Vertebrate Richness Research Articles

Effects of Dams on Vertebrate Diversity: A Global Analysis

Dams are crucial for water supply in human populations and are becoming more common globally for hydroelectric power generation. Dams alter natural habitats and their biodiversity; however, studies are inconclusive about their effects on them. This study aimed to examine the effects of dams on vertebrates and the determinants of changes in global biodiversity and their relationship with critical areas for conservation. We evaluated the effects of dams on vertebrate richness and abundance. We performed a meta-analysis based on 120 case studies. We evaluated the overall effect on richness and abundance and examined these effects regarding taxa, disturbance type, latitudinal zone, zoogeographic zone, biodiversity hotspots, dam size and purpose, and species extinction risk. We conducted an overall analysis that included all species, and then we conducted separate analyses for terrestrial and aquatic species. Dams had a negative effect on vertebrate richness but not on vertebrate abundance. These effects were influenced by larger dams with fragmentation and were more pronounced within hotspots and in countries with a low species extinction risk. Such negative effects were explained by terrestrial vertebrates (particularly birds and mammals) because species richness and the abundance of aquatic vertebrates (fish) were not affected by dams in any case. Our results showed that habitat fragmentation created by large dams changes vertebrate communities, negatively affecting species richness in some areas of conservation concern. We propose implementing reservoirs in areas where they would have a lower impact on biodiversity and avoiding large dams in priority areas for conservation and where endangered species inhabit.

Conservation planning on China's borders with Myanmar, Laos, and Vietnam.

Transboundary conservation is playing an increasingly important role in maintaining ecosystem integrity and halting biodiversity loss caused by anthropogenic activities. However, lack of information on species distributions in transboundary regions and understanding of the threats in these areas impairs conservation. We developed a spatial conservation plan for the transboundary areas between Yunnan province, southwestern China, and neighboring Myanmar, Laos, and Vietnam in the Indo‐Burma biodiversity hotspot. To identify priority areas for conservation and restoration, we determined species distribution patterns and recent land‐use changes and examined the spatiotemporal dynamics of the connected natural forest, which supports most species. We assessed connectivity with equivalent connected area (ECA), which is the amount of reachable habitat for a species. An ECA incorporates the presence of habitat in a patch and the amount of habitat in other patches within dispersal distance. We analyzed 197,845 locality records from specimen collections and monographs for 21,004 plant and vertebrate species. The region of Yunnan immediately adjacent to the international borders had the highest species richness, with 61% of recorded species and 56% of threatened vertebrates, which suggests high conservation value. Satellite imagery showed the area of natural forest in the border zone declined by 5.2% (13,255 km2) from 1995 to 2018 and monoculture plantations increased 92.4%, shrubland 10.1%, and other cropland 6.2%. The resulting decline in connected natural forest reduced the amount of habitat, especially for forest specialists with limited dispersal abilities. The most severe decline in connectivity was along the Sino‐Vietnamese border. Many priority areas straddle international boundaries, indicating demand and potential for establishing transboundary protected areas. Our results illustrate the importance of bi‐ and multilateral cooperation to protect biodiversity in this region and provide guidance for future conservation planning and practice.

Patterns of vertebrate richness across global anthromes: prioritizing conservation beyond biomes and ecoregions

There is a clear need to refocus the way we prioritize conservation actions at a global scale to incorporate human systems. Anthromes have been suggested as one tool for integrating anthropogenic effects on ecosystems, but spatially explicit comparisons of biodiversity patterns are limited at a global extent. To address this gap, we used global data sets of anthromes and terrestrial vertebrate richness. We ranked anthromes by richness to all and threatened species at a global scale, temperate and tropical extents, and within major geographic regions. We tested for correlations between overall richness and count of threatened species, between taxonomic groups (birds, mammals, amphibians), and between taxa and conservation actions. At the global scale, there is high variation in vertebrate species richness by anthrome with low species richness in wildlands and higher richness in villages, rangelands, and woodlands. Threatened species distribution follows a similar pattern with high numbers of threatened species in village and remote seminatural woodland anthromes. Analyzes at temperate and tropical extents suggests unique opportunities in different regions, for example when considering the value of land sparing or sharing. There is clear heterogeneity across geographic regions. Richness in anthromes and hotspots are spatially aligned across all taxa but not for threatened taxa. Protection was negatively correlated with threatened bird richness. Human modified ecosystems provide opportunities for conservation and global and regional ranking of anthromes helps identify priorities that can complement biome and ecoregion-based prioritization. Currently, much of conservation research and prioritization is in wildlands or perceived natural landscapes, however this data shows a clear need to focus conservation efforts on seminatural, managed, and residential lands. These data would be helpful for global conservation organizations as an updated framework that can be used to prioritize global resource allocation while considering both ecological and social systems.

Changes in agriculture-biodiversity trade-offs in relation to landscape context in the Argentine Chaco

Better balancing agricultural production and biodiversity conservation is a central goal for many landscapes. Yet, empirical work on how to best achieve such a balance has focused mainly on the local scale, thereby disregarding that landscape context might mediate biodiversity-agriculture trade-offs. Focusing on vertebrates in the Argentine Chaco, we evaluate how trade-offs between agriculture and biodiversity vary with landscape context, from landscapes where agricultural and natural areas are separated to landscapes where both are interspersed. We modelled the distributions of 226 vertebrates and use the resulting maps to describe the species richness of ecosystem-service providing guilds. We calculated three agricultural intensity metrics, and evaluated how both species richness and agricultural intensity vary along a gradient of landscape configuration, while controlling for landscape composition. Species richness and agricultural yields both varied with landscape configuration. Biodiversity was highest in mixed landscapes where agricultural and natural area are interspersed, whereas agricultural yields showed a more heterogeneous response, with some yield metrics highest in mixed and others in separated landscapes. As a result, agriculture/biodiversity trade-offs depended strongly on landscape configuration, irrespective of landscape composition. We also identified large areas with low vertebrate richness and agricultural yields, suggesting considerable potential for improving in at least one dimension. Agriculture/biodiversity trade-offs varied with landscape configuration, suggesting that landscape design can balance these trade-offs. Our simple and broadly applicable approach can provide baseline information for landscape planning aimed at realizing co-benefits between agriculture and biodiversity—in the Gran Chaco and elsewhere.

Relationships between the distribution of wildlife and livestock diversity

AbstractAimWild biodiversity and agrobiodiversity are affected by challenges such as agricultural intensification. However, it is unknown whether or not both components of biodiversity respond similarly to environmental factors and to these challenges. Here, we examine the spatial relationships between the distributions of wild biodiversity and agrobiodiversity, to quantify how and where they covary across the geography.LocationMainland Spain, a European region that harbours high values of both wild and agro‐ biodiversity.MethodsWe used geographically weighted regression models to analyse the spatial variation in the relationships between the distribution of wild vertebrates and environmental and agrobiodiversity variables. We modelled the spatial gradients in species richness of native terrestrial vertebrates—that is, specific groups of amphibians, reptiles, birds and mammals—as a function of local livestock breed richness—that is, bovine, ovine, caprine, asinine, equine and porcine—climate variables and human footprint.ResultsWe found significant covariation between the distribution of native vertebrate species richness and climate, human footprint and livestock diversity. Overall, the association between species richness of the four wild terrestrial vertebrate groups and local livestock breed richness is positive across most of the studied area. However, local breed richness of cattle and sheep breed displays contrasting patterns, where cattle breeds associate positively to most wildlife vertebrates and sheep breeds show negative associations.Main conclusionWildlife diversity distributions are significantly associated with livestock agrobiodiversity. These spatial relationships are mediated by large‐scale environmental gradients. Since both, wildlife and livestock agrobiodiversity, tend to co‐occur spatially, future strategies for conservation in agricultural landscapes could benefit from integrated approaches.

Forest canopy height co‐determines taxonomic and functional richness, but not functional dispersion of mammals and birds globally

AbstractAimsTaller forest canopies may harbour higher biodiversity by providing more and varied resources. No previous studies have assessed whether forest canopy height shapes the taxonomic and functional diversity of terrestrial vertebrates at global and regional scales. Here, we examine the roles of forest canopy height and other environmental variables in shaping global and regional patterns of species richness and functional diversity of mammals and birds.LocationGlobal.Time periodPresent day.Major taxa studiedTerrestrial mammals and birds.MethodsGlobal forest canopy height data at 1 km spatial resolution were used to measure forest vertical structure. Species richness, functional richness and functional dispersion of mammals and birds were calculated using range maps and trait data. Spatial simultaneous autoregressive error models were used to evaluate associations between species richness and functional diversity and their predictors, including mean canopy height, standard deviation of canopy height, net primary productivity, current climate and historical climate stability, topography and human activities.ResultsMean canopy height emerged as one of two predictors most associated with species richness of mammals and birds as well as mammal functional richness. However, mean canopy height had little explanatory power for functional dispersion. Mean annual temperature and net primary productivity contributed most to explain global‐scale mammal and bird functional dispersion. At the regional scale, mean canopy height, net primary productivity and mean annual temperature were the variables most associated with the species richness and functional diversity of mammals and birds.Main conclusionsForest canopy height is an important predictor of species richness and functional diversity of terrestrial vertebrates at both global and regional scales, at a similar overall level to productivity and temperature. Our study highlights the crucial role of the complex vertical structure in shaping the global and regional patterns of vertebrate diversity.

Birds and bats contribute to natural regulation of the millet head miner in tree-crop agroforestry systems

A better understanding of environmental factors driving natural pest regulation is a major challenge for designing sustainable cropping systems. The objective of the present study was to assess the association between vegetation openness in traditional tree-crop agroforestry systems in Senegal, richness and abundance of vertebrates including insectivorous birds and bats, and their contribution to the natural regulation of crop pests. The millet head miner (MHM), Heliocheilus albipunctella (Lepidoptera, Noctuidae), a major constraint to increasing millet crop productivity in sub-Saharan Africa, was selected as a model system. Ten sites separated by at least one km from each other were selected in a 100 km2 study area in the Peanut basin in Senegal. In each site, a pair of millet fields distant from at least 100 m each was selected according to a gradient of vegetation openness within a 100-m radius buffer with sampling plot (5 × 5 m) at the center. Nine insectivorous bird and bat species were recorded in millet fields over the 2017 cropping season and their predator status was confirmed by direct observation or DNA detection in fecal samples. Grain losses were reduced when panicles were accessible to birds and bats, confirming their net contribution to pest regulation. At a local scale, tree diversity and vegetation openness were important predictors of the abundance of insectivorous village weaver birds and grey-headed sparrows, respectively. Some tree species (soapberry trees and neems) indirectly contributed to natural regulation of the MHM likely by providing refuges to insectivorous vertebrates whereas other tree species (baobabs) provided disservices as possible refuges for the MHM moths. Further research is needed to better understand relationships between tree cover, food web interactions and natural pest suppression, so that specific conservation measures such as habitat management can be designed to improve pest control.

Spatial-seasonal variability of vertebrate assemblages in a Neotropical tidal flat: Recommendations for monitoring the potential impacts of port expansion

Our study aimed to understand the nekton biodiversity of a Neotropical tidal flat in southeastern Brazil (Araçá Bay) and to support its conservation, due to a potential port expansion, by determining: (1) the structure of the local assemblage of nekton (birds, fishes and turtles); (2) its spatial and seasonal variability; (3) potential processes explaining such variability; and (4) the impacts and monitoring measures related to port expansion. Araçá Bay has a high vertebrate richness (205 species, consisting of at least 126 fishes, 78 birds and one turtle species), two invasive fish species, 11 endangered species, a large abundance of target species in fisheries, and a high functional diversity in terms of life history and feeding habits. Mullets, mojarras, sardines and gobies dominate the fish assemblage, while the avifauna is mainly composed of herons and plovers. Green turtles (juveniles) were registered during high tides in all seasons. The low-tide bird and high-tide fish assemblages are spatially structured varying between the inner and the outer area of the flat. In tide pools, fish fauna varies according to bottom type. Juvenile fish predominate; fish assemblage varied according to recruitment and bird’s varied seasonally due to migration. The unique mosaic of habitats and the high productivity of the bay explain the high nekton diversity and make it a locally critical ecosystem for feeding, breeding, and growth. The port expansion would decrease the habitat diversity and productivity in the bay, negatively affecting nekton populations and their ecosystem services. We propose key aspects for nekton monitoring to mitigate port-related impacts.

Variable preservation potential and richness in the fossil record of vertebrates

AbstractVariation in preservation and sampling probability clouds our estimates of past biodiversity. The most extreme examples are Lagerstätten faunas and floras. Although such deposits provide a wealth of information and represent true richness better than other deposits, they can create misleading diversity peaks because of their species richness. Here, we investigate how Lagerstätten formations add to time series of vertebrate richness in the UK, Germany and China. The first two nations are associated with well‐studied fossil records and the last is a country where palaeontology has a much shorter history; all three nations include noted Lagerstätten in their fossil records. Lagerstätten provide a larger proportion of China's sampled richness than in Germany or the UK, despite comprising a smaller proportion of its fossiliferous deposits. The proportions of taxa that are unique to Lagerstätten vary through time and between countries. Further, in all regions, we find little overlap between the taxa occurring in Lagerstätten and in ‘ordinary’ formations within the same time bin, indicating that Lagerstätten preserve unusual faunas. As expected, fragile taxa make up a greater proportion of richness in Lagerstätten than the remainder of the fossil record. Surprisingly, we find that Lagerstätten account for a minority of peaks in the palaeodiversity curves of all vertebrates (18% in the UK; 36% in Germany and China), and Lagerstätten count is generally not a good overall predictor of the palaeodiversity signal. Vastly different sampling probabilities through taxa, locations and time require serious consideration when analysing palaeodiversity curves.

A comparison of macroecological and stacked species distribution models to predict future global terrestrial vertebrate richness

AbstractAimPredicting future changes in species richness in response to climate change is one of the key challenges in biogeography and conservation ecology. Stacked species distribution models (S‐SDMs) are a commonly used tool to predict current and future species richness. Macroecological models (MEMs), regression models with species richness as response variable, are a less computationally intensive alternative to S‐SDMs. Here, we aim to compare the results of two model types (S‐SDMS and MEMs), for the first time for more than 14,000 species across multiple taxa globally, and to trace the uncertainty in future predictions back to the input data and modelling approach used.LocationGlobal land, excluding Antarctica.TaxonAmphibians, birds and mammals.MethodsWe fitted S‐SDMs and MEMs using a consistent set of bioclimatic variables and model algorithms and conducted species richness predictions under current and future conditions. For the latter, we used four general circulation models (GCMs) under two representative concentration pathways (RCP2.6 and RCP6.0). Predicted species richness was compared between S‐SDMs and MEMs and for current conditions also to extent‐of‐occurrence (EOO) species richness patterns. For future predictions, we quantified the variance in predicted species richness patterns explained by the choice of model type, model algorithm and GCM using hierarchical cluster analysis and variance partitioning.ResultsUnder current conditions, species richness predictions from MEMs and S‐SDMs were strongly correlated with EOO‐based species richness. However, both model types over‐predicted areas with low and under‐predicted areas with high species richness. Outputs from MEMs and S‐SDMs were also highly correlated among each other under current and future conditions. The variance between future predictions was mostly explained by model type.Main conclusionsBoth model types were able to reproduce EOO‐based patterns in global terrestrial vertebrate richness, but produce less collinear predictions of future species richness. Model type by far contributes to most of the variation in the different future species richness predictions, indicating that the two model types should not be used interchangeably. Nevertheless, both model types have their justification, as MEMs can also include species with a restricted range, whereas S‐SDMs are useful for looking at potential species‐specific responses.

A meta‐analysis of recreation effects on vertebrate species richness and abundance

AbstractMost protected areas globally have a dual mission to conserve natural resources and provide access for outdoor recreation or ecotourism, yet questions remain about the ecological effects of recreation. We conducted a global meta‐analysis of the effects of recreation on vertebrate richness and abundance. We estimated that vertebrate richness (n = 15 articles) and abundance (n = 32) are lower in association with higher levels of recreation in over two‐thirds (70%) of cases. We observed a moderate negative group‐level effect of recreation on bird and mammal abundance, but the group‐level effect on fish and reptiles was not significant. Effects were stronger for carnivores and herbivores than for omnivores, and stronger for small‐bodied birds and ground‐nesting birds than larger and tree‐ and shrub‐nesting birds. Terrestrial activities were associated with reduced vertebrate abundance, whereas aquatic activities were not. Both motorized and nonmotorized activities were associated with reduced vertebrate abundance, but the effect for motorized activities was uncertain due to small sample size. These results pose a challenge to natural resource management agencies who must balance recreation access with natural resource protection, and to conservation organizations that rely on outdoor recreation for public support and funding. We recommend that managers plan recreational access at a regional scale and include some areas that are closed to recreation to minimize trade‐offs between recreation and animal conservation.

Female Blow Flies As Vertebrate Resource Indicators

Rapid vertebrate diversity evaluation is invaluable for monitoring changing ecosystems worldwide. Wild blow flies naturally recover DNA and chemical signatures from animal carcasses and feces. We demonstrate the power of blow flies as biodiversity monitors through sampling of flies in three environments with varying human influences: Indianapolis, IN and two national parks (the Great Smoky Mountains and Yellowstone). Dissected fly guts underwent vertebrate DNA sequencing (12S and 16S rRNA genes) and fecal metabolite screening. Integrated Nested Laplace Approximation (INLA) was used to determine the most important abiotic factor influencing fly-derived vertebrate richness. In 720 min total sampling time, 28 vertebrate species were identified, with 42% of flies containing vertebrate resources: 23% DNA, 5% feces, and 14% contained both. The species of blow fly used was not important for vertebrate DNA recovery, however the use of female flies versus male flies directly influenced DNA detection. Temperature was statistically relevant across environments in maximizing vertebrate detection (mean = 0.098, sd = 0.048). This method will empower ecologists to test vertebrate community ecology theories previously out of reach due practical challenges associated with traditional sampling.

Reduced vertebrate diversity independent of spatial scale following feral swine invasions.

Biological invasions often have contrasting consequences with reports of invasions decreasing diversity at small scales and facilitating diversity at large scales. Thus, previous literature has concluded that invasions have a fundamental spatial scale‐dependent relationship with diversity. Whether the scale‐dependent effects apply to vertebrate invaders is questionable because studies consistently report that vertebrate invasions produce different outcomes than plant or invertebrate invasions. Namely, vertebrate invasions generally have a larger effect size on species richness and vertebrate invaders commonly cause extinction, whereas extinctions are rare following invertebrate or plant invasions. In an agroecosystem invaded by a non‐native ungulate (i.e., feral swine, Sus scrofa), we monitored species richness of native vertebrates in forest fragments ranging across four orders of magnitude in area. We tested three predictions of the scale‐dependence hypothesis: (a) Vertebrate species richness would positively increase with area, (b) the species richness y‐intercept would be lower when invaded, and (c) the rate of native species accumulation with area would be steeper when invaded. Indeed, native vertebrate richness increased with area and the species richness was 26% lower than should be expected when the invasive ungulate was present. However, there was no evidence that the relationship was scale dependent. Our data indicate the scale‐dependent effect of biological invasions may not apply to vertebrate invasions.

Biodiversity value of remnant pools in an intermittent stream during the great California drought

Abstract In many intermittent streams, remnant pools persist after flow ceases and provide refuge for aquatic organisms able to tolerate stagnant water conditions. The conservation value of these pools may be greatly under‐appreciated, especially in regions with a Mediterranean climate, where perennial streams have been substantially modified or disturbed by human activities. Fish, amphibians, aquatic reptiles, and aquatic invertebrates were sampled from 15 remnant pools and three seeps at Coyote Creek, California, USA, in the late summer of 2014, during the height of the most intense drought that California has experienced in 500 years. Patterns of vertebrate and invertebrate species richness and community composition were compared with abiotic factors (e.g. water quality and habitat size). Thirteen vertebrate species and 172 invertebrate taxa were identified from remnant pools and seeps. Overall vertebrate richness and composition were not correlated with abiotic factors, but fish species richness increased with remnant pool size and depth. Invertebrate taxon richness increased with pool size. Invertebrate community composition differed by habitat type (pool versus seep) and gradients in composition were correlated with several abiotic factors (e.g. pool size, substrate, and canopy cover). Remnant pools at Coyote Creek supported a full assemblage of native fishes and numerous imperilled taxa, including California red‐legged frogs and California floater mussels. Nearly all native fishes and imperilled taxa are absent from artificially perennial and urbanized reaches of Coyote Creek just a few kilometres downstream of the study area. Remnant pools in intermittent streams should be a focus of conservation efforts in regions with a Mediterranean climate, especially during extreme droughts. Native fauna adapted to harsh intermittent flow regimes can thrive in these habitats, whereas non‐native taxa may fare poorly. Furthermore, remnant pools supported by deep groundwater sources, such as those along geological faults, may provide both ecological refuge and evolutionary refugia for freshwater biota.

Paleoclimate, ecoregion size, and degree of isolation explain regional biodiversity differences among terrestrial vertebrates within the Congo Basin

One of the most widely recognized patterns in ecology is the increase in species richness from poles to tropics. Literature suggests that the Congolian lowland rainforest does not follow this pattern: the Central Congolian forest (CCLF), south of the Congo River, is thought to harbor fewer vertebrate species and endemics than the Northeastern (NELF) and Northwestern lowland rainforests (NWLF) north of the Congo River. We used data from the Global Biodiversity Information Facility (GBIF) database on terrestrial vertebrates (mammals, birds, and reptiles), to test whether differences in sampling effort caused the irregular biodiversity pattern in this region. Our results show that even though the diversity within the Congolian lowland rainforests remains to be fully mapped, current differences in richness are unlikely to be caused by undersampling alone. We argue that the lower vertebrate richness in the CCLF is due to both its relatively small size and isolated position: Forest cover fluctuated throughout the history of the Congo Basin due to climatic variability, reducing speciation and increasing extinction, while immigration towards the CCLF is limited due to the barrier effect of the Congo River. The implications of these findings are discussed in the context of both fundamental ecology and conservation management.

Impacts of future climate change on species richness of land vertebrates and critical areas in South Korea

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 77:241-248 (2019) - DOI: https://doi.org/10.3354/cr01556 Impacts of future climate change on species richness of land vertebrates and critical areas in South Korea Ju-Hyun Lee1, Hee-Jin Kang1, Ha-Cheol Sung2,* 1School of Biological Sciences and Biotechnology, and 2Research Center of Ecomimetics and Department of Biological Sciences, Chonnam National University, 61186 Gwangju, South Korea *Corresponding author: shcol2002@jnu.ac.kr ABSTRACT: Climate change has extensive impacts on abundance, distribution, and conservation of species and ecosystems. The purpose of this study was to investigate impacts of future climate change on the species richness of land vertebrates, and to assess critical areas that might be continuously threatened by climate change in order to maintain high species richness in South Korea. The Climate Change Severity Index (CCSI) was calculated based on representative concentration pathway (RCP) scenarios to determine the climatic space (also known as comfort zone) of species and ecosystems under historic and future climate conditions. Regions with high species richness were then identified using survey results of species abundance and distribution. Finally, we identified critical areas with high CCSI values and high levels of species richness. These are areas where species and ecosystems are threatened the most by climate change. The number of critical areas is predicted to increase towards the late 2000s, and this increase is greater under RCP 8.5 than under RCP 4.5. Furthermore, the number of critical areas will increase more in coastal and wide plain areas than in inland mountainous areas. This study provides information useful for the conservation of species and their habitats in South Korea. It also indicates opportunities for launching protection measures and actions in highly vulnerable areas. KEY WORDS: Climate Change Severity Index · Species richness · Critical area · RCP scenarios Full text in pdf format PreviousNextCite this article as: Lee JH, Kang HJ, Sung HC (2019) Impacts of future climate change on species richness of land vertebrates and critical areas in South Korea. Clim Res 77:241-248. https://doi.org/10.3354/cr01556 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 77, No. 3. Online publication date: April 11, 2019 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2019 Inter-Research.

Where and at which scales does the latitudinal diversity gradient fail?

AbstractAimThis study analyses the places and the scales at which the latitudinal diversity gradient (LDG) for vertebrate species holds or, conversely, fails. Although much empirical support for the LDG at a global scale exists, several marked departures have also been previously reported for some regions, scales and organisms. Here, we aim to test the generality of the LDG by accurately quantifying its variability among regions and scales using a novel analysing approach applied on environmental and species data.LocationGlobal; Vertebrate species (amphibians, mammals and birds).MethodsTo test the LDG, we proceeded in two successive steps. First, we collected environmental and vertebrate species data to summarize the overall environment (likely the LDG). In a second step, we compared the two datasets (environment and species biodiversity index maps) using the Comparison Map and Profile (CMP) method. It computes the correlation between datasets in moving windows, all over both maps (at one scale), and by increasing the size (scale) of the moving windows. Cross‐correlations are then spatially computed through all scales in order to map and accurately quantify the relationship between environment and biodiversity on Earth.ResultsThe best environmental variable, explaining almost 70% of the spatial variation in vertebrate species richness, was the temperature seasonality composite (TSC), a good surrogate candidate for the LDG. While the TSC–diversity relationship followed an expected LDG‐like pattern in the Southern Hemisphere and in the tropics, it showed significant departures from latitudinal trends in Asia and North America. This observation can be explained by the increase in animal species number with increasing northern latitudes.Main conclusionsWe showed that the LDG (i.e. through the TSC surrogate) relationship fails in many places and at all scales in average. We must then reject the mainstream hypothesis of the overall worldwide LDG pattern. We suggest that it should not be taken for granted in macroecological studies, especially over the Northern Hemisphere. The spatial distribution of vertebrate richness is both area and scale dependent, and this observation is robust to changes in spatial resolution, in data coverage (e.g. ecoregions) and in taxa.

Multi-species occupancy modelling of mammal and ground bird communities in rangeland in the Karoo: A case for dryland systems globally

The transition from natural habitat to agricultural land use is widely regarded as one of the leading drivers of biodiversity loss. Despite this, most wildlife still lives outside protected areas on private agricultural land, particularly on rangeland used for livestock grazing. Understanding which species persist and which decline in agricultural landscapes is important for global biodiversity monitoring, management and conservation. In this study, we used hierarchical multi-species occupancy modelling to estimate terrestrial vertebrate (body mass > 0.5 kg) richness in the Karoo, a semi-arid region of South Africa. We evaluated species-specific responses to different anthropogenic and environmental variables in rangeland and a nearby protected area of similar size. We grouped mammal species according to trophic guild and body size and compared their occurrence between areas. In total we detected 42 species over 4035 6-day pooled trap nights across 322 sites. Community species richness was not significantly different between the two types of land use and decreased with increasing elevation in the protected area. Human disturbance did not affect individual species occupancy in either area. Carnivores, omnivores and medium-sized species occupancy probabilities were similar between the two areas but were higher for herbivores and large species in the protected area and for insectivores and small species in rangeland. Our results reveal that drylands in the South African Karoo region, including rangeland used for small-livestock farming, support a diverse community of terrestrial vertebrates. Private landowners are thus important custodians of key components of indigenous biodiversity outside of protected areas, especially in low-lying areas.

Richness and abundance of granivorous vertebrates determine acorn removal patterns in a human modified oak forest

Abstract: Most forests of the Earth have been affected by human activities and this can alter the plant-animal interactions on which depend the functional integrity of these ecosystems. In this study, we assessed the relationships between acorn removal rates and the richness and abundance of granivorous vertebrates along a forest-edge-clearing gradient. We also evaluated whether removal rates differed among oak species with different acorn size. To this purpose, a field experiment was performed including acorns of five oak species, which were exposed to seed consumers in the three different habitats (forest interior, man-made clearings and the edge between these habitats). The experimental units consisted in five paper trays containing 50 acorns of each oak species located at different distances from the edge towards the forest and the man-made clearing (0, 20 and 50 m). Experimental sites were equipped with phototraps to record the identity of the visiting granivorous vertebrates. Richness and abundance of granivores increased from the edge towards the forest interior, while the converse patterns were observed in the man-made clearing. For most oak species, acorn removal patterns was positively correlated with richness and abundances of granivores, though in all habitats small-sized acorns were removed much faster and in larger proportions than big-sized acorns. Although these results are specific for the study site, they suggest that man-made clearings reduce the richness and abundance of granivores, thus negatively affecting the secondary dispersion of zoochoric tree species towards open habitats. Further, it also seems that large-seeded oak species face greater dispersal limitations than small-seeded oaks, because of the lack of animals able to scatter them from the forest to the clearings.

Patterns of diversity along a habitat size gradient in a biodiversity hotspot

AbstractHabitat destruction and loss are the gravest threats to wildlife worldwide. We examined the correlation between habitat patch size and species richness and abundance of mammals and reptiles in a biodiversity hotspot in California. Within nine forest fragments standardized for age, topography, climate, and vegetation cover, we tested the effects of patch size and isolation on biodiversity. To measure species richness and abundance, we used wildlife cameras for meso‐and‐large vertebrates, mark‐and‐recapture analyses for small mammals, mark‐and‐resight analysis for reptiles, and standard dragging techniques for tick collections because they are frequent ectoparasites on vertebrates in oak woodland habitats. Our results show that meso‐and‐large vertebrate richness and abundance increase with patch area as does tick density. Surprisingly, small mammal species richness and abundance peak in intermediate‐sized fragments. Resource limitation and competition at the smallest habitats and predation at the largest patches may be responsible for this pattern. Further, there is a significant decrease in invasive species richness with habitat patch size. We found that habitat destruction and fragmentation are acting upon species and communities in context‐dependent ways that is critical to conservation planning, land use design, and ecosystem function.