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Trade‐offs between economic development and biodiversity conservation on a tropical island
Abstract
Resolving trade-offs between economic development and biodiversity conservation needs is crucial in currently developing countries and in particularly sensitive systems harboring high biodiversity. Yet, such a task is challenging because human activities have complex effects on biodiversity. We assessed the effects of intense economic development on Hainan Island (southern China) on different components of biodiversity. This highly biodiverse tropical island has undergone extensive economic development and conversion of forest to agriculture and urban area. We identified 3 main transformation areas (low, medium, and high transformation) based on land-use, local-climate, and economic changes across 145 grids (10 × 10 km), and estimated changes in avian biodive6rsity from 1998 to 2013. We recorded ongoing taxonomic biotic homogenization throughout the island. Differences between traditional and directional alpha diversity decreased by 5%. Phylogenetically clustering increased by 0.5 points (W = 7928, p < 0.01), and functional overdispersion increased by 1 point (W = 16,411, p < 0.01). Initial taxonomic, phylogenetic, and functional scores correlated negatively with changes in these scores across all transformation areas (all ps < 0.01). At the local scale, economic and environmental indicators showed complex and divergent effects across transformation areas and biodiversity components. These effects were only partially ameliorated in an ecological function conservation area in the mountainous central part of the island. We found complex effects of economic development on different biodiversity dimensions in different areas with different land uses and protection regimes and between local and regional spatial scales. Profound ecosystem damage associated with economic development was partially averted, probably due to enhanced biodiversity conservation policies and law enforcement, but not without regional-scale biotic homogenization and local-scale biodiversity loss.
... Finally, it should be noted that although harboring lower species richness, sites within buffer area of the natural reserve still had higher phylogenetic heterogeneity than sites outside the natural reserve. A recent study on a tropical island suggests that economic development and changes in land use may cause increased phylogenetic clustering (Pganani-Nunez et al., 2022). Our results support this idea, as sites with less economic development (i.e., sites within the natural reserve) were associated with less phylogenetic clustering. ...
Understanding the roles of ecological drivers in shaping biodiversity is fundamental for conservation practice. In this study, we explored the effects of elevation, conservation status, primary productivity, habitat diversity and anthropogenic disturbance (represented by human population density and birding history) on taxonomic, phy-logenetic and functional avian diversity in a subtropical landscape in southeastern China. We conducted bird surveys using 1-km transects across a total of 30 sites, of which 10 sites were located within a natural reserve. Metrics of functional diversity were calculated based on six functional traits (body mass, clutch size, dispersal ratio, sociality, diet and foraging stratum). We built simultaneous autoregression models to assess the association between the ecological factors and diversity of the local avian communities. Local avian diversity generally increased with increasing habitat diversity, human population density and primary productivity. We also detected phy-logenetic and functional clustering in these communities, suggesting that the avian assemblages were structured mainly by environmental filtering, rather than interspe-cific competition. Compared with sites outside the natural reserve, sites within the natural reserve had relatively lower avian diversity but a higher level of phylogenetic heterogeneity. K E Y W O R D S anthropogenic disturbance, birdwatching, functional diversity, habitat diversity, phylogenetic diversity, species richness
Biodiversity science in China has seen rapid growth over recent decades, ranging from baseline biodiversity studies to understanding the processes behind evolution across dynamic regions such as the Qinghai-Tibetan Plateau. We review research, including species catalogues; biodiversity monitoring; the origins, distributions, maintenance and threats to biodiversity; biodiversity-related ecosystem function and services; and species and ecosystems' responses to global change. Next, we identify priority topics and offer suggestions and priorities for future biodiversity research in China. These priorities include (i) the ecology and biogeography of the Qinghai-Tibetan Plateau and surrounding mountains, and that of subtropical and tropical forests across China; (ii) marine and inland aquatic biodiversity; and (iii) effective conservation and management to identify and maintain synergies between biodiversity and socio-economic development to fulfil China's vision for becoming an ecological civilization. In addition, we propose three future strategies: (i) translate advanced biodiversity science into practice for biodiversity conservation; (ii) strengthen capacity building and application of advanced technologies, including high-throughput sequencing, genomics and remote sensing; and (iii) strengthen and expand international collaborations. Based on the recent rapid progress of biodiversity research, China is well positioned to become a global leader in biodiversity research in the near future.
Significance
The current biodiversity crisis is often depicted as a struggle to preserve untouched habitats. Here, we combine global maps of human populations and land use over the past 12,000 y with current biodiversity data to show that nearly three quarters of terrestrial nature has long been shaped by diverse histories of human habitation and use by Indigenous and traditional peoples. With rare exceptions, current biodiversity losses are caused not by human conversion or degradation of untouched ecosystems, but rather by the appropriation, colonization, and intensification of use in lands inhabited and used by prior societies. Global land use history confirms that empowering the environmental stewardship of Indigenous peoples and local communities will be critical to conserving biodiversity across the planet.
This study presents a novel landscape classification map of the Republic of Ireland and is the first to identify broad landscape classes by incorporating physiographic and land cover data. The landscape classification responds to commitments to identify and classify the Irish landscape as a signatory to the European Landscape Convention. The methodology applied a series of clustering iterations to determine an objective multivariate classification of physiographic landscape units and land cover datasets. The classification results determined nine statistically significant landscape classes and the development of a landscape classification map at a national scale. A statistical breakdown of land cover area and diversity of each class was interpreted, and a comparison was extended using independent descriptive variables including farmland use intensity, elevation, and dominant soil type. Each class depicts unique spatial and composition characteristics, from coastal, lowland and elevated, to distinct and dominating land cover types, further explained by the descriptive variables. The significance of individual classes and success of the classification is discussed with particular reference to the wider applicability of the map. The transferability of the methodology to other existing physiographic maps and environmental datasets to generate new landscape classifications is also considered. This novel work facilitates the development of a strategic framework to efficiently monitor, compare and analyse ecological and other land use data that is spatially representative of the distribution and extent of land cover in the Irish countryside.
Biodiversity science in China has seen rapid growth over recent decades, ranging from baseline biodiversity studies to understanding the processes behind evolution across dynamic regions such as the Qinghai-Tibetan Plateau. We review research, including species catalogues, biodiversity monitoring, the origins, distributions, maintenance, and threats to biodiversity, biodiversity-related ecosystem function and services, and species and ecosystems' responses to global change. Next, we identify priority topics, offer suggestions and priorities for future biodiversity research in China. These priorities include 1) the ecology and biogeography of the Qinghai-Tibetan Plateau and surrounding mountains, and that of subtropical and tropical forests across China; 2) marine and inland aquatic biodiversity, and 3) effective conservation and management to identify and maintain synergies between biodiversity and socioeconomic development to fulfil China's vision for becoming an ecological civilization. In addition, we propose three future strategies: 1) translate advanced biodiversity science into practice for biodiversity conservation; 2) strengthen capacity building and application of advanced technology, including high-throughput sequencing, genomics, and remote sensing; 3) strengthen and expand international collaborations. Based on the recent rapid progress of biodiversity research, China is well-positioned to become a global leader in biodiversity research in the near future.
Urbanization is one of the most intensive forms of landscape and habitat transformation, resulting in species loss, and taxonomic and functional homogenization of different communities. Whilst green infrastructure (the network of natural and semi-natural areas in cities) has been studied extensively in terms of specific features that promote biodiversity, there have been no studies that have assessed how species richness in different types of green space (GS) varies with increasing levels of urbanization in the surrounding matrix. We studied the effects of different types of GS and urbanization in the surrounding matrix on bird communities in the mid-sized city of Göttingen, Germany. We used the point-count method for bird observations in allotments and parks. To determine the level of urbanization, we calculated percentage of impervious surfaces around GSs. Increasing levels of urbanization around GSs had no effect on the species richness, functional traits or the community composition of birds. Nevertheless, we found that species richness and functional traits varied according to GS type. Parks had a greater species richness and were found to have more ground nesting and tropical migrant birds compared to allotments. We found more cavity nesting and resident birds in allotments. As different types of GS can contribute to the presence of different species and functional trait variations, their positive effect on bird species richness can be enhanced when they are present together in urban landscapes. Our findings suggest that green spaces with a high variety of local characteristics should be incorporated into urban planning designs in order to ensure diverse bird communities in cities.
Although habitat loss is the predominant factor leading to biodiversity loss in the Anthropocene1,2, exactly how this loss manifests—and at which scales—remains a central debate3,4,5,6. The ‘passive sampling’ hypothesis suggests that species are lost in proportion to their abundance and distribution in the natural habitat7,8, whereas the ‘ecosystem decay’ hypothesis suggests that ecological processes change in smaller and more-isolated habitats such that more species are lost than would have been expected simply through loss of habitat alone9,10. Generalizable tests of these hypotheses have been limited by heterogeneous sampling designs and a narrow focus on estimates of species richness that are strongly dependent on scale. Here we analyse 123 studies of assemblage-level abundances of focal taxa taken from multiple habitat fragments of varying size to evaluate the influence of passive sampling and ecosystem decay on biodiversity loss. We found overall support for the ecosystem decay hypothesis. Across all studies, ecosystems and taxa, biodiversity estimates from smaller habitat fragments—when controlled for sampling effort—contain fewer individuals, fewer species and less-even communities than expected from a sample of larger fragments. However, the diversity loss due to ecosystem decay in some studies (for example, those in which habitat loss took place more than 100 years ago) was less than expected from the overall pattern, as a result of compositional turnover by species that were not originally present in the intact habitats. We conclude that the incorporation of non-passive effects of habitat loss on biodiversity change will improve biodiversity scenarios under future land use, and planning for habitat protection and restoration.
Generalist species — with their wide niche breadths — are often associated with urban environments, while specialist species are likely to be most at‐risk of increasing urbanization processes. But studies which quantify the relationship between trait specialization (i.e., niche breadth) and urban tolerance are generally methodologically limited, with repeatable robust methods to easily quantify this relationship among different regions and time scales often lacking. Our objective was to use novel methods to quantify the relationship between trait specialization and urban tolerance over a broad spatial scale. We used ~ 2 million citizen science observations and spatially intersected these with remotely‐sensed VIIRS night‐time light values and a novel continuous measure of a species’ trait specialization for 256 European bird species. We found a negative relationship between avian urban tolerance and an overall specialization index. Nesting site niche breadth was especially negatively associated with higher urban tolerance scores. Our results highlight that species with a high degree of trait specialization likely have a lower capacity to persist in urban ecosystems, and hence, could be most at‐risk in novel urban ecosystems. We suggest that trait specialization can be used as a proxy for the degree of risk posed by urban environments to a given species.
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Significance
The ongoing sixth mass extinction may be the most serious environmental threat to the persistence of civilization, because it is irreversible. Thousands of populations of critically endangered vertebrate animal species have been lost in a century, indicating that the sixth mass extinction is human caused and accelerating. The acceleration of the extinction crisis is certain because of the still fast growth in human numbers and consumption rates. In addition, species are links in ecosystems, and, as they fall out, the species they interact with are likely to go also. In the regions where disappearing species are concentrated, regional biodiversity collapses are likely occurring. Our results reemphasize the extreme urgency of taking massive global actions to save humanity’s crucial life-support systems.
The restoration of ecosystems provides an important opportunity to improve the provision of ecosystem services. Achieving the maximum possible benefits from restoration with a limited budget requires knowing which places if restored would produce the best combination of improved ecosystem services. Using an ecosystem services assessment and optimization algorithm, we find choices that generate maximum benefits from ecosystem restoration. We applied a set of weights to integrate multiple services into a unified approach and find the optimal land restoration option given those weights. We then systematically vary the weights to find a Pareto frontier that shows potentially optimal choices and illustrates trade-offs among services. We applied this process to evaluate optimal restoration on Hainan Island, China, a tropical island characterized by multiple ecosystem service hotspots and conditions of poverty. We analyzed restoration opportunities with the goal of increasing a provisioning service, plantation revenue, and several water-related ecosystem services that contribute to improved water quality and flood mitigation. We found obvious spatial inconsistencies in the optimal location for maximizing separate services and tradeoffs in the provision of these services. Optimized land-use patterns greatly out-performed the non-target restoration scheme. When explicit consideration of the importance of poverty alleviation was taken into account, the location of the prioritized areas shifted and trade-offs among services varied. Our study emphasizes the importance of integrating social concerns into land-use planning to mitigate conflicts and improve equity, especially in the areas where poverty and hotspots of biodiversity and ecosystem services are highly geographically coincident.
Increasing evidence—synthesized in this paper—shows that economic growth contributes to biodiversity loss via greater resource consumption and higher emissions. Nonetheless, a review of international biodiversity and sustainability policies shows that the majority advocate economic growth. Since improvements in resource use efficiency have so far not allowed for absolute global reductions in resource use and pollution, we question the support for economic growth in these policies, where inadequate attention is paid to the question of how growth can be decoupled from biodiversity loss. Drawing on the literature about alternatives to economic growth, we explore this contradiction and suggest ways forward to halt global biodiversity decline. These include policy proposals to move beyond the growth paradigm while enhancing overall prosperity, which can be implemented by combining top‐down and bottom‐up governance across scales. Finally, we call the attention of researchers and policy makers to two immediate steps: acknowledge the conflict between economic growth and biodiversity conservation in future policies; and explore socioeconomic trajectories beyond economic growth in the next generation of biodiversity scenarios.
Urbanisation is driving rapid declines in species richness and abundance worldwide, but the general implications for ecosystem function and services remain poorly understood. Here, we integrate global data on bird communities with comprehensive information on traits associated with ecological processes to show that assemblages in highly urbanised environments have substantially different functional composition and 20% less functional diversity on average than surrounding natural habitats. These changes occur without significant decreases in functional dissimilarity between species; instead, they are caused by a decrease in species richness and abundance evenness, leading to declines in functional redundancy. The reconfiguration and decline of native functional diversity in cities are not compensated by the presence of exotic species but are less severe under moderate levels of urbanisation. Thus, urbanisation has substantial negative impacts on functional diversity, potentially resulting in impaired provision of ecosystem services, but these impacts can be reduced by less intensive urbanisation practices.
Salvage logging following natural disturbances may alter the natural successional trajectories of biological communities by affecting the occurrences of species, functional groups and evolutionary lineages. However, few studies have examined whether dissimilarities between bird communities of salvaged and unsalvaged forests are more pronounced for rare species, functional groups, and evolutionary lineages than for their more common counterparts. We compiled data on breeding bird assemblages from nine study areas in North America, Europe and Asia, covering a 17‐year period following wildfire or windstorm disturbances and subsequent salvage logging. We tested whether dissimilarities based on non‐shared species, functional groups and evolutionary lineages 1) decreased or increased over time and 2) the responses of rare, common and dominant species varied, by using a unified statistical framework based on Hill numbers and null models. We found that dissimilarities between bird communities caused by salvage logging persisted over time for rare, common and dominant species, evolutionary lineages, and for rare functional groups. Dissimilarities of common and dominant functional groups increased fourteen years post‐disturbance. Salvage logging led to significantly larger dissimilarities than expected by chance. Functional dissimilarities between salvaged and unsalvaged sites were lower compared to taxonomic and phylogenetic dissimilarities. In general, dissimilarities were highest for rare, followed by common and dominant species. Synthesis and applications. Our research demonstrates that salvage logging did not decrease dissimilarities of bird communities over time and taxonomic, functional, and phylogenetic dissimilarities persisted for over a decade. We recommend resource managers and decision makers to reserve portions of disturbed forest to enable unmanaged post‐disturbance succession of bird communities, particularly to conserve rare species found in unsalvaged disturbed forests.
The time is now
For decades, scientists have been raising calls for societal changes that will reduce our impacts on nature. Though much conservation has occurred, our natural environment continues to decline under the weight of our consumption. Humanity depends directly on the output of nature; thus, this decline will affect us, just as it does the other species with which we share this world. Díaz et al. review the findings of the largest assessment of the state of nature conducted as of yet. They report that the state of nature, and the state of the equitable distribution of nature's support, is in serious decline. Only immediate transformation of global business-as-usual economies and operations will sustain nature as we know it, and us, into the future.
Science , this issue p. eaax3100
1. It is now commonplace in community ecology to assess patterns of phylogenetic or functional diversity in order to inform our understanding of the assembly mechanisms that structure communities. While both phylogenetic and functional approaches have been used in conceptually similar ways, it is not clear if they both in fact reveal similar community diversity patterns or support similar inferences. We review studies that use both measures to determine the degree to which they support congruent patterns and inferences about communities. 2. We performed a literature review with 188 analyses from 79 published papers that compared some facet of phylogenetic (PD) and functional diversity (FD) in community ecology. These studies generally report four main cases in which phy-logenetic and functional information are used together in community analyses, to determine if: (a) there were phylogenetic signals in the measured traits in communities ; (b) PD and FD were correlated with one another; (c) standardized PD and FD measures similarly revealed patterns of community over-or under-dispersion; and (d) PD and FD were both related to other explanatory variables (e.g. elevation) similarly. 3. We found that the vast majority of studies found both strong phylogenetic signals in their traits and positive correlations of PD and FD measures across sites. However, and surprisingly, we found substantial incongruencies for the other tests. Phylogenetic and functional dispersion patterns were congruent only about half the time. Specifically, when communities were phylogenetically over-dispersed , these same communities were more likely to be functionally under-dispersed. Similarly, we found that phylogenetic and functional relationships with independent predictors were incongruent in about half of the analyses. 4. Synthesis. Phylogenetic signal tests and PD-FD correlations appear to strongly support the congruence between traits and phylogeny. It is surprising that strong phylogenetic signals appeared so ubiquitous given that ecological studies often analyse phylogenetically incomplete sets of species that have undergone ecological sorting. Despite the largely congruent findings based on phylogenetic signal tests and PD-FD correlations, we found substantial incongruencies when researchers assessed either dispersion patterns or relationships with independent predictors. We discuss a number of potential ecological, evolutionary and
Rural landscape change as a consequence of human population growth is a major challenge for nature conservation in the twenty-first century. Rural regions are globally experiencing change driven by diverse factors, including agricultural intensification, new agricultural commodities, residential development, and land abandonment. Understanding how different land-use trajectories affect biodiversity is critical for making informed decisions for the conservation of species in modified environments. We examined the impact of different land-uses on bird communities in the western Strzelecki Ranges, a formerly forested but now rural region in south-east Australia. We selected 25 study landscapes, each 1 km², representing seven land-uses typical of rural regions: townships, lifestyle properties (low-density acreages or hobby farms), dairy farming, beef grazing, horticulture, tree plantation and natural forest. Terrestrial birds were systematically surveyed at 10 sites in each study landscape and the results pooled to represent the whole landscape. We recorded 80 native and 8 exotic species of birds, of which 46 species were classified a priori as forest species typical of the region. Different trajectories of land-use have generated variation in landscape structure, with a primary gradient of change from forest to rural townships. The composition of bird communities and the richness of four species-response groups showed marked differences across land-use types. The mean richness of forest species, for example, was greatest in natural forest land-use (30.0 species) and lowest in dairy farming land-use (14.5 species). Key lessons from this study include: (1) these diverse land-uses, typical of rural regions, are creating novel assemblages of birds that differ from that of the former forested environment; (2) land-use in this region is dynamic and so further re-assortment of bird communities can be expected through time; (3) despite such change, a component of the original forest avifauna persists, even in highly modified landscapes; and (4) each land-use type offers opportunities for nature conservation while also meeting the needs of people and agricultural production.
Significance
Achieving inclusive, green development is crucial to China and the world. Over the past century, great increases in agricultural production have been achieved at the expense of other ecosystem benefits, such as flood control, water purification, climate stabilization, and biodiversity conservation. We report on an application of China’s new “Ecological Development Strategy,” which aims to break these trade-offs and be scaled nationwide. Focusing on Hainan Island, where rubber production has driven loss of natural forest, we identified a two-pronged strategy that would eliminate these trade-offs, simultaneously diversifying and enhancing product provision, rural incomes, and many other ecosystem benefits. This win−win approach has broad applicability in the plantation regions in China, across South and Southeast Asia, and beyond.
Human‐mediated habitat transformation is increasingly evident around the world. Yet, how this transformation influences species’ niche width and overlap remains unclear. On the one hand, human‐mediated habitat transformation promotes increased species similarity through trait‐based filtering, and an increased prevalence of generalist species with broad niches, resulting in functional homogenization. On the other hand, species that colonize transformed habitats could use empty niches, resulting in decreased species similarity and an expansion of assemblage‐level niche space. Here we explore these two alternatives in eight highly diverse passerine assembles in natural, rural and urban habitats in South and Southwest China, a rapidly developing region of the world. Based on stable isotopes, we found that species’ niche width increased from natural to human‐made habitats, but there were no differences in niche overlap among habitats. Therefore, we found evidence for niche expansion, with generalists appearing to use empty niches created by human habitat modification, and with assemblages being comprised of complementary species. Further research is needed to determine whether increased between‐ or within‐individual niche variation is the main driver of niche expansion in transformed habitats.
Estimates of recent biodiversity change remain inconsistent, debated, and infrequently assessed for their functional implications. Here, we report that spatial scale and type of biodiversity measurement influence evidence of temporal biodiversity change. We show a pervasive scale dependence of temporal trends in taxonomic (TD) and functional (FD) diversity for an ~50-year record of avian assemblages from North American Breeding Bird Survey and a record of global extinctions. Average TD and FD increased at all but the global scale. Change in TD exceeded change in FD toward large scales, signaling functional resilience. Assemblage temporal dissimilarity and turnover (replacement of species or functions) declined, while nestedness (tendency of assemblages to be subsets of one another) increased with scale. Patterns of FD change varied strongly among diet and foraging guilds. We suggest that monitoring, policy, and conservation require a scale-explicit framework to account for the pervasive effect that scale has on perceived biodiversity change.
The concept of a pace-of-life syndrome describes inter- and intra-specific variation in several life-history traits along a slow-to-fast pace-of-life continuum, with long lifespans, low reproductive and metabolic rates, and elevated somatic defences at the slow end of the continuum and the opposite traits at the fast end. Pace-of-life can vary in relation to local environmental conditions (e.g. latitude, altitude), and here we propose that this variation may also occur along an anthropogenically modified environmental gradient. Based on a body of literature supporting the idea that city birds have longer lifespans, we predict that urban birds have a slower pace-of-life compared to rural birds and thus invest more in self maintenance and less in annual reproduction. Our statistical meta-analysis of two key traits related to pace-of-life, survival and breeding investment (clutch size), indicated that urban birds generally have higher survival, but smaller clutch sizes. The latter finding (smaller clutches in urban habitats) seemed to be mainly a characteristic of smaller passerines. We also reviewed urbanization studies on other traits that can be associated with pace-of-life and are related to either reproductive investment or self-maintenance. Though sample sizes were generally too small to conduct formal meta-analyses, published literature suggests that urban birds tend to produce lower-quality sexual signals and invest more in offspring care. The latter finding is in agreement with the adult survival hypothesis, proposing that higher adult survival prospects favour investment in fewer offspring per year. According to our hypothesis, differences in age structure should arise between urban and rural populations, providing a novel alternative explanation for physiological differences and earlier breeding. We encourage more research investigating how telomere dynamics, immune defences, antioxidants, and oxidative damage in different tissues vary along the urbanization gradient, and suggest that applying pace-of-life framework to studies of variation in physiological traits along the urbanization gradient might be the next direction to improve our understanding of urbanization as an evolutionary process.
The study of the past, present, and future state and dynamics of the tropical natural forest cover (NFC) might help to better understand the pattern of deforestation and fragmentation as well as the influence of social and natural processes. The obtained information will support the development of effective conservation policies and strategies. In the present study, we used historical data of the road network, topography, and climatic productivity to reconstruct NFC maps of Hainan Island, China, from the 1950s to the 2010s, using the random forest algorithm. We investigated the spatial and temporal patterns of NFC change from the 1950s to the 2010s and found that it was highly dynamic in both space and time. Our data showed that grid cells with low NFC were more vulnerable to NFC decrease, suggesting that conservation actions regarding natural forests need to focus on regions with low NFC and high ecological value. We also identified the hot spots of NFC change, which provides insights into the dynamic changes of natural forests over time.
The order and timing of species immigration during community assembly can affect species abundances at multiple spatial scales. Known as priority effects, these effects cause historical contingency in the structure and function of communities, resulting in alternative stable states, alternative transient states, or compositional cycles. The mechanisms of priority effects fall into two categories, niche preemption and niche modification, and the conditions for historical contingency by priority effects can be organized into two groups, those regarding regional species pool properties and those regarding local population dynamics. Specifically, two requirements must be satisfied for historical contingency to occur: The regional pool contains species that can together cause priority effects, and local dynamics are rapid enough for early-arriving species to preempt or modify niches before other species arrive. Organizing current knowledge this way reveals an outstanding key question: How are regional species pools that yield priority effects generated and maintained?
The role human activities play in reshaping biodiversity is increasingly apparent in terrestrial ecosystems. However, the responses of entire marine assemblages are not well-understood, in part, because few monitoring programs incorporate both spatial and temporal replication. Here, we analyse an exceptionally comprehensive 29-year time series of North Atlantic groundfish assemblages monitored over 5° latitude to the west of Scotland. These fish assemblages show no systematic change in species richness through time, but steady change in species composition, leading to an increase in spatial homogenization: the species identity of colder northern localities increasingly resembles that of warmer southern localities. This biotic homogenization mirrors the spatial pattern of unevenly rising ocean temperatures over the same time period suggesting that climate change is primarily responsible for the spatial homogenization we observe. In this and other ecosystems, apparent constancy in species richness may mask major changes in species composition driven by anthropogenic change.
We conducted an analysis of global forest cover to reveal that 70% of remaining forest is within 1 km of the forest’s edge, subject to the degrading effects of fragmentation. A synthesis of fragmentation experiments spanning multiple biomes and scales, five continents, and 35 years demonstrates that habitat fragmentation reduces biodiversity by 13 to 75% and impairs key ecosystem functions by decreasing biomass and altering nutrient cycles. Effects are greatest in the smallest and most isolated fragments, and they magnify with the passage of time. These findings indicate an urgent need for conservation and restoration measures to improve landscape connectivity, which will reduce extinction rates and help maintain ecosystem services.
Human activities, especially conversion and degradation of habitats, are causing global biodiversity declines. How local ecological assemblages are responding is less clear[mdash]a concern given their importance for many ecosystem functions and services. We analysed a terrestrial assemblage database of unprecedented geographic and taxonomic coverage to quantify local biodiversity responses to land use and related changes. Here we show that in the worst-affected habitats, these pressures reduce within-sample species richness by an average of 76.5%, total abundance by 39.5% and rarefaction-based richness by 40.3%. We estimate that, globally, these pressures have already slightly reduced average within-sample richness (by 13.6%), total abundance (10.7%) and rarefaction-based richness (8.1%), with changes showing marked spatial variation. Rapid further losses are predicted under a business-as-usual land-use scenario; within-sample richness is projected to fall by a further 3.4% globally by 2100, with losse
Species are characterized by physiological, behavioral, and ecological attributes that are all subject to varying evolutionary and ecological constraints and jointly determine species' role and function in ecosystems. Attributes such as diet, foraging strata, foraging time, and body size, in particular, characterize a large portion of the “Eltonian” niches of species. Here we present a global species-level compilation of these key attributes for all 9993 and 5400 extant bird and mammal species derived from key literature sources. Global handbooks and monographs allowed the consistent sourcing of attributes for most species. For diet and foraging stratum we followed a defined protocol to translate the verbal descriptions into standardized, semiquantitative information about relative importance of different categories. Together with body size (continuous) and activity time (categorical) this enables a much finer distinction of species' foraging ecology than typical categorical guild assignments allow. Attributes lacking information for specific species are flagged, and interpolated values based on taxonomy are provided instead. The presented data set is limited by, among others, these select cases missing observed data, by errors and uncertainty in the expert assessment as presented in the literature, and by the lack of intraspecific information. However, the standardized and transparent nature and complete global coverage of the data set should support an array of potential studies in biogeography, community ecology, macroevolution, global change biology, and conservation. Potential uses include comparative work involving these traits as focal or secondary variables, ecological research on the trait or trophic structure of communities, or conservation science concerned with the loss of function among species or in ecosystems in a changing world. We hope that this publication will spur the sharing, collaborative curation, and extension of data to the benefit of a more integrative, rigorous, and global biodiversity science.
Ecosystem service provision varies temporally in response to natural and human-induced factors, yet research in this field is dominated by analyses that ignore the time-lags and feedbacks that occur within socio-ecological systems. The implications of this have been unstudied, but are central to understanding how service delivery will alter due to future land-use/cover change. Urban areas are expanding faster than any other land-use, making cities ideal study systems for examining such legacy effects. We assess the extent to which present-day provision of a suite of eight ecosystem services, quantified using field-gathered data, is explained by current and historical (stretching back 150 years) landcover. Five services (above-ground carbon density, recreational use, bird species richness, bird density, and a metric of recreation experience quality (continuity with the past) were more strongly determined by past landcover. Time-lags ranged from 20 (bird species richness and density) to over 100 years (above-ground carbon density). Historical landcover, therefore, can have a strong influence on current service provision. By ignoring such time-lags, we risk drawing incorrect conclusions regarding how the distribution and quality of some ecosystem services may alter in response to land-use/cover change. Although such a finding adds to the complexity of predicting future scenarios, ecologists may find that they can link the biodiversity conservation agenda to the preservation of cultural heritage, and that certain courses of action provide win-win outcomes across multiple environmental and cultural goods.
Anecdotal evidence suggests that socioeconomic shocks strongly affect
wildlife populations, but quantitative evidence is sparse. The collapse of
socialism in Russia in 1991 caused a major socioeconomic shock, including
a sharp increase in poverty. Our goal was to analyze population trends of
eight large mammals (5 herbivores and 3 carnivores) in Russia from 1981
to 2010, i.e., before and after the collapse. We hypothesized that the
collapse would first cause population declines, primarily due to
overexploitation, and then population increases due to adaptation of
wildlife to new environments following the collapse. The extensive and
long-term Database of the Russian Federal Agency of Game Mammal
Monitoring, consisting of up to 50,000 transects that are monitored
annually, provided an exceptional data set for investigating these
population trends. We found that three species showed strong declines in
population growth rates in the decade following the collapse, while grey
wolf increased by more than 150%. However, after 2000 these trends
reversed; for example, roe deer numbers in 2010 were the highest of any
period in our study. Likely reasons for the population declines in the 1990s
include poaching and the erosion of wildlife protection enforcement. The
rapid increase of the grey wolf populations is likely due to the cessation of
governmental population control. In general, the widespread declines in
wildlife populations after the collapse of the Soviet Union highlight the
magnitude of the effects that socioeconomic shocks can have on wildlife
populations and the possible need for special conservation efforts during
such times.
Background
A principal function of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is to “perform regular and timely assessments of knowledge on biodiversity.” In December 2013, its second plenary session approved a program to begin a global assessment in 2015. The Convention on Biological Diversity (CBD) and five other biodiversity-related conventions have adopted IPBES as their science-policy interface, so these assessments will be important in evaluating progress toward the CBD’s Aichi Targets of the Strategic Plan for Biodiversity 2011–2020. As a contribution toward such assessment, we review the biodiversity of eukaryote species and their extinction rates, distributions, and protection. We document what we know, how it likely differs from what we do not, and how these differences affect biodiversity statistics. Interestingly, several targets explicitly mention “known species”—a strong, if implicit, statement of incomplete knowledge. We start by asking how many species are known and how many remain undescribed. We then consider by how much human actions inflate extinction rates. Much depends on where species are, because different biomes contain different numbers of species of different susceptibilities. Biomes also suffer different levels of damage and have unequal levels of protection. How extinction rates will change depends on how and where threats expand and whether greater protection counters them.
Advances
Recent studies have clarified where the most vulnerable species live, where and how humanity changes the planet, and how this drives extinctions. These data are increasingly accessible, bringing greater transparency to science and governance. Taxonomic catalogs of plants, terrestrial vertebrates, freshwater fish, and some marine taxa are sufficient to assess their status and the limitations of our knowledge. Most species are undescribed, however. The species we know best have large geographical ranges and are often common within them. Most known species have small ranges, however, and such species are typically newer discoveries. The numbers of known species with very small ranges are increasing quickly, even in well-known taxa. They are geographically concentrated and are disproportionately likely to be threatened or already extinct. We expect unknown species to share these characteristics. Current rates of extinction are about 1000 times the background rate of extinction. These are higher than previously estimated and likely still underestimated. Future rates will depend on many factors and are poised to increase. Finally, although there has been rapid progress in developing protected areas, such efforts are not ecologically representative, nor do they optimally protect biodiversity.
Outlook
Progress on assessing biodiversity will emerge from continued expansion of the many recently created online databases, combining them with new global data sources on changing land and ocean use and with increasingly crowdsourced data on species’ distributions. Examples of practical conservation that follow from using combined data in Colombia and Brazil can be found at www.savingspecies.org and www.youtube.com/watch?v=R3zjeJW2NVk .
Significance
A major advance of the last 20 y at the interface of biological, environmental, and conservation sciences has been the demonstration that plant biodiversity positively influences ecosystem function. Linking these results to applied conservation efforts hinges on the assumption that biodiversity is actually declining at the local scale at which diversity–function relationships are strongest. Our compilation and analysis of a global database of >16,000 repeat survey vegetation plots from habitats across the globe directly contradict this assumption. We find no general tendency for local-scale plant species diversity to decline over the last century, calling into question the widespread use of ecosystem function experiments to argue for the importance of biodiversity conservation in nature.
Increasing global demand for agricultural products will continue to affect biodiversity. Various strategies to address this tension, such as payments for ecosystem services, wildlife-friendly farming, and conservation-reserve planning, emphasize different aspects of the system and different policy approaches. We argue that the strategic approach must be matched to the region. That is, land-use policy and research agendas focusing on improving agronomic and ecological functioning need to be coordinated, and informed by integrated knowledge about the ecological, agronomic and socio-economic characteristics of a region. We trial the use of agricultural-production and biodiversity-conservation possibility sets as an integrating framework. We find two benefits. First, the process of developing production possibility frontiers enables researchers from different disciplines to jointly identify and debate the critical types and scales of interactions among production and biodiversity where there exist opportunities for improving the system. Second, we demonstrate how the shape of the biodiversity-production trade-off frontier, and where existing landscapes sit in relation to it, can determine the effectiveness of a policy in achieving production and conservation goals. Production possibility frontiers therefore provide a simple, flexible tool for a critical trans-disciplinary appraisal of policy, and can guide the choice of more sophisticated approaches to managing agricultural landscapes.
Conversion of rainforests into agriculture resulted in massive changes in species diversity and community structure. Although the conservation of the remaining rainforests is of utmost importance, identifying and creating biodiversity‐friendly agriculture landscape is vital for preserving biodiversity and their functions. Biodiversity studies in agriculture have often been conducted at low elevations. In this study, we compared the functional diversity (FD), phylogenetic diversity (PD), and community structure of birds along an interacting gradient of land‐use (protected rainforest, reserve buffer, and agriculture) and elevation (low, middle and high) in Sri Lanka. Then, we measured compositional change by identifying how ecological traits (dietary guild, vertical strata, body mass, and dispersal ability) and conservation characteristics (forest‐dependence and threatened status) responded to land‐use types. Elevation and land‐use interacted with each other to shape bird FD. Depending on the elevation, FD in agriculture was either higher or similar to forest. However, PD was similar across all elevation and land‐use types. Bird community structure in forest was functionally and phylogenetically clustered in comparison to agriculture. Insectivorous birds declined from forest to agriculture, and so did understorey and middle‐storey birds. But frugivorous and canopy birds did not change across land‐use types, while nectarivores, granivores and carnivores proliferated in agriculture. Forests were dominated by birds with low dispersal abilities, but birds in agriculture had more evenly distributed dispersal abilities. About half of all the individuals in agriculture was composed of forest species, several of which were threatened. Synthesis and applications. Most farmers in Sri Lanka practice agriculture on small farms (c. 2 ha) and rely on services (e.g., pest‐control and pollination) provided by biodiversity for their livelihoods. Our results underline the important role of these heterogenous agriculture landscapes in maintaining high functional diversity (FD) and harbouring several threatened species. While FD in agriculture was comparatively high, conservation decisions based on land‐use alone cannot be reliable, because land‐use effects were elevation dependent. Thus, priority setting exercises aimed at designing optimal agriculture landscapes should consider landscape features, in combination with elevation, to benefit both people and wildlife outside protected areas.
We present the results from our 12th annual horizon scan of issues likely to impact biological conservation in the future. From a list of 97 topics, our global panel of 25 scientists and practitioners identified the top 15 issues that we believe society may urgently need to address. These issues are either novel in the biological conservation sector or represent a substantial positive or negative step-change in impact at global or regional level. Six issues, such as coral reef deoxygenation and changes in polar coastal productivity, affect marine or coastal ecosystems and seven relate to human and ecosystem-level responses to climate change. Identification of potential forthcoming issues for biological conservation may enable increased preparedness by researchers, practitioners, and decision-makers.
Hainan Island is the largest tropical island in China, which is vulnerable to intensifying human activities, such as deforestation and urbanization affecting the quality of the eco-environment on regional scale. To quantify the temporal and spatial changes of the environment, multispectral Landsat data with 30-m spatial resolution was used to establish an Eco-environmental Quality Index (EQI) model for evaluating the ecological status of Hainan Island from 1990 to 2015. According to the EQI value, the study area was divided into different regions marked by five eco-environmental quality levels: excellent, good, normal, poor, and very poor. Finally, temporal and spatial analysis was incorporated into the eco-environmental quality assessment, and the effect of land-use changes on eco-environmental quality was discussed. The results indicated that the overall eco-environmental quality of Hainan Island belonged to the good class but with obvious spatial variation: the eco-environmental quality was excellent in the central mountainous area, good in the flat plane surrounding the mountains, whereas the quality was normal in the coastal areas. From a temporal perspective, the eco-environmental quality of Hainan Island has reduced slightly from 1990 to 2015, while the regions gaining better quality grades have exceeded those becoming worse. Land-use changes dominated eco-environmental quality variations during the study period in Hainan Island: areas of poor eco-environmental quality have expanded in residential regions and eco-environmental quality of rubber plantations has increased since its expanding area has been converted from land of worse eco-environmental quality grades. The EQI results are expected to provide a quantitative foundation for planning sustainable development and the rational use of resources in Hainan Island.
Although biodiversity is in sharp decline around the globe, collectiing precise information on changes in overall species richness remains extremely challenging. Efficient and reliable proxy methods are therefore needed, with the diversity of higher taxa representing one such potential proxy for species‐level diversity. Nonetheless, the stability of using this measure across different regions and animal taxa at the global scale has never been investigated thoroughly. Global. Up to 2016. Animalia. We used a large global dataset containing published studies on diversity in the terrestrial Animalia to analyse the relationship between diversity at the family, genus and species level across different orders. Family and species diversity were positively correlated, with the strongest correlations in Diptera, Hemiptera and Coleoptera. Correlations were slightly weaker in family–species than in genus–species relationships, whereas differences were stronger in observed richness than in diversity indices. Across all taxa, family–species correlations of Shannon diversity index values were independent of sample size, and they showed limited variation across biomes for the three orders containing sufficient case studies for this analysis. Based on the Shannon diversity index, the species diversity per site increased linearly with the increase in family diversity, with an average species : family diversity index ratio of 2.5, slightly lower than the ratio of 2.7 for observed species and family richness values. Our study confirmed that recording family‐level diversity can be a meaningful proxy for determining species‐level diversity patterns in biodiversity studies, and trade‐offs between identification costs and retained information content need to be considered when using higher taxon surrogacy.
Economic development creates challenges for land-use planners in balancing between increasing the use of natural resources and safeguarding biodiversity and ecosystem services. We developed and utilized multi-objective numeric optimization models to analyze the trade-offs between biodiversity and ecosystem services (BES). The approach was used in the land-use planning process in northern Finland when selecting potential peat production sites as a part of the development of the regional master plan. We first quantified Net Present Value (NPV) of peat production, biodiversity, greenhouse gas (GHG) emissions, and water emissions of peatlands. Then we applied multi-objective optimization to examine the trade-offs between the variables as well as to determine a cost-efficient selection of potential peat production sites, that is, a selection which would simultaneously generate the greatest possible economic returns and environmental benefits. Our results showed that with a relatively small decrease in NPV, a substantial decrease in biodiversity loss and a reduction in water emissions compared to the benchmark level could be attained. However, a significant decrease in GHG emissions resulted in a substantial decrease in NPV. We conclude that it is possible to significantly improve land-use management by applying multi-objective optimization in land-use planning.
Beta diversity has long been used to summarize the amount of variation in species composition among a set of N sampling units. However, while classical beta diversity provides an estimate of multiple-site dissimilarity among all sampling units, it is not informative on the changes of multiple-site dissimilarity as a function of sampling effort. For gamma diversity, this pattern is usually represented as a species accumulation curve, which is the graph of the number of observed species when the number of plots varies from 1 to N. Here, we will show that species accumulation curves may also be used to summarize directional and non-directional beta diversity as a function of sampling effort. The behavior of the proposed measures of beta diversity is illustrated with one worked example on plant species in Mediterranean coastal vegetation. We believe this approach to the measurement of beta diversity provides a relevant contribution to summarize multiple-site dissimilarity as the result of a species turnover process, rather than as a static indicator. For directional species accumulation curves, the method, for which we provide a custom R function, further allows summarizing the spatial autocorrelation in species composition among plots along an a-priori defined spatial, temporal or environmental gradient.
Natural capital is a limited and irreplaceable factor for human welfare and sustainability. Natural capital includes natural capital flow and natural capital stock. When natural capital flow cannot meet the needs of regional development, it begins to consume natural capital stock. Therefore, the assessment of the current utilization status of natural capital flows and stocks is not only the basis for regional ecological construction evaluation but also an important indicator of the effectiveness of regional sustainable development strategies. This study uses the three-dimensional ecological footprint model to systematically and comprehensively evaluate the utilization status of natural capital flows and stocks in Hainan Province from 2005 to 2016. The driving factors behind changes in the natural capital stock are revealed using a partial least squares method. Our results indicate the following. (1) The per capita ecological footprint of Hainan Province is increasing at an annual rate of 3.87%, and the per capita ecological deficit is increasing at an annual rate of 5.85%. The ecological footprints are mainly composed of cropland and forest land and the account composition is dominated by the biological and energy accounts; (2) The growth of water body natural capital flow promotes the total natural capital flow consumption of Hainan Province from 2005 to 2016 with an annual average of 0.41%. The natural capital flow consumption is mainly in the north, northeast and southwestern cities and counties, and the growth rate of natural capital flow consumption is greatest in the central mountainous region; (3) The consumption of total natural capital stock is growing at an average annual rate of 4.49%, from a value of 2.97 times the sustainable resource consumption of Hainan Province in 2005, increasing to a factor of 4.81 times in 2016. The natural capital stock consumption is mainly in the north and northeast in terms of quantity and growth rate; (4) The secondary industries, the year-end resident population, the total energy consumption and the total investment in fixed assets are the natural capital stock consumption of Hainan Province. These findings can provide a scientific reference for the formulation of Hainan’s economic development and environmental protection policies to promote the coordinated and sustainable development of social, economic and environmental aspects of Hainan Province.
Human impact on the environment is evident across the planet, including its most biodiverse areas. Of particular interest is the impact on the world's last wilderness areas, in which the largest patches of land relatively free from human influence remain. Here, we use the human footprint index to measure the extent to which the world's last wilderness areas have been impacted by human activities-between the years 1993 and 2009-and whether protected areas have been effective in reducing human impact. We found that overall the increase in human footprint was higher in tropical than temperate regions. Moreover, although on average the increase was lower inside protected areas than outside, in half of the fourteen biomes examined the differences were insignificant. Although reasons varied, protected areas alone are unlikely to be ubiquitously successful in protecting wilderness areas. To achieve protection, it is important to address loss and improve environmental governance.
Ecosystem services have become one of the core elements of ecosystem management and evaluation. As a key area of ecosystem services and for maintaining national ecological security, ecosystem changes and implementation effect evaluation are important in national key ecological function zones, for promoting the main function zone strategy and for improving the construction of an ecological civilization. This article studies the ecological zone of a tropical rainforest region in the central mountain area of Hainan Island, China. Multi- source satellite data and ground observation statistics are analyzed with geo-statistics method and ecological assessment model. The core analysis of this paper includes ecosystem patterns, quality and services. By means of spatial and temporal scale expansion and multidimensional space-time correlation analysis, the trends and stability characteristics of ecosystem changes are analyzed, and implementation effect evaluation is discussed. The analysis shows a variety of results. The proportion of forest area inside the ecological zone was significantly higher than the average level in Hainan Island. During 1990–2013, settlement gradually increased inside the ecological zone. After implementation of the zone in 2010, human activity intensity increased, with the main land use being urban construction and land reclamation. Water conservation in the ecological function zone was higher than that outside the zone. In general, it increased slightly, but had obvious fluctuations. Soil conservation inside the zone was also better than that outside. However, it demonstrated dramatic fluctuations and relatively poor stability during 1990–2013. The human disturbance index inside the zone was significantly lower than that outside, and had a lower biodiversity threat level. Especially in 2010–2013, the increased range of the human disturbance index inside the zone was significantly less than that outside.
For this article, I reviewed empirical studies finding significant ecological responses to habitat fragmentation per se—in other words, significant responses to fragmentation independent of the effects of habitat amount (hereafter referred to as habitat fragmentation). I asked these two questions: Are most significant responses to habitat fragmentation negative or positive? And do particular attributes of species or landscapes lead to a predominance of negative or positive significant responses? I found 118 studies reporting 381 significant responses to habitat fragmentation independent of habitat amount. Of these responses, 76% were positive. Most significant fragmentation effects were positive, irrespective of how the authors controlled for habitat amount, the measure of fragmentation, the taxonomic group, the type of response variable, or the degree of specialization or conservation status of the species or species group. No support was found for predictions that most significant responses to fragmentation should be negative in the tropics, for species with larger movement ranges, or when habitat amount is low; most significant fragmentation effects were positive in all of these cases. Thus, although 24% of significant responses to habitat fragmentation were negative, I found no conditions in which most responses were negative. Authors suggest a wide range of possible explanations for significant positive responses to habitat fragmentation: increased functional connectivity, habitat diversity, positive edge effects, stability of predator–prey/host–parasitoid systems, reduced competition, spreading of risk, and landscape complementation. A consistent preponderance of positive significant responses to fragmentation implies that there is no justification for assigning lower conservation value to a small patch than to an equivalent area within a large patch—instead, it implies just the opposite. This finding also suggests that land sharing will usually provide higher ecological value than land sparing. Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics Volume 48 is November 2, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Despite the recognised conservation value of phylogenetic diversity, little is known about how it is affected by the urbanisation process. Combining a complete avian phylogeny with surveys along urbanisation gradients from five continents, we show that highly urbanised environments supported on average 450 million fewer years of evolutionary history than the surrounding natural environments. This loss was primarily caused by species loss and could have been higher had not been partially compensated by the addition of urban exploiters and some exotic species. Highly urbanised environments also supported fewer evolutionary distinctive species, implying a disproportionate loss of evolutionary history. Compared with highly urbanised environments, changes in phylogenetic richness and evolutionary distinctiveness were less substantial in moderately urbanised environments. Protecting pristine environments is therefore essential for maintaining phylogenetic diversity, but moderate levels of urbanisation still preserve much of the original diversity.
Urbanization is increasing faster than ever, contributing to a global extinction crisis. Recently, scientists have debated whether species richness on local and regional scales is mostly declining, but long-term changes in phylogenetic richness and divergence were largely disregarded. Space-for-time approaches revealed that plant phylogenetic divergence is lower in urban than in non-urban areas. However, such approaches cannot fully disentangle the relative importance of the biotic processes that drive temporal changes in diversity. Using a unique European urban flora covering 320 years in seven time steps, combined with a comprehensive plant phylogeny, we examined (i) how species richness changed with urbanization over time; (ii) whether trends in phylogenetic richness and divergence parallel trends in species richness; and (iii) whether species extirpation or immigration is driving these changes. We found that over time urban species richness increased, but phylogenetic richness and divergence decreased. Extirpations of phylogenetically distinct native species and immigrations of phylogenetically common native and non-native species caused a non-random loss of phylogenetic diversity. Our analyses suggest that if future extirpations and immigrations continue to follow the patterns observed over history, this loss will continue. Synthesis and applications. Measures to protect phylogenetic diversity should combine the protection of threatened habitats and their species with the maintenance of habitats that mitigate heat and safeguard evolutionary history. Urban planners should consider a phylogenetically diverse set of species when designing green spaces.
1. Here, I present a new, multifunctional phylogenetics package, phytools, for the R statistical computing environment.
2. The focus of the package is on methods for phylogenetic comparative biology; however, it also includes tools for tree inference, phylogeny input/output, plotting, manipulation and several other tasks.
3. I describe and tabulate the major methods implemented in phytools, and in addition provide some demonstration of its use in the form of two illustrative examples.
4. Finally, I conclude by briefly describing an active web-log that I use to document present and future developments for phytools. I also note other web resources for phylogenetics in the R computational environment.
Urbanisation is considered an important driver of current biodiversity loss, but the underlying causes are not fully understood. It is generally assumed that this loss reflects the fact that most organisms do not tolerate well the environmental alterations associated with urbanisation. Nevertheless, current evidence is inconclusive and the alternative that the biodiversity loss is the result of random mechanisms has never been evaluated. Analysing changes in abundance between urbanised environments and their non-urbanised surroundings of > 800 avian species from five continents, we show here that although random processes account for part of the species loss associated with urbanisation, much of the loss is associated with a lack of appropriate adaptations of most species for exploiting resources and avoiding risks of the urban environments. These findings have important conservation implications because the extinction of species with particular features should have higher impact on biodiversity and ecosystem function than a random loss.
The extent to which biodiversity change in local assemblages contributes to global biodiversity loss is poorly understood.
We analyzed 100 time series from biomes across Earth to ask how diversity within assemblages is changing through time. We
quantified patterns of temporal α diversity, measured as change in local diversity, and temporal β diversity, measured as
change in community composition. Contrary to our expectations, we did not detect systematic loss of α diversity. However,
community composition changed systematically through time, in excess of predictions from null models. Heterogeneous rates
of environmental change, species range shifts associated with climate change, and biotic homogenization may explain the different
patterns of temporal α and β diversity. Monitoring and understanding change in species composition should be a conservation
priority.