parthenium hysterophorus in Group III; however, the third codominant species of groups I and III were different. In addition, Canonical correspondence analysis (CCA) unveiled that abiotic factors such as elevation (r = −0.65), mean yearly temperature (r = 0.79), annual yearly humidity (r = 0.76), and day length in hours (r = 0.79) and biotic factors such as cultivated fields (r = −0.83) and traffic density (r = 0.70) were strongly correlated on canonical axes, revealing their vital importance in determining vegetation structure. The study concluded that this naturalized species propagated efficiently in the present environmental conditions and if these conditions prevailed, the species would be established as an invasive species. Therefore, control of this naturalized species is critically important, including their exploitation for medicinal and phytochemical utilization, which will enhance the protection of native populations.
This study presents a checklist of the flora of three coniferous forests of the Himalayan biodiversity hotspot in Kashmir: low-level blue pine (BP), mixed coniferous (MC) and subalpine (SA) forests. The list includes altitudinal distribution and conservation status of 272 vascular plant species representing 196 genera and 64 families. Excluding neophytes (70 taxa, 62 genera, and 27 families), Magnoliophyta comprised 190 taxa, 139 genera, and 50 families; Pinophyta seven taxa, six genera, and three families; and Pteridophyta three taxa, three genera, and two families. Most speciose families from Magnoliophyta include Compositae, Apiaceae, and Rosaceae. Genera such as Artemisia, Potentilla, Viola, and Saussurea contributed the maximum number of species. In case of Pinophyta, the principal families are Pinaceae with four taxa followed by Cupressaceae (2 taxa), whereas genus Juniperus comprised two species. In Pteridophyta, Pteridaceae (2 taxa) formed the most speciose family. The herbs contributed 177 taxa, followed by tress (15 taxa), shrubs (8) and subshrubs (2). The maximum number of taxa belongs to SA (136 taxa) followed by MC (134 taxa) and BP (83 taxa) forests. The species distribution reveals 20, 30, and 46 taxa are exclusive to BP, MC, and SA forests. More than 16% of taxa are categorized in the International Union for Conservation of Nature (IUCN) Red List, and 24 taxa are endemic to the Himalayan landscape. The checklist provides a roadmap for research, protection and conservation of plant diversity, especially the threatened taxa.
Spatial heterogeneity, which is one of the basic characteristics of ecological and geographical elements, is substantial in mountainous areas. Research on ecosystem services (ESs) increasingly considers spatial heterogeneity in environmental management-related decision-making. This study quantified the dominant ESs and ES trade-offs for the Hengduan Mountain region in Southwest China. The spatial heterogeneity was analyzed by introducing gradients of elevation, vegetation cover, and land cover. The results showed that, in addition to inverse changes in ESs, ES change rates were important for ES trade-offs. Further, land cover was identified as the main factor influencing the spatial heterogeneity of the majority of ES trade-offs. Specifically, the net primary productivity (NPP), carbon storage (C), and habitat quality (HQ) all showed inverted U-shaped trends along the elevation gradient and HQ increased thereafter, water yield (WY) presented an overall decline but increased in high-altitude areas, and soil conservation (SC) exhibited a fluctuating trend. The change rate of SC was slower than that of NPP, C, and HQ, which led to changes in the trade-offs between SC and other ESs along the elevation gradient. The higher WY in built-up land and higher HQ in forests were the main reasons for higher trade-offs. The low trade-off for unused land was attributed to the limited levels of several ESs. Along the vegetation gradient, WY first decreased then increased, whereas all other services showed increasing trends. The limited promotion effect of vegetation on SC was the primary reason for increased trade-offs. Therefore, more attention should be devoted to improving SC via engineering measures. Furthermore, vegetation degradation on unused land should be prevented to maintain SC and reduce the trade-offs among ESs.
Tidal marsh wetlands in the Yellow River Delta provide valuable eco‐services to the local population and global ecology. However, this area is suffering from serious degradation under the stresses of social development and climate change. Hydrological connectivity, a new framework in hydrology and ecology, has been proposed as the main factor affecting the ecological processes in coastal wetlands; however, its role in hydrology–soil–vegetation interactions remains unclear. In this study, we parametrically quantified the hydrological connectivity in the tidal marsh wetlands and analyzed its relationship with Phragmites australis, one of the dominant species in this area. Our results showed threshold‐like effects on the interaction between hydrological connectivity and P. australis on the plot scale. When biomass is lower than 2.2 kg/m², the population density and structure size were found to increase with hydrological connectivity. When the biomass is higher than the threshold, the plots disconnected hydrologically because of high water consumption. Compared with soil chemistry, salinity, and water soil content, hydrological connectivity in the surface soil layer is more strongly linked to the plant traits and spatial structure in the tidal marsh wetlands due to the narrow ranges of other variables. Based on the authors’ analysis, the researchers do not recommend dense plantation of P. australis, especially near the freshwater sources in the tidal marsh, because of its high reproduction ability and competitive nature, which may cut the freshwater connectivity off, lowering the richness of plant species and habitat diversity.
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In spite of many theoretical explanations, the plant richness pattern along the mountain elevation gradient is still debatable. Here we considered East district of Sikkim state in the Eastern Himalaya to study plant richness pattern of vascular plants along an elevation gradient of 500–3300 m at 100, 200 and 300 m elevation steps. The study evaluates species-area relationships along the elevation gradient, spread over four major forest types i.e., low (tropical to sub-tropical, up to 900 m), middle (subtropical, 750–1500 m), upper (wet temperate, 1500–2700 m) and Rhododendron-Conifer Zone (cold temperate/sub-alpine, 2700–3600 m) with 664 species from 367 genera and 131 families. Pteridium aquilinum was found to be the most diverse species occurring in all 28-elevation steps along 500–3300 m, followed by Polystichum lentum, Polygonum runcinatum and Nephrolepis cordifolia those occured in 23 elevation steps. In general, a hump shaped pattern was observed for plant richness of all life forms along the elevation gradient. The peaks became prominent, with the increase in scale of extent from 100 m (R² = 50%) to 300 m (R² = 78%) through 200 m (R² = 55%) elevation steps, using 2nd order polynomial fitting. The reduction in tree height and richness was noticed beyond 2300 m allowing dominance of herbs owing to climatic constraints. Using generalized additive model, temperature could explain the maximum deviance of > 47%. Soil explained 36.4% deviance, followed by precipitation (21.6% deviance) in the plant richness. However, the ecotone effect of different forest types explained the mid-elevation peaks in plant richness more prominently than the geographic area availability. Further, inclusion of disturbance and biotic interactions may improve ecological understandings on the plant richness pattern along the elevation gradient.
Key Findings
1. Looming challenges characterize the HKH as environmental, sociocultural, and economic changes are dynamically impacting livelihoods, environmental conditions, and ultimately sustain- ability. Many challenges for sustainability are related to weak governance, natural resource overexploitation, environmental degradation, certain aspects of unregulated or rapid urbanization, and loss of traditional culture. Addressing these problems will require policy and action at local, national, and international levels, including common action among HKH states.
2. However, for mountain societies of the HKH, some changes may also bring novel opportunities for sustainable development. A range of opportunities lie in improved connectivity including transportation and communication, which increases access to information, partnerships, and markets. Enhanced access to social services may be enabled and strengthened by economic growth and the advancement of science and technology. Additionally, a growing network of local urban centres may support the transmission of new prosperity to rural populations, as the development of mountain towns and cities often can help—besides their mere economic power—to enhance the political influence of these regions within the national states.
3. The drivers of change to environmental, socio-cultural, and economic sustainability in the HKH are interactive, inextricably linked, and increasingly influenced by regional and global developments. Among the most important drivers in this intricate network of causes and effects are demographic changes and current governance systems, as well as land use and land cover change, over-exploitation of natural resources, economic growth and differentiation, and climate change.
Corresponding Author
Ning Wu, International Centre for Integrated Mountain Development, Kathmandu, Nepal; and Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China,
e-mail: wuning@cib.ac.cn
Review Editor: Marc Foggin
https://link.springer.com/chapter/10.1007/978-3-319-92288-1_2
Climate change in combination with socioeconomic processes and opportunities have an especially severe impact on people living in remote mountain areas of the Hindu Kush Himalaya. What is less well known is how changes in climate will affect in the quality of lives, livelihoods, and resources of diverse groups of people of the region. The chapter argues that it is not only important but also necessary to link climate science and climate interventions with relevant contextual experiences of the different groups of people due their differential experiences and vulnerabilities. The chapter provides illustrative cases studies to demonstrate the differential experiences and vulnerabilities of women and men as a result of the dynamics of gender relations in the context of climate change.
In this review, I discuss, and partly challenge, a number of paradigms, assumptions and definitions that apply to many fields of plant ecology. The main points include the need for a distinction between a growth- or yield-oriented versus a fitness- or biodiversity-oriented concept of limitation and stress, and the challenges of a meaningful handling of plant traits and their functional significance. Further, I discuss the central role of biological variation in plant ecology, including the various forms of adaptive adjustments, and the task of scaling plant responses in space and time. I close this review with a critical comment on data stratification in the analysis of large biological datasets (e.g. meta-analysis).
This open access volume is the first comprehensive assessment of the Hindu Kush Himalaya (HKH) region. It comprises important scientific research on the social, economic, and environmental pillars of sustainable mountain development and will serve as a basis for evidence-based decision-making to safeguard the environment and advance people’s wellbeing. The compiled content is based on the collective knowledge of over 300 leading researchers, experts and policymakers, brought together by the Hindu Kush Himalayan Monitoring and Assessment Programme (HIMAP) under the coordination of the International Centre for Integrated Mountain Development (ICIMOD). This assessment was conducted between 2013 and 2017 as the first of a series of monitoring and assessment reports, under the guidance of the HIMAP Steering Committee: Eklabya Sharma (ICIMOD), Atiq Raman (Bangladesh), Yuba Raj Khatiwada (Nepal), Linxiu Zhang (China), Surendra Pratap Singh (India), Tandong Yao (China) and David Molden (ICIMOD and Chair of the HIMAP SC). This First HKH Assessment Report consists of 16 chapters, which comprehensively assess the current state of knowledge of the HKH region, increase the understanding of various drivers of change and their impacts, address critical data gaps and develop a set of evidence-based and actionable policy solutions and recommendations. These are linked to nine mountain priorities for the mountains and people of the HKH consistent with the Sustainable Development Goals.
This study assessed the regeneration status of tree species at different elevations in Himalayan forests. For this purpose, we assessed the densities of seedlings, saplings, and adult trees of various forest-forming species to understand their population structure and regeneration patterns. Five elevational ranges-<2000, 2000-2500, 2500-3000, 3000-3500, and >3500 m above sea level-were selected in various ranges in the Bhagirathi River catchment area in the Garhwal Himalaya. The highest species richness was recorded at the lowest elevational range, and the lowest species richness was recorded at the highest elevational range. Species diversity, measured using the Simpson and Shannon-Wiener diversity indices, was highest at the lowest elevations and lowest at the highest elevations. Abies spectabilis, Cedrus deodara, Rhododendron arboreum, Pinus roxburghii, and Quercus oblongata were dominant and widely adapted with appropriate regeneration potential at various elevations, whereas Aesculus indica, Juglans regia, and Sorbus cuspidata showed less ability to regenerate, indicating a threat to their survival in the near future. Tree species of subalpine forests Abies pindrow, A. spectabilis, Acer acuminatum, Betula utilis, and R. arboreum were observed to expand their upper limits into alpine meadows. Weak regeneration by some dominant tree species, and expansion by a few less-dominant or even rare species, indicate likely future compositional changes in Himalayan forests.
Mountains are considered excellent natural laboratories for studying the determinants of plant diversity at contrasting spatial scales. To gain insights into how plant diversity is structured at different spatial scales, we surveyed high mountain plant communities in the Chilean Andes where man-driven perturbations are rare. This was done along elevational gradients located at different latitudes taking into account factors that act at fine scales, including abiotic (potential solar radiation and soil quality) and biotic (species interactions) factors, and considering multiple spatial scales. Species richness, inverse of Simpson’s concentration (Dequiv), beta-diversity and plant cover were estimated using the percentage of cover per species recorded in 34 sites in the different regions with contrasted climates. Overall, plant species richness, Dequiv and plant cover were lower in sites located at higher latitudes. We found a unimodal relationship between species richness and elevation and this pattern was constant independently of the regional climatic conditions. Soil quality decreased the beta-diversity among the plots in each massif and increased the richness, the Dequiv and cover. Segregated patterns of species co-occurrence were related to increases in richness, Dequiv and plant cover at finer scales. Our results showed that elevation patterns of alpine plant diversity remained constant along the regions although the mechanisms underlying these diversity patterns may differ among climatic regions. They also suggested that the patterns of plant diversity in alpine ecosystems respond to a series of factors (abiotic and biotic) that act jointly at different spatial scale determining the assemblages of local communities, but their importance can only be assessed using a multi-scale spatial approach.
High mountain ecosystems and their biota are governed by low‐temperature conditions and thus can be used as indicators for climate warming impacts on natural ecosystems, provided that long‐term data exist.
We used data from the largest alpine to nival permanent plot site in the Alps, established in the frame of the Global Observation Research Initiative in Alpine Environments (GLORIA) on Schrankogel in the Tyrolean Alps, Austria, in 1994, and resurveyed in 2004 and 2014.
Vascular plant species richness per plot increased over the entire period, albeit to a lesser extent in the second decade, because disappearance events increased markedly in the latter period. Although presence/absence data could only marginally explain range shift dynamics, changes in species cover and plant community composition indicate an accelerating transformation towards a more warmth‐demanding and more drought‐adapted vegetation, which is strongest at the lowest, least rugged subsite.
Divergent responses of vertical distribution groups of species suggest that direct warming effects, rather than competitive displacement, are the primary causes of the observed patterns. The continued decrease in cryophilic species could imply that trailing edge dynamics proceed more rapidly than successful colonisation, which would favour a period of accelerated species declines.
The spread of alien plant species in bio-rich mountains calls for documenting their distribution across altitudes. The present study, therefore, analysed altitudinal distribution of alien species richness in the Himalayan state of Himachal Pradesh and tested the null hypothesis that-alien species richness in Himalaya is independent of altitude. For this, information on alien species was collated from published literature. As the zone above 5000 m is mostly snow-covered and devoid of major vegetation in the Himalaya, the altitudinal range from 300-5000 m was divided into bands of 100 m each. If a species was reported occurring from 300 to 600 m, then it's presence was counted in the 300-400 m, 400-500 m, and 500-600 m bands. All the species occurring in these individual 100 m bands were tabulated.
Enhanced shrub growth and expansion are widespread responses to climate warming in many arctic and alpine ecosystems. Warmer temperatures and shrub expansion could cause major changes in plant community structure, affecting both species composition and diversity. To improve our understanding of the ongoing changes in plant communities in alpine tundra, we studied interrelations among climate, shrub growth, shrub cover and plant diversity, using an elevation gradient as a proxy for climate conditions. Specifically, we analyzed growth of bilberry (Vaccinium myrtillus L.) and its associated plant communities along an elevation gradient of ca. 600 vertical meters in the eastern European Alps. We assessed the ramet age, ring width and shoot length of V. myrtillus, and the shrub cover and plant diversity of the community. At higher elevation, ramets of V. myrtillus were younger, with shorter shoots and narrower growth rings. Shoot length was positively related to shrub cover, but shrub cover did not show a direct relationship with elevation. A greater shrub cover had a negative effect on species richness, also affecting species composition (beta-diversity), but these variables were not influenced by elevation. Our findings suggest that changes in plant diversity are driven directly by shrub cover and only indirectly by climate, here represented by changes in elevation.
Mount Oku, in North-western Cameroon holds many endemic and restricted-range species. This study identifies factors influencing the species and functional diversity of plant communities in Mount Oku forests. We specifically look at whether the altitudinal gradient, which classically structures the mountain vegetation, has shifted in response to the influence of human activities. To explore variations in the vegetation composition of the study area, we realized 102 floristic plots along an altitudinal gradient as well as environmental conditions records (abiotic and biotic variables, human proximity indexes, land uses at certain periods). Plant species identified were also characterized by a series of life traits (biological type, type of diaspore, leaf size, phytogeography, dispersal pattern, altitudinal distribution). Multivariate analysis (NMS, Coinertia) have identified the main types of forest vegetation and link functional diversity to environmental factors. The results show that Man has altered the functional composition of vegetation by rearing domestic animals in the understorey forest near to the summit. The results also show that it is sometimes difficult to separate the effect of the altitude from the effect of human presence on the plant composition. Greater efforts of biodiversity conservation in high species riched area in mount Oku should be made.
Aim: Components of scale, such as grain, focus and extent, influence the spatial patterns of alpha and gamma diversity and the relationships between them. We explored these scale relations by testing whether the gamma diversity and alpha diversity along an elevation gradient were related independent of scale and whether the elevational patterns of herbaceous and woody species richness were dependent on scale.
Location: Langtang National Park, Nepal.
Methods: We estimated alpha diversity (plot richness) for woody and herbaceous plant species along an alpine elevation gradient (3,900–5,000 m a.s.l.) in nested plots of 1 m2, 16 m2 and 100 m2 and gamma diversity (regional richness) from published sources. Generalized linear modelling was used to analyse alpha and gamma diversity and their correspondence at different grain sizes.
Results: Elevational trends of gamma and alpha diversity were significantly correlated for both woody and herbaceous species at all grain sizes. The concordance increased with increasing grain size and area for gamma diversity estimation, particularly for the monotonously decreasing elevational gamma and alpha diversity patterns of woody species. The hump-shaped patterns of elevational gamma and alpha diversity for herbaceous species were also significantly correlated, but the concordance between the alpha diversity of herbaceous species and local gamma diversity was stronger. Elevational patterns of alpha diversity were coarsely consistent across grain sizes, although the patterns became more pronounced at larger grain sizes.
Main conclusions: The correspondence of elevational gamma and alpha diversity was largely scale invariant, implying that elevational and possibly other geographical diversity patterns can reliably be studied at different spatial scales. Nonetheless, the alpha diversity pattern was the least pronounced at fine grain size, particularly for woody life-forms. This finding suggests that for large-scale patterns such as elevational gradients at regional or continental scales, coarse grain sizes and large areas for gamma estimation are more appropriate.
Himalayas provide high altitudinal gradients and extreme slopes which may rapid changes in climatic zones over a small distance which reflects noticeable changes in the forest community structures. We identified and analyzed various aspects of forest community composition with the effect of climatic variables and altitudes in the Singalila National Park (SNP), Khangchendzonga Landscape in Eastern Himalayas (India). We encountered 2075 woody individuals of 70 species within a transect (2000 m- 3636 m asl). The entire forest regime reflected a dominance of young trees and the species richness showed a negative correlation with the altitude. Climatic variables (actual evapotranspiration, potential evapotranspiration and moisture index) are the measures of available environmental energies which drive the final shape of forest community structure. Our study revealed that these forces showed a significant relationship with species richness and altitude of the forest which provides the present shape of forest community composition structure of the SNP.
Aim: Heterogenous environments can contribute to maintain biodiversity. Traditionally beta diversity studies have focused on determining the effect of environmental variables on the total dissimilarity of species composition. However, decomposing beta diversity in species replacement and nestedness could give new insights on mechanisms affecting spatial patterns of biodiversity. We aimed to answer two main questions about spatial patterns of fish diversity in a Neotropical basin: 1) whether some regions contribute differently to fish diversity, and 2) whether species turnover and nestedness are explained by environmental gradients.
Methods
Sampling sites in the main channel and tributaries of the Upper Paraná River were sampled between 2013 and 2015. We partitioned beta diversity and tested the relationship of turnover and nestedness with environmental variables.
Results
74 species were captured. Some of these species were restricted to different sites, contributing to variation in species composition. Hill numbers showed a trend for higher diversity in the tributaries than in Paraná River sampling sites, and the partition of beta diversity revealed that species replacement drove dissimilarity in species composition. Only total beta diversity and turnover were related to environmental variables, mainly conductivity and turbidity.
Conclusions
Species diversity and composition of fish assemblages in the Upper Paraná River could be related to environmental gradients. Overall, our results suggest that Paraná River tributaries contribute to increase environmental heterogeneity, and hence to maintain a high diversity and variation in species composition. For that reason, we strongly recommend preserving highly heterogeneous habitats in the region.
Background: The State of Arunachal Pradesh is part of the Himalaya biodiversity hotspots distributed over an area with the largest elevation gradients in the world, ranging from lowland tropical forests to alpine vegetation.
Methods: The vegetation was surveyed along an elevation gradient ranging from 87 to 4161 m in 354 belt transects (500 m × 10 m in size) and analyzed using various ecological indices.
Results: A total of 482 (458 identified, 24 unidentified) plants were recorded in the present study, of which 153 are non- woody herbs and grasses (145 identified) belonging to 55 families, and 329 are woody trees and shrubs (313 identified) belonging to 74 families. The 458 identified species belong to 117 families and 251 genera, of which 94.10% are phenerogams (Angiosperms: 421 species [spp.] and Gymnosperms: 10 spp.) and 5.90% cryptogams (Pteridophytes: 27 spp.). The family Fabaceae contributed the greatest species diversity with a total of 27 plant species (Papilionaceae: 10 spp., Mimosaceae: 9 spp. and Caesalpinaceae: 8 spp.) followed by Poaceae (21 spp.), Ericaceae (20 spp.), Asteraceae (18 spp.), Lauraceae (17 spp.), Euphorbiaceae (16 spp.), Urticaceae (15 spp.) and 49 monotypic families. The most dominant trees were Castanopsis indica (24 individuals per ha), followed by Quercus semicarpifolia (12 individuals per ha) and Pinus roxburghii (12 individuals per ha) and some bamboos (Dendrocalamus strictus: 69 individuals per ha; Bambusa pallida: 16 individuals per ha). The studied forest stands were rich in various bamboos; a total of 14 different bamboos were recorded in the present study including Dendrocalamus strictus, Bambusa tulda, B. pallida etc. Common IUCN red-listed species were Aquilaria malaccensis, Begonia tessaricarpa, Gledetsia assamica, Gymnocladus assamicus, Livistona jenkinsiana, Rhododendron meddenii, Rhododendron thomsonii collected from the Dirrang, Tawang, Yamcha, Itanagar, Along and Mebo areas of Arunachal Pradesh.
Conclusion: The results confirm that the Eastern Himalayan forests are very rich in terms of species diversity which decreases with increasing elevation. Species richness and distribution patterns of plants are largely regulated by altitude and other environmental factors. Intensive monitoring and management is needed to protect this fragile ecosystem from the ever-increasing anthropogenic pressure and changing climatic conditions.
Terrestrial herbs are important elements of tropical forests; however, there is a lack of research on their diversity patterns and how they respond to different intensities of forest-use. The aim of this study was to analyze the diversity of herbaceous angiosperms along gradients of elevation (50 m to 3500 m) and forest-use intensity on the eastern slopes of the Cofre de Perote, Veracruz, Mexico. We recorded the occurrence of all herbaceous angio-sperm species within 120 plots of 20 m x 20 m each. The plots were located at eight study locations separated by ~500 m in elevation and within three different habitats that differ in forest-use intensity: old-growth, degraded, and secondary forest. We analyzed species richness and floristic composition of herb communities among different elevations and habitats. Of the 264 plant species recorded, 31 are endemic to Mexico. Both α-and γ-diversity display a hump-shaped relation to elevation peaking at 2500 m and 3000 m, respectively. The relative contribution of between-habitat β-diversity to γ-diversity also showed a unimodal hump whereas within-habitat β-diversity declined with elevation. Forest-use intensity did not affect α-diversity, but β-diversity was high between old-growth and secondary forests. Overall, γ-diversity peaked at 2500 m (72 species), driven mainly by high within-and among-habitat β-diversity. We infer that this belt is highly sensitive to anthropogenic disturbance and forest-use intensification. At 3100 m, high γ-diversity (50 species) was driven by high α-and within-habitat β-diversity. There, losing a specific forest area might be compensated if similar assemblages occur in nearby areas. The high β-diversity and endemism suggest that mixes of different habitats are needed to sustain high γ-richness of terrestrial herbs along this ele-vational gradient.
Vegetation patterns and spatial organization are influenced by the changing environmental conditions and human activities. However, the effect of environment on vegetation at different vegetation classification levels has been unclear. We conducted an analysis to explore the relationship between environment and vegetation in the land use/land cover (LULC), vegetation group, vegetation type, and formation and subformation levels using redundancy analysis with seven landscape metrics and 33 environmental factors in the upper reaches of the Heihe River basin in an arid area of China to clarify this uncertainty. Atmospheric counter radiation was the most important factor at the four levels. The effect of soil was the second determinant factor at three levels (except in vegetation formation and subformation level). The number of variables whose relationship to vegetation reached significant levels varied from 26 to 28, and 20 variables were the same at all four levels. The factors affecting vegetation were basically the same at vegetation group level and vegetation-type level. It was sufficient to analyze the relationship between environmental and vegetation patterns only in LULC, vegetation group and vegetation formation and subformation level in mountainous regions; different factors should be considered at different vegetation levels.
The present study was conducted to elaborate vegetation composition structure to analyze role of edaphic and topographic factors on plant species distribution and community formation during 2013–14. A mixture of quadrat and transect methods were used. The size of quadrat for trees shrubs and herbs were 10 × 5, 5 × 2, 1 × 1 meter square respectively. Different phytosociological attribute were measured at each station. Primary results reported 123 plant species belong to 46 families. Asteraceae and Lamiaceae were dominant families with 8 species each. PCORD version 5 were used for Cluster and Two Way Cluster Analyses that initiated 4 plant communities within elevation range of 529–700 m from sea level. Indicator species analyses (ISA) were used to identify indicator species of each community. CANOCO Software (version 4.5) was used to measure the influence of edaphic and topographic variables on species composition, diversity and community formation. Whereas Canonical Correspondence Analysis (CCA) was used to measure the effect of environmental variables which showed elevation and aspect were the stronger environmental variable among topographic and CaCO3 contents, electric conductivity, soil pH were the stronger edaphic factors in determination of vegetation and communities of the Bheer Hills. Grazing pressure was one of the main anthropogenic factors in this regard.
Mountains are hotspots of biodiversity. Yet, evaluating their importance in global biodiversity inventories requires the adoption of a pertinent definition of mountains. Here, we first compare the well-established WCMC and GMBA definitions, which both use geographical information systems. We show that the WCMC approach arrives at twice the global mountain area and much higher human population numbers than the GMBA one, which is explained by the inclusion of (mostly) low latitude hill country below 600 m elevation. We then present an inventory of the world’s mountains based on the GMBA definition. In this inventory, each of the 1003 entries corresponds to a polygon drawn around a mountain or a mountain range and includes the name of the delineated object, the area of mountainous terrain it covers stratified into different bioclimatic belts (all at 2.5′ resolution), and demographic information. Taken together, the 1003 polygons cover 13.8 Mio km² of mountain terrain, of which 3.3 Mio km² are in the alpine and nival belts. This corresponds to 83.7% of the global mountain area sensu GMBA, and 94% of the alpine/nival area. The 386 Mio people inhabiting mountainous terrain within polygons represent 75% of the people globally inhabiting mountains sensu GMBA. This inventory offers a robust framework for the integration of mountain biota in regional and larger scale biodiversity assessments, for biogeography, bioclimatology, macroecology, and conservation research, and for the exploration of a multitude of socio-ecological and climate change-related research questions in mountain biota, including the potential pressure on alpine ecosystems.
In this study, we classified twenty associations, 179 families, 810 genera, 1897 species, and identified 291 rare species. The vegetation units were named following floristic-sociological approach. A cocktail determination key was used to classify the following vegetation units of association. More of the west side than the east side of the study area was at a higher altitude, and the vegetation experienced significant compression. Follow the result of detrended correspondence analysis (DCA), winter rainfall and average January temperature were the main environmental factors affecting variation in vegetation distribution by elevation gradient in this area. The particular association type on the eastern side of the study area is attributable to the northeast monsoon experienced year-round in this area, which causes relatively low temperature and humidity and wind rush, as well as the compression of the elevation range in each forest. The monsoon deciduous vegetation area exists only on the west of the low altitude mountains.
The spatial patterns of biodiversity and their underlying mechanisms have been an active area of research for a long time. In this study, a total of 63 samples (20m × 30m) were systematically established along elevation gradients on Mount Tai and Mount Lao, China. We explored altitudinal patterns of plant diversity in the two mountain systems. In order to understand the mechanisms driving current diversity patterns, we used phylogenetic approaches to detect the spatial patterns of phylogenetic diversity and phylogenetic structure along two elevation gradients. We found that total species richness had a monotonically decreasing pattern and tree richness had a unimodal pattern along the elevation gradients in the two study areas. However, altitudinal patterns in shrub richness and herbs richness were not consistent on the two mountains. At low elevation, anthropogenic disturbances contributed to the increase of plant diversity, especially for shrubs and herbs in understory layers, which are more sensitive to changes in microenvironment. The phylogenetic structure of plant communities exhibited an inverted hump-shaped pattern along the elevation gradient on Mount Tai, which demonstrates that environmental filtering is the main driver of plant community assembly at high and low elevations and inter-specific competition may be the main driver of plant community assembly in the middle elevations. However, the phylogenetic structure of plant communities did not display a clear pattern on Mount Lao where the climate is milder. Phylogenetic beta diversity and species beta diversity consistently increased with increasing altitudinal divergence in the two study areas. However, the altitudinal patterns of species richness did not completely mirror phylogenetic diversity patterns. Conservation areas should be selected taking into consideration the preservation of high species richness, while maximizing phylogenetic diversity to improve the potential for diversification in the future.
Plant biodiversity patterns were analyzed in seven temperate forest types (Populus deltoides (PD), Juglans regia (JR), Cedrus deodara (CD), Pinus wallichiana (PW), Mixed coniferous (MC), Abies pindrow (AP) and Betula utilis (BU)) of Kashmir Himalaya. A total of 177 plant species (158 genera, 66 families) were recorded. Most of the species are herbs (82.5%), while shrubs account for 9.6% and trees represent 7.9%. Species richness ranged 24 (PD) – 96 (AP). Shannon, Simpson and Fisher’s alpha varied: 0.17-1.06, 0.46-1.22 and 2.01-2.82 for trees, 0.36-0.94, 0.43-0.75 and 0.08-0.35 for shrubs and 0.35-1.41, 0.27-0.95 and 5.61-39.98 for herbs respectively. A total of 5 species were endemic. The total stems and basal area of trees were 35,794 stems (stand mean 330 stems ha-1) and 481.1 m2 (stand mean 40.2 m2 ha-1), respectively. The mean density and basal area ranged from 103 (BU) to 1201 stems ha-1 (PD), and 19.4 (BU) to 51.9 m2 ha-1 (AP) respectively. Tree density decreased with increase in diameter class. A positive relationship (R2=0.37) was obtained between elevation and species richness and also between elevation and evenness (R2= 0.19). Tree and shrub communities were homogenous in nature across the seven forest types, while herbs showed heterogeneous distribution pattern.
The variation in species richness and diversity of trees, shrubs and herbs in the mountains of Miandam, Swat, North Pakistan, along an elevation gradient between 1600 m and 3400 m was explored. Field data were collected in 18 altitudinal intervals of 100 m each. Polynomial regression was used to find relations of the different growth forms with elevation. The Shannon index was used for calculating α -diversity and the Simpson index for β-diversity. Species richness and α-diversity of herbs were unrelated to elevation. Herbaceous species turnover was high, ranging between 0.46 and 0.89, with its maximum between 2700 and 3000 m. Hump-shaped relationship was observed for shrubs with maximum richness between 2000 and 2200 m; and α -diversity decreased monotonically. Turnover of shrub species was highest between 2000 and 2500 m. Tree species richness was highest at low elevations, and α -diversity was relatively low along the entire gradient. Tree species turnover was also high in the lower zone and again at 2600-2800 m. Species richness of all vascular plants was highest at 2200-2500 m, and α - diversity was highest in the lower part of the gradient. Beta diversity of all growth forms was quite high ranging between 0.53 and 0.87along the entire gradient reflecting high species and structural turnover.
Environmental heterogeneity is among the most important factors governing community structure. Besides the widespread evidence supporting positive relationships between richness and environmental heterogeneity, negative and unimodal relationships have also been reported. However, few studies have attempted to test the role of the heterogeneity on species richness after removing the confounding effect of resource availability or environmental severity. Here we constructed an individual-based spatially explicit model incorporating a long-recognized tradeoff between competitive ability and stress-tolerance ability of species. We explored the impact of the level of resource availability (i.e. the position of the community along a gradient of environmental severity) on the heterogeneity-diversity relationship (HDR). The results indicate that the shape of HDR depends on the community position along the environmental gradient: at either end of the gradient of environmental severity, a positive HDR occurred, whereas at the intermediate levels of the gradient, a unimodal HDR emerged. Our exploration demonstrates that resource availability/ environmental severity should be considered as a potential factor influencing the shape of the HDR. Our theoretical predictions represent hypotheses in need of further empirical study.
Despite long-standing interest in elevational-diversity gradients, little is known about the processes that cause changes in the compositional variation of communities (β-diversity) across elevations. Recent studies have suggested that β-diversity gradients are driven by variation in species pools, rather than by variation in the strength of local community assembly mechanisms such as dispersal limitation, environmental filtering, or local biotic interactions. However, tests of this hypothesis have been limited to very small spatial scales that limit inferences about how the relative importance of assembly mechanisms may change across spatial scales. Here, we test the hypothesis that scale-dependent community assembly mechanisms shape biogeographic β-diversity gradients using one of the most well-characterized elevational gradients of tropical plant diversity. Using an extensive dataset on woody plant distributions along a 4,000-m elevational gradient in the Bolivian Andes, we compared observed patterns of β-diversity to null-model expectations. β-deviations (standardized differences from null values) were used to measure the relative effects of local community assembly mechanisms after removing sampling effects caused by variation in species pools. To test for scale-dependency, we compared elevational gradients at two contrasting spatial scales that differed in the size of local assemblages and regions by at least an order of magnitude. Elevational gradients in β-diversity persisted after accounting for regional variation in species pools. Moreover, the elevational gradient in β-deviations changed with spatial scale. At small scales, local assembly mechanisms were detectable, but variation in species pools accounted for most of the elevational gradient in β-diversity. At large spatial scales, in contrast, local assembly mechanisms were a dominant force driving changes in β-diversity. In contrast to the hypothesis that variation in species pools alone drives β-diversity gradients, we show that local community assembly mechanisms contribute strongly to systematic changes in β-diversity across elevations. We conclude that scale-dependent variation in community assembly mechanisms underlies these iconic gradients in global biodiversity. http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0121458
The paper describes species composition and community structure of 23 forest stands in Kumaon Himalaya (28° 43′ 55″ to 30° 30′ 12″ N and 78° 44′ 30″ to 80° 45′ E), between altitudes 1500-3000 m. A total of 902 plots was sampled following plot sampling method. Density and diversity measures were calculated for different vegetation layers of each stand. TWINSPAN identified 19 tree communities and 17 ground vegetation communities. The distribution of tree species on DCA axis 1 indicated influence of altitudinal gradient while the second axis of DCA indicated canopy cover and shrub diversity. The first component of PCA represented open to close canopy forest, while the second reflected increase in shrub density and diversity. Quercus floribunda-Rhododendron arboreum group had maximum tree density and Abies pindrow-Betula utilis the minimum. Myrsine africana was the dominant shrub species. Maximum tree species diversity and richness were recorded for Daphiadhura site whereas the Vinaiyak site expressed maximum shrub diversity. Pinus wallichiana, Betula utilis, Tsuga demosa, etc. were found to be rare tree species.
Determining how ecological and evolutionary processes produce spatial variation in local species richness remains an unresolved challenge. Using mountains as a model system, we outline an integrative research approach to evaluate the influence of ecological and evolutionary mechanisms on the generation and maintenance of patterns of species richness along and among elevational gradients. Biodiversity scientists interested in patterns of species richness typically start by documenting patterns of species richness at regional and local scales, and based on their knowledge of the taxon, and the environmental and historical characteristics of a mountain region, they then ask whether diversity–environment relationships, if they exist, are explained mostly by ecological or evolutionary hypotheses. The final step, and perhaps most challenging one, is to tease apart the relative influence of ecological and evolutionary mechanisms. We propose that elucidating the relative influence of ecological and evolutionary mechanisms can be achieved by taking advantage of the replicated settings afforded by mountains, combined with targeted experiments along elevational gradients. This approach will not only identify potential mechanisms that drive patterns of species richness, but also allow scientists to generate more robust hypotheses about which factors generate and maintain local diversity.
A comprehensive, but simple-to-use software package for executing a range of standard numerical analysis and operations used in quantitative paleontology has been developed. The program, called PAST (PAleontological STatistics), runs on standard Windows computers and is available free of charge. PAST integrates spreadsheettype data entry with univariate and multivariate statistics, curve fitting, time-series analysis, data plotting, and simple phylogenetic analysis. Many of the functions are specific to paleontology and ecology, and these functions are not found in standard, more extensive, statistical packages. PAST also includes fourteen case studies (data files and exercises) illustrating use of the program for paleontological problems, making it a complete educational package for courses in quantitative methods.
We examined the patterns of tree species richness, density and basal area in the Eastern Himalayan elevation gradient, and evaluated the roles of geometric constraints and environmental factors for the observed pattern. We followed the quadrat sampling method for this study at 23 different locations along a 300–4700 m elevation gradient in Sikkim. We used regression analysis to establish elevational pattern of trees (species richness, density and basal area) and to relate environmental factors with tree species and density. We also tested geometric constraints on species distribution by comparing empirical species richness with null model predictions generated by a Monte Carlo Simulation Programme (McCain, 2004). We observed a total of 3874 individual trees belonging to 171 species and 58 families. Tree species richness depicted unimodal pattern with a peak at 1500 m, whereas basal area peaked at 1900 m. Although density did not follow a uniform pattern, maximum value was observed at 3050 m. Climatic and energy related factors–rainfall, temperature, moisture index (MI) and actual evapotranspiration (AET)-correlated positively with tree species richness. The Mid-domain effect null model showed significant deviation of empirical richness from simulated species richness. Stepwise regression revealed that combined effects of energy (surrogated by temperature), productivity (surrogated by AET) and precipitation (reflected by MI) influenced observed tree species patterns in the Eastern Himalayan elevation gradient although historical and spatial factors might interplay.
Although covering a relatively small fraction of terrestrial land (13-25%, Körner et al. 2011; Kapos et al 2000), mountain regions host an overproportional fraction of global biodiversity, supporting an estimated third of terrestrial biological diversity. On a global and regional scale, mountains that lie in areas of high biological richness are biodiversity hot spots because the rapid altitudinal change of climatic conditions over a very short distance gives rise to a range of bioclimatically defined vegetation types in close proximity. For example, in the tropics, mountains range from submontane forests to tropical alpine ecosystems, thereby concentrating high biodiversity on an area basis. High topographic diversity, characteristic feature of mountains, results in high habitat diversity and contributes to enhancing richness in biodiversity. Mountain biota, representing islands of high-elevation habitats and separated by the surrounding lowlands, have often formed in biogeographic isolation, resulting in high numbers on endemic species that further add to the uniqueness of mountain biodiversity.
Mountain regions provide diverse goods and services to human society. At the same time, mountain ecosystems are sensitive to rapid global development. Over the past 2 decades the number of papers mentioning “ecosystem services” (ESS) has risen exponentially. While the concept holds great potential to improve the societal relevance of conservation efforts, it is at risk of dying of misuse and reduction to a buzzword. The definitions of the term often compete and the utility of the concept is under debate. The present article reviews the literature on mountain ESS to investigate whether the term was understood correctly by the community, and addresses the question whether ESS is a suitable concept to protect mountain regions. We link land use and other physical properties of terrestrial ecosystems with their capacity to provide ESS with a view to mapping the global supply of ESS and we contrast it with population density data as a proxy for the demand for ESS. The spatially explicit assessment shows that we can distinguish between mountain areas where demand and supply are well balanced from mountain areas where demand and supply are unbalanced. For these different types of mountain regions we suggest different approaches to package the concept of ESS into spatial decision-making.
We studied the patterns in distribution, population density and uses of medicinal plant species in Dhauladhar mountain range of Himachal Pradesh in Indian Himalayas. The study area was stratified into three zones on the basis of forest types and altitudes. In each zone, quadrats were laid down for sampling of plant species, and the local people were interviewed for gathering information on medicinal uses of plants. A total of 184 plant species were encountered in the sampling plots, of which 86% had medicinal uses. Among woody plant species, the use of bark was highest, whereas in herbaceous species the use of leaf and root was highest for treatment of over 32 groups of diseases. In terms of density, Pin us roxburghii was the most dominant tree species in subtropical forests, which declined in temperate regions and was absent in subalpine forests. Rhododendron arboreum was the most dominant tree species in temperate region whereas in subalpine forests it was replaced by Abies pindrow, in terms of density. Berberis asiatica and Vitex negundo were the most dominant shrubs in subtropical forests besides Lantana camera, whereas Berberis lycium dominated the temperate and Juniperus indica dominated the subalpine forests. The heavy infestation of Lantana camera in sub-tropical forests has degraded the habitats of native medicinal plant species. Spearman's correlation indicates positive correlation between local uses and density of respective medicinal plant species (P < 0.05). The results are further discussed in light of medicinal plants conservation in this part of the Indian Himalayas.
We studied the patterns in distribution, population density and uses of medicinal plant species in Dhauladhar mountain range of Himachal Pradesh in Indian Himalayas. The study area was stratified into three zones on the basis of forest types and altitudes. In each zone, quadrats were laid down for sampling of plant species, and the local people were interviewed for gathering information on medicinal uses of plants. A total of 184 plant species were encountered in the sampling plots, of which 86% had medicinal uses. Among woody plant species, the use of bark was highest, whereas in herbaceous species the use of leaf and root was highest for treatment of over 32 groups of diseases. In term s of density, Pinus roxburghii
was the most dominant tree species in subtropical forests, which declined in temperate regions and was absent in subalpine forests. Rhododendron arboreum was the most dominant tree species in temperate region whereas in subalpine forests it was replaced by Abies pindrow, in terms of density. Berberis asiatica and Vitex negundo were the most dominant shrubs in sub-tropical forests besides Lantana camera, whereas Beberis lycium dominated the temperate and Juniperus indica dominated the subalpine forests. The heavy infestation of Lantana camera in sub-tropical forests has degraded the habitats of native medicinal plant species. Spearman’s correlation indicates positive correlation between local uses and density of respective medicinal plant species (P<0.05). The results are further discussed in light of medicinal plants conservation in this part of the Indian Himalayas.
Aim
We aimed to test whether contributions of individual species (SCBD) and contributions of single sites (LCBD) to overall beta diversity can be predicted by species metrics and species characteristics and also by community metrics and ecological variables, respectively.
Location
A mainland‐island landscape in the southern Brazilian Atlantic Forest domain.
Methods
Dung beetles were sampled along 100 sampling units within four large forest fragments. We partitioned beta diversity into SCBD and LCBD aiming to explore their relationships to species and site characteristics, respectively. We then used a combination of multivariate methods and beta regression analyses to examine patterns in SCBD and LCBD. The occupancy, total abundance, niche position, niche breadth and biological traits of species were used as predictor variables for SCBD values. Community metrics, environmental and spatial variables, and temporal patterns in the beta diversity components of turnover and nestedness were used as predictor variables for LCDB values.
Results
We found that SCBD was strongly related to various species characteristics, such as occupancy, abundance and niche position, but was not related to biological traits of species and niche breadth. In particular, occupancy and its quadratic term showed a very strong unimodal relationship with SCBD, suggesting that intermediate species in terms of site occupancy contribute most to beta diversity. LCBD was mostly explained by variation in species richness, with a negative relationship being detected. Litter height and large‐scale spatial variables were also important in explaining variation in LCBD.
Main conclusions
SCBD and LCBD were highly predictably related to species occupancy and species richness, respectively. Environmental conditions and large‐scale spatial variables also correlated with LCBD values. Understanding the determinants of SCBD and LCBD may thus hold a key to various general ecological, bioassessment and conservation issues. Protecting sites with high LCBD values may be a suitable approach to practical biodiversity conservation.
This study describes differences in species richness and composition of the assemblages of galling insects and their host plants at different spatial scales. Sampling was conducted along altitudinal gradients composed of campos rupestres and campos de altitude of two mountain complexes in southeastern Brazil: Espinhaço Range and Mantiqueira Range. The following hypotheses were tested: i) local and regional richness of host plants and gall-ing insects are positively correlated; ii) beta diversity is the most important component of regional diversity of host plants and galling insects; and iii) Turnover is the main mechanism driving beta diversity of both host plants and galling insects. Local richness of galling insects and host plants increased with increasing regional richness of species, suggesting a pattern of unsaturated communities. The additive partition of regional richness (γ) into local and beta components shows that local richnesses (α) of species of galling insects and host plants are low relative to regional richness; the beta (β) component incorporates most of the regional richness. The multi-scale analysis of additive partitioning showed similar patterns for galling insects and host plants with the local component (α) incorporated a small part of regional richness. Beta diversity of galling insects and host plants were mainly the result of turnover, with little contribution from nesting. Although the species composition of galling insects and host plant species varied among sample sites, mountains and even mountain ranges, local richness remained relatively low. In this way, the addition of local habitats with different landscapes substantially affects regional richness. Each mountain contributes fundamentally to the composition of regional diversity of galling insects and host plants, and so the design of future conservation strategies should incorporate multiple scales.
