Variation In Species Composition Research Articles

Zooplankton of Pronskoye reservoir in August 2023

The aim of this study was to investigate the zooplankton of Pronskoye Reservoir during the summer period of 2023. Sampling and processing of hydrobiological zooplankton samples were carried out using standard methods in August 2023 at six monitoring stations in Pronskoye Reservoir. A total of 15 zooplankton taxa were identified in the samples: 6 taxa of rotifers, 5 taxa of cladocerans, and 4 taxa of copepods. On average, the abundance and biomass of zooplankton (mean values across stations) in Pronskoye Reservoir in August 2023 were 928.1 thousand individuals/m3 and 3.4 g/m3, respectively. Rotifers dominated in terms of abundance (63,5%), while cladocerans dominated in terms of biomass (40,3%). Pronskoye Reservoir exhibited above-average productivity in terms of zooplankton, which is favorable from a fisheries perspective. The abundance and biomass of zooplankton for all major groups (rotifers, cladocerans, and copepods) were higher in the lower part of the reservoir, separated from the middle and upper parts by a narrow neck. The increase in the abundance of the rotifer species Brachionus angularis was particularly noticeable in the lower part of the reservoir. The lower part of the water body is classified as highly productive, while the middle and upper parts has above-average productivity. The lower part of the reservoir is characterized by lower temperatures and lower dissolved oxygen concentrations in the water. The lower part of Pronskoye Reservoir exhibits a more diverse species composition compared to the middle and upper parts. It is evident that abiotic factors, in one way or another, determine the differences in the abundance, biomass, and species composition of zooplankton between the lower and upper parts of Pronskoye Reservoir.

Abundance of five sympatric stream dwelling mussels varies with physical habitat

Abstract Freshwater mussel species regularly co‐occur in streams forming assemblages, but the extent of shared versus unique instream habitat features that contribute to their distribution and abundance is poorly understood. In Massachusetts, a rare species, Alasmidonta varicosa, is often found with four other species: Alasmidonta undulata, Strophitus undulatus, Margaritifera margaritifera, and Elliptio complanata, yet variation in species composition within assemblages raises questions of potential species‐specific habitat associations. Identifying species‐level habitat information is critical at a spatial scale that malacologists can use to identify translocation or restoration areas. This study investigated whether species abundance varied by mesohabitat type (riffle, run, dam pool, scour pool), instream habitat characteristics, and within‐reach location (centre versus edge). From 2016 to 2019, freshwater mussel surveys were conducted in nine streams across Massachusetts and associated habitat information was collected. Species abundances were similar across mesohabitat types. Elliptio complanata was the exception, whereby higher abundances occurred in runs and dammed pools than in riffles. Unique species relationships with habitat existed for M. margaritifera with macroalgae and emergent vegetation, and A. varicosa with heterogeneous substrate. Flow transitions, such as depositional areas that create heterogeneous substrates, may provide habitats for A. varicosa. Most mussel species were distributed with higher abundance in the river centre than the edge; E. complanata was the only species with a higher abundance at the river edge. Locations with high abundance varied based on unique relationships with pebble heterogeneity (A. varicosa), depth (A. undulata), large wood (A. undulata), and canopy closure (E. complanata). Including physical characteristics in a holistic assessment of habitat that incorporates fish and landscape attributes may further an understanding of river reaches that best support translocated and propagated freshwater mussels.

Variation in understorey floristic composition regeneration and fire hazard under Acacia invaded forest canopy in New Zealand

Acacia species are considered invasive exotic species in many regions globally, and influence the floristic composition and fire hazard of ecosystems they invade. Managing such species requires an understanding of their invasion capability, and persistence through succession in the community. New Zealand is one of the countries that have experienced Acacia invasion in the forest canopy, however, the potential long-term successional trajectories and future fire hazards of these communities have rarely been studied impeding management. We investigated the variation in woody plant species composition that was regenerating at different height tiers, and the comparative flammability of constituent species, under the canopy of Acacia-invaded forest sites in New Zealand, and evaluated the likely long-term changes in vegetation succession and fire hazards. From the floristic survey of 24 10 × 10 m plots in Acacia-invaded sites, we found a significantly higher number of native species (7.33 ± 0.67) than exotic species (4.83 ± 0.38) regenerating under Acacia-invaded canopies. While exotic stems dominated the lowest height tiers (<0.3 m), native stems outnumbered exotics at other understorey height tiers (0.3–2 m, 2–5 m and 5–12 m) and were recruiting successfully. We also found that invaded Acacia species and other exotic species at the sites were comparatively higher in flammability than most of the native species in the area, and can potentially increase the flammability of the invaded forest area if not managed appropriately. The successful regeneration and recruitment of natives in all height tiers under the Acacia canopy indicates a potential native succession in the longer term. Thus, the Acacia invasion can be managed through passive restoration where the dominant Acacia-invaded canopy in the forest area is replaced by native species, while also likely decreasing the fire hazard of the vegetation. This study provides evidence for the regeneration potential of native species in the understorey of Acacia-invaded forest sites and the knowledge helps forest managers make appropriate decisions to manage this woody exotic invasion and fire hazard of the invaded forest sites in New Zealand as well as other Acacia-invaded sites globally.

Variability and determinants of vascular plant species composition in patches of old managed oak forest stands dispersed within Scots pine monocultures

In the temperate zone of Europe, Scots pine forests are expected to occupy the poorest habitats which are unfavourable for deciduous trees. However, as a result of deforestation of the most fertile habitats and the preference for Pinus sylvestris in silviculture, pine forests have become the dominant feature of the landscape in Central Europe. As a result, the area of optimal habitat for deciduous forest flora has been significantly reduced. Nevertheless, remnant patches of deciduous forest persist as habitat islands within extensive pine forest complexes and may serve as important refugia for meso- and eutrophilic forest species. However, the factors that contribute to the variation in species composition of such habitat islands and their role in maintaining biodiversity remain poorly understood. This paper aims to fill this knowledge gap.The studied deciduous (oak) stands exhibited a diverse vegetation, with species composition influenced by overstorey attributes, oak age, patch location, and the area and circularity of the deciduous forest. Species traits related to environmental variables included mainly preferences for closed or open forests, requirements for soil moisture, reaction, and fertility, and requirements for light conditions. The key message from our research is that oak islands are not simply patches of trees that are different from the surrounding area. Instead, they represent distinct plant communities that have developed to adapt to the prevailing environmental conditions by recruiting species with particular traits. The presence of oak islands within Scots pine monocultures is therefore important for increasing the diversity of the forest complex.The most relevant recommendation from our research for forest management is to maintain as many patches of deciduous tree stands as possible within a single pine forest complex, as even small habitat islands can make a significant contribution to the biodiversity of the forest complex.

Middle Pleistocene history of vegetation in the Lotus Lake basin in the extreme south of the Russian Far East

The evolution of vegetation in the Lotus Lake basin in the Middle Pleistocene has been studied. Six phases of paleovegetation evolution based on palynological data have been identified. It has been established that in warm epochs correlating with MIS 11, 9 and 7 in the Lotus Lake Basin were dominated by broad-leaved and coniferous forests with a diverse species composition. Under cooling in MIS 10, the distribution of coniferous-small-leaved forests with the participation of shrubby birch increased. In MIS 8 and 6, the main type of vegetation was represented by coniferous-small-leaved forests with the dominance of pine, birch, spruce and the participation of elm and oak.

Prevalence of tick-borne pathogens in ticks collected from the wild mountain ungulates mouflon and chamois in 4 regions of France.

Ticks are major vectors of various pathogens of health importance, such as bacteria, viruses and parasites. The problems associated with ticks and vector-borne pathogens are increasing in mountain areas, particularly in connection with global climate change. We collected ticks (n=2,081) from chamois and mouflon in 4 mountainous areas of France. We identified 6 tick species: Ixodes ricinus, Rhipicephalus bursa, Rh. sanguineus s.l., Haemaphysalis sulcata, H. punctata and Dermacentor marginatus. We observed a strong variation in tick species composition among the study sites, linked in particular to the climate of the sites. We then analysed 791 ticks for DNA of vector-borne pathogens: Babesia/Theileria spp., Borrelia burgdorferi s.l., Anaplasma phagocytophilum, A. marginale, A. ovis, and Rickettsia of the spotted fever group (SFG). Theileria ovis was detected only in Corsica in Rh. bursa. Babesia venatorum (2 sites), Borrelia burgdorferi s.l. (B. afzelii and B. garinii; 2 sites) and Anaplasma phagocytophilum (3 sites) were detected in I. ricinus. Anaplasma ovis was detected at one site in I. ricinus and Rh. sanguineus s.l. SFG Rickettsia were detected at all the study sites: R. monacensis and R. helvetica in I. ricinus at the 3 sites where this tick is present; R. massiliae in Rh. sanguineus s.l. (1 site); and R. hoogstraalii and Candidatus R. barbariae in Rh. bursa in Corsica. These results show that there is a risk of tick-borne diseases for humans and domestic and wild animals frequenting these mountain areas.

Species diversity pattern of mosquitoes (Diptera: Culicidae) breeding in different permanent, temporary and natural container habitats of Peshawar, KP Pakistan.

To determine the species composition, relative abundance and seasonal variation of different mosquitoes Genera (Aedes, Anopheles, Armigeres, Culex, and Culiseta) in different habitats the present research work was carried out in Entomology Research Laboratory of The University of Peshawar. Sampling performed from variety of permanent and temporary breeding habitats was carried out on monthly basis from targeted breeding sites for two consecutive years through dipping method. Species diversity in the survey sites was noted. Collection from these seventeen various types of potential larval habitats, yielded a total of 42,430 immature constituting 41,556 larvae and 874 pupae. Among these only 19,651 adult mosquitoes emerged comprising 11,512 female and 8,139 male mosquitoes. 78% (n= 15333) of mosquito larvae were from permanent and 22% (n=4318) were from temporary breeding sites. This study showed that Peshawar valley harbours 15 species from the genera Aedes, Anopheles, Armigeres, Culex and Culiseta. When the density of each species was examined, Culex quinquifasciatus was found to be dominant (79%) and constant in distribution. Among the temporary habitats Aedes albopictus was found as the most prevalent species particularly from tree holes and water cisterns. The highest intensity of mosquitoes was in June (2243 emerged adults) and November (2667 emerged adults) while the lowest was in January (203 emerged adults). A perfect positive correlation (r = +0.8) was found between temperature and population of mosquitoes (df 10 and α 0.05). The species diversity index for mosquitoes remained between 0.12 and 1.76. The Margalef's richness components was noticeably low for bamboo traps (0.2) and fairly high for rice fields, Percolating water and Animal tracks (1.3) which shows the abundance of mosquito species in these habitats. Similarly Pielou's Evenness was highest for bamboo traps (E=1) showing species uniform distribution. Animal tracks were presumed not only the diverse habitat rather also possessed high value for species richness and species evenness. Temperature, rainfall, humidity and other related attributes responsible for species variation and abundance need to be analysed further to pave way for controlling vector species in their oviposition targeted sites.

Comparison of Abundance and Structure of Larval Fish Assemblages between Autumn and Spring in the Waters Surrounding Taiwan Bank, Western North Pacific

The fluctuations in both time and space of larval fish assemblages in relation to hydrographic characteristics in the waters surrounding Taiwan Bank were studied in October 2021 (autumn) and March 2022 (spring). Throughout the study period, we identified a total of 149 taxa of fish larvae, encompassing 96 genera and 71 families. Engraulis japonicus, Diaphus slender type, unidentified Gobiidae, Apogon sp., unidentified Clupeidae, and Benthosema pterotum were the six dominant taxa and together constituted 47.39% of the total catch. There were no notable temporal variations observed in the abundance of fish larvae, but the species number of fish larvae was greater in spring than in autumn. Significant variations in species composition were observed between the different cruises, and the cluster analysis unveiled a distinct temporal structure of the assemblages of fish larvae. The dynamics of the prevailing currents induced by seasonal monsoons contribute significantly to the transportation of fish larvae. The distribution of fish larvae showed a good association with hydrographic characteristics, where seawater temperature and salinity emerged as the primary explanatory factors influencing the composition of larval fish assemblages in the waters surrounding Taiwan Bank. While the increased influx of nutrients from upwelling ensures abundant food availability, the hydrographic conditions may not be suitable for every fish larva.

Diversity, Composition and Environmental Relations of Periphytic Rotifer Assemblages in Lentic Freshwater Bodies (Flanders, Lower Belgium)

Periphytic rotifer assemblages from lentic habitats are understudied. To improve knowledge on the principal environmental determinants of their structure and composition, we examined summer periphyton from 184 freshwater bodies from a taxonomic and multi-trait-based perspective. Only the latter allowed consideration of all bdelloids. Alpha diversity decreased with electrolyte and aluminium concentration but increased with macrophyte richness, pointing at salinization, metal toxicity and loss of structural niche heterogeneity as potential threats for rotifer diversity. Replacement was the prominent component of beta diversity, with acidified sites showing the highest local contributions. Variation partitioning indicated that local conditions explained variation in species composition best, but general setting (soil type, land cover, connectivity) and spatial context were also not insignificant. Redundancy analysis related species composition more particularly to gradients of pH and trophic status, whereas the representation of functional groups was structured mainly by phytoplankton productivity. Mirroring shifts observed in the plankton, high phytoplankton productivity associated with larger size and more detritibacterivory. Dominance of collectors constrained variation in guild ratios, underlining the need for more refined functional approaches. To aid the use of periphytic rotifers in regional water quality assessment, we identified indicators and community thresholds for pH and trophic variables and determined optima and tolerances for individual taxa.

Taxonomic Studies on Family Euphorbiaceae Based on Some Morphological, Biochemical and Molecular Characteristics

An informal group of scientists from multiple nations formed the Angiosperm Phylogeny Group (APG), in which experts work together for the development of taxonomy of angiosperms. The group took into account all new information about diverse plant species using a high steering phylogenetic investigation. The APG has developed four classification systems from 1998 through 2003 and 2009 up until 2016. Since, the previously classified angiosperm species and their wild relatives were not fully based on monophyletic grouping, the classification has a lot of shortcoming and faults. According to the Angiosperm Phylogeny Group system, the Phyllanthaceae of order Malpighiales is most important with Euphorbiaceae sensu lato as a pantropical family comprised of hundreds of genera and thousands of species. It has several physical characteristics which are the same as Euphorbiaceae sensu stricto. The most important characteristics include unisexual flowers and a syncarpous ovary. Further, the flowers have an axile-apical placentation without pistillode (rudimentary pistil). In the Middle East region, the critical taxonomic review of six important genera from 10 taxa of sub-families Phyllanthaceae and Euphorbiaceae were studied for various characteristics using the latest nomenclature, type citation, and keys for each genus and species. Euphorbia are very rich in natural plant products which have an incredible chemical composition and functional diversity. Compounds were found highly significant and have been the subject of extensive research globally. Further, the genetic composition of Euphorbia is diverse, maturing in various growth forms, cyathial features, and habitats. The molecular characterization of the family Euphorbiaceae also showed a diverse species composition. The members of the family Euphorbiaceae exhibit a palisadal exotegmen with cellular bundles in association with vascular bundles on inner integument as synapomorphies for several major clades. Within current studies on phylogeny and classification of Euphorbia subg. Esula are burning topics comprised of diverse species that make the genus most significant in the kingdom plantae..

Barcoding a glass eel migration: a snapshot of taxa migrating upstream in the Palu River, Central Sulawesi, Indonesia

Eels of the genus Anguilla are high value food fish with a catadromous life cycle. As tropical anguillid glass eels migrate to freshwater in multi-species schools, effective management of these and other diadromous resources requires reliable data. Previous research using two morphological methods concluded that between three and five anguillid eels recruit to the Palu River in Central Sulawesi, Indonesia with interannual and seasonal variations in species composition, size structure, and co-migrating taxa. Some glass eels and other taxa could not be identified based on external morphology. To clarify the taxonomic uncertainty regarding species recruiting to the Palu River this study applied DNA barcoding using the Cytochrome Oxidase I (COI) mitochondrial DNA (mtDNA) molecular marker. Taxa identified from the first sampling of glass eels and other taxa recruiting in these mixed schools included three anguillid eels, five other fishes, two crustacea and one mollusc, presenting a snapshot of taxa migrating upstream in the Palu River. Current GenBank accessions did not enable species level identification of two fish larvae (families Eleotridae and Tetraroginae). The sequences will add to Indonesian accessions in the GenBank repository and inform resource management, including the use of environmental DNA (eDNA) methods for monitoring Indonesian anguillid eels.

Flies in the high for floral hike? Altitudinal variation in species diversity and composition of Diptera (Insecta) in the eastern Himalaya, India

Species diversity and composition enable us to understand the conservation and management of an ecosystem. There is scarcity of knowledge in understanding the diversity change across the gradients of elevation, especially in the Himalaya. Here, we focused in the eastern Himalaya to investigate the patterns of taxonomic and functional diversity of true flies with relation to variation in altitude. The study was conducted in protected area (Neora Valley National Park) in the eastern Himalaya, India and the survey was conducted at five altitudinal zones (from 500 to 3,000 m). A total of 201 species of Diptera, with 105 genera and 33 families were recorded, of which 25 species are new to the state of West Bengal and eight species are new to India. The species diversity increased with elevation (maximum was near 2,500 m) and most of the flies preferred to be close to bushes with flowers, with a substantial percentage of them being pollinator species. Flies adapt to the various vegetation and climate patterns, which was evident by the abundance of fly species at high altitudes (1,500–2,500 m). Hence, it is very important to implement appropriate actions to protect the diversity of true flies in this Himalayan landscape.

Short-term functional response to post-fire vegetation dynamic: A case study in a Mediterranean Pinus halepensis forest

Wildfire events significantly affect plant communities. Understanding the post-fire vegetation dynamics and how native and alien species interact to shape the composition and structure of the community is crucial to address conservation policy. Dispersal mechanisms and resource exploration strategies are two functional strategies which can explain variability in species response to disturbance. Here, we investigated how functional traits shape the short-term dynamic after a wildfire event in a Mediterranean pine forest. We collected plant co-occurrences and abundances in permanent plots of 100 m2 across four distinct sampling sessions (from late winter to early autumn, every 2 months). Functionally relevant traits including leaf traits and dispersal-related traits were also retrieved for the recorded species. We then derived the Grime's strategies of the recorded species from the collected leaf traits, and we computed the dispersal ability of each species as a function of the corresponding dispersal traits. To compare Grime's strategies and leaf traits across the monitoring cycles, we calculated the community weighted mean for each cycle as the average of species trait values in each plot. Further, we estimated variations in species abundances and species composition within each plot by using temporal turnover analysis, which showed a continuous post-fire increase in community-level vegetation cover and a strong compositional change driven by a spread of alien species. Associating these patterns to the recorded functional traits revealed that dispersal ability is crucial in post-fire recolonization. Moreover, ruderal species, being the most represented strategy soon after the fire, give way over time to more competitive species showing higher leaf area. Thus, short-term vegetation recovery involves different species-specific strategies that shape the ecological succession over time. Our case study highlights that knowledge about how functional traits drive plant colonization strategies is critical to assess the post-fire restoration status of Mediterranean pine forests.

Human settlement density, not late Holocene climate change, influenced Artiodactyla species abundance in northeastern California faunal assemblages

Variation in late Holocene artiodactyl (e.g., deer, pronghorn, bighorn sheep) hunting in northern California has often been examined from a behavioral ecological perspective to understand past foraging and land-use practices and related changes in human behavior, including settlement patterns, technological change, social signaling, large-scale resource intensification, and anthropogenic resource depression. However, rarely are past climate records and proxies of human population density coupled with zooarchaeological estimates of artiodactyl abundance to evaluate the ecological and anthropogenic drivers of changes in species representation over time. To better understand changes in human behavior related to past large game hunting, we disentangle the causal relationships between late Holocene climate change, human demography, and artiodactyl abundance to assess whether climate change, human hunting, or both impacted the abundance of artiodactyls in zooarchaeological assemblages from northeastern California. We evaluate how climatic variability and inferred human settlement density impacted artiodactyl abundance using modeled paleoclimatic reconstructions, distributions of radiocarbon dates, and faunal data derived from 35 archaeological sites and 37,319 individual faunal specimens. Using piecewise structural equation models, we assess the direct and mediating effects between climate, human settlement density, and artiodactyl abundance and determine the individual effects of these variables on large game species representation in zooarchaeological assemblages. We find that expanding human settlement density and related increases in logistical foraging—not late Holocene climate change—directly impacts the relative abundance of artiodactyls in these assemblages. Moreover, our findings reveal that the effects of climate change are entirely mediated through human settlement density. While our study is unable to decipher if observed changes in human behavior were motivated by goals related to energetic maximization or costly signaling, our study does provide a useful framework for separating the effects of human- and climate-induced explanations for variation in species composition in faunal assemblages.

The relationship between forest structure and naturalness in the Finnish national forest inventory

Abstract There is considerable interest in identifying and locating natural forests as accurately as possible, because they are deemed essential in preventing biodiversity loss. In the boreal region, natural forests contain a substantial amount of dead wood and exhibit considerable variation in tree age, size, and species composition. However, it is difficult to define natural forests in a quantitative manner. This is an issue, for example, in the Finnish national forest inventory. If naturalness could be related to the metrics derived from tree measurements, it would be easier to locate natural forests based on the inventory data. In this study, we investigated the value of metrics computed from tree locations and tree sizes for the characterization of a key aspect of naturalness, namely, structural naturalness as defined in the Finnish national forest inventory. We used L-moments, Gini coefficient, Lorenz asymmetry, and interquartile range to quantify the variations in tree size at the plot level. We summarized the spatial pattern of trees with a spatial aggregation index. We compared the structural metrics, species proportions, and stand age using the classes of structural naturalness described in the Finnish national forest inventory, which have been determined in the field without strict numerical rules. These categories are ‘natural’, ‘near-natural’, and ‘non-natural’. We found that the forests evaluated as structurally natural had larger variations in tree size and species composition and showed a more clustered spatial pattern of trees on average, although the variation in the structural metrics was considerable in all three classes. In addition, we used the structural metrics to predict naturalness by employing a random forest algorithm. Based on the structural metrics, it was possible to obtain high precision in the classification only if we simultaneously accepted low recall, and vice versa; the link between the inspected metrics and naturalness evaluated in the field was weak. The stand age separated the three classes more clearly and it also improved the classification.

How gradients of climate and soil determine Mediterranean annual‐rich dryland vegetation

AbstractQuestionsDryland annual plant communities constitute the most species‐rich small‐scale vegetation in the Mediterranean. Nevertheless, the composition and diversity of these units and the factors controlling their variation are still insufficiently understood. Therefore, we investigated species composition and richness patterns in relation to important environmental gradients provided by climate and soil.LocationCentral Crete, Greece.MethodsThe study is based on 82 plots of 4 m2 sampled at altitudes between 11 and 1400 m a.s.l. We conducted vegetation relevés and soil analyses. We used generalised additive models to model species richness and community characteristics along the studied gradients. We then performed distance‐based redundancy analysis to determine the main environmental factors influencing species composition. To determine species of diagnostic value for bedrock types, we applied an indicator species analysis. Correlation tests were used to test the performance of the South Aegean Plant Indicator Values on our dataset.ResultsWe recorded 347 taxa (species and subspecies) of 43 plant families, and mean species numbers of 47.2 ± 12.5 per plot. While overall species richness varied only slightly along the analysed environmental gradients, significant changes were observed for relative proportions of species from different life forms and families. Soil pH and elevation had the highest influence on the variation in species composition (21.0% explained). We found 22 species indicative of calcareous rock and 24 species indicative of lime‐deficient rock types. The South Aegean Plant Indicator Values were relatively strongly correlated with environmental variables.ConclusionsResults indicate considerable species turnover both along climatic (elevation) and soil gradients, highlighting the special importance of soil pH. The data provided by our study are expected to supply relevant ecological background information for a pending classification of East Mediterranean annual‐rich vegetation.

Distribution patterns of alpine flora for long-term monitoring of global change along a wide elevational gradient in the Western Himalayas

In the current context of climate change, the Western Himalayas are thought to be warming faster than the global average rate. Despite this rapid warming, our understanding of alpine vegetation composition and the underlying factors shaping its patterns in the Western Himalayan alpine highlands of Pakistan remains limited. Extensive field sampling was conducted at 24 sites ranging in altitude from 3300 m to 4200 m. The entire altitudinal range was divided into three belts i.e., low-altitude sites, medium-altitude sites, and high-altitude sites (HAS). Results revealed that alpine flora consisted of 251 species (belonging to 51 families. The findings revealed that 83 of the 251 species evaluated contributed significantly to the change in species composition between three altitudinal sites. The species that contributed the most to the variance in species composition between communities made up 75 % of the total, demonstrating that these species are important in structuring plant communities at different altitudes. Among the alpine flora, a significant (49 %) dominance was observed from nine families, comprising a total of 123 species. The largest family, Asteraceae, had the highest number of species, followed by Poaceae and Rosaceae. Hemicryptophytes emerged as the prevailing life form, while Microphylls were the dominant leaf type. Phytosociological Indices revealed that diversity levels decreased with increasing altitude, indicating a significant impact of altitude on plant diversity. Canonical correspondence analysis suggested that altitude, grazing, and soil erosion are important in explaining variance in plant distribution patterns in the alpine flora. Twelve indicator species were discovered in three different altitudinal groups. In the LAS, Bistorta affinis, Geranium himalayense, Poa nemoralis, and Sibbaldia cuneata, had a significant indicator value, whereas in the medium-altitude sites MAS Allium humile, Bistorta affinis, Juniperus communis, and Rhododendron campanulatum had significant p-values. In high altitude sites HAS, indicator plants were Bistorta affinis, Juniperus communis. Our results identified 51 vulnerable species with very low abundance values whereas 17 threatened species having extremely low (<0.1) abundance values are a vital conservation priority in the region. Results may be helpful to formulate immediate conservation management strategies to conserve the precious floristic wealth of the alpine Region.

Illuminating Plant Community Assembly on Karst Mountain Road Slopes through Plant Traits and Environmental Filters

Understanding how assembly processes shape local plant assemblages from the potential species pool is crucial for biodiversity conservation and revegetation. Mountainous regions are global biodiversity hotspots with high levels of diversity, concentration, and vulnerability. Road construction in these areas poses ecological challenges, including habitat loss and reduced biodiversity. Feature-based ecology highlights non-biological filtering as a key driver of habitat-specific community formation. Analyzing trait structures and their association with the environment can reveal community assembly processes under specific environmental conditions. However, quantifying species-environment-traits interactions during community assembly on roadside slopes is still underexplored. In our study, 76 naturally recovered roadside slopes, 656 self-established plant communities and 113 plant species across ten functional traits, along with their environmental associations, in the karst mountain region of southwestern China, were examined. Our findings show that there are still abundant native plants with colonization potential settled on steep roadside slopes in karst mountain areas. Diffusion constraints stemming from distance to the core species pool, elevation, and differences in adjacent vegetation types emerged as key factors causing variations in species composition of self-established communities. The slope environment exerts strong selective pressures leading to a convergence pattern in traits related to dispersal and colonization while showing a divergence pattern in traits linked to competitive strategies and regeneration. These findings identify critical functional traits and environmental factors shaping roadside plant communities and illustrate the predictability of environmental filtering and fundamental community assembly. Overall, our study sheds light on the intricate interactions among assembly processes, functional traits, and environmental factors driving local plant assemblages in mountainous regions, providing insights for effective diversity conservation and revegetation strategies.

Anticipated impacts of climate change on the structure and function of phytobenthos in freshwater lakes

Climate change threatens surface waters worldwide, especially shallow lakes where one of the expected consequences is a sharp increase in their water temperatures. Phytobenthos is an essential, but still less studied component of aquatic ecosystems, and it would be important to learn more about how global warming will affect this community in shallow lakes. In this research, the effects of different climate change scenarios (SSP2-4.5 and SSP5-8.5, as intermediate and high emission scenarios) on the structure and function of the entire phytobenthos community using species- and trait-based approaches were experimentally investigated in an outdoor mesocosm system. Our results show that the forecasted 3 °C increase in temperature will already exert significant impacts on the benthic algal community by (1) altering its species and (2) trait composition (smaller cell size, lower abundance of colonial and higher of filamentous forms); (3) decreasing Shannon diversity; and (4) enhancing the variability of the community. Higher increase in the temperature (+5 °C) will imply more drastic alterations in freshwater phytobenthos by (1) inducing very high variability in species composition and compositional changes even in phylum level (towards higher abundance of Cyanobacteria and Chlorophyta at the expense of Bacillariophyta); (2) continuing shift in trait composition (benefits for smaller cell volume, filamentous life-forms, non-motile and weakly attached taxa); (3) further reducing the functional diversity; (4) increasing biofilm thickness (1.4 μm/°C) and (5) decreasing maximum quantum yield of photosystem II. In conclusion, already the intermediate emission scenario will predictably induce high risk in biodiversity issues, the high emission scenario will imply drastic impacts on the benthic algae endangering even the function of the ecosystem.

Seasonal rearrangements in the use of coastal habitat mosaics by tropical fishes create a cyclic functional trajectory

Coastal habitat mosaics are among the most productive ecosystem on earth, having important functions for fish species throughout their life cycle. The complex dynamic of these areas, marked by constant changes in environmental conditions, creates spatial and temporal rearrangements of assemblages that may have significant impacts on ecosystem functioning. Thus, this study aimed to assess how seasonal variations in species composition affect the diversity of functions in these areas. We identified functional guilds of fish species found in three coastal habitat mosaics and used their functional traits as indicators of ecosystem functionality. Our results demonstrated that coastal habitat mosaics exhibit significant spatial and temporal variations in both, guilds, and functions, with remarkable differences in between-habitat responses to the onset of the tropical rainy season. More specifically, we found that mangroves exhibit a clear linear relationship between rainfall and functions, whereas in seagrass beds, functional diversity increases at low levels of rainfall and decreases at high levels. Lastly, sandy beaches have its functions increased by rainfall, but reaches an asymptote. These patterns point out to habitat-specific functional trajectories through time, which can be explained by the movements of species through the coastal mosaic in response to environmental variability, and to ontogenetic migration as species grow.