The value of the IUCN Red List for conservation

The IUCN Red List of Threatened Species is the most comprehensive resource detailing the global conservation status of plants and animals. The 2004 edition represents a milestone in the four-decade long history of the Red List, including the first Global Amphibian Assessment and a near doubling in assessed species since 2000. Moreover, the Red List assessment process itself has developed substantially over the past decade, extending the value of the Red List far beyond the assignation of threat status. We highlight here how the Red List, in conjunction with the comprehensive data compiled to support it and in spite of several important limitations, has become an increasingly powerful tool for conservation planning, management, monitoring and decision making.     

Using the IUCN Red List to determine effective conservation strategies

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. Yet 37 mammal species genuinely improved in status in the 2009 IUCN Red List, suggesting there are ways to successfully conserve biodiversity. Here, I compare the threats and conservation actions (proposed and implemented) by the expert assessors of the Red List of improving species to a further 144 declining mammal species to determine whether specific threats were more easily remedied, and whether certain conservation actions were more successful than others. Declining species were faced with different threatening processes to mammals improving in status suggesting some threats were easier to treat (e.g. hunting) than others (climate change, invasive species). Declining species had different proposed and implemented conservation actions than improving species suggesting some actions are more successful than others. Threatened species were invariably found in conservation areas, suggesting protected area creation alone is not an overly successful strategy for species at risk of extinction. Conservation actions were more frequently implemented for improving than declining species suggesting active conservation is effective in improving the status of biodiversity. There were significant differences between proposed and implemented conservation actions suggesting some actions are easier to implement than others. Reintroduction, captive breeding and hunting restriction were more effective in conserving mammals than site creation and invasive species control. These findings highlight effective conservation actions for mammals worldwide and allow the rationalisation of threat mitigation measures to ensure economically justifiable biodiversity conservation strategies.     

Using species distribution models for IUCN Red Lists of threatened species

Red Lists have been used for years globally and regionally in many countries to highlight species that need special attention because of the rarity or rapid decline of their populations. To ensure homogenized classification at the global and regional level, the International Union for Conservation of Nature (IUCN) defined categories of threat, and criteria to attribute the taxa to these categories. Nevertheless, the strict application of the criteria is not always straightforward, especially for invertebrates, because of the difficulties associated with precise estimates of the size and viability of their populations. This paper presents a method for the estimation of extent of occurrence (EOO) and area of occupancy (AOO) based on species distribution models using multivariate adaptive regression splines. To achieve this, presence data have been modeled against topographical and climatic explanatory variables. Predictions from the statistical distribution models have then been cut using the minimal convex hull around (EOO) or the watersheds in which (AOO) the species have really been observed in recent years. This allows us to delimit the EOO and AOO according to the IUCN criteria, and better take into account the ecological requirements of the species. Furthermore, the method allows for the use of historical data (e.g. from museum’s collections) and the direct comparison of historical and recent distributions of species. The method has been tested on six species of butterflies. The results show the possibility of using species distribution models to define the Red Lists status according to the IUCN guidelines, and shows that the results are consistent with previous Red Lists assessments.     

Prioritizing species for conservation planning

The efforts to protect biological diversity must be prioritized because resources for nature conservation are limited. Conservation prioritization can be based on numerous criteria, from ecological integrity to species representation, but in this review I address only species-level prioritization. Criteria used for species prioritization range from aesthetical to evolutionary considerations, but I focus on the aspects that are biologically relevant. I distinguish between two main aspects of diversity that are used as objectives: Maintenance of biodiversity pattern, and maintenance of biodiversity process. I identify two additional criteria typically used in species prioritization that serve for achieving the objectives: The species’ need of protection, and cost and effectiveness of conservation actions. I discuss how these criteria could be combined with either of the objectives in a complementarity-based benefit function framework for conservation prioritization. But preserving evolutionary process versus current diversity pattern may turn out to be conflicting objectives that have to be traded-off with each other, if pursued simultaneously. Although many reasonable criteria and methods exist, species prioritization is hampered by uncertainties, most of which stem from the poor quality of data on what species exist, where they occur, and what are the costs and benefits of protecting them. Surrogate measures would be extremely useful but their performance is still largely unknown. Future challenges in species prioritization lie in finding ways to compensate for missing information.     

Application of IUCN Red Listing Criteria at the Regional and National Levels: A Case Study from Central Asia

We assessed the threatened status of 163 Central Asian vertebrates using the IUCN Red List Criteria (Version 3.1) at the national and regional levels, and compared these assessments to the global assessments given in the IUCN 2002 Red List. We thus compared threat status at three spatial scales; national for five countries separately (Kazakhstan, Kyrgyzstan, Tadjikistan, Turkmenistan, Uzbekistan), regional for the five countries together, and global. This analysis was undertaken as a test of the applicability of IUCN criteria at the sub-global level. Generally the criteria worked well. In 4% of cases, the threat category was lower at the smaller scale of assessment. This was predominately caused by the use of decline rate criteria at the larger scale when populations at the smaller scale were stable. We also encountered issues with the listing of migratory species at the sub-global level. We used our data to carry out a preliminary assessment of Protected Area coverage in the region, and found evidence suggesting that threatened species and endemics are not well covered by the current protected area system.     

Application of IUCN criteria and Red List categories to species of five Anacardiaceae genera in Madagascar

The conservation status of five genera of Anacardiaceae in Madagascarwas determined by applying IUCN risk assessment criteria to recent taxonomicrevisions and available specimen data. A major problem in establishing protocolsfor efficiently protecting and conserving Madagascar's biodiversity is the lackof essential biological information. In light of this, primary occurrence dataappears to be an invaluable tool for assessing both current and historic speciesdistributions. GIS technology was used to create species distribution maps forhistoric vs. recent occurrence data to analyze the change in conservationstatus, extent of occurrence, and area of occupancy for each of the targetspecies. A GAP analysis reveals that 14 (100%) of the target species for whichdata were available are considered threatened by IUCN standards. Furthermore, 11(79%) species showed a decrease both in the number of subpopulations and theirextent of occurrence when compared to historic distributions. This studyhighlights the importance of two factors necessary to address modernconservation questions. Sound conclusions regarding the conservation status ofindividual species requires a strong taxonomic framework and good collectiondata for a species distribution. However, because specimen data are very oftenincomplete and biased both geographically and taxonomically, reaching soundconclusions requires field knowledge of individual species to compensate forthese limitations.     

Application to the terrestrial vertebrates of Italy of a system proposed by IUCN for a new classification of national Red List categories

The criteria for classification set down in the new system of the IUCN Red List categories were applied to national distribution areas. Application of the new criteria to national distribution areas calls for an estimate of the rate of immigration. Classification was applied to the Italian autochthonous terrestrial vertebrate species that reproduce in Italy (Amphibia, Reptilia, Aves and Mammalia). Species with both marine and land habitats were included, but Cetaceans were excluded. Eighty-eight species of the autochthonous species that reproduce in Italy were classified in the threatened categories at the national level. One of the main purposes of the present classification of the risk of extinction in national distribution areas is to provide the information needed to define global conservation priorities of species present on national territory. The species nationally and/or globally endangered or at lower risk were grouped into four priority classes, on the basis of their reproductive phenology on national territory and the size of temporarily present contingents. Of the 551 species present regularly or seasonally on Italian territory, 149 (27.0%) are in the initial indicative list of conservation priorities.     

Using long-term ornithological studies in setting targets for conservation in Britain

Long-term studies are necessary in conservation work for two main purposes: monitoring of population parameters, and defining habitat requirements to set targets for conservation action. Apart from their intrinsic interest, birds may be of value also as a means of monitoring the wider environment. Current developments include the integration of measures of breeding performance and survival with those of population size. This will also aid early warning of changes. The range of normal variation in these measures needs assessment to identify limits beyond which action is needed. Monitoring studies need to be reported in appropriate habitat or geographical units, but cover as wide a geographical area as possible in a coordinated manner, to provide context. Long-term studies are required for defining requirements, as needs may vary with overall population size, weather conditions, and other features which differ between years. Population studies based on age-structures at a moment in time may not be a good approximation of the real performance as assessed by following age-cohorts through time. This may be especially so in rare species. For these, sample sizes also present problems in short studies. Long-term studies may be required also to identify the needs of less obvious components of populations, such as immature individuals.     

The pitfall-trap of species conservation priority setting

To elucidate the factors underlying species conservation priority setting, we analysed the relationships among species’ structural complexity, scientific attention, threatened species listing, and conservation investments at different organisational levels, including global, European, national, and sub-national. Although the literature often highlights the need to consider criteria other than extinction risk status, our results show that an excessive use of Red lists still persists in the setting of conservation priorities. We found that organismal complexity, available scientific information, and species listing combine together to create a positive feed-back loop, in which more complex organisms have a larger proportion of threatened species in the Red lists and legal lists. This bias promotes research that is devoted to understanding conservation problems as well as more funds invested to solve them. We propose that a sort of pitfall-trap is currently constraining the species conservation priority setting, in which few species, mainly threatened and better-known species, tend to receive most of the funds and policy attention. To counteract this pitfall-trap, we highlight the need to increase scientific effort on lower taxa and expand Red lists to assess lesser-known taxonomic groups as well as the need to use other criteria for species conservation prioritisation.     

Associations of invasive alien species and other threats to IUCN Red List species (Chordata: vertebrates)

Apart from acting synergistically or additively, threats to species may be associated or disassociated. Here we link global data on threatened Chordata species, mainly birds, mammals, and amphibians, with a probabilistic methodology to test whether the impact from invasive alien species co-occurs purely randomly, associated, or disassociated with impact from nine other major threats to biodiversity listed in the International Union for Conservation of Nature Red List database. Impacts from several of the other threats, in particular from natural disasters, are associated with the impact from invasive alien species. Three of the threats of anthropogenic origin, namely habitat loss, harvesting, and human disturbance, co-occur randomly with impact from invaders, and we suggest several explanations to this unexpected relationship, such as ambiguous evidence for associations between them and human-induced disturbances. Impact from invasive alien predators has a strong association with impact from native predators, indicating that similarity in autecology affects co-occurrences between threats. The threat from invasive predators is disassociated from intrinsic factors on islands, probably because species suffering from for instance inbreeding problems have low densities and rarely encounter invasive alien predators. The analysis of co-occurrence of impact from invasive alien species and other threats is a first step to understand and mitigate vulnerability of a community to the simultaneous exposure to invasive alien species and other threats. Association or disassociation between threats may depend on correlations between exposures and sensitivity to the threats or on the presence of one threat increasing or decreasing the sensitivity to another.     

Applying the IUCN Red List criteria to small-sized plants on oceanic islands: conservation implications for threatened bryophytes in the Canary Islands

The International Union for Conservation of Nature (IUCN) Red List categories and criteria were applied to small-sized spore-producing plants with high dispersal capacities (bryophytes). The application of some of the IUCN criteria to bryophytes in small and highly environmental diverse islands implies several problems. The criteria applicability increases when the occupancy area is reduced. However, for common species restricted to a single type of vegetation belt, the use of the IUCN criteria is problematic because of inapplicable and/or misleading thresholds. We adapted the IUCN criteria by modifying the occupancy and occurrence area sizes and by specifying the location. This approach allowed us to establish the first Red List for the bryophyte species in the Canaries, which comprises 105 species (67 mosses and 38 liverworts); among them, 7 are critically endangered, 20 are endangered and 78 are vulnerable. Twenty-six species were classified as near-threatened, 245 were considered to be at low risk and 125 were data deficient (DD). Among the DD ones, 19 corresponded to newly reported species (DD-n) and 40 had no records during the last 30?years (DD-va). Our findings show that the freshwater habitats as well as the habitats in the most restricted cloud forests (with Erica platycodon) contain the majority of the threatened species, followed by other types of laurel forests and high mountain habitats.     

Prioritizing species,pathways, and sites to achieve conservation targets for biological invasion

Prioritization is indispensable for the management of biological invasions, as recognized by the Convention on Biological Diversity, its current strategic plan, and specifically Aichi Target 9 that concerns invasive alien species. Here we provide an overview of the process, approaches and the data needs for prioritization for invasion policy and management, with the intention of informing and guiding efforts to address this target. Many prioritization schemes quantify impact and risk, from the pragmatic and action-focused to the data-demanding and science-based. Effective prioritization must consider not only invasive species and pathways (as mentioned in Aichi Target 9), but also which sites are most sensitive and susceptible to invasion (not made explicit in Aichi Target 9). Integrated prioritization across these foci may lead to future efficiencies in resource allocation for invasion management. Many countries face the challenge of prioritizing with little capacity and poor baseline data. We recommend a consultative, science-based process for prioritizing impacts based on species, pathways and sites, and outline the information needed by countries to achieve this. This should be integrated into a national process that incorporates a broad suite of social and economic criteria. Such a process is likely to be feasible for most countries.     

Risks of biological control for conservation purposes

Striking successes in classical biological control in agriculture and rangelands engender great interest in using this technology for wildlands conservation and environmental purposes. However, well known unintended consequences of several biological control projects have led to concern that possible environmental benefits do not warrant inherent risks. Four risks demand attention: (1) direct attack on non-targets; (2) indirect effects on non-targets; (3) dispersal of a biocontrol agent to a new area, either autonomously or with deliberate or inadvertent human assistance; (4) changed relationships between a control agent and a native species, particularly as generated by global climate change. Procedures for assessing risk of direct attack on non-targets by phytophagous biological control agents have steadily improved and an expanded centrifugal phylogenetic approach appears to provide adequate insight. Direct non-target impacts by entomophages are more difficult to predict. Myriad possible indirect effects, some subtle but nonetheless important, present a far greater challenge, and techniques of assessing such risks are in their earliest infancy and not as closely regulated. Despite prominent examples in both the general invasion literature and that for biological control, the risk that a species, once introduced, will spread beyond its intended range, and the consequences of such spread, are not routinely treated by risk assessors. This phenomenon deserves far more attention. Global changes—especially climate change—can lead to modified ranges and efficacies of introduced biological control agents and their targets. Although many examples show that climatic niches are often not conserved, an important first routine step would be to combine climatic envelopes with general circulation models for predicted future climates. Finally, actions based on a risk assessment are always implemented in a framework of predicted costs and benefits, which are inevitably asymmetric, so it is critically important that all stakeholders, including conservationists, participate in the decision-making process.     

A practical guide to the application of the IUCN Red List of Ecosystems criteria

The newly developed IUCN Red List of Ecosystems is part of a growing toolbox for assessing risks to biodiversity, which addresses ecosystems and their functioning. The Red List of Ecosystems standard allows systematic assessment of all freshwater, marine, terrestrial and subterranean ecosystem types in terms of their global risk of collapse. In addition, the Red List of Ecosystems categories and criteria provide a technical base for assessments of ecosystem status at the regional, national, or subnational level. While the Red List of Ecosystems criteria were designed to be widely applicable by scientists and practitioners, guidelines are needed to ensure they are implemented in a standardized manner to reduce epistemic uncertainties and allow robust comparisons among ecosystems and over time. We review the intended application of the Red List of Ecosystems assessment process, summarize ‘best-practice’ methods for ecosystem assessments and outline approaches to ensure operational rigour of assessments. The Red List of Ecosystems will inform priority setting for ecosystem types worldwide, and strengthen capacity to report on progress towards the Aichi Targets of the Convention on Biological Diversity. When integrated with other IUCN knowledge products, such as the World Database of Protected Areas/Protected Planet, Key Biodiversity Areas and the IUCN Red List of Threatened Species, the Red List of Ecosystems will contribute to providing the most complete global measure of the status of biodiversity yet achieved.     

关于IUCN红色名录类型和标准的应用

１９９４年底,ＩＵＣＮ（世界保护联盟）正式公布了“红色名录类型”,对物种受威胁的情况作了比较客观的分类,提出了许多具体的数量标准以便进行分析判断。本文概略介绍该分类系统及其划分标准的实际应用,供开展物种受威胁的评估工作参考     

Green Plants in the Red: A Baseline Global Assessment for the IUCN Sampled Red List Index for Plants

Plants provide fundamental support systems for life on Earth and are the basis for all terrestrial ecosystems; a decline in plant diversity will be detrimental to all other groups of organisms including humans. Decline in plant diversity has been hard to quantify, due to the huge numbers of known and yet to be discovered species and the lack of an adequate baseline assessment of extinction risk against which to track changes. The biodiversity of many remote parts of the world remains poorly known, and the rate of new assessments of extinction risk for individual plant species approximates the rate at which new plant species are described. Thus the question ‘How threatened are plants?’ is still very difficult to answer accurately. While completing assessments for each species of plant remains a distant prospect, by assessing a randomly selected sample of species the Sampled Red List Index for Plants gives, for the first time, an accurate view of how threatened plants are across the world. It represents the first key phase of ongoing efforts to monitor the status of the world’s plants. More than 20% of plant species assessed are threatened with extinction, and the habitat with the most threatened species is overwhelmingly tropical rain forest, where the greatest threat to plants is anthropogenic habitat conversion, for arable and livestock agriculture, and harvesting of natural resources. Gymnosperms (e.g. conifers and cycads) are the most threatened group, while a third of plant species included in this study have yet to receive an assessment or are so poorly known that we cannot yet ascertain whether they are threatened or not. This study provides a baseline assessment from which trends in the status of plant biodiversity can be measured and periodically reassessed.