Future Biodiversity Loss Research Articles

Sudden change of fish functional compositions during a drought in the wet season of the middle Yangtze River, China

Climate anomalies such as drought may lead to cascading effects on river ecosystems, ultimately resulting in the change of aquatic biocenosis. Here, we investigated functional assemblies of fish communities at three sites below the Gezhouba Dam of the middle Yangtze River in China before and during a drought event from 2021 to 2022. As the drought proceeded, the richness of the fish functional groups decreased, and the abundance of demersal/invertivore species increased. These changes might indicate adaptive responses of fish communities to the reduction in water volume and shrinkage in habitat areas. The shifts in functional structure also caused fish communities to become more similar during the drought. The null model based on functional traits showed a distance effect of the fish community assembly rules. The communities close to the dam were structured more stochastically under drought stress, which may be attributed to the impact of ecological operation by cascade hydro-junctions. In contrast, the communities far away from the dam were structured by environmental filtering. Our results support the hypothesis that the natural hydrological regime is the main force driving the spatiotemporal dynamic of riverine fish assemblages, and the drought stress on fish communities may need more attention to cope with future biodiversity loss under global climate changes.

Underprediction of extirpation and colonisation following climate and land‐use change using species distribution models

AbstractAimTo evaluate the performance of species distribution models in predicting observed colonisations, persistences and extirpations in response to changes in climate and land use over a multi‐decadal period.LocationSweden.MethodsWe use historical (early 20th century) land use and climate data to build species distribution models for 84 plant species across three provinces of Sweden. Model performance was then evaluated internally using a subset of the historical data for cross‐validation, as well as by using the models to project occurrences to the modern day and validating them with observed occurrences from 1990 to 2020. We then analysed predicted and observed occurrences in the modern period in terms of persistence, extirpation (local extinction) and colonisation in relation to species' habitat and climate associations.ResultsWe found overall high agreement between evaluation methods, although internal evaluation gave consistently higher values for model performance (using true skill statistic, TSS). Overall, extirpations were worst predicted, with on average fewer than one‐third of each species' extirpations being foreseen by the models. Colonisations were better predicted, while persistences were relatively well‐predicted. Predictive accuracy of colonisations was higher for species with relatively warmer temperature associations (climate‐driven expansion), while extirpations were better predicted in cool‐related species (retractions at cool edges). Colonisations of forest‐associated species were more common than predicted (underpredicted), despite widespread patterns of afforestation. Assessing grid‐cell level turnover, we found that in grid cells that experienced the largest changes in terms of climate and land use, predicted extirpations were less likely to have happened.Main ConclusionsWe found that commonly applied modelling approaches have limited ability to predict observed changes in species occurrences, especially extirpations. This suggests that we should take predictions of future biodiversity loss very seriously. However, the ability for species to (at least temporarily) persist in unsuitable conditions could be an opportunity for biodiversity conservation.

Protecting wild bird nests against predators: A systematic review and meta‐analysis of non‐lethal methods

Abstract Implementing effective, affordable and ethical conservation management will be crucial for minimising future biodiversity losses. Such management requires reliable foundational evidence to help managers make informed choices about how to address the needs of their target species. Unfortunately, such evidence is still lacking for many species and management scenarios. One major global challenge is improving the reproductive success of threatened species in the context of predation. We conducted a systematic review and meta‐analysis of in situ experiments that used non‐lethal methods to protect bird nests against predators, with the aims of summarising global trends in nest protection efforts, comparing the effectiveness of different protection measures and informing future research and management. We considered peer‐reviewed studies in English. We detected a large geographic and taxonomic bias in the evidence base with 58% of articles conducted in North America and 76% on ground‐nesting birds. Less than 3% of articles involved taxa listed as Endangered or Critically Endangered and 51% of study units lasted just a single breeding season. Nests protected with exclosures, fences and guards were more likely to be successful than their unprotected controls. Interventions involving deterrents, conditioned taste aversion, chemical camouflage and diversionary feeding did not have a significant positive effect on nest success, but the interventions in these categories were less common and more diverse in nature. Synthesis and applications. To increase their conservation value, future non‐lethal nest protection experiments should whenever possible clearly state overall aims, take place over multiple seasons, use a comparable control and test non‐lethal protection methods independently of lethal predator control. Greater focus is required on under‐studied taxa such as cup‐nesting songbirds and birds in South America, Africa and Asia, and novel protection techniques such as deterrents and chemical camouflage. Practitioners should consider the evidence we synthesise here when deciding whether non‐lethal nest protection approaches are optimal for their study system, to increase conservation success and reduce ethical and financial costs.

Additive, antagonistic and synergistic interactions of future climate and land use change on Theaceae species assemblages in China

While climate and land use change are commonly known to interactively affect biodiversity worldwide, their interactive effects have rarely been explored, hindering our understanding of the attribution of biodiversity change to each of these two drivers. Here, we used ensemble species distribution models to project the potential distribution of 200 Chinese Theaceae species in the 2070s under three types of climate and land use change scenarios: (1) dynamic climate and constant land use, (2) constant climate and dynamic land use and (3) dynamic climate and dynamic land use. We further assessed the single and combined effects of climate and land use change on Theaceae species assemblages in China, and their interactive effects (i.e., additive, antagonistic and synergistic effects) on species losses and gains. Our results revealed that the mean species richness is predicted to change ranging from − 3.43–0.07 species by the 2070 s in China and the predicted species turnover values range from 1.38% to 18.65%. Additive and antagonistic interactions would dominate species losses and gains in at least 26.54% and 30.17% of the study area, respectively, while synergistical interactions would only occur in < 9.14% of the study area. Moreover, there were significant negative correlations between the single effects of land use and climate change and their interactive effects. These findings highlight the importance of understanding the interactive effects of climate and land use change on biodiversity and will help to better minimize risks of future biodiversity loss and exploit opportunities provided by land use-climate change interactions.

Species–area relationships of plants and microbes are driven by different mechanisms in patchy grassland fragments

Abstract The island species–area relationship (SAR) describes how the number of species on an island varies with its area and provides important information about the maintenance of species diversity and how species might be lost as habitats are lost and fragmented. While the island SAR has been widely studied among macroorganisms, patterns for soil microbes have been less forthcoming, as have analyses of potential underlying mechanisms. We examined the SAR patterns of plants, soil fungi and bacteria among remnant grassland fragments isolated by degraded habitat matrix in a steppe grassland. As expected, we found that the total species richness of plants, fungi and bacteria in the entire fragment decreased with decreasing fragment area. However, the mechanisms differed among taxa. For plants, the lower diversity was most likely because of decreases in habitat quality and habitat heterogeneity on smaller fragments. For fungi, we found similar results, but also an important interaction with plant diversity, suggesting they were coupled via their functional associations. For bacteria, the lower diversity on smaller fragments primarily resulted from a sampling effect from the larger species pool, which outweighed the effect of higher habitat heterogeneity on smaller fragments. Synthesis: Our study highlights that fragmentation‐induced loss of diversity can have many different underlying mechanisms and that understanding these mechanisms can provide useful insights to project future biodiversity loss and conservation.

Deep sequencing of extracellular eDNA enables total biodiversity assessment of ecosystems

The global decline in biodiversity driven by anthropogenic factors necessitates biomonitoring of ecosystems. However, current approaches are limited to targeted detection of taxa and fail to capture the total biodiversity of ecosystems. We postulated that extracellular environmental DNA (eDNA) represents a genetic repertoire of all the life forms in an ecosystem, which can be retrieved by deep sequencing. The feasibility and effectiveness of this approach were tested through a spatiotemporal study in Chilika Lagoon, a large and biodiverse Ramsar wetland ecosystem in India. Extracellular eDNA was enriched from large-volume filtered water samples using lysis-free methods and over 10.96 billion extracellular eDNA fragments were sequenced from 16 PCR-free shotgun sequencing libraries. The taxonomic classification results show that organisms from all the domains of life, including the low-abundant non-microbial taxa, can be detected with high sensitivity for taxonomic families with representative genomes. Interestingly, despite Bacteria representing a large proportion (87%) of the taxonomically classified reads, Eukaryotes showed the highest taxonomic diversity (73%). Further, using incidence-based asymptotic richness analysis, the total taxonomic diversity of Chilika was estimated to be 1071 families across the tree of life, comprising approximately 799 families of Eukaryotes, 230 families of Bacteria, 27 families of Archaea, and 13 families of DNA Viruses. We also quantified the compositional changes using Bray-Curtis dissimilarity and showed that extracellular eDNA can resolve the broad-scale spatiotemporal variation of biodiversity across the tree of life. These results demonstrate that PCR-free deep sequencing of extracellular eDNA is an effective approach for taxonomic diversity assessment across the tree of life in large ecosystems. With the increasing genomic resources and decreasing sequencing costs, we foresee its widespread application to monitor future biodiversity loss and support conservation, restoration, and management efforts in the Anthropocene.

Predation pressure by arthropods, birds, and rodents is interactively shaped by tree species richness, vegetation structure, and season

Tree species richness, forest structure, and seasonal fluctuations between rainy and dry seasons can strongly affect trophic interactions in forest ecosystems, but the inter- and scale dependence of these variables remains unclear. Using artificial caterpillars (~18,000 replicates), we analyzed predation pressure by arthropods, birds, and rodents along a tree species richness gradient across seasons in a subtropical tree diversity experiment (BEF-China). The aim of the study was to test if forest structure, in addition to tree species richness, has an effect on predation pressure and to further specify which structural variables are important in driving predation. We assessed the effects of tree species richness and forest structure at the plot and local neighborhood levels. We also included fine-scale placement covariates, plot size, and topographical covariates of the study site. Forest structure and tree species richness independently and interactively affected predation pressure. The spatial scale was an important determinant for tree species richness and structural effects, extending from within plot scales to the overall heterogeneity of the plots’ surrounding environment. For example, the effect of branch density in the local neighborhood depended on both surrounding tree species richness and plot-level vegetation density. Similarly, visibility-enhancing factors increased attacks by arthropods (lack of branches in close surroundings) and by birds (open area), depending on the surrounding vegetation. A comparison of structural measures showed that predation pressure can be addressed in much greater detail with multiple specific structural features than with overall forest complexity. Seasonal change also affected predation pressure, with foliage being a stronger attractant in spring, but also by presumable topography-driven study plot differences in sun exposure and humidity between rainy and dry seasons. Our study demonstrates that predation pressure is not simply a function of tree species richness or structure but is shaped by the interplay of structural elements, spatial scale, and seasonal dynamics along gradients of tree species richness and forest structure. The structural and seasonal effects are important to take into account when addressing how current and future biodiversity loss may change top‐down control of herbivory and overall ecosystem functioning.

Monitoring and Mapping Vegetation Cover Changes in Arid and Semi-Arid Areas Using Remote Sensing Technology: A Review

Vegetation cover change is one of the key indicators used for monitoring environmental quality. It can accurately reflect changes in hydrology, climate, and human activities, especially in arid and semi-arid regions. The main goal of this paper is to review the remote sensing satellite sensors and the methods used for monitoring and mapping vegetation cover changes in arid and semi-arid. Arid and semi-arid lands are eco-sensitive environments with limited water resources and vegetation cover. Monitoring vegetation changes are especially important in arid and semi-arid regions due to the scarce and sensitive nature of the plant cover. Due to expected changes in vegetation cover, land productivity and biodiversity might be affected. Thus, early detection of vegetation cover changes and the assessment of their extent and severity at the local and regional scales become very important in preventing future biodiversity loss. Remote sensing data are useful for monitoring and mapping vegetation cover changes and have been used extensively for identifying, assessing, and mapping such changes in different regions. Remote sensing data, such as satellite images, can be obtained from satellite-based and aircraft-based sensors to monitor and detect vegetation cover changes. By combining remotely sensed images, e.g., from satellites and aircraft, with ground truth data, it is possible to improve the accuracy of monitoring and mapping techniques. Additionally, satellite imagery data combined with ancillary data such as slope, elevation, aspect, water bodies, and soil characteristics can detect vegetation cover changes at the species level. Using analytical methods, the data can then be used to derive vegetation indices for mapping and monitoring vegetation.

Achieving global biodiversity goals by 2050 requires urgent and integrated actions

Achieving global biodiversity goals by 2050 requires urgent and integrated actions

Comparative transcriptome analysis to reveal the genes and pathways associated with adaptation strategies in two different populations of Manila clam (Ruditapes philippinarum) under acute temperature challenge

Increasing temperature is causing rapid changes in oceanic environments. Understanding the responses of marine animals to such changes remains a major challenge, yet it is key to predicting future biodiversity loss or gain. In this study, we investigated molecular mechanisms of adaptation to acute temperature change in low and high latitude populations of the Manila clam Ruditapes philippinarum. Using transcriptome analysis, we studied temperature-responsive genes and pathways in clams cultured under acute temperature stress (−1°C and 28°C) and identified an extensive set of genes and pathways that respond to acute temperature stress. Physiological changes at the molecular level were compared to explore potential differences in the response of clams and their adaptation to temperature change and to uncover the underlying mechanisms of resilience or sensitivity to stress conditions in the two clam populations. The enrichment of genes involved in protein processing in the endoplasmic reticulum was integral to the adaptation of clams to stressful conditions. Furthermore, phagosome-related genes and pathways were significantly enriched under acute high temperature stress. The upregulation of xenobiotic metabolism by cytochrome P450 showed a population-specific response in the low-latitude clams under both heat and cold stress but not in the high-latitude clams, whereas genes encoding peroxisomes were upregulated in high-latitude clams under heat stress but not in low-latitude clams. This study provides useful information related to the response of R. philippinarum to temperature stress, which could be helpful for improving the temperature stress resistance of these clams in the aquaculture industry. Our results may also help predict future biodiversity trends under temperature change scenarios.

Untapped potential of physiology, behaviour and immune markers to predict range dynamics and marginality.

Linking environmental conditions to the modulators of individual fitness is necessary to predict long‐term population dynamics, viability, and resilience. Functional physiological, behavioral, and reproductive markers can provide this mechanistic insight into how individuals perceive physiological, psychological, chemical, and physical environmental challenges through physiological and behavioral responses that are fitness proxies. We propose a Functional Marginality framework where relative changes in allostatic load, reproductive health, and behavior can be scaled up to evidence and establish causation of macroecological processes such as local extirpation, colonization, population dynamics, and range dynamics. To fully exploit functional traits, we need to move beyond single biomarker studies to develop an integrative approach that models the interactions between extrinsic challenges, physiological, and behavioral pathways and their modulators. In addition to providing mechanistic markers of range dynamics, this approach can also serve as a valuable conservation tool for evaluating individual‐ and population‐level health, predicting responses to future environmental change and measuring the impact of interventions. We highlight specific studies that have used complementary biomarkers to link extrinsic challenges to population performance. These frameworks of integrated biomarkers have untapped potential to identify causes of decline, predict future changes, and mitigate against future biodiversity loss.

Predictions of primate-parasite coextinction.

Future biodiversity loss threatens the integrity of complex ecological associations, including among hosts and parasites. Almost half of primate species are threatened with extinction, and the loss of threatened hosts could negatively impact parasite associations and ecosystem functions. If endangered hosts are highly connected in host-parasite networks, then future host extinctions will also drive parasite extinctions, destabilizing ecological networks. If threatened hosts are not highly connected, however, then network structure should not be greatly affected by the loss of threatened hosts. Networks with high connectance, modularity, nestedness and robustness are more resilient to perturbations such as the loss of interactions than sparse, nonmodular and non-nested networks. We analysed the interaction network involving 213 primates and 763 parasites and removed threatened primates (114 species) to simulate the effects of extinction. Our analyses revealed that connections to 23% of primate parasites (176 species) may be lost if threatened primates go extinct. In addition, measures of network structure were affected, but in varying ways because threatened hosts have fewer parasite interactions than non-threatened hosts. These results reveal that host extinctions will perturb the host-parasite network and potentially lead to secondary extinctions of parasites. The ecological consequences of these extinctions remain unclear. This article is part of the theme issue 'Infectious disease macroecology: parasite diversity and dynamics across the globe'.

The preservation potential of terrestrial biogeographic patterns.

Extinction events in the geological past are similar to the present-day biodiversity crisis in that they have a pronounced biogeography, producing dramatic changes in the spatial distributions of species. Reconstructing palaeobiogeographic patterns from fossils therefore allows us to examine the long-term processes governing the formation of regional biotas, and potentially helps build spatially explicit models for future biodiversity loss. However, the extent to which biogeographic patterns can be preserved in the fossil record is not well understood. Here, we perform a suite of simulations based on the present-day distribution of North American mammals, aimed at quantifying the preservation potential of beta diversity and spatial richness patterns over extinction events of varying intensities, and after applying a stepped series of taphonomic filters. We show that taphonomic biases related to body size are the biggest barrier to reconstructing biogeographic patterns over extinction events, but that these may be compensated for by both the small mammal record preserved in bird castings, as well as range expansion in surviving species. Overall, our results suggest that the preservation potential of biogeographic patterns is surprisingly high, and thus that the fossil record represents an invaluable dataset recording the changing spatial distribution of biota over key intervals in Earth History.

Shade‐growing practices lessen the impact of coffee plantations on multiple dimensions of ant diversity

Abstract Land use management influence changes in biodiversity beyond the targeted species. Management practices in coffee plantations have shifted from coffee growing below accompanying (shade) trees, to intensified monocultures in which coffee grows fully exposed to the sun. Anthropogenic disturbance causes changes in species composition relative to adjacent natural patches and reduces their biotic heterogeneity. Here, we assessed the impact of coffee plantation management practices on the taxonomical, phylogenetic and functional composition of ant communities, an ecologically dominant group and crucial biological pest controller in these agroecosystems. We hypothesized that shade‐grown coffee plantations would harbour ant communities similar to those of nearby forest patches, but dissimilar to those of intensified monocultures. We surveyed ant diversity in eight shade‐grown coffee farms, eight intensive coffee monocultures and eight forest patches. We used a combination of active and passive sampling methods over two field campaigns spanning 6 months. Our results support our hypothesis for all diversity dimensions. Additionally, ant communities in intensified monocultures were taxonomically and functionally, but not phylogenetically, more homogeneous than those found in forest patches and shade‐grown plantations. Synthesis and applications. Our findings support the idea that practices in shade‐grown coffee plantations buffer the impoverishment of multiple diversity dimensions after forest conversion. Additionally, we identified that leaf‐litter depth and number of twigs mitigate ant diversity loss which, in turn, can favour the presence of potential biocontrol agents. By assessing and integrating multiple biodiversity dimensions into management strategies, farmers and interested parties can minimize future biodiversity and ecosystem service loss.

Bending the curve of terrestrial biodiversity needs an integrated strategy.

Increased efforts are required to prevent further losses to terrestrialbiodiversity and the ecosystem services that it provides1,2. Ambitious targets have been proposed, such as reversing the declining trends in biodiversity3; however, just feeding the growing human population will make this a challenge4. Here we use an ensemble of land-use and biodiversity models to assess whether-and how-humanity can reverse the declines in terrestrial biodiversity caused by habitat conversion, which is a major threat to biodiversity5. We show that immediate efforts, consistent with the broader sustainability agenda but of unprecedented ambition and coordination, could enable the provision of food for the growing human population while reversing the global terrestrial biodiversity trends caused by habitat conversion. If we decide to increase the extent of land under conservation management, restore degraded land and generalize landscape-level conservation planning, biodiversity trends from habitat conversion could become positive bythe mid-twenty-first century on average across models (confidence interval, 2042-2061), but this was not the case for all models. Food prices could increase and, on average across models, almost half (confidence interval, 34-50%) of the future biodiversity losses could not be avoided. However, additionally tackling the drivers of land-use change could avoid conflict with affordable food provision and reduces the environmental effects of the food-provision system. Through further sustainable intensification and trade, reduced food waste and more plant-based human diets, more than two thirds of future biodiversity losses are avoided and the biodiversity trends from habitat conversion are reversed by 2050 for almost all of the models. Although limiting further loss will remain challenging in several biodiversity-rich regions, and other threats-such as climate change-must be addressed to truly reverse the declines in biodiversity, our results show that ambitious conservation efforts and food system transformation are central to an effective post-2020 biodiversity strategy.

Recent responses to climate change reveal the drivers of species extinction and survival

Climate change may be a major threat to biodiversity in the next 100 years. Although there has been important work on mechanisms of decline in some species, it generally remains unclear which changes in climate actually cause extinctions, and how many species will likely be lost. Here, we identify the specific changes in climate that are associated with the widespread local extinctions that have already occurred. We then use this information to predict the extent of future biodiversity loss and to identify which processes may forestall extinction. We used data from surveys of 538 plant and animal species over time, 44% of which have already had local extinctions at one or more sites. We found that locations with local extinctions had larger and faster changes in hottest yearly temperatures than those without. Surprisingly, sites with local extinctions had significantly smaller changes in mean annual temperatures, despite the widespread use of mean annual temperatures as proxies for overall climate change. Based on their past rates of dispersal, we estimate that 57-70% of these 538 species will not disperse quickly enough to avoid extinction. However, we show that niche shifts appear to be far more important for avoiding extinction than dispersal, although most studies focus only on dispersal. Specifically, considering both dispersal and niche shifts, we project that only 16-30% of these 538 species may go extinct by 2070. Overall, our results help identify the specific climatic changes that cause extinction and the processes that may help species to survive.

Improving averted loss estimates for better biodiversity outcomes from offset exchanges

AbstractBiodiversity offsetting aims to achieve at least no net loss of biodiversity by fully compensating for residual development-induced biodiversity losses after the mitigation hierarchy (avoid, minimize, remediate) has been applied. Actions used to generate offsets can include securing site protection, or maintaining or enhancing the condition of targeted biodiversity at an offset site. Protection and maintenance actions aim to prevent future biodiversity loss, so such offsets are referred to as averted loss offsets. However, the benefits of such approaches can be highly uncertain and opaque, because assumptions about the change in likelihood of loss as a result of the offset action are often implicit. As a result, the gain generated by averting losses can be intentionally or inadvertently overestimated, leading to offset outcomes that are insufficient for achieving no net loss of biodiversity. We present a method and decision tree to guide consistent and credible estimation of the likelihood of biodiversity loss for a proposed offset site with and without protection, for use when calculating the amount of benefit associated with the protection component of averted loss offsets. In circumstances such as when a jurisdictional offset policy applies to most impacts, plausible estimates of averted loss can be very low. Averting further loss of biodiversity is desirable, and averted loss offsets can be a valid approach for generating tangible gains. However, overestimation of averted loss benefits poses a major risk to biodiversity.

Does Indonesia’s fisheries governance ready to achieve SDG’s 14? The role of multi-stakeholder in fisheries policy

Sustainable development goals (SDG’s) 14 in Indonesia has a target for fisheries and aquaculture conservation and sustainable production, and it integrates within a set of regulation of fisheries and aquaculture value chain. However, it is a challenge to have an engagement of stakeholders, especially business, practitioners following the Government of Indonesia’s (GOI) regulations for their readiness and preparedness. This research objective is to assess current Indonesia’s fisheries management and governance in sustainable development. The study was carried out based on a desk study, and it was combined using a focus group discussion (FGD) and in-depth interviews. The result linked to the possible impact on SDG’s 14. The results proved that the regulations and practices of GOI in sustainable fisheries were directed by business practitioners to achieve SDG’s 14. Indeed, the study also found that many business practitioners had limited readiness and preparedness on sustainable fisheries management engagement. It could be an obstacle for sustainable fisheries management and governance implementation, as it could not protect Indonesia from future biodiversity loss. The problem of imbalance between the SDG’s 14 goal and stakeholders’ readiness and preparedness could be improved by the support of the role of multi-stakeholders in national fisheries institutions. This study concluded that multi-stakeholders’ engagement is essential to achieve SGD’s 14.

Extinction debt of fishes in Great Lakes coastal wetlands

Declines in North American freshwater biodiversity can be largely attributed to anthropogenic disturbances that reduce habitat quantity, quality, and connectivity. In the Laurentian Great Lakes, wetlands have been significantly lost as a result of agricultural land-use practice, yet high species richness and several at-risk fishes persist. These patterns lead to the hypothesis that Great Lakes wetland fishes are in extinction debt, meaning there is a time lag between habitat loss and local extinction. To test this hypothesis, we sampled current species richness of wetland-specialist fishes in protected and unprotected wetlands in the Lake Erie basin. We predicted species richness in unprotected wetlands using parameter estimates (slope and intercept) from protected wetlands. Extinction debt was measured as a positive difference between predicted and observed species richness. We determined how much area would be required to support current species richness and compared this to minimum-area requirements for eight at-risk fishes. Species richness was significantly higher than predicted in unprotected wetlands, indicating that fishes in them are in extinction debt. This result indicates that there is time available to restore disturbed wetlands and prevent local extinction. We identified 17 wetlands of high priority for restoration (>10 species bound for extinction) and determined that the restoration of 178 km2 of wetland habitat would reduce the risk of future biodiversity loss. This is the first direct study of extinction debt in freshwater fishes. Additional extinction-debt assessments in aquatic systems are needed to extend the ecological theory and fundamental application of extinction debt beyond terrestrial systems.

Ex situ collections and their potential for the restoration of extinct plants.

The alarming current and predicted species extinction rates have galvanized conservationists in their efforts to avoid future biodiversity losses, but for species extinct in the wild, few options exist. We posed the questions, can these species be restored, and, if so, what role can ex situ plant collections (i.e., botanic gardens, germplasm banks, herbaria) play in the recovery of plant genetic diversity? We reviewed the relevant literature to assess the feasibility of recovering lost plant genetic diversity with using ex situ material and the probability of survival of subsequent translocations. Thirteen attempts to recover species extinct in the wild were found, most of which used material preserved in botanic gardens (12) and seed banks (2). One case of a locally extirpated population was recovered from herbarium material. Eight (60%) of these cases were successful or partially successful translocations of the focal species or population; the other 5 failed or it was too early to determine the outcome. Limiting factors of the use of ex situ source material for the restoration of plant genetic diversity in the wild include the scarcity of source material, low viability and reduced longevity of the material, low genetic variation, lack of evolution (especially for material stored in germplasm banks and herbaria), and socioeconomic factors. However, modern collecting practices present opportunities for plant conservation, such as improved collecting protocols and improved cultivation and storage conditions. Our findings suggest that all types of ex situ collections may contribute effectively to plant species conservation if their use is informed by a thorough understanding of the aforementioned problems. We conclude that the recovery of plant species currently classified as extinct in the wild is not 100% successful, and the possibility of successful reintroduction should not be used to justify insufficient in situ conservation.