No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Developing new biodiversity conservation strategies in response to global change
... Biodiversity is critical for ecosystem function and services on which humans depend, and is directly linked to the economic, social, and environmental components of sustainability (Heywood 2010). Unfortunately, human modification of the ecosystems has led to alterations of biodiversity worldwide, across marine and freshwater ecosystems, and other portions of the biosphere and thus this diversity is increasingly threatened by human activities. ...
Biodiversity is critical for sustainability but it is being increasingly threatened by anthropogenic activities, such as abitats’ degradation through deforestation, unsustainable shifting cultivation and draining of wetlands; as well as industrialisation and overexploitation of flora and fauna which includes unsustainable fishing, excessive consumption of fuel wood and overharvesting of medicinal plants. Human modification of the ecosystems does not only lead to biodiversity loss but can also cause a continuous shift in earth’s ecological equilibrium, resulting in degradation and environmental stress. Notably, the United Nations’ Sustainable Development Goal 15 (SDG 15) is aimed at averting this impending crisis. This article examines the impact of environmental degradation and conservation on biodiversity in Nigeria and espouses suggestions towards the attainment of sustainable development goals.
... On the other hand, it should be noted that the focus of species recovery and similar actions such as population reinforcement is essentially on species populations in the wild (in situ) and with ex situ, if involved at all, acting as a source of material not as a conservation measure'. the net and have been effectively passed over by the CBD (Heywood, 2010). It may be that the procedures involved in in situ species conservation and recovery are either poorly appreciated or alternatively are regarded as too onerous for them to be widely implemented by the Parties although there are some notable exceptions such as Australia, New Zealand, Canada, USA and many European countries. ...
Despite the massive efforts that have been made to conserve plant diversity across the world during the past few decades, it is becoming increasingly evident that our current strategies are not sufficiently effective to prevent the continuing decline in biodiversity. As a recent report by the CBD indicates, current progress and commitments are insufficient to achieve the Aichi Biodiversity Targets by 2020. Threatened species lists continue to grow while the world’s governments fail to meet biodiversity conservation goals. Clearly, we are failing in our attempts to conserve biodiversity on a sufficient scale. The reasons for this situation are complex, including scientific, technical, sociological, economic and political factors. The conservation community is divided about how to respond. Some believe that saving all existing biodiversity is still an achievable goal. On the other hand, there are those who believe that we need to accept that biodiversity will inevitably continue to be lost, despite all our conservation actions and that we must focus on what to save, why and where. It has also been suggested that we need a new approach to conservation in the face of the challenges posed by the Anthropocene biosphere which we now inhabit. Whatever view one holds on the above issues, it is clear that we need to review the effectiveness of our current conservation strategies, identify the limiting factors that are preventing the Aichi goals being met and at the same time take whatever steps are necessary to make our conservation protocols more explicit, operational and efficient so as to achieve the maximum conservation effect. This paper addresses the key issues that underlie our failure to meet agreed targets and discusses the necessary changes to our conservation approaches. While we can justifiably be proud of our many achievements and successes in plant conservation in the past 30 years, which have helped slow the rate of loss, unless we devise a more coherent, consistent and integrated global strategy in which both the effectiveness and limitations of our current policies, action plans and procedures are recognized, and reflect this in national strategies, and then embark on a much bolder and ambitious set of actions, progress will be limited and plant diversity will continue to decline.
... Although we now understand much better the drivers of biodiversity loss (Millennium Ecosystem Assessment , 2005 ), we have underestimated the diffi culties of controlling the relentless forces of destruction. As I have stressed elsewhere (Heywood, 2010 ), we are not winning the argument for biodiversity conservation , a concept that many of the public do not really understand. Moreover, in the last few years the focus is moving away to climate change, although of course biodiversity and climate change are intimately interrelated. ...
Introduction: the changed context When I contributed the final chapter to Plants and Islands (Bramwell, 1979), my conclusions about the future of island organisms and communities were described by the editor as ‘rightly pessimistic’. Now 30 years later, it is perhaps even more difficult to be optimistic about their future. This is despite the fact that the intervening years have seen the coming into force of international treaties and agreements such as CITES, the Convention on Biological Diversity, the Climate Convention, the Migratory Species Convention, the Leipzig Report and the International Treaty on Plant Genetic Resources for Food and Agriculture, as well as the publication of a series of major reports and assessments such as the Agenda 21, the Global Biodiversity Assessment and the Millennium Ecosystem Assessment. The period has also witnessed major advances in our understanding of island floras, their nature, origin, evolution, biogeography, the threats to them and conservation responses, as the preceding chapters in this volume will testify.
Protected Areas (PAs) are fundamental to preserve biodiversity and ecosystem services. Moreover, PAs also provide different cultural, economic and social services for human populations. The interaction of visitors with natural habitats of PAs through contemplation or ecotourism activities (sports, education, and other activities), provides important cultural and social services for human population, reducing the stress and increasing physical and mental health of people. Here, we tested whether the number of tourists in Brazilian Protected Areas is influenced by aquatic resources and their cultural services. Moreover, we evaluated the influence of other variables to explain the number of ecotourism in PAs: size area, age, geographic distance to urban areas, population density of cities around the PA and PA’s popularity. Brazil has a total of 334 Protected Areas administered by the Brazilian Federal Government, from which we obtained the number of tourists to a total of 125 PAs. In 2019, the total number of tourists that visited Brazilian Federal PAs was 14,475,124, moreover, the most visited PA was the National Park of Tijuca situated in the Rio de Janeiro. Our results indicated that PAs more visited presented frequently recreational activities like swimming, canoeing, fishing, boat ride. Besides, PAs more visited are closer to cities, have higher population densities, and have greater popularity (number of hits in the internet). Thus, our results reinforce the importance of aquatic ecosystems as a cultural service jointly with social and demographic factors for Brazilian Protected Areas tourism. Also, it reinforces the importance of developing good strategies with the interaction among different players in the conservation process.
Abstract Concern for climate change has not yet been integrated in protocols for reserve selection. However if climate changes as projected, there is a possibility that current reserve-selection methods might provide solutions that are inadequate to ensure species' long-term persistence within reserves. We assessed, for the first time, the ability of existing reserve-selection methods to secure species in a climate-change context. Six methods using a different combination of criteria (representation, suitability and reserve clustering) are compared. The assessment is carried out using European distributions of 1200 plant species and considering two extreme scenarios of response to climate change: no dispersal and universal dispersal. With our data, 6–11% of species modelled would be potentially lost from selected reserves in a 50-year period. Measured uncertainties varied in 6% being 1–3% attributed to dispersal assumptions and 2–5% to the choice of reserve-selection method. Suitability approaches to reserve selection performed best, while reserve clustering performed poorly. We also found that 5% of species modelled would lose their entire climatic envelope in the studied area; 2% of the species modelled would have nonoverlapping distributions; 93% of the species modelled would maintain varying levels of overlapping distributions. We conclude there are opportunities to minimize species' extinctions within reserves but new approaches are needed to account for impacts of climate change on species; especially for those projected to have temporally nonoverlapping distributions.
Range shifts due to climate change may cause species to move out of protected areas. Climate change could therefore result in species range dynamics that reduce the relevance of current fixed protected areas in future conservation strategies. Here, we apply species distribution modeling and conservation planning tools in three regions (Mexico, the Cape Floristic Region of South Africa, and Western Europe) to examine the need for additional protected areas in light of anticipated species range shifts caused by climate change. We set species representation targets and assessed the area required to meet those targets in the present and in the future, under a moderate climate change scenario. Our findings indicate that protected areas can be an important conservation strategy in such a scenario, and that early action may be both more effective and less costly than inaction or delayed action. According to our projections, costs may vary among regions and none of the three areas studied will fully meet all conservation targets, even under a moderate climate change scenario. This suggests that limiting climate change is an essential complement to adding protected areas for conservation of biodiversity.
International agreements, environmental laws, resource management agencies, and environmental nongovernmental organizations
all establish objectives that define what they hope to accomplish. Unfortunately, quantitative objectives in conservation
are typically set without consistency and scientific rigor. As a result, conservationists are failing to provide credible
answers to the question “How much is enough?” This is a serious problem because objectives profoundly shape where and how
limited conservation resources are spent, and help to create a shared vision for the future. In this article we develop guidelines
to help steer conservation biologists and practitioners through the process of objective setting. We provide three case studies
to highlight the practical challenges of objective setting in different social, political, and legal contexts. We also identify
crucial gaps in our science, including limited knowledge of species distributions and of large-scale, long-term ecosystem
dynamics, that must be filled if we hope to do better than setting conservation objectives through intuition and best guesses.
Potential impacts of projected climate change on biodiversity are often assessed using single-species bioclimatic 'envelope' models. Such models are a special case of species distribution models in which the current geographical distribution of species is related to climatic variables so to enable projections of distributions under future climate change scenarios. This work reviews a number of critical methodological issues that may lead to uncertainty in predictions from bioclimatic modelling. Particular attention is paid to recent developments of bioclimatic modelling that address some of these issues as well as to the topics where more progress needs to be made. Developing and applying bioclimatic models in a informative way requires good understanding of a wide range of methodologies, including the choice of modelling technique, model validation, collinearity, autocorrelation, biased sampling of explanatory variables, scaling and impacts of non-climatic factors. A key challenge for future research is integrating factors such as land cover, direct CO 2 effects, biotic interactions and dispersal mechanisms into species-climate models. We conclude that, although bioclimatic envelope models have a number of important advantages, they need to be applied only when users of models have a thorough understanding of their limitations and uncertainties.
Priority setting is an essential component of biodiversity conservation. Existing methods to identify priority areas for conservation have focused almost entirely on biological factors. We suggest a new relative ranking method for identifying priority conservation areas that integrates both biological and social aspects. It is based on the following criteria: the habitat's status, human population pressure, human efforts to protect habitat, and number of endemic plant and vertebrate species. We used this method to rank 25 hotspots, 17 megadiverse countries, and the hotspots within each megadiverse country. We used consistent, comprehensive, georeferenced, and multiband data sets and analytical remote sensing and geographic information system tools to quantify habitat status, human population pressure, and protection status. The ranking suggests that the Philippines, Atlantic Forest, Mediterranean Basin, Caribbean Islands, Caucasus, and Indo-Burma are the hottest hotspots and that China, the Philippines, and India are the hottest megadiverse countries. The great variation in terms of habitat, protected areas, and population pressure among the hotspots, the megadiverse countries, and the hotspots within the same country suggests the need for hotspot-and country-specific conservation policies.
Key Words national parks, conservation and development, deforestation, tropics ■ Abstract The world's system of protected areas has grown exponentially over the past 25 years, particularly in developing countries where biodiversity is greatest. Con-currently, the mission of protected areas has expanded from biodiversity conservation to improving human welfare. The result is a shift in favor of protected areas allowing local resource use. Given the multiple purposes of many protected areas, measuring effectiveness is difficult. Our review of 49 tropical protected areas shows that parks are generally effective at curtailing deforestation within their boundaries. But defor-estation in surrounding areas is isolating protected areas. Many initiatives now aim to link protected areas to local socioeconomic development. Some of these initiatives have been successful, but in general expectations need to be tempered regarding the capacity of protected areas to alleviate poverty. Greater attention must also be paid to the broader policy context of biodiversity loss, poverty, and unsustainable land use in developing countries.
Modelling strategies for predicting the potential impacts of climate change on the natural distribution of species have often focused on the characterization of a species’ bioclimate envelope. A number of recent critiques have questioned the validity of this approach by pointing to the many factors other than climate that play an important part in determining species distributions and the dynamics of distribution changes. Such factors include biotic interactions, evolutionary change and dispersal ability. This paper reviews and evaluates criticisms of bioclimate envelope models and discusses the implications of these criticisms for the different modelling strategies employed. It is proposed that, although the complexity of the natural system presents fundamental limits to predictive modelling, the bioclimate envelope approach can provide a useful first approximation as to the potentially dramatic impact of climate change on biodiversity. However, it is stressed that the spatial scale at which these models are applied is of fundamental importance, and that model results should not be interpreted without due consideration of the limitations involved. A hierarchical modelling framework is proposed through which some of these limitations can be addressed within a broader, scale-dependent context.
Existing complementarity-based reserve selection techniquesconcerned with maximal biodiversity representation within minimum landarea do not necessarily ensure the long-term maintenance ofbiodiversity. These approaches often ignore the maintenance of naturalprocesses, turnover of feature diversity and the need to minimisethreats within conservation areas. We address these three emergentissues in the identification of potential avian conservation areas inthe Northern Province of South Africa, by combining ordination andspatial autocorrelation analyses, as well as land transformation datainto complementarity-based reserve selection techniques. Existingconservation areas are biased and inefficient and complementarity-basedmethods do little to correct this skew. The inclusion of speciesassemblage structure as well as the underlying environmental gradientsensures a conservation area network that strives to maintain bothbiodiversity pattern and process. Spatial autocorrelation analysisallows for the identification of areas with high diversity,important areas for the long-term maintenance of biodiversity. Theinclusion of land transformation data leads to viable conservation areanetworks and highlights areas of potential conflict between biodiversityconservation interests and human land-use issues. These combinedimprovements on complementarity-based reserve selection techniques bringus a step closer to ensuring the long-term maintenance of biodiversitywithin conservation areas in the northern province.
Aim: Many attempts to predict the potential range of species rely on environmental niche (or 'bioclimate envelope') modelling, yet the effects of using different niche-based methodologies require further investigation. Here we investigate the impact that the choice of model can have on predictions, identify key reasons why model output may differ and discuss the implications that model uncertainty has for policy-guiding applications. Location: The Western Cape of South Africa. Methods: We applied nine of the most widely used modelling techniques to model potential distributions under current and predicted future climate for four species (including two subspecies) of Proteaceae. Each model was built using an identical set of five input variables and distribution data for 3996 sampled sites. We compare model predictions by testing agreement between observed and simulated distributions for the present day (using the area under the receiver operating characteristic curve (AUC) and kappa statistics) and by assessing consistency in predictions of range size changes under future climate (using cluster analysis). Results: Our analyses show significant differences between predictions from different models, with predicted changes in range size by 2030 differing in both magnitude and direction (e.g. from 92% loss to 322% gain). We explain differences with reference to two characteristics of the modelling techniques: data input requirements (presence/absence vs. presence-only approaches) and assumptions made by each algorithm when extrapolating beyond the range of data used to build the model. The effects of these factors should be carefully considered when using this modelling approach to predict species ranges. Main conclusions: We highlight an important source of uncertainty in assessments of the impacts of climate change on biodiversity and emphasize that model predictions should be interpreted in policy-guiding applications along with a full appreciation of uncertainty.
The activities of modern humans have increased the extinction rate of the world's species by up to 1,000 times that observed from the fossil record (1). This extinction crisis has motivated the scientific community to understand the consequences of reduced biodiversity for the dynamics of ecosystems, especially those that provide basic services to human societies. In many cases, we are in the process of damaging ecosystems that we rely on intimately for our own livelihoods. Nevertheless, our understanding of how ecosystems respond to losses of biodiversity remains rudimentary, and ecologists are struggling to understand the implications of future species losses. In a recent issue of PNAS, McIntyre et al. (2) provide an ambitious attempt to understand how the cycling of limiting nutrients in species-rich aquatic ecosystems varies as species are lost from their fish communities. The results presented in that article show that the deterioration of fish biodiversity in the tropics has important consequences for the ecosystems these fish inhabit but also highlight several key points that have been underappreciated by much of biodiversity science.
Protected-area targets of 10% of a biome, of a country, or of the planet have often been used in conservation planning. The
new World Database on Protected Areas shows that terrestrial protected-area coverage now approaches 12% worldwide. Does this
mean that the establishment of new protected areas can cease? This was the core question of the “Building Comprehensive Protected
Area Systems” stream of the Fifth World Parks Congress in Durban, South Africa, in 2003. To answer it requires global gap
analysis, the subject of the special section of BioScience for which this article serves as an introduction. We also provide an overview of the extraordinary data sets now available
to allow global gap analysis and, based on these, an assessment of the degree to which existing protected-area systems represent
biodiversity. Coverage varies geographically, but is less than 2% for some bioregions, and more than 12% of 11,633 bird, mammal,
amphibian, and turtle species are wholly unrepresented. The global protected-area systems are far from complete.
"Despite the volume of the academic conservation biology literature, there is little evidence as to what effect this work is having on endangered species recovery efforts. Using data collected from a national review of 136 endangered and threatened species recovery plans, we evaluated whether recovery plans were changing in response to publication trends in four areas of the academic conservation biology literature: metapopulation dynamics, population viability analysis, conservation corridors, and conservation genetics. We detected several changes in recovery plans in apparent response to publication trends in these areas (e.g., the number of tasks designed to promote the recovery of an endangered species shifted, although these tasks were rarely assigned a high priority). Our results indicate that, although the content of endangered species recovery plans changes in response to the literature, results are not uniform across all topics. We suggest that academic conservation biologists need to address the relative importance of each topic for conservation practice in different settings."
Explicit, quantitative procedures for identifying biodiversity priority areas are replacing the often ad hoc procedures used in the past to design networks of reserves to conserve biodiversity. This change facilitates more informed choices by policy makers, and thereby makes possible greater satisfaction of conservation goals with increased efficiency. A key feature of these procedures is the use of the principle of complementarity, which ensures that areas chosen for inclusion in a reserve network complement those already selected. This paper sketches the historical development of the principle of complementarity and its applications in practical policy decisions. In the first section a brief account is given of the circumstances out of which concerns for more explicit systematic methods for the assessment of the conservation value of different areas arose. The second section details the emergence of the principle of complementarity in four independent contexts. The third section consists of case studies of the use of the principle of complementarity to make practical policy decisions in Australasia, Africa, and America. In the last section, an assessment is made of the extent to which the principle of complementarity transformed the practice of conservation biology by introducing new standards of rigor and explicitness.
The Fifth World Parks Congress in Durban, South Africa, announced in September 2003 that the global network of protected areas now covers 11.5% of the planet's land surface. This surpasses the 10% target proposed a decade earlier, at the Caracas Congress, for 9 out of 14 major terrestrial biomes. Such uniform targets based on percentage of area have become deeply embedded into national and international conservation planning. Although politically expedient, the scientific basis and conservation value of these targets have been questioned. In practice, however, little is known of how to set appropriate targets, or of the extent to which the current global protected area network fulfils its goal of protecting biodiversity. Here, we combine five global data sets on the distribution of species and protected areas to provide the first global gap analysis assessing the effectiveness of protected areas in representing species diversity. We show that the global network is far from complete, and demonstrate the inadequacy of uniform--that is, 'one size fits all'--conservation targets.
Climate change has already triggered species distribution shifts in many parts of the world. Increasing impacts are expected for the future, yet few studies have aimed for a general understanding of the regional basis for species vulnerability. We projected late 21st century distributions for 1,350 European plants species under seven climate change scenarios. Application of the International Union for Conservation of Nature and Natural Resources Red List criteria to our projections shows that many European plant species could become severely threatened. More than half of the species we studied could be vulnerable or threatened by 2080. Expected species loss and turnover per pixel proved to be highly variable across scenarios (27-42% and 45-63% respectively, averaged over Europe) and across regions (2.5-86% and 17-86%, averaged over scenarios). Modeled species loss and turnover were found to depend strongly on the degree of change in just two climate variables describing temperature and moisture conditions. Despite the coarse scale of the analysis, species from mountains could be seen to be disproportionably sensitive to climate change (≈60% species loss). The boreal region was projected to lose few species, although gaining many others from immigration. The greatest changes are expected in the transition between the Mediterranean and Euro-Siberian regions. We found that risks of extinction for European plants may be large, even in moderate scenarios of climate change and despite inter-model variability.
• Intergovernmental Panel on Climate Change storylines
• species extinction
• species turnover
• niche-based model
Predictions of future climate are of central importance in determining actions to adapt to the impacts of climate change and in formulating targets to reduce emissions of greenhouse gases. In the absence of analogues of the future, physically based numerical climate models must be used to make predictions. New approaches are under development to deal with a number of sources of uncertainty that arise in the prediction process. This paper introduces some of the concepts and issues in these new approaches, which are discussed in more detail in the papers contained in this issue.
Atmospheric brown clouds are mostly the result of biomass burning and fossil fuel consumption. They consist of a mixture of light-absorbing and light-scattering aerosols and therefore contribute to atmospheric solar heating and surface cooling. The sum of the two climate forcing terms-the net aerosol forcing effect-is thought to be negative and may have masked as much as half of the global warming attributed to the recent rapid rise in greenhouse gases. There is, however, at least a fourfold uncertainty in the aerosol forcing effect. Atmospheric solar heating is a significant source of the uncertainty, because current estimates are largely derived from model studies. Here we use three lightweight unmanned aerial vehicles that were vertically stacked between 0.5 and 3 km over the polluted Indian Ocean. These unmanned aerial vehicles deployed miniaturized instruments measuring aerosol concentrations, soot amount and solar fluxes. During 18 flight missions the three unmanned aerial vehicles were flown with a horizontal separation of tens of metres or less and a temporal separation of less than ten seconds, which made it possible to measure the atmospheric solar heating rates directly. We found that atmospheric brown clouds enhanced lower atmospheric solar heating by about 50 per cent. Our general circulation model simulations, which take into account the recently observed widespread occurrence of vertically extended atmospheric brown clouds over the Indian Ocean and Asia, suggest that atmospheric brown clouds contribute as much as the recent increase in anthropogenic greenhouse gases to regional lower atmospheric warming trends. We propose that the combined warming trend of 0.25 K per decade may be sufficient to account for the observed retreat of the Himalayan glaciers.
Recent attempts at projecting climate change impacts on biodiversity have used the IUCN Red List Criteria to obtain estimates of extinction rates based on projected range shifts. In these studies, the Criteria are often misapplied, potentially introducing substantial bias and uncertainty. These misapplications include arbitrary changes to temporal and spatial scales; confusion of the spatial variables; and assume a linear relationship between abundance and range area. Using the IUCN Red List Criteria to identify which species are threatened by climate change presents special problems and uncertainties, especially for shorter-lived species. Responses of most species to future climate change are not understood well enough to estimate extinction risks based solely on climate change scenarios and projections of shifts and/or reductions in range areas. One way to further such understanding would be to analyze the interactions among habitat shifts, landscape structure and demography for a number of species, using a combination of models. Evaluating the patterns in the results might allow the development of guidelines for assigning species to threat categories, based on a combination of life history parameters, characteristics of the landscapes in which they live, and projected range changes.
Aim Concern over the implications of climate change for biodiversity has led to the use of species–climate ‘envelope’ models to forecast risks of species extinctions under climate change scenarios. Recent studies have demonstrated significant variability in model projections and there remains a need to test the accuracy of models and to reduce uncertainties. Testing of models has been limited by a lack of data against which projections of future ranges can be tested. Here we provide a first test of the predictive accuracy of such models using observed species’ range shifts and climate change in two periods of the recent past.
Location Britain.
Methods Observed range shifts for 116 breeding bird species in Britain between 1967 and 1972 (t1) and 1987–91 (t2) are used. We project range shifts between t1 and t2 for each species based on observed climate using 16 alternative models (4 methods × 2 data parameterizations × 2 rules to transform probabilities of occurrence into presence and absence records).
Results Modelling results were extremely variable, with projected range shifts varying both in magnitude and in direction from observed changes and from each other. However, using approaches that explore the central tendency (consensus) of model projections, we were able to improve agreement between projected and observed shifts significantly.
Conclusions Our results provide the first empirical evidence of the value of species–climate ‘envelope’ models under climate change and demonstrate reduction in uncertainty and improvement in accuracy through selection of the most consensual projections.
Over the last three decades a great deal of research, money, and effort have been put into the development of theory and techniques designed to make conservation more efficient. Much of the recent emphasis has been on methods to identify areas of high conservation interest and to design efficient networks of nature reserves. Reserve selection algorithms, gap analysis, and other computerized approaches have much potential to transform conservation planning, yet these methods are used only infrequently by those charged with managing landscapes. We briefly describe different approaches to identifying potentially valuable areas and methods for reserve selection and then discuss the reasons they remain largely unused by conservationists and land-use planners. Our informal discussions with ecologists, conservationists, and land managers from Europe and the United States suggested that the main reason for the low level of adoption of these sophisticated tools is simply that land managers have been unaware of them. Where this has been the case, low levels of funding, lack of understanding about the purpose of these tools, and general antipathy toward what is seen as a prescriptive approach to conservation all play a part. We recognize there is no simple solution but call for a closer dialogue between theoreticians and practitioners in conservation biology. The two communities night be brought into closer contact in numerous ways, including carefully targeted publication of research and Internet communication. However it is done, we feel that the needs of land managers need to be catered to by those engaged in conservation research and that managers need to be more aware of what science can contribute to practical conservation.
Climate envelope models (CEMs) have been used to predict the distribution of species under current, past, and future climatic conditions by inferring a species' environmental requirements from localities where it is currently known to occur. CEMs can be evaluated for their ability to predict current species distributions but it is unclear whether models that are successful in predicting current distributions are equally successful in predicting distributions under different climates (i.e. different regions or time periods). We evaluated the ability of CEMs to predict species distributions under different climates by comparing their predictions with those obtained with a mechanistic model (MM). In an MM the distribution of a species is modeled based on knowledge of a species' physiology. The potential distributions of 100 plant species were modeled with an MM for current conditions, a past climate reconstruction (21 000 years before present) and a future climate projection (double preindustrial CO2 conditions). Point localities extracted from the currently suitable area according to the MM were used to predict current, future, and past distributions with four CEMs covering a broad range of statistical approaches: Bioclim (percentile distributions), Domain (distance metric), GAM (general additive modeling), and Maxent (maximum entropy). Domain performed very poorly, strongly underestimating range sizes for past or future conditions. Maxent and GAM performed as well under current climates as under past and future climates. Bioclim slightly underestimated range sizes but the predicted ranges overlapped more with the ranges predicted with the MM than those predicted with GAM did. Ranges predicted with Maxent overlapped most with those produced with the MMs, but compared with the ranges predicted with GAM they were more variable and sometimes much too large. Our results suggest that some CEMs can indeed be used to predict species distributions under climate change, but individual modeling approaches should be validated for this purpose, and model choice could be made dependent on the purpose of a particular study.
Global average surface temperatures have increased rapidly over the last 100 years and there is accumulating evidence that climate change is already causing shifts in species’ distributions. We use extensive abundance data and expected range shifts across altitudinal gradients to predict changes in total population size of rainforest birds of Australian tropical rainforests in response to climate warming. According to our most conservative model scenario, 74% of rainforest birds of north-eastern Australia are predicted to become threatened (including 26 critically endangered species) as a result of projected mid-range warming expected within the next 100 years. Extinction risk varies according to where along the altitudinal gradient a species is currently most abundant. Upland birds are most affected and are likely to be immediately threatened by even small increases in temperature. In contrast, there is a capacity for the population size of lowland species to increase, at least in the short term. We conclude that abundance data collected across climatic gradients will be fundamental to gaining an understanding of population size change associated with climate warming.
Key needs for the creation of a nature reserve system are outlined: formulating goals, selecting management categories, taking inventory, identifying gaps, designing reserves, measuring reserve condition and vulnerability, and recognizing the relationship between research and management. Some essential components are highlighted: a regional perspective, diversification of management categories, focus on the economics of human welfare, not ignoring the opportunities small reserves can provide for some biota, addition of marine reserves, and the importance of a focus on natural processes. The view some Americans have of indigenous people and protected areas is not compatible with third world realities. Since the problems and challenges of protecting areas in northern and southern countries are alike in many ways, however, a Eurocentric seeking to articulate the special circumstances faced by tropical countries offers these suggestions.
A prerequisite for preserving maximum biological diversity in a given biological domain is to identify a reserve network which includes every possible species. Two algorithms are presented which define the smallest number of wetlands on the Macleay Valley floodplain, Australia, which include all of the wetland plant species. One of these algorithms maximises species richness. The other is constrained to ensure each of nine wetland types is represented, as well as all species.To represent every plant species at least once, only 4·6% of the total number of wetlands is required, but they constitute 44·9% of the total wetland area. In order to represent all types of wetlands, as well as all plant species, 75·3% of the total wetland area is required. The results can be constrained to achieve other conservation goals such as preserving naturalness, rarity, population size, etc., by imposing conditions on rules within the algorithms. In this way a reserve network chosen to maximise diversity can be manipulated to optimise other conservation values.
Nature conservation has changed from an idealistic philosophy to a serious technology(J. Harper, 1992)A review is given of the major conceptual changes that have taken place during the last 50 years in our understanding of the nature of plant conservation and of the principal methodological advances in undertaking conservation assessments and actions, largely through the incorporation of tools and techniques from other disciplines. The interrelationships between conservation and sustainable use are considered as well as the impact of the development of the discipline of conservation biology, the effects of the general acceptance of the concept of biodiversity and the practical implications of the implementation of the Convention on Biological diversity. The effect on conservation policy and management of the accelerating loss or conversion of habitats throughout the world and approaches for combating this are discussed.
The forests and highlands along the southern portion of the Nigeria-Cameroon border and on the island of Bioko have long been recognized as being biologically diverse. This region (referred to as the Biafran forests and highlands) is a center of endemism for a wide variety of taxa including, but not limited to, primates, anuran amphibians, birds, freshwater fish, butterflies, dragonflies, and trees. Though these groups have diverse distributions, conservation efforts have to date largely been focused on lowland areas. We conducted a GIS-based analysis of point locality records for three groups characterized by high endemism (primates, anuran amphibians, birds) in order to examine both their spatial and altitudinal distribution throughout the study area. We also evaluated the distribution of existing and potential protected areas relative to highland areas and the distribution of endemics. Our analysis suggests that the existing protected area system provides poor coverage of montane habitats and their associated endemic taxa. Complementarity analysis suggests that, if the protected area network were expanded to include a small number of highland sites, coverage of endemic taxa could be significantly improved. Many of these important highland sites are currently under intense pressure from habitat loss and hunting. If the full range of biodiversity present in the Biafran forests and highlands is to be preserved, new protected areas should be gazetted that take the varied distributions of the regions endemic taxa into account.
Throughout history, increasing population has driven the need to increase agricultural efficiency, so averting successive 'malthusian' disasters. In the twentieth century, the application of scientific knowledge to agriculture yielded tremendous dividends, enabling cereal yields to increase threefold since 1950. But with the world's population projected to reach nine billion by the middle of this century, new ways must be found to increase yields while preserving natural habitats and biodiversity.
The intention and practice of conservation reserve selection are different. A major reason for systems of reserves is to sustain biological diversity. This involves protecting examples of as many natural features, e.g. species, communities or environments, as possible. In reality, however, new reserves have rarely been dedicated for their representation of features. Furthermore, the opportunism that has characterized the development of reserve systems can actually jeopardize the representation of all features in reserves through the inefficient allocation of limited resources. More systematic approaches are essential if reserves are to play their role in protecting biodiversity. Some basic principles for conservation planning are emerging from recent systematic procedures for reserve selection. These principles will help to link intention and practice.
Restoration of different kinds of habitat require the establishment of a set of general ecological principles, which are addressed in this volume via sections on assembling whole systems in the field (where practical expertise in reclaiming derelict land, prairies, forests and lakes is reported); synthetic ecology (laboratory assembly of marine microcosms and changing Drosophila community structures); partial restoration in the field (with contributions on reintroduction as a means of studying bird behaviour, colonisation and persistence in plant communities, population interactions, mycorrhizae and succession, and mutualism in disturbed habitats); restored systems as opportunities for basic research (including examples from forest and prairie landscapes); and problems of actually undertaking restoration ecology (eg in scaling, and in predicting minimal viable population sizes). -P.J.Jarvis
There is now clear scientific evidence that emissions from economic activity, particularly the burning of fossil fuels for energy, are causing changes to the Earth´s climate. A sound understanding of the economics of climate change is needed in order to underpin an effective global response to this challenge. The Stern Review is an independent, rigourous and comprehensive analysis of the economic aspects of this crucial issue. It has been conducted by Sir Nicholas Stern, Head of the UK Government Economic Service, and a former Chief Economist of the World Bank. The Economics of Climate Change will be invaluable for all students of the economics and policy implications of climate change, and economists, scientists and policy makers involved in all aspects of climate change.
Climate change over the past approximately 30 years has produced numerous shifts in the distributions and abundances of species and has been implicated in one species-level extinction. Using projections of species' distributions for future climate scenarios, we assess extinction risks for sample regions that cover some 20% of the Earth's terrestrial surface. Exploring three approaches in which the estimated probability of extinction shows a power-law relationship with geographical range size, we predict, on the basis of mid-range climate-warming scenarios for 2050, that 15-37% of species in our sample of regions and taxa will be 'committed to extinction'. When the average of the three methods and two dispersal scenarios is taken, minimal climate-warming scenarios produce lower projections of species committed to extinction ( approximately 18%) than mid-range ( approximately 24%) and maximum-change ( approximately 35%) scenarios. These estimates show the importance of rapid implementation of technologies to decrease greenhouse gas emissions and strategies for carbon sequestration.
This study is focused on the global expansion of protected-area coverage that occurred during the 1980--2000 period. We examine the multi-scale patterning of four of the basic facets of this expansion: i) estimated increases at the world-regional and country-level scales of total protected-area coverage; ii) transboundary protected areas; iii) conservation corridor projects; and iv) type of conservation management. Geospatial patterning of protected-area designations is a reflection of the priorities of global conservation organizations and the globalization of post-Cold War political and economic arrangements. Local and national-level factors (political leadership and infrastructure) as well as international relations such as multilateral and bilateral aid combine with these globalization processes to impact the extent, type, and location of protected-area designations. We conclude that the interaction of these factors led to the creation and reinforcement of marked spatial differences (rather than tendencies toward worldwide evenness or homogenization) in the course of protected-area expansion during the 1980--2000 period.
The centrality of protected areas in biodiversity conservation has not changed over the past three decades, but we now know that biodiversity conservation represents a much more complex and dynamic picture than was once thought. In contrast to the earlier primarily aesthetic motivation (and still valid in its own right), the role of protected areas in biodiversity conservation is now widely accepted. Internationally, their importance has been recognized by the Convention on Biological Diversity and by the creation of intergovernmental funding agencies such as the Global Environmental Facility. As I discuss here, the rate of creation of new protected areas has increased rapidly to meet the need for a protected representative set of the ecosystems of the world. But that is only the start of the task.
Reserve networks figure prominently in conservation strategies that aim to reduce extinction rates. We tested the effectiveness of the current reserve network at protecting species at risk in Canada, where relatively extensive wilderness areas remain. We compared numbers of terrestrial species at risk included in existing reserves to randomly generated networks with the same total area and number of reserves. Existing reserve networks rarely performed better than randomly selected areas and several included fewer endangered species than expected by chance, particularly in the most biologically imperiled regions. The extent of protected area and density of species at risk were unrelated at either broad (countrywide) or finer spatial scales (50 x 50 km grids), although there was a tendency for the most threatened regions of the country to have few or no protected areas (1.5% of areas with >30 endangered species were in reserves). Although reserves will play a useful role in conserving endangered species that occur within them, reducing extinction rates in a region with much of the world's remaining wilderness will require integrating conservation strategies with agricultural and urban land-use plans outside formally protected areas.
Indicator groups may be important tools with which to guide the selection of networks of areas for conservation. Nevertheless, the literature provides little guidance as to what makes some groups of species more suitable than others to guide area selection. Using distributional data on all sub-Saharan birds and mammals, we assessed factors that influence the effectiveness of indicator groups. We assessed the influence of threatened, endemic, range-restricted, widespread, and large-bodied species by systematically varying their number in indicator groups. We also assessed the influence of taxonomic diversity by systematically varying the number of distinct genera and families within the indicator groups. We selected area networks based on the indicator groups and tested their ability to represent a set of species, which, in terms of species composition, is independent of the indicator group. Increasing the proportion of threatened, endemic, and range-restricted species in the indicator groups improved effectiveness of the selected area networks; in particular it improved the effectiveness in representing other threatened and range-restricted species. In contrast increasing the proportion of widespread and large-bodied species decreased effectiveness. Changes in the number of genera and families only marginally affected the performance of indicator groups. Our results reveal that a focus on species of special conservation concern, which are legitimate conservation targets in their own right, also improves the effectiveness of indicator groups, in particular in representing other species of conservation concern.
