Patterns Of Species Diversity Research Articles

Phylogenetic diversity patterns of woody species across different tree sizes and spatial scales in a tropical forest community on Con Dao Islands

Understanding the maintenance of diversity and the assembly of communities is a primary concern in community ecology. This study explored the phylogenetic structure of an evergreen broadleaved tree community in Con Dao National Park, Vietnam. The survey, conducted in December 2023, encompassed all tree individuals with a diameter at breast height (DBH) ≥ 2.5 cm within a 4-ha study plot. These individuals were identified by species name, and their DBH was measured. Subsequently, a community phylogenetic tree was constructed using the Phylomatic online platform. The 4-ha study plot was subdivided into there different subplots based on three spatial scales (25 m × 25 m, 50 m × 50 m, and 100 m × 100 m) and all trees were classified into three different DBH classes (2.5 cm ≤ DBH < 10 cm representing small trees; 10 cm ≤ DBH < 20 cm as medium trees; and DBH ≥ 20 cm as large trees). The net relatedness index (NRI) and net nearest taxon index (NTI) were utilized to evaluate the phylogenetic structure and infer ecological processes. Our findings revealed a consistent decrease in both NRI and NTI with increasing spatial scales and tree sizes. These results suggest an overdispersed phylogenetic structure within the community across different spatial scales and tree sizes. Additionally, negative density dependence was found to have a pronounced effect on the phylogenetic structure, with a more significant impact on tree individuals from small and medium DBH classes than large ones. This study underscores the significance of phylogenetic density dependence as a primary mechanism governing species diversity and shaping the community structure of evergreen broadleaved forests in Vietnam.

Microbiological and Molecular Study of Paranasal Sinus Infections of Children with Malignancy and Unknown Origin Fever in Markazi Province, Iran

BackgroundChildren with malignancies are vulnerable to various infections, including sinus infections. Sinusitis is primarily caused by bacterial infections, followed by fungal infections. Due to this issue, evaluating the occurrence, diversity, and antibiotic susceptibility patterns of bacterial species that cause paranasal sinus infections in children with malignancy and unexplained fever is important. ObjectiveInvestigate the bacterial species accountable for sinusitis in children with malignancy and unexplained fever, and determine their susceptibility to antibiotics. MethodsThe study involved collecting 90 sinus samples from children aged 5-15 years with malignancy in Arak city. The isolates were identified using a combination of phenotypic, biochemical, and molecular techniques, including specific PCR and 16S rRNA gene sequencing. drug susceptibility testing was performed following the CLSI 2021 guidelines. ResultsA total of 36 isolates (40%) were obtained, including 4 isolates of Nocardia (11.12%), 4 isolates of E. coli (11.12%), 3 isolates of K. pneumoniae (8.33%), 5 isolates of P. aeruginosa (13.88%), 3 isolates of A. baumannii (8.33%), 4 isolates of S. aureus (11.12%), 3 isolates of S. epidermidis (8.33%), 5 isolates of S. agalactiae (13.88%), 2 isolates of S. pneumoniae (5.55%), and 3 isolates of E. faecium (8.33%). The isolates showed the most sensitivity to imipenem and trimethoprim-sulfamethoxazole and the least sensitivity to erythromycin and tetracycline. ConclusionsThe findings of the study indicate that sinusitis can contribute to fever of unknown origin in cancer patients. Therefore, it is recommended to use a combination of molecular and phenotypic methods for accurate identification of isolates. This approach can provide more reliable and precise results, leading to better diagnosis and treatment of sinusitis infections in children with malignancy.

Diversity and Distribution of Avifauna in the Northeast of Addis Ababa, Central Ethiopia.

Exploring avian species diversity and distribution patterns is vigorous for conservation efforts in biodiversity-rich countries such as Ethiopia. Compared to other species, birds are relatively well-known and easily observed, making them great markers of productivity or biodiversity. Although bird species are found all across the world, their survival and range have been negatively impacted by habitat loss, fragmentation, and destruction. Thus, the goal of this study is to provide baseline data on avifaunal diversity in the Northeast of Addis Ababa, including species richness, distribution, and relative abundance in various habitats conducted from January 2023 to September 2023 using a stratified sampling design into three habitat types: settlement, farmland, and abattoir. A fixed-width line transect sampling method was used at the farmland and settlement, and a point transect was employed at the abattoir site to collect the bird data. The data were compared using Mann-Whitney and Kruskal-Wallis statistical tests in both seasons and habitat types. A total of 42 bird species belonging to twenty-three families, and nine orders were recorded during the study period. Of these, blue-winged goose and wattled ibis are endemic to Ethiopia. Hooded vultures and White-backed vultures are critically endangered species. The mean abundance of bird species significantly varied in the three habitat types (χ2 = 13.6, df = 2, p=0.001). The abundance of bird species was nonsignificant difference between wet and dry seasons (U = -0.874, p=0.381). The highest diversity (H' = 2.74) was recorded at settlement, and the lowest diversity index (H' = 1.09) was recorded at the abattoir in the dry season. In the wet season, the highest diversity (H' = 2.66) was recorded in the farmland, and the lowest (H' = 1.08) was recorded at the abattoir. The highest evenness (J = 0.94 and J = 0.93) was recorded on the farmland in the wet and dry seasons, respectively. In the study area, urbanization is extremely impacting the environment and altering ecosystem services upon which human civilization depends. Most of the avian species observed in the study area are capable and tolerant of human-induced habitats in the city. Therefore, city planners must consider conserving urban bird species' habitats and feeding sites.

Species diversity and distribution pattern of venerable trees in tropical Jianfengling National Forest Park (Hainan, China)

Venerable trees are precious natural-cum-cultural heritage and an important component of regional biodiversity, with significant social, cultural and ecological values. A thorough understanding of their spatial patterns in relation to environmental factors can foster co-management for conservation and sustainable resource use. The Jianfengling National Forest Park in tropical China is a unique and rare primary tropical forest protected area with exceptionally high biodiversity and a rich endowment of venerable trees. This study evaluated the venerable tree stock regarding botanical makeup and factors shaping spatial patterns. We collected detailed tree data (species, age, dimensions, location, etc.) and environmental variables (elevation, slope and soil). The environmental variations were analyzed concerning tree abundance, species richness and tree age. The results identified 2134 venerable trees from 72 species, 55 genera and 30 families. Lithocarpus fenzelianus dominated with maximum importance value, followed by Cyclobalanopsis patelliformis, Madhuca hainanensis, Altingia obovata and Castanopsis tonkinensis. The top-ranking species were predominantly Fagaceae members. The age pattern demonstrated an inverted J-shape, with mainly 100-299 years trees and a few >500 years. DBH, tree height, and crown width displayed an approximately normal distribution. Spatial distributions by age tiers were uneven, with more in the northeast part. The altitudinal gradient significantly influenced the spatial patterns of tree abundance and species richness. The unimodal distribution marked tree and species concentration at circa 600 m mid-elevation. The findings have implications for venerable-tree conservation and management in tropical protected areas with similar threatened and remnant-tree status.

Microbial signatures predictive of short-term prognosis in severe pneumonia.

This retrospective cohort study aimed to investigate the composition and diversity of lung microbiota in patients with severe pneumonia and explore its association with short-term prognosis. A total of 301 patients diagnosed with severe pneumonia underwent bronchoalveolar lavage fluid metagenomic next-generation sequencing (mNGS) testing from February 2022 to January 2024. After applying exclusion criteria, 236 patients were included in the study. Baseline demographic and clinical characteristics were compared between survival and non-survival groups. Microbial composition and diversity were analyzed using alpha and beta diversity metrics. Additionally, LEfSe analysis and machine learning methods were employed to identify key pathogenic microorganism associated with short-term mortality. Microbial interaction modes were assessed through network co-occurrence analysis. The overall 28-day mortality rate was 37.7% in severe pneumonia. Non-survival patients had a higher prevalence of hypertension and exhibited higher APACHE II and SOFA scores, higher procalcitonin (PCT), and shorter hospitalization duration. Microbial α and β diversity analysis showed no significant differences between the two groups. However, distinct species diversity patterns were observed, with the non-survival group showing a higher abundance of Acinetobacter baumannii, Klebsiella pneumoniae, and Enterococcus faecium, while the survival group had a higher prevalence of Corynebacterium striatum and Enterobacter. LEfSe analysis identified 29 distinct terms, with 10 potential markers in the non-survival group, including Pseudomonas sp. and Enterococcus durans. Machine learning models selected 16 key pathogenic bacteria, such as Klebsiella pneumoniae, significantly contributing to predicting short-term mortality. Network co-occurrence analysis revealed greater complexity in the non-survival group compared to the survival group, with differences in central genera. Our study highlights the potential significance of lung microbiota composition in predicting short-term prognosis in severe pneumonia patients. Differences in microbial diversity and composition, along with distinct microbial interaction modes, may contribute to variations in short-term outcomes. Further research is warranted to elucidate the clinical implications and underlying mechanisms of these findings.

Global patterns of herbivorous eriophyoid mite species diversity: A reply to Ozman‐Sullivan and Sullivan (2024)

AbstractAimThe global patterns of phytophagous eriophyoid mite species diversity have been poorly studied for several decades. In a previous paper, we compiled a dataset covering 97% (4278/4400) of named eriophyoid mite species and 22,973 occurrence sites from 102 countries (Li et al., 2023). Using this dataset, we aimed to predict the global distribution patterns and species diversity of eriophyoid mites. Our findings revealed that the species richness of eriophyoid mites is particularly high in temperate regions, which is in contrast to the patterns of plants (Li et al., 2023). However, our results were criticized by Ozman‐Sullivan and Sullivan (2024), who argue that our analysis is based on a biased dataset of eriophyoid mites, because it is likely that there are many undescribed eriophyoid species in the tropics.LocationGlobal.TaxonEriophyoid mites (Acari: Eriophyoidea).Main ConclusionsHowever, using plant species to predict eriophyoid mite diversity, as Ozman‐Sullivan and Sullivan propose, may result in an overestimation of species richness. We leave ‘whether the species richness of eriophyid mites is high in tropical regions’ as an open question and a potential area for future research.

Applying regional climatic indicators to study plant diversity patterns in Inner Mongolia

Climate factors have a major influence on biodiversity patterns have often used their mean values to reflect the distribution of different organisms, reducing the faceted information of the study unit to point information, a situation that may affect the accuracy of the study results. However, there has been a lack of systematic and comprehensive discussion on regional climatic indicators and their selection. To address this, we evaluated plant distribution and meteorological data from 88 banners and counties in Inner Mongolia considering five regional climatic indicators that reflect the state of climate factors, heterogeneity, and total resources in each sampling unit. Additionally, we compared and analyzed the advantages of the regional climatic indicators over mean climate indicators to determine the dominant climate factors driving the diversity patterns of plant families, genera, and species. Our results showed that the regional climatic indicators were better than the mean values at reflecting the diversity patterns of plant families and genera. In Inner Mongolia, plant species diversity patterns were mainly influenced by total precipitation and temperature heterogeneity indicators; and concurrently, the correlation between plant family and genus diversity patterns and regional climatic indicators was also higher than the mean values. The extent to which climate explains the diversity patterns of plants increases with decreasing plant taxonomic rank. The results of this study expand the available selection and use of climate indicators in biodiversity research and deepen the understanding of the effects of climate on plant family diversity patterns in arid and semi-arid regions. Therefore, this study provides new perspectives for the rational selection and accurate use of climate or environmental indicators in biodiversity conservation and restoration research.

Effects of land use types and environmental factors on woody species diversity in agricultural landscapes of Jimma Ganati District, Western Oromia, Ethiopia

Nowadays agricultural expansion and the concurrent climate variability jointly jeopardized global biodiversity in general and plant species diversity in particular. Assessing current diversity status of different land uses is a proxy for anticipating their individualistic resilience against future climatic variability. Here we explored woody species composition, diversity, distribution, and indicator species across five agricultural land uses. For this we employed a systematic sampling design to collect phytosociological attributes of woody plant species from 103 plots in four landscapes at a regular distance following transect lines. For comparative diversity analysis, we used linear mixed effects model using the lmer function and subsequently, post hoc pairwise comparisons with the emmeans function of R software. To visualize species composition dissimilarities between the land uses, we applied NMDS ordination based on Bray-Curtis dissimilarity index and subsequently, adonis2 () function (R software) was used for testing its significance and pair-wise PERMANOVA analysis. Linear regression model and multiple regression model by Envfit function was used to test the effect of environmental topographic variables on the species distribution. The result indicated that, 104 woody plant species belonging to 52 families were collected, in which significant differences in species richness and composition among the five land use types were showed. The result reveal that, forest is with the most diversified species assemblage followed by home gardens. However, grazing land is the least in species diversity. Among topographic variables, elevation gradient shows significant influence on diversity and species compositional dissimilarity among the five agricultural land uses in which 38 species were significantly contributed to the dissimilarity of species composition. Species richness and woody stem abundance declines with increasing elevation. However, slope and aspect does not show significant effect on these attributes analysis. Indicator species assessment (IndVal.) showed that, 20 species were significantly (P ≤ 0.001) associated with at least one of the five land use classes in agricultural landscape. In sum, this study highlights that, changes in woody species diversity, composition and spatial patterns are the responses to types of land uses of varying disturbance intensities and topographic elevation as a proxy to different environmental factors.

DNA barcoding of marine fish species in the waters surrounding Hainan Island, northern South China Sea

IntroductionHainan Island is encompassed within the shallow waters of the tropical continental shelf in China, which is recognized as a significant hotspot for fish biodiversity. Despite extensive research conducted on marine fish taxonomy surrounding Hainan Island, there remains a substantial gap between our current understanding and the actual fish diversity within this oceanic area.MethodsIn this study, we employed DNA barcoding and molecular identification approaches to explore the species diversity and distribution pattern of marine fish in both the northern and southern sea areas of Hainan Island in the northern South China Sea.ResultsA total of 186 sequences were obtained from the collected marine fish samples in the two sea areas surrounding Hainan Island. Through DNA identification, it was confirmed that all 186 sequences corresponded to typical fish species found in the northern South China Sea, all sequences represented a total of 56 species, 47 genera, 34 families, and 17 orders. The average Kimura 2-parameter (K2P) distances within species, genus, family, order and class were 0.15%, 6.53%, 13.17%, 16.95% and 24.81%, respectively.DiscussionOur investigation in the northern sea areas of Hainan Islands identified a total of 33 distinct species, while the southern sea areas exhibited 29 distinct species, with only 5 species found to be shared between both regions. These findings clearly indicate a significant disparity in the species composition of fish communities between the northern and southern sea regions.

Effect of environmental drivers of fish assemblage and diversity patterns in temporal scale in Mongra Reservoir: A case study from one of the tributaries of Mahanadi Basin, Central India

AbstractInfluence of seasonal variations in environmental parameters on fish assemblage and species diversity patterns was studied in a tropical reservoir of Central India during March 2021 to February 2022. A total of 41 species belonging to 7 orders, 15 families and 29 genera were recorded with highest diversity during post‐monsoon season compared to the pre‐monsoon season and monsoon season. The fish abundance similarity between the monsoon and post‐monsoon reached a maximum of 89%. Seasonal variations in the mean species abundance, Simpson dominance index, Shannon diversity index, Pielou's evenness index and Margalef's richness index were determined. One‐way ANOVA revealed a significant difference (P < 0.05) at the temporal scale. There was a significant seasonal difference in species abundance (P = 0.0006) and evenness index (P = 0.02) among the diversity indices. During the study period, three ‘vulnerable’ species, three ‘near threatened’ species and two ‘endangered’ species were caught. Carnivore dominance was evident throughout the year in the trophic guild of fishes. The Pearson correlation test revealed that water pH, dissolved oxygen, sediment organic carbon and clay percentage were positively correlated to all four diversity indices. Simpson and Margalef species richness diversity indices were positively correlated to sediment pH. Fish abundance was positively associated with sediment pH, silt, phosphorus and nitrogen content. Canonical correspondence analysis was used to investigate the relationships between fish assemblages and environmental conditions. Among the 19 physicochemical parameters, nine (dissolved oxygen, total dissolved solids, conductivity, transparency, hardness, phosphate and chlorophyll‐a, sediment nitrogen and phosphorus) characteristics were shown to be statistically significant (P < 0.05) in determining fish diversity. Dissolved oxygen, total dissolved solids, conductivity, transparency, hardness, phosphate and chlorophyll‐a of water and sediment nitrogen and phosphorus qualities were the key factors for the species abundance. The reservoir boasts a diverse fish population that allows multi‐species fishing and generates revenue for numerous local fishers. Fish habitats should be protected in order to maintain diversity and long‐term ecological benefits.

Impress of Climate Change in the Himalaya on Plant Evolution

Currently, species diversity has become a hotpot to biologist. Some researchers find mountains contribute disproportionately to Earth's terrestrial biodiversity, especially in the tropics, where there are unusually rich and confusing hot spots. But current assumptions about large-scale geographic patterns of species diversity cannot explain the extremely high biodiversity in mountain regions, especially in the tropics, where is characterized by a complex spatial configuration of terrain and climate. This paper focuses on three prominent and brief factors which impact species differentiation most in Himalaya to illuminate some researches up to now, include geographical, climatic, and biological. Geographic affect plant diversity by bring alien species, and format monsoon and plateau environment through uplift. Monsoon can advance the formation of landform also. Further, the period climate change can induce variation of endemic species, and the pollinator can impact variation by reproduction, thus the mismatch between pollinator and plants recently may lead the decline of certain species. Besides these, nowadays palynology evidence has become a credible two-way entry point to research plant evolution and climate change in the past era by authenticating how subspecies formatted. What’s more, because the vagaries of climate have prompted the breeding of endemic species, the rising temperature currently may alter the vegetation in alpine area.

Microtopographic Variation in Biomass and Diversity of Living and Dead Wood in a Forest in Dongling Mountains, China

Habitat heterogeneity caused by topographic variations at the local scale is the environmental basis for the establishment and evolution of biodiversity and biomass patterns. The similarities and distinctions between the effects of microtopographic variables on living wood (LWD) and dead wood (CWD) remain unknown. In the present study, the response mechanisms of biomass and species diversity patterns of living wood (LWD) and coarse woody debris (CWD) to microtopographic parameters were quantified in a warm temperate secondary forest located in Dongling Mountain, China. This quantification was achieved using a generalized additive model on a completely mapped 20-hectare permanent plot. The evaluation of biomass and species diversity of woody plants was carried out by utilizing the total basal area of all individuals and the species richness within each 20 m × 20 m quadrat as a standard. The results indicate that there are notable disparities in the influence of microtopographic elements on the LWD and CWD. In the case of LWD, microtopography accounts for 22.90% of the variation in total basal area, with convexity making a greater relative contribution than elevation, slope, and aspect. Additionally, microtopography explains 46.20% of the variation in species richness, with aspect making a greater relative contribution than elevation, convexity, and slope. Nevertheless, the influence of microtopography on CWD may only account for a deviation of 10.20% in the total basal area and 4.95% in the species richness; aspect and slope have been identified as the primary drivers in this regard. The inclusion of microtopographic factors in the model resulted in a 23.10% increase in the explanatory deviations of LWD biomass and an 8.70% increase in the explanatory deviations of CWD biomass. The findings suggest that topographic considerations have a greater impact on the biomass distribution of LWD compared to that of CWD. Conversely, the biomass of CWD is more influenced by the species richness. The presence of microtopography plays a vital role in determining the spatial distribution of species and biomass at local scales, reflecting the multiple response mechanisms and growth strategies of vegetation in response to redistribution in water, soil, and light.

Going across taxa in functional ecology: Review and perspectives of an emerging field

Abstract The emergence of functional ecology has changed the focus of ecological research from investigating patterns of species diversity to understanding how species traits relate to specific ecological processes generating these patterns. Traits, ecological patterns and processes can be shared and driven by species from distantly related taxonomic groups. Crossing the boundaries among distantly related taxonomic groups is still a challenge and a critical knowledge frontier in functional ecology. A cross‐taxa approach, merging trait data across distantly related taxonomic groups, could fill this gap. In this context, functionally analogous traits, that is traits that may have distinct ontogenetic origins yet represent similar processes, comprise an important recent advance in functional ecology. However, which taxa and traits (be them analogous or not) have been used in research with multiple taxa, and whether (and how) these data have been combined, still needs to be elucidated. We reviewed articles published in the last 75 years to investigate the use of traits in functional research involving multiple taxa. Our search returned 1006 articles, and a subset of 96 was filtered for data extraction. Studies covered a total of 134 taxa and 491 different traits; they were predominantly observational, and focussed on community ecology and ecosystem monitoring. Our review showed that current knowledge in this field relies on a limited number of response variables, particularly taxonomic diversity (e.g. species richness and abundance within functional groups). Also, the field relies on a limited number of taxa (e.g. plants, birds and mammals) and trait types (diet, size, habitat and dispersal). Two‐thirds of the articles (n = 72) used functionally analogous traits, and one‐third of them (n = 32) employed a cross‐taxa approach. We mapped the limitations of current research in functional ecology involving multiple taxa, presented ecological questions to a functional cross‐taxa research and showed directions to pushing the limits of this research field. Our review aimed to encourage researchers in the field of functional ecology to move beyond single taxa and traits, and to integrate more branches and dimensions of the Tree of Life in their research. Read the free Plain Language Summary for this article on the Journal blog.

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.

Historical Assembly of Andean Tree Communities.

Patterns of species diversity have been associated with changes in climate across latitude and elevation. However, the ecological and evolutionary mechanisms underlying these relationships are still actively debated. Here, we present a complementary view of the well-known tropical niche conservatism (TNC) hypothesis, termed the multiple zones of origin (MZO) hypothesis, to explore mechanisms underlying latitudinal and elevational gradients of phylogenetic diversity in tree communities. The TNC hypothesis posits that most lineages originate in warmer, wetter, and less seasonal environments in the tropics and rarely colonize colder, drier, and more seasonal environments outside of the tropical lowlands, leading to higher phylogenetic diversity at lower latitudes and elevations. In contrast, the MZO hypothesis posits that lineages also originate in temperate environments and readily colonize similar environments in the tropical highlands, leading to lower phylogenetic diversity at lower latitudes and elevations. We tested these phylogenetic predictions using a combination of computer simulations and empirical analyses of tree communities in 245 forest plots located in six countries across the tropical and subtropical Andes. We estimated the phylogenetic diversity for each plot and regressed it against elevation and latitude. Our simulated and empirical results provide strong support for the MZO hypothesis. Phylogenetic diversity among co-occurring tree species increased with both latitude and elevation, suggesting an important influence on the historical dispersal of lineages with temperate origins into the tropical highlands. The mixing of different floras was likely favored by the formation of climatically suitable corridors for plant migration due to the Andean uplift. Accounting for the evolutionary history of plant communities helps to advance our knowledge of the drivers of tree community assembly along complex climatic gradients, and thus their likely responses to modern anthropogenic climate change.

Global gradients in species richness of marine plankton functional groups

Abstract The patterns of species diversity of plankton functional groups (PFGs) remain poorly understood although they matter greatly for marine ecosystem functioning. Here, we use an ensemble of empirical species distribution models for 845 plankton species to estimate the global species richness of three phytoplankton and 11 zooplankton functional groups as a function of objectively selected environmental predictors. The annual mean species richness of all PFGs decreases from the low to the high latitudes, but the steepness and the shape of this decrease vary significantly across PFGs. Pteropods, small copepods (Oithonids and Poecilostomatoids) and Salps have the steepest latitudinal gradients, whereas Amphipods and the three phytoplankton groups have the weakest ones. Temperature, irradiance and nutrient concentration are the first-order control on the latitudinal richness patterns, whilst the environmental conditions associated to upwelling systems, boundary currents and oxygen minimum zones modulate the position of the peaks and troughs in richness. The species richness of all PFGs increases with net primary production but decreases with particles size and the efficiency of the biological carbon pump. Our study puts forward emergent biodiversity–ecosystem functioning relationships and hypotheses about their underlying drivers for future field-based and modelling research.

Accelerated body size evolution in upland environments is correlated with recent speciation in South American freshwater fishes

Speciation rates vary greatly among taxa and regions and are shaped by both biotic and abiotic factors. However, the relative importance and interactions of these factors are not well understood. Here we investigate the potential drivers of speciation rates in South American freshwater fishes, the most diverse continental vertebrate fauna, by examining the roles of multiple biotic and abiotic factors. We integrate a dataset on species geographic distribution, phylogenetic, morphological, climatic, and habitat data. We find that Late Neogene-Quaternary speciation events are strongly associated with body-size evolution, particularly in lineages with small body sizes that inhabit higher elevations near the continental periphery. Conversely, the effects of temperature, area, and diversity-dependence, often thought to facilitate speciation, are negligible. By evaluating multiple factors simultaneously, we demonstrate that habitat characteristics associated with elevation, as well as body size evolution, correlate with rapid speciation in South American freshwater fishes. Our study emphasizes the importance of integrative approaches that consider the interplay of biotic and abiotic factors in generating macroecological patterns of species diversity.

The geography of climate and the global patterns of species diversity.

Climate's effect on global biodiversity is typically viewed through the lens of temperature, humidity and resulting ecosystem productivity1-6. However, it is not known whether biodiversity depends solely on these climate conditions, or whether the size and fragmentation of these climates are also crucial. Here we shift the common perspective in global biodiversity studies, transitioning from geographic space to a climate-defined multidimensional space. Our findings suggest that larger and more isolated climate conditions tend to harbour higher diversity and species turnover among terrestrial tetrapods, encompassing more than 30,000 species. By considering both the characteristics of climate itself and its geographic attributes, we can explain almost 90% of the variation in global species richness. Half of the explanatory power (45%) may be attributed either to climate itself or to the geography of climate, suggesting a nuanced interplay between them. Our work evolves the conventional idea that larger climate regions, such as the tropics, host more species primarily because of their size7,8. Instead, we underscore the integral roles of both the geographic extent and degree of isolation of climates. This refined understanding presents a more intricate picture of biodiversity distribution, which can guide our approach to biodiversity conservation in an ever-changing world.

Vegetation diversity pattern during spring season in relation to topographic and edaphic variables in sub-tropical zone

BackgroundThe present study was conducted to explore the diversity pattern of spring vegetation under the influence of topographic and edaphic variables in sub-tropical zone, District Malakand. In the present vegetation study, 252 species of 80 families were recorded in the study area. It included 39 species of trees, 43 species of shrubs, 167 species of herbs and 3 climber species. As a whole, 12 communities were established on the basis of topographic and edaphic characteristics in 12 different stations.ResultsThe results of the present study revealed that all diversity indices (species diversity, evenness index, species richness index, maturity index) during spring showed that the communities in plains lying at lower altitudes had higher diversity while the communities formed at high altitudes had lower diversity. The results of the similarity index showed that there was low similarity (below 50%) amongst the communities in different stations.ConclusionsIt can be concluded that variations in topographic and edaphic factors affect species diversity and communities pattern.

Spatial patterns of phylogenetic and species diversity of Fennoscandian vascular plants in protected areas

Protected areas are one of the main strategic means for conserving biodiversity. Yet, the design of protected areas usually neglects phylogenetic diversity, an important diversity measure. In this paper we assess the phylogenetic diversity and species richness of vascular plants in Fennoscandian protected areas. We evaluate how much species richness and phylogenetic diversity is found within and outside protected areas, and the differences in plant diversity between different categories of protected areas. We also assess the differences in the diversity-area relationship of the different protected area categories in terms of both species richness and phylogenetic diversity. We build a multi-locus phylogeny of 1,519 native vascular plants of Norway, Sweden, and Finland. We estimate the phylogenetic diversity and species richness by combining the phylogeny with publicly available occurrence data and the currently protected area system of Fennoscandia. Our results indicate that protected areas in Fennoscandia hold more plant diversity when larger, and that phylogenetic diversity increases faster with area than species richness. We found evidence for more plant diversity outside of protected areas of the different countries of Fennoscandia than inside of protected areas, but no evidence for plant diversity differences between areas with different protection status. Hence, our results indicate that the current protected area system in Fennoscandia is no more effective in conserving phylogenetic diversity and species richness of vascular plants than a random selection of localities. Our results also indicate that planning conservation strategies around phylogenetic diversity, rather than species richness, might be a first step to protect vascular plant diversity more effectively.