Measures Of Species Diversity Research Articles

Does forest restoration assist the recovery of threatened species? A study of cloud forest amphibian communities

Forest restoration may support recovery and conservation of biodiversity. However, the response of biodiversity to forest restoration is likely to vary depending on the restoration strategy used and taxa considered. Our goal was to assess the recovery of amphibians, a highly threatened biological group, in three cloud forests under different restoration strategies. We compared different measures of species diversity in cattle pasture, 13-year-old forest under passive restoration (P13), 23-year-old forest under passive restoration (P23), 23-year-old forest under active restoration (A23) and mature cloud forest in Mexico. We sampled amphibians in 45 plots and measured landscape and habitat variables to assess their influence on amphibian recovery. We found a total of 13 amphibian species, of which 23% are in the Vulnerable (VU) category of the IUCN Red List and 15% are Critically Endangered (CR). All forests under restoration recovered amphibian species richness and composition, including that of the threatened species, but abundance differed among restoration strategies. Abundance of VU and CR species was higher in A23 than in P13 and P23, but that of CR species was highest in cloud forest. Responses to forest restoration differed among taxa; recovery of salamanders was lower than that of anurans. Proximity to water bodies, as well as high canopy and leaf litter cover, had a strong positive influence on amphibian recovery. Our results indicate that recovery of threatened biodiversity could be promoted through forest restoration, particularly active restoration, and highlight the essential role of mature forest in the maintenance and recovery of amphibian communities.

Insights into reproductive isolation within the pelagic copepod Pleuromamma abdominalis with high genetic diversity using genome-wide SNP data

Species complexes with multiple genetic clades are frequently observed using mitochondrial DNA (mtDNA) markers in pelagic copepods. However, reproductive isolation among clades is not fully understood because of low sequence variations in common nuclear markers. In the present study, genome-wide single nucleotide polymorphisms (SNPs) were obtained for copepod, Pleuromamma abdominalis, with high genetic diversity and sympatric mtDNA clades using multiplexed inter-simple sequence repeat genotyping by sequencing (MIG-seq). Sequences of mitochondrial cytochrome oxidase subunit I (mtCOI) were classified into six clades in 31 P. abdominalis that co-existed in the western subtropical North Pacific. Four mtCOI clades with genetic distances ≥ 0.082 were monophyletic according to the phylogenetic analyses based on SNPs in MIG-seq. The other two mtCOI clades with mean 0.082 genetic distance were not separated in the MIG-seq phylogenetic tree. The results from our phylogenetic analysis of MIG-seq agreed with those from other genome-wide methods of double digest restriction site-associated DNA sequencing, and reproductive isolation and interbreeding between mtCOI clades were also supported by Bayesian clustering analysis. The two mtCOI clades that had possibly interbred exhibited different distribution patterns, suggesting secondary contact without reproductive isolation in the sampling area. The genome-wide SNP data supported the high cryptic species diversity in P. abdominalis, which was inferred from mitochondrial genes. Further genome-wide studies, especially those that use PCR-based approaches including MIG-seq for small copepods, can lead to appropriate measurements of pelagic species diversity in the ocean.

Site fertility drives temporal turnover of vegetation at high latitudes.

Experimental evidence shows that site fertility is a key modulator underlying plant community changes under climate change. Communities on fertile sites, with species having fast dynamics, have been found to react more strongly to climate change than communities on infertile sites with slow dynamics. However, it is still unclear whether this generally applies to high‐latitude plant communities in natural environments at broad spatial scales. We tested a hypothesis that vegetation of fertile sites experiences greater changes over several decades and thus would be more responsive under contemporary climate change compared to infertile sites that are expected to show more resistance. We resurveyed understorey communities (vascular plants, bryophytes, and lichens) of four infertile and four fertile forest sites along a latitudinal bioclimatic gradient. Sites had remained outside direct human disturbance. We analyzed the magnitude of temporal community turnover, changes in the abundances of plant morphological groups and strategy classes, and changes in species diversity. In agreement with our hypothesis, temporal turnover of communities was consistently greater on fertile sites compared to infertile sites. However, our results suggest that the larger turnover of fertile communities is not primarily related to the direct effects of climatic warming. Furthermore, community changes in both fertile and infertile sites showed remarkable variation in terms of shares of plant functional groups and strategy classes and measures of species diversity. This further emphasizes the essential role of baseline environmental conditions and nonclimatic drivers underlying vegetation changes. Our results show that site fertility is a key determinant of the overall rate of high‐latitude vegetation changes but the composition of plant communities in different ecological contexts is variously impacted by nonclimatic drivers over time.

Niche and Neutrality Work Differently in Microbial Communities in Fluidic and Non-fluidic Ecosystems.

This data-intensive study investigated the delicate balance of niche and neutrality underlying microbial communities in freshwater ecosystems through comprehensive application of high-throughput sequencing, species abundance distribution (SAD), and the neutral community model (NCM), combined with species diversity and phylogenetic measures, which unite the traditional and microbial ecology. On the genus level, 45.10% and 41.18% of the water samples could be explained by the log-normal and Volkov model respectively, among which 31.37% could fit both models. Meanwhile, 55.56% of the sediment samples could be depicted by the log-normal model, and Volkov-fitted samples comprised only 13.33%. Besides, operational taxonomic units (OTUs) from water samples fit Sloan's neutral model significantly better than those in sediment. Therefore, it was concluded that deterministic processes played a great role in both water and sediment ecosystems, whereas neutrality was much more involved in water assemblages than in non-fluidic sediment ecosystems. Secondly, log-normal fitted samples had lower phylogenetic species variability (PSV) than Volkov-fitted ones, indicating that niche-based communities were more phylogenetically clustered than neutrally assembled counterparts. Additionally, further testing showed that the relative richness of rare species was vital to SAD modeling, either niche-based or neutral, and communities containing fewer rare species were more easily captured by theoretical SAD models.

High rates of primary production in structurally complex forests.

Structure-function relationships are central to many ecological paradigms. Chief among these is the linkage of net primary production (NPP) with species diversity and canopy structure. Using the National Ecological Observatory Network (NEON) as a subcontinental-scale research platform, we examined how temperate-forest NPP relates to several measures of site-level canopy structure and tree species diversity. Novel multidimensional canopy traits describing structural complexity, most notably canopy rugosity, were more strongly related to site NPP than were species diversity measures and other commonly characterized canopy structural features. The amount of variation in site-level NPP explained by canopy rugosity alone was 83%, which was substantially greater than that explained individually by vegetation area index (31%) or Shannon's index of species diversity (30%). Forests that were more structurally complex, had higher vegetation-area indices, or were more diverse absorbed more light and used light more efficiently to power biomass production, but these relationships were most strongly tied to structural complexity. Implications for ecosystem modeling and management are wide ranging, suggesting structural complexity traits are broad, mechanistically robust indicators of NPP that, in application, could improve the prediction and management of temperate forest carbon sequestration.

Landforms contribute to plant biodiversity at alpha, beta and gamma levels

AbstractAimGeodiversity underpins biodiversity, but the contribution of specific geofeatures or landforms has rarely been explored. In this study, we use multiple vascular plant species diversity measures on alpha, beta and gamma levels to explore the linkage between biodiversity and co‐located landforms (e.g. gullies, dunes and lake shores). We hypothesize that biodiversity will be positively related to geodiversity, which is founded on distinct landforms. Additionally, we propose that different landforms will sustain different amounts of biodiversity and that high alpha and gamma diversity values are related to landform‐driven moisture availability whereas high beta diversity relates especially to landform‐specific microtopographic variation.LocationRokua UNESCO Global Geopark area, Finland.TaxonVascular plants.MethodsWe compare vascular plant species richness measures, Shannon's and Simpson's diversity indices, rarity‐weighted richness and local contribution to beta diversity at altogether three levels of biodiversity (alpha, beta and gamma) for different landforms. Landform information is compiled from aerial photos, spatial data layers and targeted field surveys. We compare results to control habitat (i.e. sites without any distinct landforms) within the study area.ResultsVascular plant diversity was higher on landforms than in control habitat. There was also notable variation between species diversity of different landforms. Moisture‐rich gullies and river shores were especially diverse at all three levels, whereas aapa mires hosted most unique species composition (highest beta diversity). Beta diversity patterns were rather comparable with alpha and gamma diversity patterns, which contradict our hypothesis.Main conclusionsThis study quantitatively established a strong connection between terrestrial plant communities and multiple landforms. Our results highlighted the landform‐controlled variation in soil moisture, microclimate and microtopography in enhancing plant species diversity. Based on the results, we promote the inclusion of landform‐based geodiversity information in conservation management and in further biogeographical studies.

The effects of sex and APOE genotype on the gut microbiome in EFAD transgenic mice

While the gut microbiome (GM), the collective genome of bacteria in the gastrointestinal tract, is primarily studied in metabolism and immune defense, the GM may also serve as a diagnostic tool and therapeutic target in neurological disorders, including Alzheimer's disease (AD). While age is the greatest risk factor for AD, the e4allele of APOE is the greatest genetic risk factor, increasing risk up to 15‐fold compared to APOE3, the common genotype. APOE4 is associated with the accelerated accumulation of the peptide amyloid‐b(Ab), which can aggregate to form both amyloid plaques and small soluble aggregates or oligomeric Ab (oAb), the latter considered a proximal neurotoxin. Importantly, among APOE4 carriers, females have an increased AD risk, rate of cognitive loss and accumulation of Ab42 compared to males. Although the GM of individuals with AD exhibit specific microbial differences compared to healthy controls, a greater understanding of how age, APOE genotype and sex contribute to the altered GM in AD may help determine the diagnostic potential of the GM composition. To study the interactions among these AD risk factors, we developed the EFAD‐transgenic mice, which express the human APOE genotypes and over‐express human Ab42. Thus, our hypothesis is that APOE genotype and sex interact to modulate the GM composition in EFAD mice. Fecal samples from 4 month (M) ♂ and ♀ E3FAD and E4FAD mice were sequenced and compared. The Shannon H index, a measure of species richness and diversity, identified a negative correlation between diversity and severity of AD pathology in the 4M EFAD cohorts of mice: ♂E4FAD > ♀E4FAD and ♀E3FAD > ♀E4FAD. Analysis of similarities (ANOSIM) demonstrated significant differences in the GM in E3FAD vs E4FAD across different taxonomic levels (operational taxonomic unit/OTU, Genus, and Family). Comparison across sex within APOE genotype revealed a significant difference between ♂E3FAD vs ♂E4FAD and ♀E3FAD vs ♀E4FAD at all taxonomic levels. Additionally, there is a significant effect for ♂E4FAD vs ♀E4FAD, though only at the OTU level. Further, heatmap analysis demonstrates clustering of ♀E4FAD samples based on 29 OTUs. Therefore, the synergistic effect of APOE4 and female sex on AD risk is exhibited by the GM, observed by the stratification of the EFAD cohorts. This study is the first step in defining the composition of the GM as a function APOE genotype and sex modulation of AD pathology.Support or Funding InformationLaDu lab funding includes institutional funds from the University of Illinois College of Medicine, the Bridge to the Doctorate Fellowship, and the Honor's College Undergraduate Research Award at the University of Illinois at Chicago.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Weighting effective number of species measures by abundance weakens detection of diversity responses

Abstract The effective number of species (ENS) has been proposed as a robust measure of species diversity that overcomes several limitations in terms of both diversity indices and species richness (SR). However, it is not yet clear if ENS improves interpretation and comparison of biodiversity monitoring data, and ultimately resource management decisions. We used simulations of five stream macroinvertebrate assemblages and spatially extensive field data of stream fishes and mussels to show (a) how different ENS formulations respond to stress and (b) how diversity–environment relationships change with values of q, which weight ENS measures by species abundances. Values of ENS derived from whole simulated assemblages with all species weighted equally (true SR) steadily decreased as stress increased, and ENS‐stress relationships became weaker and more different among assemblages with increased weighting. The amount of variation in ENS across the fish and mussel assemblages that was associated with environmental gradients decreased with increasing q. Synthesis and applications. Species diversity is valued by many human societies, which often have policies designed to protect and restore it. Natural resources managers and policy makers may use species richness and diversity indices to describe the status of ecological communities. However, these traditional diversity measures are known subject to limitations that hinder their interpretation and comparability. The effective number of species (ENS) was proposed to overcome the limitations. Unfortunately, our analyses show that ENS does not improve interpretability of how species diversity responds to either stress or natural environmental gradients. Moreover, incorporating the relative abundance of individuals in different species (evenness) into diversity measures as implemented in ENS can actually weaken detection of diversity responses. Natural resources managers and policy makers therefore need to be cautious when interpreting diversity measures, including ENS, whose values are jointly influenced by richness and evenness. We suggest that both researchers and practitioners measure and report three aspects of diversity (species richness, evenness, and composition) separately when assessing and monitoring the diversity of ecological communities.

A simple translation from indices of species diversity to indices of phylogenetic diversity

Measures of phylogenetic diversity have two main objectives: first disentangling the processes that drive species assemblages and second defining priorities of conservation while considering how much each species might contribute to biodiversity. A now widely used approach for measuring phylogenetic diversity consists in summing branch lengths on phylogenetic trees. Thanks to this approach, a change of perspective has been done since the 90s in the ecological literature: to measure biodiversity in sites, species in compositional indices have been replaced, often implicitly and sometimes explicitly, with phylogenetic units (units on the branch lengths of a phylogenetic tree). Here we highlight how any traditional index of species diversity, can be adapted, with this simple change of perspective, to measure phylogenetic diversity. We analyze other potentials of this simple family of indices: the ratio of phylogenetic diversity to the associated species diversity may offer a meaningful way to apprehend phylogenetic uniqueness in communities; and the phylogenetic diversity standardized by its maximum value may provide a meaningful way to apprehend phylogenetic evenness. Theoretically, the same approach could be applied to functional dendrograms to assess functional diversity, evenness and uniqueness. However this requires, somehow, to force functional data to adhere to a hierarchical structure of functional differences between species. As an illustration, we analyze phylogenetic and functional diversity in plant communities along a primary succession in Italy. Overall, this simple framework has a critical potential for future analyses of tree-based diversity as it benefits from myriads of previous researches on the measures of species diversity and species evenness.

Community Ecology and Phylogeography of Bats in the Guianan Savannas of Northern South America

The Guiana Shield of South America contains savannas within one of the largest contiguous expanses of pristine tropical rainforest remaining in the world, but biodiversity in the grasslands is poorly known. In lowland Neotropical areas, bats typically comprise the most species-rich group of mammals. We compare the bat faunal community and phylogeography in the savanna habitats of the Llanos in Venezuela, Rupununi in Guyana, and Sipaliwini in Suriname. Measures of species diversity and relative abundance from standardized field survey methodology enable comparison among these three grassland regions. Genetic variation is summarized by DNA barcoding to examine biogeographic patterns across larger forest–savanna landscapes. A total of 76 species of bats is documented, of which 18 species are reported from all 3 savannas and 30 species are reported from only 1 of the savannas. Endemism is low with 5 taxa restricted primarily to dry, open habitats. However, 7 other species have divergent phylogeographic lineages associated with savanna populations. Although bat species are usually distributed over wide regions of the Neotropics, the habitat mosaics of the Guiana Shield have different faunal assemblages. Going back into the Miocene, the contractions and expansions of forest–savanna paleoenvironments over time have contributed to speciation and the current high levels of biodiversity in South America.

Measuring Biodiversity and Extinction-Present and Past.

How biodiversity is changing in our time represents a major concern for all organismal biologists. Anthropogenic changes to our planet are decreasing species diversity through the negative effects of pollution, habitat destruction, direct extirpation of species, and climate change. But major biotic changes-including those that have both increased and decreased species diversity-have happened before in Earth's history. Biodiversity dynamics in past eras provide important context to understand ecological responses to current environmental change. The work of assessing biodiversity is woven into ecology, environmental science, conservation, paleontology, phylogenetics, evolutionary and developmental biology, and many other disciplines; yet, the absolute foundation of how we measure species diversity depends on taxonomy and systematics. The aspiration of this symposium, and complementary contributed talks, was to promote better understanding of our common goals and encourage future interdisciplinary discussion of biodiversity dynamics. The contributions in this collection of papers bring together a diverse group of speakers to confront several important themes. How can biologists best respond to the urgent need to identify and conserve diversity? How can we better communicate the nature of species across scientific disciplines? Where are the major gaps in knowledge about the diversity of living animal and plant groups, and what are the implications for understanding potential diversity loss? How can we effectively use the fossil record of past diversity and extinction to understand current biodiversity loss?

Effects of canopy structure and species diversity on primary production in upper Great Lakes forests

Canopy structure and tree species diversity, shaped by succession, disturbance, and community composition, are linked to numerous ecosystem functions, including net primary production (NPP). Understanding of how ecosystem structural metrics are interrelated and mechanistically link to NPP, however, is incomplete. We characterized leaf area index (LAI), Simpson's index of Diversity (D', a measure of species diversity), and canopy rugosity (Rc, a measure of canopy physical complexity) in 11 forest stands comprising two chronosequences varying in establishing disturbance, and in three late successional communities. We related LAI, D', and Rc to wood NPP (NPPw), and examined whether absorption of photosynthetically active radiation and light use-efficiency (LUE) link NPPw with ecosystem structure. We found that recovery of LAI and D' was delayed following more severe establishing disturbances, but that the development of Rc was strikingly conserved regardless of disturbance, converging on a common mean value in late-successional stands irrespective of differences in leaf area index and species diversity. LAI was significantly correlated with NPPw in each stage of ecosystem development, but NPPw was only correlated with Rc in early successional stages and with D' in late successional stages. Across all stands, NPPw was coupled with LAI and Rc, (but not D') through positive relationships with light absorption and LUE. We conclude by advocating for better integration of ecological disciplines investigating structure-function interactions, suggesting that improved understanding of such relationships will require ecologists to traverse disciplinary boundaries.

Biodiversity and human health: mechanisms and evidence of the positive health effects of diversity in nature and green spaces.

Natural environments and green spaces provide ecosystem services that enhance human health and well-being. They improve mental health, mitigate allergies and reduce all-cause, respiratory, cardiovascular and cancer mortality. The presence, accessibility, proximity and greenness of green spaces determine the magnitude of their positive health effects, but the role of biodiversity (including species and ecosystem diversity) within green spaces remains underexplored. This review describes mechanisms and evidence of effects of biodiversity in nature and green spaces on human health. We identified studies listed in PubMed and Web of Science using combinations of keywords including 'biodiversity', 'diversity', 'species richness', 'human health', 'mental health' and 'well-being' with no restrictions on the year of publication. Papers were considered for detailed evaluation if they were written in English and reported data on levels of biodiversity and health outcomes. There is evidence for positive associations between species diversity and well-being (psychological and physical) and between ecosystem diversity and immune system regulation. There is a very limited number of studies that relate measured biodiversity to human health. There is more evidence for self-reported psychological well-being than for well-defined clinical outcomes. High species diversity has been associated with both reduced and increased vector-borne disease risk. Biodiversity supports ecosystem services mitigating heat, noise and air pollution, which all mediate the positive health effects of green spaces, but direct and long-term health outcomes of species diversity have been insufficiently studied so far. Additional research and newly developed methods are needed to quantify short- and long-term health effects of exposure to perceived and objectively measured species diversity, including health effects of nature-based solutions and exposure to microbiota.

The use of response measures in meta-analyses of land-use impacts on ecological communities: a review and the way forward

Species richness and total abundance are two of the most commonly used response measures in empirical studies of the effects of anthropogenic land-use on biodiversity, in spite of the fact that they are insensitive to changes in a range of community attributes. We evaluated the extent to which meta-analyses about the effects of forest land-use on ecological communities make use of gross species richness, diversity and abundance measures (hereafter low-informative measures) as opposed to more refined response variables conveying a higher degree of conservation-relevant information, e.g., by accounting for compositional or functional changes in the communities (high-informative measures). Nearly one-half of the 221 included meta-analyses were based solely on low-informative measures. The prevalence of low-informative measures was higher for meta-analyses belonging to studies encompassing a broad taxonomic scope and it has increased since 2002. Few differences were detected in the use of response measures among taxonomic groups, although there were indications that some better-known groups tended to be more often studied with high-informative measures. To provide guidance for future work, we synthesized the high-informative measures of biodiversity used in the reviewed studies. For better-informed meta-analyses, we encourage the use of more refined approaches to quantify impacts on communities in addition to species richness and total abundance measures. This may involve, for example, the use of β diversity and functional diversity measures, as well as separate analyses for different ecological groups or conservation status categories.

Climate-smart sustainable agriculture in low-to-intermediate shade agroforests

Meeting demands for agricultural production while maintaining ecosystem services, mitigating and adapting to climate change and conserving biodiversity will be a defining challenge of this century. Crop production in agroforests is being widely implemented with the expectation that it can simultaneously meet each of these goals. But trade-offs are inherent to agroforestry and so unless implemented with levels of canopy cover that optimize these trade-offs, this effort in climate-smart, sustainable intensification may simply compromise both production and ecosystem services. By combining simultaneous measurements of production, soil fertility, disease, climate variables, carbon storage and species diversity along a shade-tree cover gradient, here we show that low-to-intermediate shade cocoa agroforests in West Africa do not compromise production, while creating benefits for climate adaptation, climate mitigation and biodiversity. As shade-tree cover increases above approximately 30%, agroforests become increasingly less likely to generate win–win scenarios. Our results demonstrate that agroforests cannot simultaneously maximize production, climate and sustainability goals but might optimise the trade-off between these goals at low-to-intermediate levels of cover. Agroforests can combine crop production with ecosystem service provisioning, but how they should be implemented to balance their costs and benefits remains unknown. This study finds that low-to-intermediate shade cocoa agroforests in West Africa benefit biodiversity and climate without compromising production.

Indicators of Ventenata (Ventenata dubia) Invasion in Sagebrush Steppe Rangelands

AbstractVentenata [Ventenata dubia(Leers) Coss.], an invasive winter annual grass, significantly reduces forage production in grassland systems and displaces species within both perennial- and annual-dominated grasslands within the Inland Northwest. The range ofV. dubiais expanding into sagebrush steppe communities, an expansive habitat critical for forage production, wildlife, and recreation. Currently, there is limited knowledge ofV. dubia’s distribution and abundance within sagebrush steppe communities. We performed field surveys at 15 locations in sagebrush steppe rangelands in southern Idaho and eastern Oregon to assess whereV. dubiaoccurs, with the aim of providing insight about its niche in this new habitat. Specifically, we evaluated biotic and abiotic factors of the plant community as indicators ofV. dubiapresence. We also correlated species diversity measures with no, low (<12.5%), and high (>12.5%)V. dubiacover. Though widely distributed throughout the study region,V. dubiaonly appeared in 45% of the 225 plots, and foliar cover was typically less than 50%. It was primarily found in ephemerally wet microhabitats. Species richness and the Shannon diversity index were lowest in plots with highV. dubiacover. Nonmetric multidimensional scaling analysis revealed thatV. dubiaand medusahead [Taeniatherum caput-medusae(L.) Nevski] were closely associated. Furthermore, chi-square indicator analysis showed thatT. caput-medusaewas more prevalent, while mountain big sagebrush [Artemisia tridentataNutt. spp.vaseyana(Rydb.) Beetle] was less prevalent, in plots containingV. dubia. Abiotic factors that explained variation inV. dubiaabundance included rock cover, soil depth, and a north/south aspect. HigherV. dubiacover also correlated with higher clay content and lower phosphorus and potassium concentrations in the soil. We suggest that at this point, detection survey efforts to locate incipient infestations ofV. dubiain sagebrush steppe communities should focus on moist areas and sites susceptible to invasion byT. caput-medusae.

Bat cave vulnerability index (BCVI): A holistic rapid assessment tool to identify priorities for effective cave conservation in the tropics

The identification of important habitats for wildlife is essential in order to plan and promote strategies for long-term effective conservation. Caves and subterranean habitats are frequently overlooked habitats with diverse communities, which are frequently endemic to a region, karst outcrop or even a single cave. These cave species include a wide range of taxa adapted to cave environments. Within cave systems, bats are key providers of energy for other cave-dependent species. However, identifying caves for conservation prioritisation requires an understanding of cave-dwelling species diversity, patterns of endemism, and conservation status, in addition to a standard mechanism to evaluate risk. In this paper, we present the ‘Bat Cave Vulnerability Index’ (BCVI) as a standard index for evaluating bat caves for conservation prioritisation by determining Biotic Potential (BP) and Biotic Vulnerability (BV) of caves. The Biotic Potential is represented by various species diversity and rarity measurements. The Biotic Vulnerability is represented by the cave geophysical characteristics and human-induced disturbance present. Pilot testing in the southern Philippines has demonstrated that the index is an effective and practicable method to identify bat caves for conservation prioritisation. The biotic potential variables assess the presence of endemic, rare, and threatened bat species and assays the priority level based on an equation. Relative risk and vulnerability were assayed using landscape vulnerability variables, which showed anthropogenic activities were important factors in conservation prioritisation. The application and mechanism of the index potentially provides a valuable, rapid and simple assessment tool in cave conservation with special relevance to bat diversity and vulnerability. Furthermore, the multiple and holistic criteria of the BCVI, and the accessible information for both biotic and landscape features can be adapted to prioritise caves in a wider scale in the tropics, and in other regions with diverse cave ecosystems.

Hidden diversity of forest birds in Madagascar revealed using integrative taxonomy

Madagascar is renowned as a global biodiversity hotspot with high levels of microendemism. However, there are few molecular phylogenetic studies of Malagasy birds, particularly for forest-dwelling species, signifying a substantial gap in current measures of species diversity in the absence of genetic data. We evaluated species limits and explored patterns of diversification within the genus Newtonia (Family Vangidae), a group of forest-dwelling songbirds endemic to Madagascar. Our modern systematics approach combined genomic, morphometric, and ecological niche data to analyze the evolutionary history of the group. Our integrative analysis uncovered hidden species-level diversity within N. amphichroa, with two deeply divergent and morphologically distinct lineages isolated in different regions of humid forest. We describe the southern lineage as a new species. Conversely, N. brunneicauda, which we initially hypothesized may harbor cryptic diversity owing to its large distribution spanning a range of habitats, was found to have no distinct lineages and shared haplotypes across much of its distribution. The contrasting diversification patterns between Newtonia lineages may be the result of their elevational tolerances. Newtonia brunneicauda has a broad habitat tolerance and elevational range that appears to have facilitated population expansion and gene flow across the island, limiting opportunities for diversification. On the other hand, N. amphichroa is found predominantly in mid-elevation and montane humid forests, a restriction that appears to have promoted speciation associated with climatic fluctuations during the Pleistocene. Our findings indicate that species diversity of Malagasy forest-dwelling birds may be greater than currently recognized, suggesting an urgent need for further studies to quantify biodiversity in Madagascar’s rapidly disappearing native forests.

Estimating tree species diversity in the savannah using NDVI and woody canopy cover

Remote sensing applications in biodiversity research often rely on the establishment of relationships between spectral information from the image and tree species diversity measured in the field. Most studies have used normalized difference vegetation index (NDVI) to estimate tree species diversity on the basis that it is sensitive to primary productivity which defines spatial variation in plant diversity. The NDVI signal is influenced by photosynthetically active vegetation which, in the savannah, includes woody canopy foliage and grasses. The question is whether the relationship between NDVI and tree species diversity in the savanna depends on the woody cover percentage. This study explored the relationship between woody canopy cover (WCC) and tree species diversity in the savannah woodland of southern Africa and also investigated whether there is a significant interaction between seasonal NDVI and WCC in the factorial model when estimating tree species diversity. To fulfil our aim, we followed stratified random sampling approach and surveyed tree species in 68 plots of 90m×90m across the study area. Within each plot, all trees with diameter at breast height of >10cm were sampled and Shannon index − a common measure of species diversity which considers both species richness and abundance − was used to quantify tree species diversity. We then extracted WCC in each plot from existing fractional woody cover product produced from Synthetic Aperture Radar (SAR) data. Factorial regression model was used to determine the interaction effect between NDVI and WCC when estimating tree species diversity. Results from regression analysis showed that (i) WCC has a highly significant relationship with tree species diversity (r2=0.21; p<0.01), (ii) the interaction between the NDVI and WCC is not significant, however, the factorial model significantly reduced the error of prediction (RMSE=0.47, p<0.05) compared to NDVI (RMSE=0.49) or WCC (RMSE=0.49) model during the senescence period. The result justifies our assertion that combining NDVI with WCC will be optimal for biodiversity estimation during the senescence period.

Phylogenetic diversity anomaly in angiosperms between eastern Asia and eastern North America

Although eastern Asia (EAS) and eastern North America (ENA) have similar climates, plant species richness in EAS greatly exceeds that in ENA. The degree to which this diversity difference reflects the ages of the floras or their rates of evolutionary diversification has not been quantified. Measures of species diversity that do not incorporate the ages of lineages disregard the evolutionary distinctiveness of species. In contrast, phylogenetic diversity integrates both the number of species and their history of evolutionary diversification. Here we compared species diversity and phylogenetic diversity in a large number of flowering plant (angiosperm) floras distributed across EAS and ENA, two regions with similar contemporary environments and broadly shared floristic history. After accounting for climate and sample area, we found both species diversity and phylogenetic diversity to be significantly higher in EAS than in ENA. When we controlled the number of species statistically, we found that phylogenetic diversity remained substantially higher in EAS than in ENA, although it tended to converge at high latitude. This pattern held independently for herbs, shrubs, and trees. The anomaly in species and phylogenetic diversity likely resulted from differences in regional processes, related in part to high climatic and topographic heterogeneity, and a strong monsoon climate, in EAS. The broad connection between tropical and temperate floras in southern Asia also might have played a role in creating the phylogenetic diversity anomaly.