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In addition to habitat loss and fragmentation, demographic processes—the vagaries of births, deaths and sex ratio fluctuations—pose substantial threats to wild giant panda populations. Additionally, climate change and plans for the Giant Panda National Park may influence (in opposing directions) the extinction risk for wild giant pandas. The Fourth National Giant Panda Census showed pandas living in 33 isolated populations. An estimated 259 animals live in 25 of these groups, ~14% of the total population. We used individual-based models to simulate time series of these small populations for 100 years. We analysed the spatial pattern of their risk of extinction under current conditions and multiple climate change models. Furthermore, we consider the impact of the proposed Giant Panda National Park. Results showed that 15 populations face a risk >90%, and for 3 other populations the risk is >50%. Of the 15 most at-risk populations, national parks can protect only 3. Under the Representative Concentration Pathway 8.5 climate change scenario, the 33 populations will probably further divide into 56 populations. Some 41 of them will face a risk >50% and 35 face a risk >90%. Although national parks will probably connect some fragmented habitats, 26 populations will be outside national park planning. Our study gives practical advice for conservation policies and management and has implications for the conservation of other species in the world that live in isolated, fragmented habitats. The authors model likely outcomes for the 33 isolated populations reported in the Fourth National Giant Panda Census under multiple RCP scenarios and with the provision of the planned Giant Panda National Park. They find that, although the National Park may connect some fragmented habitats, most of the populations with high extinction risk fall outside the current plans.

Conservation science is a new and evolving discipline, so it seems prudent to explore different approaches. That said, we should examine what we know and, vitally, what works to conserve biodiversity and what does not. Ecosystem processes determine the fate of many species, but many attempts to theorise about ecosystems have led to ever more fanciful descriptions of nature. All conservation is local. It will only succeed if we find ways to accommodate people and nature. That does not mean indigenous knowledge acquired over millennia will be sufficient to our ever more overcrowded planet. Observational and experimental studies of small populations of wild species, however, do provide practical insights into how to manage biodiversity across much larger geographical extents.

How has the global network of protected areas developed - and which decisions have guided this development? Answering these questions may give insight into what might be possible in the next decade. In 2021, China will host the Convention of Biological Diversity's Conference, which will influence the coming decade's agenda. We consider how China expanded its protected areas in the last half-century. Did concerns about biodiversity protection drive those decisions, or were other factors responsible? Like other countries, China has protected remote places with few people that are unusually cold or dry or both. Despite that, species with small geographical ranges that have the highest risk of extinction are better protected than expected. Importantly, while the growth of total area and number of protected areas has slowed for the last decade, increases in protection of forested ecosystems and the species they contain have steadily increased. China's future reserve expansion must consider where to protect biodiversity, not just how much area to protect.

The U.N. has declared 2021-2030 the 'decade of restoration' (https://www.decadeonrestoration.org). This initiative aspires to many actions, but its agenda must include 'reconnecting nature'. Even when natural habitats remain, they often come in fragments too small or isolated to sustain viable populations. Human activities surround habitats with unsuitable areas or constrict animals' movements with artificial barriers, such as roads or fences. The harm this fragmentation causes is evident. Here, we discuss various actions to mitigate its problems, seeking explicit evidence of their efficacy. These actions range from small-scale, controlled experiments to continent-wide programmes to allow species the freedom to roam. Even simple connections, such as highway overpasses or tunnels, usually allow movement such that the genetic and demographic problems that beset small, isolated populations may be diminished. Showing that species move when we give them the chance to do so may be a sufficient measure of success, even if we do not always understand the consequences in detail.

Long-term studies to understand biodiversity changes remain scarce-especially so for tropical mountains. We examined changes from 1911 to 2016 in the bird community of the cloud forest of San Antonio, a mountain ridge in the Colombian Andes. We evaluated the effects of past land-use change and assessed species vulnerability to climate disruption. Forest cover decreased from 95% to 50% by 1959, and 33 forest species were extirpated. From 1959 to 1990, forest cover remained stable, and an additional 15 species were lost-a total of 29% of the forest bird community. Thereafter, forest cover increased by 26% and 17 species recolonized the area. The main cause of extirpations was the loss of connections to adjacent forests. Of the 31 (19%) extirpated birds, 25 have ranges peripheral to San Antonio, mostly in the lowlands. Most still occurred regionally, but broken forest connections limited their recolonization. Other causes of extirpation were hunting, wildlife trade, and water diversion. Bird community changes included a shift from predominantly common species to rare species; forest generalists replaced forest specialists that require old growth, and functional groups, such as large-body frugivores and nectarivores, declined disproportionally. All water-dependent birds were extirpated. Of the remaining 122 forest species, 19 are vulnerable to climate disruption, 10 have declined in abundance, and 4 are threatened. Our results show unequivocal species losses and changes in community structure and abundance at the local scale. We found species were extirpated after habitat loss and fragmentation, but forest recovery stopped extirpations and helped species repopulate. Land-use changes increased species vulnerability to climate change, and we suggest reversing landscape transformation may restore biodiversity and improve resistance to future threats.Extirpaciones de Aves y las Dinámicas Comunitarias en un Bosque Nuboso Andino durante más de Cien Años de Cambios de Uso de Suelo Resumen Los estudios a largo plazo para entender cambios en la biodiversidad todavía son escasos - especialmente en las montañas tropicales. Examinamos los cambios en la comunidad de aves del bosque de San Antonio en los Andes colombianos, desde 1911 hasta 2016. Evaluamos los efectos pasados del cambio en el uso del suelo y analizamos la vulnerabilidad de las especies ante la disrupción climática. La cobertura del bosque disminuyó del 95% al 50% para el año 1959, y 33 especies de bosque fueron extirpadas. Desde 1959 y hasta 1990, la cobertura permaneció estable y se perdieron 15 especies más - un total del 29% de la comunidad de aves de bosque. A partir de ahí la cobertura del bosque incrementó en un 26% y 17 especies recolonizaron el área. La principal causa de las extirpaciones fue la pérdida de conectividad con los bosques adyacentes. De las 31 (19%) especies de aves extirpadas, 25 especies tienen una distribución periférica a San Antonio, principalmente en las tierras bajas. La mayoría de las especies aún tenían presencia regional, pero las conexiones rotas entre los bosques limitaron su recolonización. Otras causas de las extirpaciones fueron la caza, el mercado de fauna y el desvío de cursos de agua. Los cambios en la comunidad de aves incluyeron una transición de especies predominantemente comunes a especies raras; las especies generalistas de bosque reemplazaron a las especies especialistas que requieren bosques maduros y los grupos funcionales, como los grandes frugívoros y nectarívoros, declinaron desproporcionadamente. Todas las aves dependientes del agua fueron extirpadas. De las 122 especies que permanecen en el bosque, 19 son vulnerables a la disrupción climática, diez han disminuido en abundancia y cuatro se encuentran amenazadas. Nuestros resultados muestran una pérdida inequívoca de especies y cambios en la estructura y abundancia de la comunidad de aves a escala local. En general, encontramos que las especies fueron extirpadas después de la pérdida y fragmentación del hábitat, pero la recuperación del bosque detuvo las extirpaciones y ayudó a las especies a recolonizar. Los cambios en el uso de suelo incrementaron la vulnerabilidad de las especies ante el cambio climático, por lo que sugerimos que revertir la transformación del paisaje podría restaurar la biodiversidad y aumentar la resistencia a futuras amenazas.目前, 关于生物多样性变化的长期研究还很少见, 特别是在热带山区。我们研究了哥伦比亚安第斯山脉圣安东尼奥地区一个云雾林在 1911-2016 年间的鸟类群落变化。本研究评估了过去土地利用变化的影响和物种对气候变化的脆弱性。 1911-1959 年, 该地区森林覆盖率由 95% 下降到 50%, 33 种森林物种局部灭绝。 1959-1990 年, 森林覆盖率保持稳定, 但仍有 15 种鸟类绝迹, 占森林鸟类群落总数的 29% 。此后, 森林覆盖率增加了 26%, 且有 17 个物种在该地区重新定殖。物种局部灭绝的主要原因是相邻森林之间的连接被破坏。在 31 种 (19%) 灭绝的鸟类中, 25 种在圣安东尼奥周围也有分布, 且主要在低地地区。这些鸟类大多仍有区域性分布, 但森林连接被破坏限制了它们重新定殖。局部灭绝的其它原因还包括狩猎、野生动物贸易和引水工程。鸟类群落的变化包括占优势的鸟种从常见种向稀有种转变; 森林中的广幅种取代了需要原始林的狭域种; 而包括大型食果动物和食蜜动物在内的功能群则不成比例地减少。所有依赖水体的鸟类都消失了。在残余的 122 种森林物种中, 19 种易受到气候变化的影响, 10 种种群数量已大量下降, 还有 4 种受到胁迫。我们的研究结果展现了局部尺度上明确的物种灭绝和种群结构及数量变化。一般来说, 栖息地丧失和破碎化会导致物种局部灭绝, 但森林恢复可以阻止灭绝, 并帮助物种重建种群。土地利用变化增加了物种对气候变化的脆弱性, 我们认为逆转景观改造有助于恢复生物多样性, 并提高物种对未来威胁的抵抗力。【翻译: 胡怡思; 审校: 聂永刚】.

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species includes assessment of extinction risk for 98 512 species, plus documentation of their range, habitat, elevation, and other factors. These range, habitat and elevation data can be matched with terrestrial land cover and elevation datasets to map the species’ area of habitat (AOH; also known as extent of suitable habitat; ESH). This differs from the two spatial metrics used for assessing extinction risk in the IUCN Red List criteria: extent of occurrence (EOO) and area of occupancy (AOO). AOH can guide conservation, for example, through targeting areas for field surveys, assessing proportions of species’ habitat within protected areas, and monitoring habitat loss and fragmentation. We recommend that IUCN Red List assessments document AOH wherever practical., Trends in Ecology & Evolution, 34 (11), ISSN:0169-5347, ISSN:1872-8383

As a landscape becomes increasingly fragmented through habitat loss, the individual patches become smaller and more isolated and thus less likely to sustain a local population. Metapopulation theory is appropriate for analyzing fragmented landscapes because it combines empirical landscape features with species‐specific information to produce direct information on population extinction risks. This approach contrasts with descriptions of habitat fragments, which provide only indirect information on risk. Combining a spatially explicit metapopulation model with empirical data on endemic species’ ranges and maps of habitat cover, we calculated the metapopulation capacity—a measure of a landscape's ability to sustain a metapopulation. Mangroves provide an ideal model landscape because they are of conservation concern and their patch boundaries are easily delineated. For 2000–20015, we calculated global metapopulation capacity for 99 metapopulations of 32 different bird species endemic to mangroves. Northern Australia and Southeast Asia had the highest richness of mangrove endemic birds. The Caribbean, Pacific coast of Central America, Madagascar, Borneo, and isolated patches in Southeast Asia in Myanmar and Malaysia had the highest metapopulation losses. Regions with the highest loss of habitat area were not necessarily those with the highest loss of metapopulation capacity. Often, it was not a matter of how much, but how the habitat was lost. Our method can be used by managers to evaluate and prioritize a landscape for metapopulation persistence., Article impact statement: Application of metapopulation theory shows where area of habitat loss is highest; metapopulation capacity is not necessarily also the highest.

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 socio-economic 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.

Summary To counter their widespread loss, global aspirations are for no net loss of remaining wetlands [ 1 ]. We examine whether this goal alone is sufficient for managing China’s wetlands, for they constitute 10% of the world’s total. Analyzing wetland changes between 2000 and 2015 using 30-m-resolution satellite images, we show that China’s wetlands expanded by 27,614 km2 but lost 26,066 km2—a net increase of 1,548 km2 (or 0.4%). This net change hides considerable complexities in the types of wetlands created and destroyed. The area of open water surface increased by 9,110 km2, but natural wetlands—henceforth “marshes”—decreased by 7,562 km2. Of the expanded wetlands, restoration policies contributed 24.5% and dam construction contributed 20.8%. Climate change accounted for 23.6% but is likely to involve a transient increase due to melting glaciers. Of the lost wetlands, agricultural and urban expansion contributed 47.7% and 13.8%, respectively. The increase in wetlands from conservation efforts (6,765 km2) did not offset human-caused wetland losses (16,032 km2). The wetland changes may harm wildlife. The wetland loss in east China threatens bird migration across eastern Asia [ 2 ]. Open water from dam construction flooded the original habitats of threatened terrestrial species and affected aquatic species by fragmenting wetland habitats [ 3 ]. Thus, the “no net loss” target measures total changes without considering changes in composition and the corresponding ecological functions. It may result in “paper offsets” and should be used carefully as a target for wetland conservation.

International audience; Human actions challenge nature in many ways. Ecological responses are ineluctably complex, demanding measures that describe them succinctly. Collectively, these measures encapsulate the overall ‘stability’ of the system. Many international bodies, including the Intergovernmental Science‐Policy Platform on Biodiversity and Ecosystem Services, broadly aspire to maintain or enhance ecological stability. Such bodies frequently use terms pertaining to stability that lack clear definition. Consequently, we cannot measure them and so they disconnect from a large body of theoretical and empirical understanding. We assess the scientific and policy literature and show that this disconnect is one consequence of an inconsistent and one‐dimensional approach that ecologists have taken to both disturbances and stability. This has led to confused communication of the nature of stability and the level of our insight into it. Disturbances and stability are multidimensional. Our understanding of them is not. We have a remarkably poor understanding of the impacts on stability of the characteristics that define many, perhaps all, of the most important elements of global change. We provide recommendations for theoreticians, empiricists and policymakers on how to better integrate the multidimensional nature of ecological stability into their research, policies and actions.

We discuss institutional reforms to China's protected area management. Currently (as elsewhere), protected areas suffer fragmented management, lack of a comprehensive classification, inadequate coverage of biodiversity and ecosystem services, and divided, inconsistent legislation. We recommend establishing a new system of protected area management that can address past difficulties by using ongoing institutional reforms as unprecedented opportunities.

We analyze recently-collected feather tissues from two species of seabirds, the sooty tern (Onychoprion fuscatus) and brown noddy (Anous stolidus), in three ocean regions (North Atlantic, North Pacific, South Pacific) with different human impacts. The species are similar morphologically and are similar in the trophic levels from which they feed within each location. In contrast, we detect reliable differences in trophic position amongst the regions. Trophic position appears to decline as the intensity of commercial fishing increases, and is at its lowest in the Caribbean. The spatial gradient in trophic position we document in these regions exceeds those detected over specimens from the last 130 years in the Hawaiian Islands. Modeling suggests that climate velocity and human impacts on fish populations strongly align with these differences.

Just protecting Earth’s wilderness will not be sufficient to conserve most of its species; quality, not overall size, matters., It is theoretically possible to protect large fractions of species in relatively small regions. For plants, 85% of species occur entirely within just over a third of the Earth’s land surface, carefully optimized to maximize the species captured. Well-known vertebrate taxa show similar patterns. Protecting half of Earth might not be necessary, but would it be sufficient given the current trends of protection? The predilection of national governments is to protect areas that are “wild,” that is, typically remote, cold, or arid. Unfortunately, those areas often hold relatively few species. Wild places likely afford the easier opportunities for the future expansion of protected areas, with the expansion into human-dominated landscapes the greater challenge. We identify regions that are not currently protected, but that are wild, and consider which of them hold substantial numbers of especially small-ranged vertebrate species. We assess how successful the strategy of protecting the wilder half of Earth might be in conserving biodiversity. It is far from sufficient. (Protecting large wild places for reasons other than biodiversity protection, such as carbon sequestration and other ecosystem services, might still have importance.) Unexpectedly, we also show that, despite the bias in establishing large protected areas in wild places to date, numerous small protected areas are in biodiverse places. They at least partially protect significant fractions of especially small-ranged species. So, while a preoccupation with protecting large areas for the sake of getting half of Earth might achieve little for biodiversity, there is more progress in protecting high-biodiversity areas than currently appreciated. Continuing to prioritize the right parts of Earth, not just the total area protected, is what matters for biodiversity.

The notion of a ‘safe operating space for biodiversity’ is vague and encourages harmful policies. Attempts to fix it strip it of all meaningful content. Ecology is rapidly gaining insights into the connections between biodiversity and ecosystem stability. We have no option but to understand ecological complexity and act accordingly.

Technologies to identify individual animals, follow their movements, identify and locate animal and plant species, and assess the status of their habitats remotely have become better, faster, and cheaper as threats to the survival of species are increasing. New technologies alone do not save species, and new data create new problems. For example, improving technologies alone cannot prevent poaching: solutions require providing appropriate tools to the right people. Habitat loss is another driver: the challenge here is to connect existing sophisticated remote sensing with species occurrence data to predict where species remain. Other challenges include assembling a wider public to crowdsource data, managing the massive quantities of data generated, and developing solutions to rapidly emerging threats.

Estimates of global forest area vary widely; this discrepancy is now shown to originate primarily from ambiguity in the definition of ‘forest’. Monitoring and reporting should focus on measures more directly relevant to ecosystem function. Deforestation is a major driver of climate change1 and the major driver of biodiversity loss1,2. Yet the essential baseline for monitoring forest cover—the global area of forests—remains uncertain despite rapid technological advances and international consensus on conserving target extents of ecosystems3. Previous satellite-based estimates4,5 of global forest area range from 32.1 × 106 km2 to 41.4 × 106 km2. Here, we show that the major reason underlying this discrepancy is ambiguity in the term ‘forest’. Each of the >800 official definitions6 that are capable of satellite measurement relies on a criterion of percentage tree cover. This criterion may range from >10% to >30% cover under the United Nations Framework Convention on Climate Change7. Applying the range to the first global, high-resolution map of percentage tree cover8 reveals a discrepancy of 19.3 × 106 km2, some 13% of Earth’s land area. The discrepancy within the tropics alone involves a difference of 45.2 Gt C of biomass, valued at US$1 trillion. To more effectively link science and policy to ecosystems, we must now refine forest monitoring, reporting and verification to focus on ecological measurements that are more directly relevant to ecosystem function, to biomass and carbon, and to climate and biodiversity.

The Eastern Arc Mountains of Tanzania and the Atlantic Forest of Brazil are two of the most fragmented biodiversity hotspots. Species–area relationships predict that their habitat fragments will experience a substantial loss of species. Most of these extinctions will occur over an extended time, and therefore, reconnecting fragments could prevent species losses and allow locally extinct species to recolonize former habitats. An empirical relaxation half-life vs. area relationship for tropical bird communities estimates the time that it takes to lose one-half of all species that will be eventually lost. We use it to estimate the increase in species persistence by regenerating a forest connection 1 km in width among the largest and closest fragments at 11 locations. In the Eastern Arc Mountains, regenerating 8,134 ha of forest would create >316,000 ha in total of restored contiguous forest. More importantly, it would increase the persistence time for species by a factor of 6.8 per location or ∼2,272 years, on average, relative to individual fragments. In the Atlantic Forest, regenerating 6,452 ha of forest would create >251,000 ha in total of restored contiguous forest and enhance species persistence by a factor of 13.0 per location or ∼5,102 years, on average, relative to individual fragments. Rapidly regenerating forest among fragments is important, because mean time to the first determined extinction across all fragments is 7 years. We estimate the cost of forest regeneration at $21–$49 million dollars. It could provide one of the highest returns on investment for biodiversity conservation worldwide.

The conservation status of the iconic giant panda is a barometer of global conservation efforts. The IUCN Red List has downgraded the panda’s extinction risk from “endangered” to “vulnerable”. Newly obtained, detailed GIS and remotely sensed data applied consistently over the last four decades show that panda habitat covered less area and was more fragmented in 2013 than in 1988 when the species was listed as endangered. Despite recent IUCN downgrading of the giant panda’s conservation status from ‘endangered’ to ‘vulnerable’, new GIS and remote sensing data reveal panda habitats to cover less area and be more fragmented than previously.

A key measure of humanity's global impact is by how much it has increased species extinction rates. Familiar statements are that these are 100–1000 times pre-human or background extinction levels. Estimating recent rates is straightforward, but establishing a background rate for comparison is not. Previous researchers chose an approximate benchmark of 1 extinction per million species per year (E/MSY). We explored disparate lines of evidence that suggest a substantially lower estimate. Fossil data yield direct estimates of extinction rates, but they are temporally coarse, mostly limited to marine hard-bodied taxa, and generally involve genera not species. Based on these data, typical background loss is 0.01 genera per million genera per year. Molecular phylogenies are available for more taxa and ecosystems, but it is debated whether they can be used to estimate separately speciation and extinction rates. We selected data to address known concerns and used them to determine median extinction estimates from statistical distributions of probable values for terrestrial plants and animals. We then created simulations to explore effects of violating model assumptions. Finally, we compiled estimates of diversification—the difference between speciation and extinction rates for different taxa. Median estimates of extinction rates ranged from 0.023 to 0.135 E/MSY. Simulation results suggested over- and under-estimation of extinction from individual phylogenies partially canceled each other out when large sets of phylogenies were analyzed. There was no evidence for recent and widespread pre-human overall declines in diversity. This implies that average extinction rates are less than average diversification rates. Median diversification rates were 0.05–0.2 new species per million species per year. On the basis of these results, we concluded that typical rates of background extinction may be closer to 0.1 E/MSY. Thus, current extinction rates are 1,000 times higher than natural background rates of extinction and future rates are likely to be 10,000 times higher. Estimacion de la Tasa Normal de Extincion de Especies

Habitat loss is the principal threat to species. How much habitat remains-and how quickly it is shrinking-are implicitly included in the way the International Union for Conservation of Nature determines a species' risk of extinction. Many endangered species have habitats that are also fragmented to different extents. Thus, ideally, fragmentation should be quantified in a standard way in risk assessments. Although mapping fragmentation from satellite imagery is easy, efficient techniques for relating maps of remaining habitat to extinction risk are few. Purely spatial metrics from landscape ecology are hard to interpret and do not address extinction directly. Spatially explicit metapopulation models link fragmentation to extinction risk, but standard models work only at small scales. Counterintuitively, these models predict that a species in a large, contiguous habitat will fare worse than one in 2 tiny patches. This occurs because although the species in the large, contiguous habitat has a low probability of extinction, recolonization cannot occur if there are no other patches to provide colonists for a rescue effect. For 4 ecologically comparable bird species of the North Central American highland forests, we devised metapopulation models with area-weighted self-colonization terms; this reflected repopulation of a patch from a remnant of individuals that survived an adverse event. Use of this term gives extra weight to a patch in its own rescue effect. Species assigned least risk status were comparable in long-term extinction risk with those ranked as threatened. This finding suggests that fragmentation has had a substantial negative effect on them that is not accounted for in their Red List category.

S1 File. Additional methods and supporting results and references. This file contains Supporting Information Materials and Methods; Figure A (study schematic), Figure B (23 time series and best-fit population models); Figure C (partial residual plots of components of model averaged GLM to explain PIKE values from MIKE sites); Figure D (comparison of GAMs to explain extracted stable densities with and without influential points); Figure E (histogram of ecological benchmark estimates for each of 73 protected areas illustrating results of Monte Carlo simulation to incorporate uncertainty); Figure F (histogram of cumulative ecological benchmark across 73 protected areas recalculated for each of 1x10^6 runs from the Monte Carlo simulation to incorporate uncertainty); Table A (alternative candidate models to describe the population dynamics of 23 time-series populations); Table B (summary information on time series and extracted stable density and SE); Table C (summary information for 43 MIKE sites and the explanatory variables used to explain PIKE); Table D (Summary statistics and variables included in most likely quasi-binomial generalized linear models to explain PIKE for 43 MIKE sites across Africa and final predictive average model used to generate PIKE estimates for non-MIKE sites); Table E (selection parameters of candidate generalized additive models explaining variation in extracted stable population size for 18 populations); Table F (summary information, predicted stable density (give current PIKE), and ecological benchmark density (given zero PIKE), and comparisons between most recent density and population size estimates and ecological benchmark density and population size for 73 protected areas across 21 countries); and Supporting Information References.

The World Bank is the largest international funder of biodiversity conservation. It invests in protected areas to conserve species and spaces, protect ecosystems, and provide food, shelter, and other ecosystem services to local communities. It spends on average, $275 million annually supporting parks in developing countries. We examined their protected areas investment portfolio from 1988 to 2008 to understand how they allocate these funds. We found that more money is allocated to countries with progressively larger GDPs. Many, but not all, of these investments correlate with consensus opinions of high biodiversity priorities. But the World Bank's investments are not proportional; poorer countries receive relatively more funds than richer ones, regardless of biodiversity importance. We suggest that these investments focus on supporting parks that provide benefits to local communities, particularly in poorer nations, rather than on biodiversity priorities in a vacuum. This mirrors their mission to work for a world without poverty.

We synthesize findings to date from the world’s largest and longest-running experimental study of habitat fragmentation, located in central Amazonia. Over the past 32 years, Amazonian forest fragments ranging from 1 to 100 ha have experienced a wide array of ecological changes. Edge effects have been a dominant driver of fragment dynamics, strongly affecting forest microclimate, tree mortality, carbon storage, fauna, and other aspects of fragment ecology. However, edge-effect intensity varies markedly in space and time, and is influenced by factors such as edge age, the number of nearby edges, and the adjoining matrix of modified vegetation surrounding fragments. In our study area, the matrix has changed markedly over the course of the study (evolving from large cattle pastures to mosaics of abandoned pasture and regrowth forest) and this in turn has strongly influenced fragment dynamics and faunal persistence. Rare weather events, especially windstorms and droughts, have further altered fragment ecology. In general, populations and communities of species in fragments are hyperdynamic relative to nearby intact forest. Some edge and fragment-isolation effects have declined with a partial recovery of secondary forests around fragments, but other changes, such as altered patterns of tree recruitment, are ongoing. Fragments are highly sensitive to external vicissitudes, and even small changes in local land-management practices may drive fragmented ecosystems in markedly different directions. The effects of fragmentation are likely to interact synergistically with other anthropogenic threats such as logging, hunting, and especially fire, creating an even greater peril for the Amazonian biota.

Theories suggest that food webs might consist of groups of species forming ‘blocks’, ‘compartments’ or ‘guilds’. We consider ecological networks – subsets of complete food webs – involving species at adjacent trophic levels. Reciprocal specializations occur when (say) a pollinator (or group of pollinators) specializes on a particular flower species (or group of such species) and vice versa. Such specializations tend to group species into guilds. We characterize the level of reciprocal specialization for both antagonistic interactions – particularly parasitoids and their hosts – and mutualistic ones – such as insects and the flowers that they pollinate. We also examine whether trophic patterns might be ‘palimpsests’ – that is, there might be reciprocal specialization within taxonomically related species within a network, but these might be obscured when these relationships are combined. Reciprocal specializations are rare in all these systems when tested against the most conservative null model.

Deforestation causes habitat loss, fragmentation, degradation, and can ultimately cause extinction of the remnant species. Tropical montane birds face these threats with the added natural vulnerability of narrower elevational ranges and higher specialization than lowland species. Recent studies assess the impact of present and future global climate change on species' ranges, but only a few of these evaluate the potentially confounding effect of lowland deforestation on species elevational distributions. In the Western Andes of Colombia, an important biodiversity hotspot, we evaluated the effects of deforestation on the elevational ranges of montane birds along altitudinal transects. Using point counts and mist-nets, we surveyed six altitudinal transects spanning 2200 to 2800 m. Three transects were forested from 2200 to 2800 m, and three were partially deforested with forest cover only above 2400 m. We compared abundance-weighted mean elevation, minimum elevation, and elevational range width. In addition to analysing the effect of deforestation on 134 species, we tested its impact within trophic guilds and habitat preference groups. Abundance-weighted mean and minimum elevations were not significantly different between forested and partially deforested transects. Range width was marginally different: as expected, ranges were larger in forested transects. Species in different trophic guilds and habitat preference categories showed different trends. These results suggest that deforestation may affect species' elevational ranges, even within the forest that remains. Climate change will likely exacerbate harmful impacts of deforestation on species' elevational distributions. Future conservation strategies need to account for this by protecting connected forest tracts across a wide range of elevations.

Unqualified, the statement that ≈1.3% of the ≈10,000 presently known bird species have become extinct since A.D. 1500 yields an estimate of ≈26 extinctions per million species per year (or 26 E/MSY). This is higher than the benchmark rate of ≈1 E/MSY before human impacts, but is a serious underestimate. First, Polynesian expansion across the Pacific also exterminated many species well before European explorations. Second, three factors increase the rate: ( i ) The number of known extinctions before 1800 is increasing as taxonomists describe new species from skeletal remains. ( ii ) One should calculate extinction rates over the years since taxonomists described the species. Most bird species were described only after 1850. ( iii ) Some species are probably extinct; there is reluctance to declare them so prematurely. Thus corrected, recent extinction rates are ≈100 E/MSY. In the last decades, the rate is

Darwin used the metaphor of a 'tangled bank' to describe the complex interactions between species. Those interactions are varied: they can be antagonistic ones involving predation, herbivory and parasitism, or mutualistic ones, such as those involving the pollination of flowers by insects. Moreover, the metaphor hints that the interactions may be complex to the point of being impossible to understand. All interactions can be visualized as ecological networks, in which species are linked together, either directly or indirectly through intermediate species. Ecological networks, although complex, have well defined patterns that both illuminate the ecological mechanisms underlying them and promise a better understanding of the relationship between complexity and ecological stability.

In the face of worldwide habitat fragmentation, managers need to devise a time frame for action. We ask how fast do understory bird species disappear from experimentally isolated plots in the Biological Dynamics of Forest Fragments Project, central Amazon, Brazil. Our data consist of mist-net records obtained over a period of 13 years in 11 sites of 1, 10, and 100 hectares. The numbers of captures per species per unit time, analyzed under different simplifying assumptions, reveal a set of species-loss curves. From those declining numbers, we derive a scaling rule for the time it takes to lose half the species in a fragment as a function of its area. A 10-fold decrease in the rate of species loss requires a 1,000-fold increase in area. Fragments of 100 hectares lose one half of their species in

We aspired to set conservation priorities in ways that lead to direct conservation actions. Very large-scale strategic mapping leads to familiar conservation priorities exemplified by biodiversity hotspots. In contrast, tactical conservation actions unfold on much smaller geographical extents and they need to reflect the habitat loss and fragmentation that have sharply restricted where species now live. Our aspirations for direct, practical actions were demanding. First, we identified the global, strategic conservation priorities and then downscaled to practical local actions within the selected priorities. In doing this, we recognized the limitations of incomplete information. We started such a process in Colombia and used the results presented here to implement reforestation of degraded land to prevent the isolation of a large area of cloud forest. We used existing range maps of 171 bird species to identify priority conservation areas that would conserve the greatest number of species at risk in Colombia. By at risk species, we mean those that are endemic and have small ranges. The Western Andes had the highest concentrations of such species-100 in total-but the lowest densities of national parks. We then adjusted the priorities for this region by refining these species ranges by selecting only areas of suitable elevation and remaining habitat. The estimated ranges of these species shrank by 18-100% after accounting for habitat and suitable elevation. Setting conservation priorities on the basis of currently available range maps excluded priority areas in the Western Andes and, by extension, likely elsewhere and for other taxa. By incorporating detailed maps of remaining natural habitats, we made practical recommendations for conservation actions. One recommendation was to restore forest connections to a patch of cloud forest about to become isolated from the main Andes.

Theories abound as to why the tropics harbor such amazing biodiversity compared to higher latitudes. In their Perspective, Pimm and Brown discuss the pros and cons of three popular hypotheses.

The IUCN Red List has assessed the global distributions of the majority of the world's amphibians, birds and mammals. Yet these assessments lack explicit reference to widely available, remotely-sensed data that can sensibly inform a species' risk of extinction. Our first goal is to add additional quantitative data to the existing standardised process that IUCN employs. Secondly, we ask: do our results suggest species of concern-those at considerably greater risk than hitherto appreciated? Thirdly, these assessments are not only important on a species-by-species basis. By combining distributions of species of concern, we map conservation priorities. We ask to what degree these areas are currently protected and how might knowledge from remote sensing modify the priorities? Finally, we develop a quick and simple method to identify and modify the priority setting in a landscape where natural habitats are disappearing rapidly and so where conventional species' assessments might be too slow to respond. Tropical, mainland Southeast Asia is under exceptional threat, yet relatively poorly known. Here, additional quantitative measures may be particularly helpful. This region contains over 122, 183, and 214 endemic mammals, birds, and amphibians, respectively, of which the IUCN considers 37, 21, and 37 threatened. When corrected for the amount of remaining natural habitats within the known elevation preferences of species, the average sizes of species ranges shrink to

Estimates of non-microbial diversity on Earth range from 2 million to over 50 million species, with great uncertainties in numbers of insects, fungi, nematodes, and deep-sea organisms. We summarize estimates for major taxa, the methods used to obtain them, and prospects for further discoveries. Major challenges include frequent synonymy, the difficulty of discriminating certain species by morphology alone, and the fact that many undiscovered species are small, difficult to find, or have small geographic ranges. Cryptic species could be numerous in some taxa. Novel techniques, such as DNA barcoding, new databases, and crowd-sourcing, could greatly accelerate the rate of species discovery. Such advances are timely. Most missing species probably live in biodiversity hotspots, where habitat destruction is rife, and so current estimates of extinction rates from known species are too low.

BackgroundProtected areas are the first, and often only, line of defense in efforts to conserve biodiversity. They might be detrimental or beneficial to rural communities depending on how they alter economic opportunities and access to natural resources. As such, protected areas may attract or repel human settlement. Disproportionate increases in population growth near protected area boundaries may threaten their ability to conserve biodiversity.Methodology/principal findingsUsing decadal population datasets, we analyze population growth across 45 countries and 304 protected areas. We find no evidence for population growth near protected areas to be greater than growth of rural areas in the same country. Furthermore, we argue that what growth does occur near protected areas likely results from a general expansion of nearby population centers.Conclusions/significanceOur results contradict those from a recent study by Wittemyer et al., who claim overwhelming evidence for increased human population growth near protected areas. To understand the disagreement, we re-analyzed the protected areas in Wittemyer et al.'s paper. Their results are simply artifacts of mixing two incompatible datasets. Protected areas may experience unusual population pressures near their edges; indeed, individual case studies provide examples. There is no evidence, however, of a general pattern of disproportionate population growth near protected areas.

Researchers predict that new infrastructure development will sharply increase the rate and extent of deforestation in the Brazilian Amazon. There are no predictions, however, of which species it will affect. We used a spatially explicit model that predicts the location of deforestation in the Brazilian Amazon by 2020 on the basis of historical patterns of deforestation following infrastructure development. We overlaid the predicted deforested areas onto maps of bird ranges to estimate the amount of habitat loss within species ranges. We also estimated the amount of habitat loss within modified ecoregions, which were used as surrogates for areas of bird endemism. We then used the extent of occurrence criterion of the World Conservation Union to predict the future conservation status of birds in the Brazilian Amazon. At current rates of development, our results show that at least 16 species will qualify as threatened or will lose more than half of their forested habitat. We also identified several subspecies and isolated populations that would also qualify as threatened. Most of the taxa we identified are not currently listed as threatened, and the majority are associated with riverine habitats, which have been largely ignored in bird conservation in Amazonia. These habitats and the species they hold will be increasingly relevant to conservation as river courses are altered and hydroelectric dams are constructed in the Brazilian Amazon.

Small geographical range size is the single best predictor of threat of extinction in terrestrial species. Knowing how small a species' range has to be before authorities consider it threatened with extinction would allow prediction of a species' risk from continued deforestation and warming climates and provide a baseline for conservation and management strategies aspiring to mitigate these threats. To determine the threshold at which forest-dependent bird species become threatened with extinction, we compared the range sizes of threatened and nonthreatened species. In doing so, we present a simple, repeatable, and practical protocol to quantify range size. We started with species' ranges published in field guides or comparable sources. We then trimmed these ranges, that is, we included only those parts of the ranges that met the species' requirements of elevation and types of forest preferred. Finally, we further trimmed the ranges to the amount of forest cover that remains. This protocol generated an estimate of the remaining suitable range for each species. We compared these range estimates with those from the World Conservation Union Red List. We used the smaller of the two estimates to determine the threshold, 11,000 km2, below which birds should be considered threatened. Species considered threatened that have larger ranges than this qualified under other (nonspatial) red list criteria. We identified a suite of species (18) that have not yet qualified as threatened but that have perilously small ranges--about 11% of the nonthreatened birds we analyzed. These birds are likely at risk of extinction and reevaluation of their status is urgently needed.

Managers in southern Africa are concerned that continually increasing elephant populations will degrade ecosystems. Culling, translocation and birth control are flawed solutions. An alternative is providing elephants more space but this hinges on identifying landscape preferences. We examined two diverse eco- systems and uncovered similarities in elephant habitat use, expressing these as 'rules'. We considered arid Etosha National Park, (Namibia) and the tropical wood- lands of Tembe Elephant Park (South Africa) and Maputo Elephant Reserve (Mozambique). Landscape data con- sisted of vegetation types, distances from water and settlements. To surmount issues of scale and availability we incorporated elephant movements as a function that declined as distance from an elephant's location in- creased. This presumes that elephants optimize trade- offs between benefiting from high-quality resources and costs to find them. Under a likelihood-based approach we determined the important variables and shapes of their relationships to evaluate and compare models separated by gender, season and location. After consid- ering elephants' preferences for areas nearby, habitat use usually increased with proximity to water in all loca- tions. Elephants sought places with high proportions of vegetation, especially when neighbouring areas had low vegetative cover. Lastly, elephants avoided human set- tlements (when present), and cows more so than bulls. In caricature, elephants preferred to move little, drink easily, eat well, and avoid people. If one makes more areas available, elephants will probably favour areas near water with high vegetative cover (of many different types) and away from people. Managers can oblige elephants' preferences by supplying them. If so, they should anticipate higher impacts to neighbouring vegetation.

1. We test MacArthur and Wilson's theory about the biogeography of communities on isolated habitat patches using bird breeding records from 16 small islands off the coasts of Britain and Ireland. 2. A traditional examination of patterns of species richness on these islands suggests that area and habitat diversity are important predictors, but that isolation and latitude have a negligible impact in this system. 3. Unlike traditional studies, we directly examine the fundamental processes of colonization and local extinction (cessation of breeding), rather than higher-order phenomena such as species richness. 4. We find that many of MacArthur and Wilson's predictions hold: colonization probability is lower on more isolated islands, and extinction probability is lower on larger islands and those with a greater diversity of habitats. 5. We also find an unexpected pattern: extinction probability is much lower on more isolated islands. This is the strongest relationship in these data, and isolation is the best single predictor of colonization and extinction. 6. Our results show that examination of species richness alone is misleading. Isolation has a strong effect on both of the dynamic processes that underlie richness, and in this system, the reductions in both colonization and extinction probability seen on more distant islands have opposing influences on species richness, and largely cancel each other out. 7. We suggest that an appropriate model for this system might be optimal foraging theory, which predicts that organisms will stay longer in a resource patch if the distance to a neighbouring patch is large. If nest sites and food are the resources in this system, then optimal foraging theory predicts the pattern we observe. 8. We advance the hypothesis that there is a class of spatial systems, defined by their scale and by the taxon under consideration, at which decision-making processes are a key driver of the spatiotemporal dynamics. The appropriate theory for such systems will be a hybrid of concepts from biogeography/metapopulation theory and behavioural ecology.

Interspecific interactions affect biodiversity, but in unpredictable ways that change over time and space. There is little evidence for the ‘ill wind that blows no good’ to any species. So how can we manage nature?

Contrary to the view taken by some, individual species matter: they are valuable for their contribution to the stability of the ecosystems they inhabit.

Our actions have driven top predators from much of the world, resulting in complex consequences for many ecosystems, explains Stuart Pimm.

Sixteen years ago, Pimm [1] caricatured most ecological studies as covering a few hectares, spanning a few years and involving a handful of species. Although satellite imagery for visualizing and monitoring terrestrial ecosystems began earlier, only the past decade has provided inexpensive, global remote sensing – and desktop computer software for its analysis [2]. Comparisons of ecological patterns and changes over decades on huge spatial scales are now routine. Everyone can visualize current study sites (and select future ones) on GoogleEarth (http://earth.google.com/), increasingly with a spatial resolution that shows individual tree canopies.

One dilemma for conservation biologists is to ponder whether ecological processes are better targets for conservation than are species. In this chapter, we discuss this dilemma under the assumption that not all species are equal in terms of the size, shape, orientation of their geographic range, and their density distribution within the range. Conserving a single species found only in a restricted area (endemic) may not preserve global biodiversity, but on the other hand, conserving an ecosystem and the processes therein may still lead to a reduction in biodiversity within the conservation area, and at the same time leave a large proportion of “rare” species unprotected. Obviously both approaches should be used to maintain global biodiversity, but the question remains how we target those areas that need protection. With a view to setting conservation priorities, we map an ecological unit of measurement henceforth known as M, which for any group of species, at any geographic scale (in this case 1° latitude by 1° longitude), is equal to the sum of the reciprocals of the area of each species’ geographic range.

Ecological communities do not spring into existence overnight, but develop during the process we call assembly. As in other complex systems, random assemblies may generate surprising patterns. In previous models, sequential invasion and extinction moved successive species mixes toward a persistent one. Other species present in the pool could not invade this persistent mix. Chance events early in the assembly produced persistent mixes of different compositions. Most model species survived somewhere by belonging to one or more of these different persistent mixes. We show that with more rapid invasion, communities move through complex cycles of composition, where each species gets its turn. These complementary views offer insights into the diversity of natural communities. Importantly, they have practical implications for those attempting to restore diversity to damaged ecosystems.

A History of the Ecosystem Concept in Ecology: More than the Sum of the Parts. By Frank Benjamin Golley. Yale University Press: 1993. Pp. 254. £25, $30.

Early studies suggested that simple ecosystems were less stable than complex ones, but later studies came to the opposite conclusion. Confusion arose because of the many different meanings of ‘complexity’ and ‘stability’. Most of the possible questions about the relationship between stability–complexity have not been asked. Those that have yield a variety of answers.