Similarity In Species Composition Research Articles

Abandonment or biomass production? Phytodiversity responses to land-use changes of semi-natural grasslands in northern Europe

European semi-natural grasslands are hotspots for biodiversity and important for the provisioning of multiple ecosystem services, but their extent has declined considerably during the past century. Increasing demands for agricultural and forest biomass risk causing further loss of grasslands, raising concern about a goal conflict between climate mitigation and biodiversity conservation. This study focused on the loss of semi-natural grasslands in a mixed farm-forest landscape in southern Sweden by comparing plant diversity in grasslands with continuous grazing regimes to recently abandoned grasslands, improved grasslands (sown leys), and afforested grasslands. Compared to actively grazed grasslands, grasslands where grazing had been abandoned showed a lower plant species richness and fewer plant species of conservation concern, but similar species composition. In contrast, both improved and afforested grasslands showed >50 % lower species richness than abandoned and grazed grasslands, with profoundly different species composition. The dissimilarity in plant diversity between sites was primarily driven by the replacement of species (turnover), and trait-based analyses indicated that environmental filtering of light, management, and nutrient requirements of plants shaped the community differences. Furthermore, an increased cover of semi-natural grassland around the sites positively related to plant species richness and diversity, while an increased cropland coverage around the sites showed a negative relationship. Our results emphasize the importance of integrated land-use strategies that prioritize biodiversity conservation in mixed farm-forest landscapes, such as restoration of semi-natural grasslands and strategic planning of biomass production to avoid serious biodiversity losses.

Temporal changes in species richness, composition and diversity of the forest stands over 36-year period, Western Himalaya, India

This study investigates the temporal changes in species richness, composition, and diversity in forest stands spanning a 36-year period in the Western Himalaya. Four forest stands (subtropical Sal-forest, subtropical Chir-pine forest, temperate Banj-oak forest, and temperate Mixed-oak Forest) studied in 1980-1981 were resurveyed using similar methods. Over the past 36 years, 19 new species have been recorded in the four stands; eight species planted and eleven species naturally introduced. Dominant species continue to dominate in the forest stands. However, their contribution to the total tree density has decreased over the year. Species diversity, richness, and evenness increased in all forests except the Sal stand. Three species were newly introduced in the Sal stand, seven in the Chir-pine stand, eight in the Banj-oak stand, and seven in the Mixed-oak stand. The highest similarity in species composition was observed in the Sal stand (59%), followed by the mixed-oak stand (57%), Chir-pine stand (50%), and Banj-oak stand (47%). The results indicate an increase in tree density across all sites, with the Mixed-oak forest exhibiting the highest increase in tree density due to least biotic pressure. The findings of this study, based on two-time composition datasets, provide valuable insights into forest dynamics, supporting biodiversity conservation and management planning.

Vertical distribution patterns of macrofauna in the sediments of the Arctic cross-shelf trough and adjacent shelf - Similarities and differences from lower latitudes

Vertical distribution of macrobenthos in sediments remains poorly studied; data from higher latitudes are especially scarce. At the same time, it is believed to contain important information about communities that should not be neglected. Hence, our main objectives are to study the peculiarities of macrobenthos vertical patterns in the Arctic and to find out features specific to this region. For this, 24 stations were sampled in 2019 aboard the R/V “Akademik Tryoshnikov” while drifting in the North Barents Sea and along a transect south-west of the Franz Joseph Land. Sediments were obtained using a box corer; afterwards, subsamples were taken by a tube corer and cut into vertical sub-cores. Three to four strata (depending on biotope) characterized by similar species composition and abundance were distinguished. No direct relation between the increase in species richness and the complication of vertical structure was found. Avoiding competition through dwelling in different layers at one station was observed in some groups of closely related species. Factors playing important roles in determining infaunal properties depended on the layer. The thin upper layer played a more important role in terms of species number and abundance as compared to lower latitudes. However, the most abundant and widespread polychaete species Spiochaetopterus typicus penetrated down to 30 cm. It formed vertical distribution patterns in deeper sediment layers at most stations, including facilitating penetration into deep layers for other species. The exception was stations dominated by large maldanid polychaetes. Such a vertical pattern, with a particularly large share of species richness and abundance concentrated in the several upper cm combined with the very deep penetration of a few species, is likely typical of the Eurasian Arctic shelf.

Structure and Carbon Capture of a Temperate Mixed Forest across Altitudinal Gradients in Northern Mexico

Maximizing the ability of forests to capture carbon (C) from the atmosphere is critical to mitigate global warming. This is a daunting task as the warming climate is adversely affecting forests with increasing forest fires, pests, and a shift to tree species that can tolerate the newer climate conditions. A large (about 1 million hectares) mixed pine–oak forest in Chihuahua, Mexico, was characterized via 151 plots to determine its floristic diversity and biomass with respect to species, age (tree diameter), and at four altitudinal gradients equally distributed between 1850 and 2850 masl. Higher richness and diversity were found at the altitudinal gradient of 2101–2350 m with 36 species and a Shannon’s index (H’) of 2.95, and the lowest at 2601–2850 m with 17 species and H’ of 2.37. The Sorensen Index showed a high similarity in species composition, with the highest values (71% to 79%) obtained for the 2351–2600 gradient. C storage of the mixed forest increased with altitude from 7.85 Mg C ha−1 in the 1850–2100 m gradient to 14.82 Mg C ha−1 in the 2601–2850 m gradient. C storage in oak decreased with altitude while C storage of pine increased. Viable strategies to maximize C storage under changing climate conditions are discussed, including social safeguards and sale of carbon credits.

Current Status and Resources of Alhagi pseudalhagi (Fabaceae) in the Atyrau Region, Western Kazakhstan

Alhagi pseudalhagi, which grows in the arid zone of the Atyrau region, and an assessment of the current state of its raw material reserves were studied. Botanical characteristics, ontogenetic spectra, morphological indicators, productivity, areas of thickets, and reserves of raw materials of above-ground organs were assessed. The structural parameters of these populations in the Zhangyr and Coneu Rivers valleys, in the vicinity of Imankara Mountain, and on the Taisoigan sands were studied. It was established that the species composition of the populations includes 63 species from 54 genera and 30 families. The most common species include 49 species, which, according to their occurrence in populations of A. pseudalhagi, are distributed in the following classes: 17 species—class II (0–20%); 7 species—class III (41–60%); and 2 species—classes IV (61–80%) and V (81–100%). The maximum similarity in species composition was noted between populations in the Zhangyr and Coneu Rivers valleys. The highest morphometric indicators were observed among the population of the Coneu river valley, and the lowest are located on the Taisoigan sands. Analysis of the age spectra made it possible to determine that the populations in the Zhangyr and Coneu River valleys are characterized as young and those in the area of Imankara Mountain and on the Taisoigan sands as stable and middle-aged.

Effects of land use and climate on the diversity and population structure in natural stands of Detarium microcarpum Guill. & Perr. (Fabaceae) in Burkina Faso (West Africa)

Detarium microcarpum Guill. & Perr. is a multipurpose species, providing many ecosystem services. However, in its geographical range, its multiple uses represent a major challenge to the sustainable management and conservation of its resources. This study aimed to determine the effect of climatic zones, land uses, and their interaction on the natural stands of D. microcarpum. Inventories were conducted in 165 plots in two climatic zones and land use types in Burkina Faso. Hill diversity indices were used to determine the effects of climatic zones, land uses, and their interaction on D. microcarpum stand diversity. Generalized linear models were used to assess the effect of the abiotic and biotic factors on the species' structural parameters. Land uses and climatic zones significantly affected D. microcarpum stand diversity and structure. The lowest stand diversity was recorded in the unprotected areas. The similarity in woody species composition between land uses and climatic zones was low, indicating high beta diversity. The generalized linear model showed that rainfall, temperature, habitat heterospecific density, and habitat-specific richness significantly influenced the structural parameters of the D. microcarpum population. The diameter classes’ distribution revealed unstable populations for the adult stratum, independent of climatic zones and land use types, except for the protected area in the Sudanian zone. The height class distribution of the juvenile stratum highlighted the instability regeneration of D. microcarpum populations. This study highlighted the instability of D. microcarpum populations and the specific effects of biotic and abiotic variables on the species' structural parameters. Thus, the findings suggest urgent conservation measures to ensure sustainable utilisation and management of the species.

Latitudinal variation in seagrass communities with special emphasis on post-tsunami status in the Andaman and Nicobar archipelago, India.

We studied spatial variation in seagrass communities in the Andaman and Nicobar archipelago (ANI), India using latitude as a surrogate variable. We classified the ANI into five latitudinally distinct island groups: North & Middle Andaman, Ritchie's archipelago, South Andaman, Little Andaman, and the Nicobar archipelago. We evaluated the Importance Value Index (IVI) for species to determine the ecologically dominant seagrasses within each Island group. Later, we related our findings to investigate the three decadal pre- and post-tsunami status of seagrass habitats in the ANI which were severely impacted by the Indian Ocean tsunami of 2004. Six of the 11 observed species, such as Halophila ovalis, Halophila beccarii, Halophila minor, Halodule pinifolia, Thalassia hemprichii, and Cymodocea rotundata, dominated the seagrass population among all island groups. Seagrass composition significantly varied across the five investigated latitudinal gradients. Seagrass communities in 'Ritchie's Archipelago and Nicobar' and 'South Andaman and Little Andaman' revealed the highest and lowest variation. Further, Ritchie's Archipelago and Nicobar had the highest species richness (n = 10), followed by North & Middle Andaman (n = 8), and the lowest in South and Little Andaman (n = 6). Despite similar species richness and composition, Nicobar contributed to the highest seagrass coverage compared to the lowest recorded in the Ritchie's Archipelago. Our observations on the re-colonization of disturbed areas by early successional and historical species suggest recovery of the seagrass population in the ANI post-disturbance. Lastly, co-variates associated with latitude as a surrogate warrant further investigation.

Legume (Fabaceae) and seed beetle (Coleoptera, Chrysomelidae, Bruchinae) species of Europe: distribution and host specialization

The paper investigates the distributions of legumes (Fabaceae) and their associated seed beetle species (Bruchinae) across vegetation zones and regions of Europe and evaluates the host range and specialization of seed beetles. 1584 legume species/subspecies/varieties were included in the study and ca. 16% of these serve as known hosts by the 175 seed beetle species found in Europe. Both plant and seed beetle species richness increased from the Boreal to Mediterranean zones/regions. 717 legume species occurred only in single zones/regions and only 4.7% of these (34 species) were hosts for 38 bruchine species specific to a zone/region. Europe has 664 native legume species and 381 of these are Eu-endemics. There were 52 alien legume species found. Similarities in plant species composition by the Sørensen index were pronounced between the Central-European and the Mediterranean, between the Transcaucasian and Mediterranean, and between the Colchis-Caucasian and the Pontic-Caspian areas. The most species-rich genus is Astragalus L. with 334 species and 16 subspecies. Of the two major pre-dispersal seed predator genera, Bruchidius Schilsky species are sensu lato oligophagous, using a wide range of leguminous tribes as hosts, but restricted to few host species within a tribe. In contrast, members of the Bruchus L. genus are sensu stricto oligophagous species and, despite being constrained to the Fabeae tribe, most of them feed on several Lathyrus L. and Vicia L. species. The ways annual and perennial life cycles as well as chemical constituents of legumes might affect the colonization success of the seed beetles are discussed.

Endophytic Fungal Diversity of Mangrove Ferns Acrostichum speciosum and A. aureum in China.

Microbial communities are an important component of mangrove ecosystems. In order to reveal the diversity of endophytic fungi in the mangrove ferns Acrostichum speciosum and A. aureum in China, the internal transcribed spacer (ITS) regions of endophytic fungi in four plant tissues (leaves, petioles, roots, and rhizomes) from three locations (Zhanjiang, Haikou, and Wenchang) were sequenced. The richness, species composition, and community similarity were analyzed. The main results are as follows: the dominant fungi in A. speciosum and A. aureum belonged to the phyla Ascomycota and Basidiomycota, accounting for more than 75% of the total identified fungi; in terms of species composition at the operational taxonomic unit (OTU) level, the endophytic fungi in A. aureum were more diverse than those in A. speciosum, and the endophytic fungi in rhizomes were more diverse than in other tissues. In Zhanjiang, both A. speciosum and A. aureum showed the richest diversity of endophytic fungi, both at the OTU classification level and in terms of species composition. Conversely, the richness of endophytic fungi in the samples of A. speciosum from Wenchang and Haikou is extremely low. The regional differences in dominant fungi increase with the degrading of taxonomic levels, and there were also significant differences in the number of unique fungi among different origins, with Zhanjiang samples having a larger number of unique fungi than the other locations. There were significant differences in the dominant fungi among different tissues, with Xylariales being the dominant fungi in rhizomes of A. speciosum and Hypocreales being the dominant fungi in the petioles, roots, and rhizomes of A. aureum. Overall, the community similarity of endophytic fungi among locations is moderately dissimilar (26-50%), while the similarity between tissues is moderately similar (51-75%). The low diversity of endophytic fungi could be one of the main reasons for the endangerment of A. speciosum. The protection of the diversity of endophytic fungi in the underground parts of A. speciosum is essential for the conservation of this critically endangered mangrove fern.

Effect of fast heating rate and alkaline catalyst on composition and characteristic of volatile products during catalytic upgrading of oil sand bitumen

The study was devoted to exploring the fundamental study on the upgrading of Buton oil sand bitumen (OSB) via fast alkaline catalytic pyrolysis based on the fluid pyrolysis technology. The effect of fast heating rate on the composition and molecular distribution of volatile products from the high-temperature fast pyrolysis of OSB was investigated by Py-GC/TOF-MS that could simulate the fast heating rate of industrial fluid pyrolysis process. The results showed that the volatile products of OSB under heating rates ranging from 10 to 1000 °C/s had the similar species composition. It was found that there were the highest relative content of low-carbon alkenes (C2-C4) and light aromatics (C6-C8) in volatile products under the 1000 °C/s, indicating that the fast heating rate favored the production of light alkenes and aromatics. Subsequently, a laboratory-scale fluidized bed apparatus was employed to further gain insight into fast alkaline catalytic pyrolysis behaviors of OSB. The investigation on the yield distribution, fractional- and molecular-level chemical characteristic of volatile products obtained from the fast alkaline catalytic upgrading of OSB over calcium aluminate was carried out with the aid of the comparison with that over Y zeolite-based FCC catalyst and silica sand. The results revealed that three-phase products over calcium aluminate possessed the larger selectivity of C2−C4 alkenes, larger yield of light oil and the lower coke output, which were 51.88%, 45.49% and 7.96%, respectively. On basis of the chemical structure analysis of liquid products, the alkaline catalytic upgrading of OSB over calcium aluminate could heighten the content of chain alkyl structures as well as alkyl-substituents attached to aromatic ring in liquid products. This indicated that the fast heating rate and alkaline catalyst that adopted in catalytic upgrading process of OSB could play an energetic role in optimizing the composition of volatile products. The alkaline catalytic upgrading of OSB based on fluid pyrolysis technology with the fast heating rate could heighten the yield of low-carbon olefins and light oil and lessen coke yield, meanwhile modify the chemical structure characteristics of liquid products that were conducive to the generation of valuable chemicals (light alkanes and BTX) during secondary processing of liquid products.

Delayed response of bryophytes to wind disturbance and salvage logging in hemiboreal mixed forests

Climate change accompanied by altered natural disturbance regimes threatens the resilience of boreal and hemiboreal forests. Bryophytes, an important part of plant biomass and diversity, fulfill numerous important functions in forests, thus markedly contributing to the resilience of these ecosystems. We studied abundance, richness, diversity and community composition of bryophyte species 20–21 years after wind disturbance in moderately damaged, heavily damaged and heavily damaged and subsequently salvage-logged stands; overmature forest stands with similar tree species composition were included in the study as a reference group. The community characteristics were linked with treatment and accompanying environmental variables. Altogether, 108 bryophyte taxa (81 mosses and 27 liverworts) were identified in study plots. We found that bryophytes responded to windthrow severity level and salvage logging in terms of species richness, diversity, and composition; diversity of microhabitats was the most important environmental variable explaining the variation in diversity metrics. Besides exhibiting greater overall species richness, uncleared wind-disturbed plots contained more bryophyte species with high conservational value as well, compared to salvage-logged and control plots. The largest number of bryophyte taxa was associated with deadwood substrates. Ordination analysis further emphasized the importance of deadwood substrate for liverworts. In order to fulfill the objective of biodiversity conservation, wind-disturbed forests should be left to recover naturally, to ensure a favorable status of all naturally occurring species and to improve the status of endangered and rare species. Retaining a proportion of surviving and/or wind-damaged trees while salvaging might also alleviate the unfavorable environmental conditions for bryophyte species while “lifeboating” some species through the following successional stages.

Floristic homogenization of South Pacific islands commenced with human arrival

The increasing similarity of plant species composition among distinct areas is leading to the homogenization of ecosystems globally. Human actions such as ecosystem modification, the introduction of non-native plant species and the extinction or extirpation of endemic and native plant species are considered the main drivers of this trend. However, little is known about when floristic homogenization began or about pre-human patterns of floristic similarity. Here we investigate vegetation trends during the past 5,000 years across the tropical, sub-tropical and warm temperate South Pacific using fossil pollen records from 15 sites on 13 islands within the biogeographical realm of Oceania. The site comparisons show that floristic homogenization has increased over the past 5,000 years. Pairwise Bray–Curtis similarity results also show that when two islands were settled by people in a given time interval, their floristic similarity is greater than when one or neither of the islands were settled. Importantly, higher elevation sites, which are less likely to have experienced human impacts, tended to show less floristic homogenization. While biotic homogenization is often referred to as a contemporary issue, we have identified a much earlier trend, likely driven by human colonization of the islands and subsequent impacts.

Small mammal abundance and diversity along an altitudinal gradient in the Simien Mountains National Park, Ethiopia

Abstract Species richness, abundance, diversity, and distribution of rodents and shrews along altitudinal gradients in the Simien mountains national park, Ethiopia, were studied using Sherman traps. Rodents and shrews were trapped at four altitudinal ranges (2,800 m a.s.l., 3,200 m a.s.l., 3,600 m a.s.l. and 4,000 m a.sl.). A total of 202 individuals were captured, comprising 184 rodents and 18 shrews. In total, there were eight species of rodents and one shrew species. The relative abundances of Lophuromys simensis and Stenocephalemys albipes were the highest in the early dry season, dry season, and wet season. The relative abundances of Desmomys harringitoni (7.43%), Dendromys lovati (4.46%), and Mus imberbis (1.98%) were the lowest across the study area. The highest species diversity was recorded at an altitude of 2,800 m a.s.l. (H’ = 1.82). Species composition of rodents and shrews found at altitudes of 2,800 m a.s.l. and 3,200 m a.s.l. were highly similar (Sij = 0.97363). In contrast, the least similar species composition was between altitudes of 2,800 m a.s.l. and 4,000 m a.s.l. (Sij = 0.15632). The abundance, distribution, and diversity of rodents and shrews were significantly correlated with altitude (p = 0.000). Species abundance, distribution, and diversity in the Simien Mountains National Park were significantly correlated with altitude (0.377) and habitat types (0.306). Species composition of small mammals varied among altitudes, seasons, and habitat types, with six rodents and one shrew species being endemic. Notably, the park is subjected to various environmental disturbances, such as fires, grazing, and agriculture, which can negatively impact these small mammals, particularly the endemic species.

DYNAMICS OF SPECIES CHANGE OF LIVING ABOVE GROUND COVER IN YOUNG CULTURES OF ZHEREBKIVO FORESTRY

The species composition of herbaceous vegetation in oak plantations before their closure were analyzed. It was found that after cutting down the mother stand, the diversity of plants from different families begins to increase already in the first year. According to the results of field observations, a sharp reduction of shade-tolerant species and an increase of light-loving and drought-resistant species was revealed. As a result, non-forest edifiers increase and the change of tree communities by grassy non-forest formations, uncharacteristic for forest biocenoses. Representatives of the Poaceae family, as well as Fabaceae and Rosales, characteristic of the steppe zone, begin to actively appear on a fresh log. In the following years, the dominant position is occupied by the family of Asteraceae. In the first year after felling, about 40 species were identified, over the years their number decreases, and already in the sixth year, the number of species is about 17 species. Analysis of the coenomorphic structure shows that in the first years the number of sylvans significantly decreases, some species disappear altogether from the plantations. Instead, ruderants (from 55% in the first year to 35% in the sixth) and pratants (from 28% to 35%) begin to dominate. In the trophomorphic structure of the living ground cover on the lands not covered by forest, there is a significant decrease of mesotrophic species between 1–2 and 3–5 years. A significant decrease in oligotrophs (from 6% to 0%) and mesomegatrophs (from 3% to 0%) is also observed. No significant difference in the change of megatrophic species was found. According to the hygromorphic structure, mesophytic vegetation (46%-58%) is dominant in all studied areas. The greatest floristic similarity of grass cover is characterized by 2-3-year crops with 45% similarity of species composition, 4-5-year crops (46%) and 5-6-year crops (46%). The same types of grass vegetation grow on these Фlogs, acting as indicators of ecological conditions in the forest phytocenosis.

Small river’s ichtyofauna in the zone of quarry coal mining of Kuzbass (Western Siberia)

The fish complex of the tributaries of the Upper Tom’ river (Nizhnyaya Tykhta and Talda), were studied. The surveyed rivers flow through the territory of the western part of the Kuznetsk Alatau (Tardanovsky Uplands). Against the background of a high level of oxygen in both rivers, in terms of the volume of easily oxidized organic matter, the N. Tykhta River is more polluted than the Talda River. Four species inhabit in the Talda River and 7 species were registered in Nizhnyaya Tykhta. Watercourses are characterized by low levels of species richness and abundance of fish. An uneven distribution of fish in both rivers was revealed, which is associated with differences in the biotopic confinement of different species. Microbiotopes characteristic of different species act as refugia. The complex of alien includes crucian Carassius auratus, bleak Alburnus alburnus and verkhovka Leucaspius delineatus) and minnow Gobio gobio, dace Leuciscus leuciscus, siberian loach Cobitis melanoleuca, perch Perca fluviatilis and pike Esox lucius are representatives of native fauna. Despite the proximity of the rivers, the level of similarity of species composition is low, less than 30% (Jaccard index is 27.30). Species diversity according to the Shannon-Weaver index is 1.50 for the Nizhnyaya Tykhta River and 1.09 for the Talda River. The presence of alien species in the ichthyofauna of a more polluted river testifies to their higher adaptability to changing environment (shallowing, decrease in runoff, increase in the concentration of organic matter) compared to the populations of native species.

Diversity, abundance, and habitat utilization of medium and large-sized mammals in Debre-Libanos Monastery Forest, central part of Ethiopia

Abstract The present study aimed to estimate the diversity, abundance, and habitat utilization patterns of medium and large-sized mammals in the Debre-libanos Monastery forest, Ethiopia. The survey was conducted from December 2019 to October 2020, considering the wet and dry seasons. A stratified sampling design was applied, dividing the study area into four habitat types based on the vegetation composition and cover (i.e., Natural forest, Plantation, Cliff/Rocky, and Settlement). Both direct and indirect observations were used along the transect lines to identify mammal species. Indirect evidence included tracks, dens, droppings, hair, and other signs. Nineteen transect lines of 0.5‒1 km in length were established. The distance between transects was 200 m to avoid double counting. A total of 11 medium and large-sized mammal species belonging to 6 orders and eight families were identified during the study period. Carnivores and primates were the dominant orders, accounting for 36.4% and 27.3% of the species, respectively. Among primates, the Gelada baboon (Theropithecus gelada) is endemic to Ethiopia. The highest diversity of medium and large-sized mammals was observed in the natural forest during the dry season (Hʹ = 1.44), and the lowest diversity was recorded in the settlement during the dry season (Hʹ = 0.77). The abundance of different mammal species varied significantly from an even distribution (χ2 = 7344.9, df = 10, p < 0.001) and was not consistent among the four habitat types (Species × Habitat type interaction; Fisher-Freeeman-Halton exact test; χ2 = 649.3, df = 30, p < 0.001). High similarity in species composition was observed between the natural forest and plantation (SI = 0.94), whereas low similarity occurred between the cliff/rocky and settlement habitat types (SI = 0.18). Gelada baboon abundance was high; therefore, communities and government bodies must pay attention and conserve this species in the area.

Fallow Lands of Tuva (Russia): 30 years of Steppe Demutation

Tuva has been a cattle-breeding region since ancient times, extremely continental climate of this region is little suitable for agriculture. However, the steppes of intermountain depressions in Tuva were heavily plowed by the early 1980s. In the 1990s most of the arable lands were abandoned; the process of restoration (demutation) of natural vegetation on fallow lands began. By now, 30 years later, the old fallows are expected to achieve the stage of the secondary steppe. The purpose of this work is to estimate the differences between virgin steppes and corresponding secondary steppes in Tuva. Tussock, hummock, and desert virgin steppes have been compared with corresponding to three types of 30-year-old fallow communities. For this study, 330 geobotanical releves have been used. The criteria for comparison have been chosen as follows: the similarity of species composition, the spectrum of dominant species, species richness, grass cover, and grass height. The statistical validity of their differences has been verified. According to these criteria, virgin steppes and their 30-year-old fallow derivatives are shown to differ significantly.

Connected headwaters: Indelible field evidence of dispersal by a diverse caddisfly assemblage up stream valleys to dry catchment boundaries

Abstract1. Integral to many ecological models is the notion that dispersal connects populations and communities in disparate locations. For stream insects, however, there is very little empirical information about which species and what proportion of the species in a community are likely to disperse, in what direction and how far they travel, and whether dispersal is successful in connecting populations and communities. This study examines whether species of caddisfly can disperse between catchments and potentially connect communities.2. We used a novel sampling design comprising five pairs of streams. Each stream in a pair flowed from the same boundary, but in opposite directions and into isolated catchments. We surveyed abundances of adult caddisflies on the catchment boundary (boundary species) where there was no water (Up location), and on two locations per stream (Middle, Down locations) where there was permanently flowing water (resident species). If caddisflies fly along the topographic features of stream valleys, then we expected to find adults on the ridge between catchments and, if dispersal is successful, stream communities in adjacent catchments should have similar species composition.3. Over 130 species of caddisfly (from 18 families) were collected. Approximately half of them occurred on at least one catchment boundary, and Up locations averaged almost 20 species. Boundary species included both the smallest‐ and largest‐bodied taxa and they were a near perfect subset of species in resident assemblages. However, boundary species were not simply the most common in resident assemblages. There was no evidence of sex‐biased dispersal. Unsurprisingly, assemblage composition varied across the landscape, within and among catchments. However, resident assemblages within stream pairs were significantly more similar to one another than unpaired streams in either the same or in different catchments.4. Our results suggest that a surprisingly diverse set of caddisflies disperse up to catchment boundaries and potentially connect streams on either side of catchment divides. Nevertheless, many other caddisfly species were never recorded at Up sites and hence may never or only rarely reach catchment boundaries.5. These outcomes suggest, firstly, that some caddisflies are capable of trans‐catchment dispersal but it is incorrect to assume that all caddisflies are good dispersers, as is often stated in the literature. Secondly, caddisfly assemblages in headwater streams may be less isolated than is often considered and the dendritic structure of stream networks may be less important for their distribution patterns than the proximity of tributaries in neighbouring catchments, in many landscapes. Trans‐catchment dispersal could ensure community connectivity and facilitate recovery after catchment‐wide extinctions.

Biodiversity data synthesis on trees of Indian Himalayan Region: Policy and management implications

The recent adoption of Kunming-Montreal Global Biodiversity Framework requires empirical synthesis of biodiversity data spanning across broad biogeographic scales to inform conservation policy and management. Although the availability and access to biodiversity databases have recently improved, yet majority of these databases lack sufficient geographic coverage, especially from the biodiversity hotspot regions of developing countries, thereby severely limiting their utility and generalizability across the globe. Here, we present a comprehensive tree database (2199 species) of the Indian Himalayan Region (IHR) – home to two global biodiversity hotspots – collated from a quantitative synthesis of 234 studies published over the last one century. Taking leverage of this novel database, we unravel the patterns of diversity, distribution, and drivers of the trees of IHR. We found that the species richness, compositional similarity, distribution patterns, and biome affiliation of the tree diversity vary significantly across the IHR, with nearly half of the tree species affiliated with the wet tropical biome. Of the 10 climatic and environmental drivers used, the annual mean temperature and elevation width in combination best predicted the variation in tree diversity across the IHR. We also document 117 endemic and 88 threatened tree species in the IHR, which merit conservation priority. Our findings have significant utility in formulating management and restoration strategies for biodiversity conservation across the IHR. Overall, our study showcases a model biodiversity database with wide policy implications in the planning and management of tree-focussed environmental programs to restore the degraded forest landscapes and plantation-specific climate change mitigation strategies in the region.

Diversity of medium and large-sized mammal species in Chilimo Forest, West Shoa Zone, Ethiopia

Abstract Investigating species distribution and diversity patterns is vital for conservation efforts in biodiversity-rich countries such as Ethiopia. The present study examined the diversity of medium and large-sized mammal species in the Chilimo forest, West Shoa Zone, Ethiopia. It was conducted from January 2022 to October 2022 by stratifying the study area into three habitat types: natural forest, plantation, and human-modified forest. A fixed-width line transect sampling method was used to collect the mammalian data. A total of 14 medium and large mammal species belonging to 11 families and six orders, were recorded in the forest during the study period. Of these, 11 were medium, and 3 were large-sized mammals. The Olive Baboon (Papio anubis) was the most abundant mammal species, accounting for 41.7 % of the total abundance. The abundance of medium and large-sized mammals varied significantly among the three habitat types (Species × Habitat; Chi-square test of independence; χ2 = 163.385, df = 26, p < 0.001) and between the wet and dry seasons (Species × Season; Chi-square test of independence; χ2 = 43.753, df = 13, p < 0.001). During the dry season, species diversity was the highest in the natural forest and plantation habitat (H’ = 1.76 in both). The natural forest also supported the highest species diversity during the wet season (H’ = 1.57), followed by the plantation and human-modified habitats (H’ = 1.54 in both). An 88% similarity in species composition was observed between the natural and human-modified forests. The occurrence of 14 species of medium and large-sized mammals in the study area calls for immediate conservation actions in collaboration with respective stakeholders to protect the area’s biodiversity.