The direct drivers of recent global anthropogenic biodiversity loss

Efficient estimation of plant species diversity in desert regions using UAV-based quadrats and advanced machine learning techniques

Understanding the distribution of plant species diversity(PSD) along spatial and environmental gradients is essential for implementing effective conservation strategies. However, effective monitoring of large-scale PSD in desert regions remain challenging. In this study, traditional and unmanned aerial vehicle (UAV) quadrat surveys were employed to monitor the vegetation composition in the desert regions of the Junggar Basin, China. By combining multi-source data, two variable selection methods (elastic net regression and Boruta) and two machine learning algorithms (support vector machines and boosted regression trees) were used to develop PSD estimation models. This study aimed to investigate spatiotemporal variations in PSD and their driving factors. The results are as follows. (1) UAV method is more efficient and accurate than traditional methods in investigating PSD in desert areas. (2) The model combining variables selected by Elastic Net Regression and the Boosted Regression Trees algorithm is the optimal model for estimating PSD in desert areas(R2 = 0.476-0.613, RMSE = 0.135-2.2, MAE = 0.1-1.72). (3) The central region of the basin exhibited lower PSD, whereas the peripheral regions demonstrated higher PSD but were more heavily impacted by external disturbances. Over the past 20 years, 5.99 %-13.87 % of the area has shown a significant decline in PSD. (4) Cumulative precipitation and soil organic carbon are the primary drivers of PSD's spatial patterns, while human disturbance dictates its temporal dynamics. This study introduced a novel method for estimating PSD, providing a theoretical foundation for ecological restoration, and biodiversity conservation in the study region.

Return of diversity: Wetland plant community recovery following purple loosestrife biocontrol

Spread of non-native species can be important drivers of biodiversity declines, leading to precautionary management based on assumptions that (1) non-native biota have negative impacts and are "guilty" of causing harm and (2) reducing a non-native species' abundance will reduce these negative impacts, in turn, benefiting native species. However, we frequently lack data to gauge both negative impacts of non-native species and success or failure of chosen management interventions to benefit native species. Addressing these knowledge gaps is critical to improving management outcomes for native species while maintaining public trust to sustain funding of management activities. Here, we investigated the response of Lythrum salicaria (purple loosestrife) and associated plant communities to implementation of biological control in more than 10 wetland sites in New York State for up to 28 years. Introduced to North America from Europe in the 1800s, L. salicaria is a prime example of a non-native species with a continent-wide distribution that could not be suppressed by mechanical and chemical treatments. In the 1980s, waterfowl biologists, wetland managers, and conservationists alike worried about the loss of diverse wetland plant communities associated with the rapid expansion of L. salicaria. In response, after careful assessments of safety, and potential costs and benefits, four highly host-specific insect herbivores were released in North America in the early 1990s to reduce L. salicaria abundance and its negative ecological impacts. In a companion paper, Blossey et al. documented reduced L. salicaria occupancy and stem densities following insect releases over time (i.e., biological success), irrespective of site-specific differences in starting plant communities or L. salicaria abundance. Here, we show that reduced abundance of L. salicaria leads to the ultimate goal of non-native plant management: increased cover, abundance, and diversity of species, often of native species (i.e., ecological success). We also conduct analyses to provide inference about which plant species are most sensitive to L. salicaria, including changes in L. salicaria stem density. Overall, we provide an important conservation success story: our findings emphasize that biocontrol of non-native plants can be effective and safe, allowing native species to recover as a dominant non-native species gradually declines.

Assessing the combined effects of elevated temperature and chlorpyrifos on meiobenthic community structure in intertidal and mangrove estuarine ecosystems

In the age of anthropocene, elevated temperatures and pesticide pollution represent critical environmental challenges with profound ecological implications. As crucial bio-indicator, meiobenthic organisms play a pivotal role to assess the impacts of these disturbances on ecosystem health. Despite their ecological significance, the combined impacts of these stressors on meiobenthic community structures remain unexplored. This study investigates the acute exposure of elevated temperature (34 °C) and chlorpyrifos contamination (at 3 μg L-1 and 4.5 μg L-1) on meiobenthic community structure from mangrove mudflat and intertidal sandflat. A 10-days acute benthocosm experiment unveiled significant declines in total meiobenthic abundance under high-stress conditions; 75 % and 73 % in mangrove mudflat and intertidal sandflat respectively. A 4-factor PERMANOVA revealed significant effects of temperature, pesticide, and exposure duration on meiobenthic abundance (p < 0.05). Sensitive taxa such as kinorhyncha, bivalvia, and ostracoda were eliminated from treated benthocosms. Nematode species composition also affected and shifted under stress, with opportunistic and stress tolerant species became dominant. Nematode abundance decreased by up to 65 % and 63 % in the mangrove mudflat and intertidal sandflat, correspondingly. Species diversity, richness, and Shannon-Wiener index (H') significantly declined, with changes in the Maturity Index (MI) and Index of Trophic Diversity (ITD). The effects of combined stressors were more pronounced than individual stressors and mangrove mudflat displayed slightly higher susceptibility than intertidal sandflat. According to Hierarchical Modelling of Species Communities (HMSC) a noticeable influence of habitat type, stressors levels and exposure duration on the sensitivity of nematode species has been observed.

Biodiversity Impacts of Land Occupation for Renewable Energy Infrastructure in a Globally Connected World

The transition to renewable energy exacerbates direct land occupation by infrastructure, leading to habitat degradation and biodiversity loss. However, biodiversity loss driven by the production and consumption of different renewable energy deployment scenarios remains largely unquantified. Quantifying biodiversity loss associated with land occupation of renewable energy infrastructure is essential for a sustainable energy transition. Here, we developed a novel data set to evaluate renewable energy-related biodiversity loss by considering the current infrastructure setting and future development pathways. We found that the land occupation of renewable energy infrastructure resulted in global biodiversity loss equivalent amounting to 19 × 10-4 global pdf in 2015. Severe biodiversity loss was concentrated primarily in densely populated and economically advanced countries, such as China, the United States, Brazil, India, Australia, Russia, and countries across Western Europe. International trade accounted for 14% of the biodiversity loss. Future renewable energy transition scenarios will lead to a global cumulative biodiversity loss of 1.2 × 10-2-2.2 × 10-2 global pdf during 2015-2060. By 2060, ambitious energy transition policies are projected to increase the biodiversity loss by 1.7-1.8 times. The results underscore that while renewable energy could tackle climate change, its deployment should avoid encroaching on biodiversity hotspots.

Vulnerability of biodiversity to social and ecological stressors in the Yarlung Tsangpo River Basin

Biodiversity is vital to the sustainable future of human beings, yet environmental changes and anthropogenic activities cause an alarming rate of species extinction globally, threatening the conservation of biodiversity. Here, we assessed the vulnerabilities of one of the most biodiverse but also most fragile ecosystems in the world, the Yarlung Tsangpo River Basin (YTRB), to multiple ecological and social stressors. We conducted an indicator-based assessment to quantify the vulnerability of the YTRB to multiple social and ecological stressors; and evaluated the interactions among aspects of vulnerabilities by comparing their spatial patterns. Our results show that areas with the highest ecological vulnerabilities were highly clustered, and the most critical determinants for ecological vulnerability were temperature and precipitation variations. Also, increases in population density and high human footprint were the most vulnerable aspects of social vulnerability, accounting for 39 % and 31 % of the total area. Spatial patterns of social and ecological vulnerabilities were different. Areas with high ecological vulnerability were mostly observed in the west and north part of the basin; whereas high social vulnerabilities mostly along the central river and the southeast part. The selected ten variables representing social and ecological vulnerabilities were highly independent, especially the four variables relating to social vulnerability. Our results reveal significant conflicts between conservation and development because of the large areas showing high social and ecological vulnerabilities (22 % of the entire area). For the part of the YTRB belonging to the global biodiversity hotspots, also being the forested areas, the most vulnerable ecological aspect was vegetation loss, rather than climate variations. Our study provides a temporally dynamic and spatially explicit evaluation of social and ecological vulnerabilities of the YTRB, contributing to informed decision-making to sustain the biodiversity of this highly fragile ecosystem, meaningful to global biodiversity conservation.

Concrete consequences: construction on prime honey bee habitat doubles foraging distances

Human-induced land-use change is a well-documented driver of species decline, including bees, but its true cost may be underestimated. The effects of habitat conversion on honey bee foraging metabolic costs are not well documented. Here, we quantify the impact of land use change on the foraging of freely flying honey bees (Apis mellifera) before (2018-2019, n=382) and after (2022, n=502) their historical foraging habitat is developed. We decoded and analyzed honey bee waggle dances, through which returning foragers communicate the vector of forage. We found that bees increased (from 2.4% to 8.4%) their use of undisturbed microhabitat within the development. The small-scale developments, covering just 1% of the foraging range, nearly doubled flight distance and energy expenditure. Average distance increased from 0.69 to 1.28 kilometers (from 7 to 13 Joules). Our study updates our understanding of land development costs on local bees, revealing concrete consequences to changing land upon which pollinators depend.

Life at new extremes: Integrating stress physiology and the bio-exposome in the Anthropocene

Conventional physiological research has focused on elucidating the endogenous mechanisms that underly the adaptations of species to life in extreme habitats, such as polar regions or deserts. In this review article, we argue that even habitats that are not considered extremes are facing unpredictable, rapid, and strong modifications due to human activities that expose animals to novel extreme conditions. Thus, physiological research on these animals can offer insight on the role of physiological plasticity in driving their resilience and adaptation. To this end, we discuss how stress physiology (with a particular focus on oxidative stress) has a central role in mediating the interaction between the exposome (measure of all the environmental exposures of an individual in a lifetime) and cellular processes (bio-exposome) in the contexts of relevant extreme anthropogenic changes to the habitat conditions. We also provide concrete examples on the relationship between oxidative stress and the bio-exposome in free-living animals, and how this research can be relevant to human health. Finally, we propose future research directions integrating the bio-exposome and the One Health framework to achieve a holistic understanding of the proximate mechanisms underlying individual responses to extreme anthropogenic environmental changes.

Xenometabolomics in Ecotoxicology: Concepts and Applications

Nontargeted high-resolution mass spectrometry (HRMS) allows for the characterization of a large fraction of the exposome, i.e., the entirety of chemicals an organism is exposed to, and helps detect important exogenous chemical compounds that could be key drivers of toxicological impact. Along with these chemical compounds occur endogenous metabolites that are essential for the health of the host organism. Chemical compounds derived from the biotransformation of xenobiotics present in the exposome are referred to as the xenometabolome, while endogenous metabolites derived from the host organism are referred to as the endometabolome. Recent advancements in HRMS technology allow for the detection of chemical features of biological and ecological importance in the context of chemical safety assessments with unprecedented sensitivity and resolution. In this perspective, we highlight the application of HRMS-based metabolomics of organisms in the context of ecotoxicology, the complexity of comprehensively characterizing the endometabolome, and distinguishing chemical compounds of the xenometabolome.

Pesticide Pollution Reduces the Functional Diversity of Macroinvertebrates in Urban Aquatic Ecosystems

Urbanization accelerates innovation and economic growth but imposes significant ecological challenges, particularly to aquatic biodiversity and ecosystem functionality. Among urban stressors, pesticide-driven chemical pollution represents a critical, yet under-recognized, global threat. Quantifying the causes and consequences of pesticides on biodiversity loss and ecosystem degradation is vital for ecological risk assessment and management, offering insights to promote sustainable societal development. This study evaluated anthropogenic stressors and macroinvertebrate communities at 42 sites across two major drainages in Beijing using chemical analysis and environmental DNA (eDNA), focusing on macroinvertebrate responses to pesticide exposure in the context of multiple anthropogenic stressors. Pesticides significantly impacted the α- and β-functional diversity of macroinvertebrates, accounting for 18.46 and 14.6% of the total observed variation, respectively, underscoring the role of functional groups in pesticide risk assessment. Land use and flow quantity directly influenced pesticide levels, which in turn affected macroinvertebrate functional diversity, while basic water quality had a less pronounced effect. These results provide empirical evidence of pesticide pollution's impact on macroinvertebrate functional diversity at the watershed scale under field conditions in a highly urbanized area. The findings highlight the importance of considering multiple stressors and sensitive taxa in pesticide risk assessment and management for urban aquatic ecosystems.

Highs and Lows of Arboreal Life: Space use and Movement Strategies of Lion-Tailed Macaques (Macaca silenus) in the Western Ghats of India

Lion-tailed macaques (Macaca silenus), endemic to the Western Ghats of India, are increasingly threatened by habitat loss and degradation, and are vulnerable to environmental change. Insights into their spatial ecology can reveal the strategies that enable these macaques to navigate and use spatially complex heterogeneous spaces. This is crucial for conservation, given the increasing human disturbance in and around the Western Ghats. This study, conducted in Silent Valley National Park between January and June of 2019, 2022, and 2023, focused on two macaque troops occupying habitats with varying human presence-in the park's core (Sairandhri) and in the buffer (Keeripara). The observed group sizes of the Sairandhri and Keeripara troops were 51 and 21, respectively. We examined differences in the spatial ecology of these troops by assessing their vertical space use, two-dimensional (2D) and three-dimensional (3D) home ranges, and using an integrated step-selection function to understand movement-based habitat selection. We observed similarities in movement patterns across the two troops, with notable differences mainly in their vertical use of the forest. The Keeripara troop, resident in a more disturbed area, utilized a smaller home range (1.80 km²). They spent 94.2% of their time in mid-level canopy (6-20 m), descending rarely (1.1%) into lower strata (≤ 5 m), likely due to perceived high risk from predators and humans, and proximity to roads. The Sairandhri troop, resident in the less disturbed area, had a larger home range (3.05 km²) and exhibited greater terrestriality (11.3%), with 84.2% observed time in mid-canopies. Both troops preferred areas with canopy cover and fruiting trees, displaying similar slow movements (indicated through small step lengths and large turning angles) near these resources. Our findings suggest that lion-tailed macaques may be less strictly arboreal than previously believed, displaying more terrestriality in less disturbed habitats. Strategic use of 3D space based on local ecological and anthropogenic conditions highlights the need for conservation efforts that maintain canopy connectivity to support the ecological flexibility of this vulnerable species.

Connectivity Benefits Most Woodland Invertebrate Species but Only in Landscapes With Low Woodland Cover

Connectivity is widely assumed to benefit biodiversity, but this has not been extensively quantified across multiple taxa and landscapes. Focusing on the UK, where woodland cover is low (13%), we analysed species occurrence records from citizen science for over 800 broadleaf woodland-associated invertebrate species from 15 taxonomic groups in relation to woodland cover and connectivity. Overall, increased woodland connectivity positively affects broadleaf-associated species occurrence (effect of connectivity across species, accounting for positive effect of broadleaf cover). The benefits of connectivity varied considerably by species: 39% of species showed a significant positive effect, while for 3% it was significantly negative. However, the interaction between cover and connectivity revealed that, overall, connectivity benefits are only found in low cover landscapes. Our findings emphasise potential biodiversity benefits from maximising connectivity when increasing woodland cover and highlight the importance of spatial targeting in restoration efforts, especially in landscapes with low woodland cover.

Global impoverishment of natural vegetation revealed by dark diversity

Anthropogenic biodiversity decline threatens the functioning of ecosystems and the many benefits they provide to humanity1. As well as causing species losses in directly affected locations, human influence might also reduce biodiversity in relatively unmodified vegetation if far-reaching anthropogenic effects trigger local extinctions and hinder recolonization. Here we show that local plant diversity is globally negatively related to the level of anthropogenic activity in the surrounding region. Impoverishment of natural vegetation was evident only when we considered community completeness: the proportion of all suitable species in the region that are present at a site. To estimate community completeness, we compared the number of recorded species with the dark diversity-ecologically suitable species that are absent from a site but present in the surrounding region2. In the sampled regions with a minimal human footprint index, an average of 35% of suitable plant species were present locally, compared with less than 20% in highly affected regions. Besides having the potential to uncover overlooked threats to biodiversity, dark diversity also provides guidance for nature conservation. Species in the dark diversity remain regionally present, and their local populations might be restored through measures that improve connectivity between natural vegetation fragments and reduce threats to population persistence.

Achieving the Global Biodiversity Framework Under Climate Change

We have committed to ambitious targets under the Global Biodiversity Framework, but projected climate change makes the achievement of many of these targets extremely difficult and will effectively require a significant rethinking in how to achieve multiple targets. In this Opinion, we have chosen to focus on selected targets, considering how their achievement is likely to be compromised by climate change but also what the possibility of real response options might be. We focus on restoration (Target 2), spatial planning and integration (Targets 1, 2, 3 and 10), sustainable use and sustainable benefits to people (Targets 5, 9 and 10) and, finally, equity and social justice (Targets 13, 20-23 and Goal C). Now more than ever, the window for effective action on climate change and biodiversity is closing, requiring rapid and, most importantly, collective action.

Adaptive response in waterbirds after mink introduction in subantarctic ecosystems

Ground-nesting birds on islands are particularly vulnerable to the introduction of terrestrial carnivores because the former often lack defensive behaviors, displaying high levels of naivety under absence of co-evolutionary history. Relatively few studies have addressed such potentially adaptive responses. In this study, we investigated whether two bird species, upland geese (Chloephaga picta) and flightless steamer ducks (Tachyeres pteneres) have modified their nesting strategies as a response to the novel predatory pressure imposed by the invasive American mink (Neogale vison) on Navarino Island, southernmost Chile, since its arrival in 2001. We used discriminant analysis and pairwise Wilcoxon tests to compare two data sets (n = 140 nests in total) regarding the macro- and microhabitat where nests were placed, separated by a time span of 15 years. We found that upland geese currently nest in less dense habitat (macrohabitat), hide their nests in shorter shrubs with lower top and side cover (microhabitat), and breed later in the season. In contrast, flightless steamer ducks retain almost the same nesting habitat characteristics. We discuss our findings in the context of ecological and evolutionary restrictions to adaptation.

Understanding and promoting nature connectedness: A human ecological perspective

People's subjective sense of their relationship with nature - or nature connectedness - is consistently found to relate to both well-being and pro-environmental values and behaviors. Yet human perceptions of their relationships with the rest of nature are complex and, in many cases, reflect cultural beliefs and historical legacies. In this paper we identify a tension within the research literature on nature connectedness and associated efforts to understand, measure, and promote nature connectedness. The tension is between what we describe as (1.) human exceptionalist perspectives, which envision nature as the absence of humans, and (2.) human ecological perspectives, which understand humans as part of nature. We offer three main interrelated recommendations for a more concertedly human ecological perspective: (1.) to move away from a focus on exposure to nature toward a greater emphasis on engagement with nature, (2.) to learn more about the positive associations between feeling connected with nature and feelings of connection with other collectivities (e.g., sense of community), and (3.) to emphasize everyday engagement with nature in specific nearby places, and the associations between nature connectedness and feeling connected to place (e.g., place attachment/sense of place). Our aim is to enhance clarity and specificity about the concept of nature connectedness, which may improve efforts to promote it and realize its associated benefits to humans, non-humans, and their shared ecologies.

Revision of nitrogen critical loads for Natura 2000 Habitat types in The Netherlands

Critical loads for atmospheric deposition of nitrogen are increasingly used as official standards in national legislation. This requires unique values (i.e., not ranges) based on state-of-the-art scientific knowledge. In The Netherlands such values have been derived in the past by combining the empirical critical load ranges for Europe with local simulated values. We describe this method in detail, resulting in a unique critical load value for each Habitat type of the European Habitats Directive that occurs in The Netherlands. As the empirical values have been adjusted downward several times in recent decades while the simulation model was not updated since 2004, there is an increasing gap between the empirical and the simulated values. Here we use the new, empirical response model DOREN to bridge this gap, but we argue that a new simulation model is urgently needed. Our results show critical load exceedance in 61 % of the total area of nitrogen-sensitive Habitat types in The Netherlands. The most threatened Habitat types are oligotrophic freshwater, bog, species-rich grassland, and beech forest; either because they have a low critical load, or because they occur in areas where nitrogen deposition is high.

Global extent and change in human modification of terrestrial ecosystems from 1990 to 2022

Habitat loss and degradation associated with industrial development is the primary threat and dominant driver of biodiversity loss globally. Spatially-explicit datasets that estimate human pressures are essential to understand the extent and rate of anthropogenic impacts on ecosystems and are critical to inform conservation commitments and efforts under the Global Biodiversity Framework. We leveraged the human modification framework to generate comprehensive, consistent, detailed, robust, temporal, and contemporary datasets to map cumulative and individual threats associated with industrial human activities to terrestrial biodiversity and ecosystems from 1990 to 2022. In ~2022, 43% of terrestrial lands had very low levels of modification, while 27%, 20%, and 10% had low, moderate, and high modification, respectively. Nearly 2/3 of biomes and 1/2 of ecoregions currently are moderately-modified, and 24% of terrestrial ecosystems (31 M km2) experienced increased modification from 1990 to 2020. About 29% of countries and 31% of ecoregions might also be particularly vulnerable to biodiversity loss given their above-average increased modification and less than 30% protection.

2030 conservation targets for European terrestrial mammals using the favourable conservation status concept

The European Habitats Directive lists species and habitats of conservation priority for member states of the European Union, and prescribes that they achieve a favourable conservation status. The benchmark for assessing whether species achieve this status is provided by favourable reference values of distribution and population size. These values cannot be used directly as conservation targets, because they are incomplete, incomparable as they are identified through different methods, and not necessarily achievable in a specified time frame. We set conservation targets for the year 2030 for 81 European terrestrial mammals listed in Annexes II and IV of the Habitats Directive, and/or threatened at European level according to the IUCN Red List of Threatened Species, based on the concept of favourable onservation statuts. We used several methods, including models of population growth and range expansion to 2030, and a reference-based approach. These targets can be used to plan conservation actions for priority mammals, such as increasing protected area coverage to 30% of Europe as envisaged in the European Biodiversity Strategy 2030.

Reduced Body Mass in a Highly Insectivorous Mammal, the Garden Dormouse-Ecological Consequences of Insect Decline?

Biodiversity is decreasing worldwide, and early indicators are needed to identify endangered populations before they start to decline in abundance. In mammals, body mass (BM) is regarded as an indicator of fitness, and its loss is used as an early warning signal preceding population decline. The garden dormouse (Eliomys quercinus, Gliridae, BM: 60-110 g) is a small mammalian hibernator that has disappeared from over 50% of its former range in the last decades. The aim of this study was to investigate whether garden dormice from a presumably thriving and stable population already show early warning signals, which may precede a population decline. We therefore conducted capture-mark-recapture studies during 2003-2005 (Period 1) and 2018-2021 (Period 2) in the Northern Black Forest, one of its last natural distribution areas in Germany. We collected fecal samples, measured BM, and tibia length as a proxy for size and age. Results revealed that in Period 2 adult dormice had a significantly lower (12%) pre-hibernation BM, corrected for body size, and juveniles showed a significantly lower BM gain after weaning than nearly two decades ago. Fecal samples collected in Period 2 showed that arthropods represented the main food residues in fecal samples during juvenile growth and pre-hibernation fattening. Ambient temperature during hibernation showed no correlation with BM at emergence. We could not detect a phenological time shift in reproduction; however, we found only one birth peak in Period 2, compared with two birth peaks in Period 1. Observed changes in BM and reproduction pattern represent early warning signals, as they point to an insufficient availability of high-quality food, which prevents dormice from meeting their nutritional requirements, with potentially serious consequences for their reproductive success and survival. As arthropods are the dominant food resource, their decline may at least partly explain this phenomenon.

Novel Regimes of Extreme Climatic Events Trigger Negative Population Rates in a Common Insect

The IPCC predicts that events at the extreme tail of the probability distribution will increase at a higher rate relative to less severe but still abnormal events. Such outlier events are of particular concern due to nonlinear physiological and demographic responses to climatic exposure, meaning that these events are expected to have disproportionate impacts on populations over the next decades (so called low-likelihood, high-impact events -LLHI). Because such events are historically rare, forecasting how biodiversity will respond requires mechanistic models that integrate the fundamental processes driving biological responses to our changing climate. Here we built a matrix population model (MPM) from long-term monitored populations of an insect model species in a Mediterranean area. The model simultaneously integrates the effects of extreme microclimatic heat exposure and drought-induced host-plant scarcity on early life stages, a key methodological step forward because these understudied life stages are usually very susceptible to climatic events. This model for the first time allowed us to forecast the demographic impacts that LLHI events will have on a well-known insect considering their whole life cycle. We found that juveniles were the life stage with the largest relative contribution to population dynamics. In line with field observations, simulated population rates in current climatic regimes were importantly determined by drought impacts, producing a regional mosaic of non-declining and declining populations. The simulations also indicated that in future, climate scenarios not meeting the Paris Agreement, LLHI heat extremes triggered regionally widespread and severe declines in this currently abundant species. Our results suggest that LLHI events could thus emerge as a critical new -but overlooked- driver of the declines in insect populations, risking the crucial ecosystem functions they perform. We suggest that process-based and whole-cycle modelling approaches are a fundamental tool with which to understand the true impacts of climate change.

Three-Dimensional Habitat Structure Drives Avian Functional and Trait Diversity Across North America

Understanding how three-dimensional (3D) habitat structure drives biodiversity patterns is key to predicting how habitat alteration and loss will affect species and community-level patterns in the future. To date, few studies have contrasted the effects of 3D habitat composition with those of 3D habitat configuration on biodiversity, with existing investigations often limited to measures of taxonomic diversity (i.e., species richness). Here, we examined the influence of Light Detecting and Ranging (LiDAR)-derived 3D habitat structure-both its composition and configuration-on multiple facets of bird diversity. Specifically, we used data from the National Ecological Observatory Network (NEON) to test the associations between 11 measures of 3D habitat structure and avian species richness, functional and trait diversity, and phylogenetic diversity. We found that 3D habitat structure was the most consistent predictor of avian functional and trait diversity, with little to no effect on species richness or phylogenetic diversity. Functional diversity and individual trait characteristics were strongly associated with both 3D habitat composition and configuration, but the magnitude and the direction of the effects varied across the canopy, subcanopy, midstory, and understory vertical strata. Our findings suggest that 3D habitat structure influences avian diversity through its effects on traits. By examining the effects of multiple aspects of habitat structure on multiple facets of avian diversity, we provide a broader framework for future investigations on habitat structure.

Farm revegetation has substantial potential to improve biodiversity outcomes

Agricultural expansion and intensification has caused habitat loss, contributing to the current biodiversity crisis. Reliable, efficient and consistent information at the farm-scale is critical to understand the magnitude of recent changes in biodiversity and to inform future management actions aimed at reversing historical declines. We apply a habitat-based biodiversity assessment approach to examine the potential for grazing farms across Australia to improve outcomes for biodiversity by revegetating 10 % of the farm area. Fourteen case-study farms distributed across Australia with diverse attributes were assessed, including an analysis of likely benefits for biodiversity 30 years after commencing a hypothetical revegetation scenario, within the context of estimates of recent historical changes. From 2004 to 2020, the three biodiversity indicators considered decreased for the majority of farms. The scenario for revegetating 10 % of the farm area was estimated to substantially increase the biodiversity indicators, with half of the farms estimated to achieve recovery for all 3 indicators to greater than 2004 levels by 2050. Smaller farms with lower average ecosystem condition in 2020 were estimated to achieve the greatest gains in biodiversity from the revegetation scenario, relative to their indicator values in 2020. Farm revegetation actions have substantial potential to improve outcomes for biodiversity, though such gains may be difficult and time consuming to achieve, emphasising the importance of avoiding further habitat loss through removal or degradation of native vegetation.

Species turnover does not rescue biodiversity in fragmented landscapes

Habitat fragmentation generally reduces biodiversity at the patch scale (α diversity)1. However, there is ongoing debate about whether such negative effects can be alleviated at the landscape scale (γ diversity) if among-patch diversity (β diversity) increases as a result of fragmentation2-6. This controversial view has not been rigorously tested. Here we use a dataset of 4,006 taxa across 37 studies from 6 continents to test the effects of fragmentation on biodiversity across scales by explicitly comparing continuous and fragmented landscapes. We find that fragmented landscapes consistently have both lower α diversity and lower γ diversity. Although fragmented landscapes did tend to have higher β diversity, this did not translate into higher γ diversity. Our findings refute claims that habitat fragmentation can increase biodiversity at landscape scales, and emphasize the need to restore habitat and increase connectivity to minimize biodiversity loss at ever-increasing scales.

Widespread ecological novelty across the terrestrial biosphere

Human activities have transformed many wild and semiwild ecosystems into novel states without historical precedent. Without knowing the current distribution of what drives the emergence of such novelty, predicting future ecosystem states and informing conservation and restoration policies remain difficult. Here we construct global maps of three key drivers generating novel conditions-climate change, defaunation and floristic disruption-and summarize them to a measure of total novelty exposure. We show that the terrestrial biosphere is widely exposed to novel conditions, with 58% of the total area exposed to high levels of total novelty. All climatic regions and biomes are exposed to substantial levels of novelty. Relative contributions of individual drivers vary between climatic regions, with climate changes and defaunation the largest contributors globally. Protected areas and key biodiversity areas, whether formally protected or not, have similar exposure, with high total novelty experienced in 58% of cells inside protected areas and 56% inside key biodiversity areas. Our results highlight the importance of investigating ecosystem and biodiversity responses to rising ecological novelty for informing actions towards biosphere stewardship.

Avoiding Cognitive Trap in Habitat Restoration: A Case Study of the World's Rarest Primate

The lack of knowledge regarding the basic ecological traits of an endangered species may lead to traps in habitat restoration efforts. Understanding the ranging ecology of endangered species is essential in avoiding these traps. The Hainan gibbon (Nomascus hainanus), the world's rarest primate, reportedly takes refuge in suboptimal montane habitats and occupies an abnormally large home range, resulting in suggestions for enhancing montane habitat quality with high priority. However, these conservation suggestions and actions are not based on solid science. For the first time, we habituated two groups of Hainan gibbon, and studied their ranging ecology over a year from January to December 2022. We found that the average home range size of these groups was 164.5 ± 70.6 ha (95% KDE-href) and 155.2 ± 71.1 ha (95% MCP), which is comparable to other Nomascus gibbons and represents an adaptive trait in response to their heterogeneous habitat. Furthermore, gibbons have shown a preference for higher-altitude habitats between 800 and 1100 m, where food is more abundant than in low-altitude habitats. Our findings, combined with the evidence of favorable food conditions and short interbirth intervals of the Hainan gibbon, indicate that montane habitats meet gibbons' life-history requirements and are suitable for them. The idea that "montane habitat is suboptimal" is a cognitive trap. Given the Hainan gibbons' isolated habitat is approaching saturation, we suggest prioritizing ecological corridor construction to enable gibbons to rapidly gain access to other suitable montane forests.

Riverine Realities: Evaluating Climate Change Impacts on Habitat Dynamics of the Critically Endangered Gharial (Gavialis gangeticus) in the Indian Landscape

The endemic and critically endangered gharial, Gavialis gangeticus, experienced a severe population decline in its range. However, conservation efforts, notably through the implementation of "Project Crocodile" in India, have led to a significant recovery of its population. The present study employs an ensemble Species Distribution Model (SDM) to delineate suitable habitats for G. gangeticus under current and future climatic scenarios to understand the impact of climate change. The model estimates that 46.85% of the area of occupancy is suitable under the present scenario, with this suitable area projected to increase by 145.16% in future climatic conditions. States such as Madhya Pradesh, Uttar Pradesh, and Assam are projected to experience an increase in habitat suitability, whereas Odisha and Rajasthan are anticipated to face declines. The study recommends conducting ground-truthing ecological assessments using advanced technologies and genetic analyses to validate the viability of newly identified habitats in the Lower Ganges, Mahanadi, and Brahmaputra River systems. These areas should be prioritized within the Protected Area network for potential translocation sites allocation. Collaborative efforts between the IUCN-SSC Crocodile Specialist Group and stakeholders are vital for prioritizing conservation and implementing site-specific interventions to protect the highly threatened gharial population in the wild.

Three-quarters of species' ranges have not been covered by protected areas in global borders

Borderlands are increasingly recognized as critically important for biodiversity conservation owing to their ecological significance and high political profile. However, the species ranges covered by protected areas and their influencing factors in transboundary areas are still largely unknown worldwide. Here, based on the distributional ranges of 19,039 terrestrial vertebrates, we find that three-quarters of species' ranges in global borders remain uncovered by protected areas, particularly in tropical areas of Southeast Asia and West Africa. The average protected area coverage of species ranges is lower in transboundary areas than non-transboundary areas after accounting for geographical differences in sampling efforts. We also observe that protected area coverage of species ranges increases with governance effectiveness, collaboration abilities, protection levels, sizes and establishment years of protected areas, and topographic complexity, but decreases with human population density, human development index, and cropland expansion. Furthermore, protected areas simultaneously face threats of ongoing global challenges from climate change, land-use modification, and alien species invasion, and the proportions of borderlands threatened by global changes are higher than elsewhere. All these findings demonstrate that cross-border cooperation is urgently needed to achieve the ambitious goal of global biodiversity conservation by 2050.

Effects of Climate and Land Use on the Population Dynamics of the Bank Vole (Clethrionomys glareolus) in the Southernmost Part of Its Range

This study investigated the effects of habitat structure and climatic variables on populations of bank voles (Clethrionomys glareolus), a northern species with adaptations to cooler climate, at the southern end of their range in Western Europe over a 16-year period. This is the first long-term analysis of its kind in this region. The study aims to understand how these variables influence the population dynamics and occupancy of bank voles. The results suggested that warmer years and extreme precipitation events lead to a reduction in bank vole abundance. Although changes in land use were minimal in the plots studied, changes in forest composition, particularly the expansion of coniferous forests at the expense of deciduous forests, were also related to lower bank vole abundance. Occupancy models, taking into account detectability, indicated stable occupancy in all regions. Our results suggest that climate change and habitat alterations, such as changes in forest composition, could pose threats to bank vole populations in these regions.

Long-term effects of widespread pharmaceutical pollution on trade-offs between behavioural, life-history and reproductive traits in fish

In our rapidly changing world, understanding how species respond to shifting conditions is of paramount importance. Pharmaceutical pollutants are widespread in aquatic ecosystems globally, yet their impacts on animal behaviour, life-history and reproductive allocation remain poorly understood, especially in the context of intraspecific variation in ecologically important traits that facilitate species' adaptive capacities. We test whether a widespread pharmaceutical pollutant, fluoxetine (Prozac), disrupts the trade-off between individual-level (co)variation in behavioural, life-history and reproductive traits of freshwater fish. We exposed the progeny of wild-caught guppies (Poecilia reticulata) to three field-relevant levels of fluoxetine (mean measured concentrations: 0, 31.5 and 316 ng/L) for 5 years, across multiple generations. We used 12 independent laboratory populations and repeatedly quantified activity and risk-taking behaviour of male guppies, capturing both mean behaviours and variation within and between individuals across exposure treatments. We also measured key life-history traits (body condition, coloration and gonopodium size) and assessed post-copulatory sperm traits (sperm vitality, number and velocity) that are known to be under strong sexual selection in polyandrous species. Intraspecific (co)variation of these traits was analysed using a comprehensive, multivariate statistical approach. Fluoxetine had a dose-specific (mean) effect on the life-history and sperm trait of guppies: low pollutant exposure altered male body condition and increased gonopodium size, but reduced sperm velocity. At the individual level, fluoxetine reduced the behavioural plasticity of guppies by eroding their within-individual variation in both activity and risk-taking behaviour. Fluoxetine also altered between-individual correlations in pace-of-life syndrome traits: it triggered the emergence of correlations between behavioural and life-history traits (e.g. activity and body condition) and between life-history and sperm traits (e.g. gonopodium size and sperm vitality), but collapsed other between-individual correlations (e.g. activity and gonopodium size). Our results reveal that chronic exposure to global pollutants can affect phenotypic traits at both population and individual levels, and even alter individual-level correlations among such traits in a dose-specific manner. We discuss the need to integrate individual-level analyses and test behaviour in association with life-history and reproductive traits to fully understand how animals respond to human-induced environmental change.

Climate Impacts on Lake Food-Webs Are Mediated by Biological Invasions

Climate change and biological invasions are among the most important drivers of biodiversity and ecosystem change. Despite major advances in understanding their ecological impacts, these drivers are often considered individually, overlooking their possible complex interrelationship. By applying structural equation modeling to an extensive nationwide dataset of 430 fish communities across 257 French lakes, we investigated how taxonomic, size, and trophic diversities are impacted by climate warming and exotic species occurrence. Our goal was to compare their relative signature or lasting impacts after these factors had taken effect and to determine whether climate warming and biological invasions mediate the current state of community diversities. Drawing on a set of interconnected hypotheses, we suggest that biological invasions could be an important indirect effect of climate warming. This aspect must be considered to fully grasp the overall effects of climate change, beyond just its direct thermal impacts. Our results support our hypothesis that climate warming negatively impacts size and trophic diversities. However, these effects are mostly mediated by the warming-induced increase in exotic species richness, which, in turn, promotes total species richness. These results suggest that exotic species have a substantial role in determining the impact of climate change, obscuring the diversity patterns predicted by temperature alone. We conclude that the impacts of climate change cannot be understood without considering its mediated effects via biological invasions, underscoring the need to grasp their intertwined roles in predicting and managing ecological consequences.

The role of social and personal norms in biodiversity conservation: A segmentation of Swiss farmers

The agricultural sector is a major contributor to global biodiversity loss. Ecological focus areas (EFAs), such as extensively used meadows, hedges, and buffer strips, are a cornerstone in promoting biodiversity conservation. Previous research highlights social and personal norms as strong predictors of farmers' efforts to conserve biodiversity. Accordingly, we aim to segment Swiss farmers according to their social and personal norms and analyze how these segments differ in terms of pro-environmental behavior. Furthermore, we are interested in whether these segments differ in terms of farmer's self-efficacy, the importance of farm sales and biodiversity payments, farmers' political priorities, and socio-demographic and farm characteristics. For the empirical analyses, we used a unique dataset combining data from a survey of Swiss farmers (N = 882) with data on registered EFAs from the Swiss Agricultural Information System. We explored the segments based on responses to four items capturing social and personal norms toward biodiversity conservation using latent class analysis. To estimate the mean differences between segments, we used an analysis of variance and covariance. Our results showed that farmer segments with high social and personal norms implemented more EFAs than those with lower social and personal norms. Moreover, high social and personal norms were associated with enhanced self-efficacy, higher importance of biodiversity payments for farm income, stronger priority for environmental policies, and less intensive agricultural production practices. This study informs policymakers in designing social norm interventions that, for example, include information about society's approval of farmers' biodiversity conservation efforts.

Spatial Distribution Patterns, Environmental Drivers, and Hotspot Dynamics of the European Rabbit on a Mediterranean Island: Implications for Conservation and Management

The European rabbit (Oryctolagus cuniculus) presents a significant conservation and management challenge in Greece. While it has been listed in national biodiversity assessments, its population dynamics on the island of Lemnos demonstrate the characteristics of a highly adaptable and rapidly expanding species, exerting substantial ecological and economic impacts. Addressing this issue requires a spatially explicit understanding of its distribution patterns and habitat preferences, particularly given its extensive population growth over the past three decades. To this end, we conducted 40 field surveys across the island, documenting 1534 presence records of the species. We applied Kernel Density Estimation, Getis-Ord Gi *, and Anselin Local Moran's I to identify the spatial distribution patterns and significant hotspots. A spatial lag model was used to quantify hotspot intensity and clustering dynamics, while abiotic, biotic, and anthropogenic factors were analyzed to assess habitat associations. Our results revealed that rabbit hotspots are predominantly concentrated in fertile lowland agroecosystems, with nearly 60% of high-density areas overlapping conservation zones. Soil and field conditions, grazing-supporting landscapes, and arable and subsidized agricultural areas emerged as significant predictors of O. cuniculus presence. The observed spatial dependencies indicated that while hotspot intensities and clustering dynamics are influenced by the conditions in neighboring areas, habitat characteristics remain fundamental in shaping their distribution, highlighting the broader landscape-scale spatial patterns affecting rabbit populations. These findings underscore the necessity of adopting spatially informed management strategies that mitigate agricultural impacts while accounting for interconnected spatial dynamics, providing a foundation for informed decision-making to manage rabbit populations while balancing conservation and agricultural priorities.

Environmental variability across space and time drives the recolonization pattern of a historically persecuted large carnivore

Wildlife populations are not static. Intrinsic and extrinsic factors affect individuals, which lead to spatiotemporal variation in population density and range. Yet, dynamics in density and their drivers are rarely documented, due in part to the inherent difficulty of studying long-term population-level phenomena at ecologically meaningful scales. We studied the spatiotemporal density dynamics in a recolonizing large carnivore population, the wolverine Gulo gulo, across the Scandinavian Peninsula over nine years. We fitted open-population spatial capture-recapture models to noninvasive genetic sampling data collected across Norway and Sweden to estimate annual density surfaces and their drivers. This approach allowed us to model sex-specific changes in wolverine density and the effect of landscape-level environmental determinants over time. Our results revealed that, as wolverines successfully recolonized many parts of their historical range in Scandinavia, the relationship with spatial determinants of density has changed over time. We also found support for sex-specific responses of the Scandinavian wolverine to the environmental determinants of density and differences in the temporal dynamics of their relationships, indicating disproportionate recolonization ability and anthropogenic pressures. We observed significant changes in the relationship of female wolverine density with several determinants during the study period, suggesting still ongoing expansion of female wolverines whereas males might have already reached the range limits. These findings show that the Scandinavian wolverine population is still recovering from centuries of persecution and severe range contraction. Our study sheds light on the dynamics and challenges of recolonizing large carnivores in human-dominated landscapes across time and space.

Global meta-analysis shows action is needed to halt genetic diversity loss

Mitigating loss of genetic diversity is a major global biodiversity challenge1-4. To meet recent international commitments to maintain genetic diversity within species5,6, we need to understand relationships between threats, conservation management and genetic diversity change. Here we conduct a global analysis of genetic diversity change via meta-analysis of all available temporal measures of genetic diversity from more than three decades of research. We show that within-population genetic diversity is being lost over timescales likely to have been impacted by human activities, and that some conservation actions may mitigate this loss. Our dataset includes 628 species (animals, plants, fungi and chromists) across all terrestrial and most marine realms on Earth. Threats impacted two-thirds of the populations that we analysed, and less than half of the populations analysed received conservation management. Genetic diversity loss occurs globally and is a realistic prediction for many species, especially birds and mammals, in the face of threats such as land use change, disease, abiotic natural phenomena and harvesting or harassment. Conservation strategies designed to improve environmental conditions, increase population growth rates and introduce new individuals (for example, restoring connectivity or performing translocations) may maintain or even increase genetic diversity. Our findings underscore the urgent need for active, genetically informed conservation interventions to halt genetic diversity loss.

Effects of Bti on the diversity and community composition of three Chironomidae subfamilies across different micro-habitats

The mosquito control agent Bacillus thuringiensis subsp. israelensis (Bti) is considered environmentally friendly due to its highly specific mode of action. Nevertheless, adverse effects of Bti have been observed in non-biting midges of the family Chironomidae. In this study, we applied the maximum field rate of Bti three times from April to May to six out of twelve floodplain pond mesocosms. Chironomidae larvae were sampled two weeks after the third application in three different micro-habitats and DNA metabarcoding was used to identify the larvae. We observed Bti effects on the Chironomidae subfamily Chironominae, while Tanypodinae and Orthocladiinae remained unaffected. The interspecific diversity of Chironominae was significantly reduced by 27% in the Bti treatment. Although the interaction between treatment and habitat was not significant, a notable decrease in interspecific diversity of Chironominae between the control and Bti treatment in two out of three micro-habitats was detected (47% and 41%, respectively). We observed a significant habitat-dependent change in intraspecific diversity of Chironominae, with a 28% decline in one habitat and a 21% increase in another. The Chironominae community composition differed between the control and Bti treatment in two out of three habitats. These outcomes highlight the variability of Bti's impact on Chironomidae communities across subfamilies and micro-habitats, potentially elucidating discrepancies reported in prior studies and emphasising the necessity for comprehensive risk assessments that encompass diversity at various taxonomic levels and environmental variation at different spatial scales.

If a fish comes out of the river and speaks, we should believe it: South African perspective on fish kills

In South Africa, fish kill events are increasing in frequency because of multiple stressors associated with managing natural resources. Despite the ecosystem services associated with fish, South Africa's progressive legislation towards environmental protection seems to negate the management of fish kills. In this study, we provide an overview of reports and regulations associated with acute pollution spills resulting in fish kill events in South Africa. In addition, we highlight the implication of these using a fish kill event from 2019 on the Msunduzi River, South Africa, as a case study. The fish kill on the Msunduzi River showed a decline in relative abundance by up to 41%, and its ecological condition was already impaired by poor management. The poor condition of the Msunduzi River has jeopardised the recovery of the fish populations, and intervention is needed to restore the fish population that includes species red-listed as vulnerable by the International Union for the Conservation of Nature. We found that despite the severity of fish kills and the detriment to the fish fauna, including near-threatened species, there is a general apathy, incapacity and lack of knowledge on managing fish kills in South Africa. In addition, although several legislated Acts have good intentions for protecting nature, they do not align and show that a fish kill is an afterthought rather than a need to prevent. Poor management practices have exacerbated this in an already stressed state from excessive use of environmental water. As a way forward, the alignment of the various Acts associated with various ministerial departments in South Africa is needed so that better protection of the environment may occur. Finally, we argue that the African proverb 'If the fish comes out of the river to tell you that the crocodile has one eye, you should believe it' is not considered when managing water resources and that with the present ecological state and water resource use there may be no fish to 'come out of the water' warning us that our water is unsafe even for human consumption and use.

Business-as-usual trends will largely miss 2030 global conservation targets

To address climate change and global biodiversity loss, the world must hit three important international conservation targets by 2030: protect 30% of terrestrial and marine areas, halt and reverse forest loss, and restore 350 Mha of degraded and deforested landscapes. Here, we (1) provide estimates of the gaps between these globally agreed targets and business-as-usual trends; (2) identify examples of rapid past trend-shifts towards achieving the targets; and (3) link these past trend-shifts to different levers. Our results suggest that under a business-as-usual scenario, the world will fail to achieve all three targets. However, trend-shifts that rapidly "bend the curve" have happened in the past and these should therefore be fostered. These trend-shifts are linked to transformative change levers that include environmental governance, economic factors, values, and knowledge. Further research on trend-shifts, as well as bold action on underlying levers, is urgently needed to meet 2030 global conservation targets.

Quantifying the impacts of future shoreline modification on biodiversity in a case study of coastal Georgia, United States

People often modify the shoreline to mitigate erosion and protect property from storm impacts. The 2 main approaches to modification are gray infrastructure (e.g., bulkheads and seawalls) and natural or green infrastructure (NI) (e.g., living shorelines). Gray infrastructure is still more often used for coastal protection than NI, despite having more detrimental effects on ecosystem parameters, such as biodiversity. We assessed the impact of gray infrastructure on biodiversity and whether the adoption of NI can mitigate its loss. We examined the literature to quantify the relationship of gray infrastructure and NI to biodiversity and developed a model with temporal geospatial data on ecosystem distribution and shoreline modification to project future shoreline modification for our study location, coastal Georgia (United States). We applied the literature-derived empirical relationships of infrastructure effects on biodiversity to the shoreline modification projections to predict change in biodiversity under different NI versus gray infrastructure scenarios. For our study area, which is dominated by marshes and use of gray infrastructure, when just under half of all new coastal infrastructure was to be NI, previous losses of biodiversity from gray infrastructure could be mitigated by 2100 (net change of biodiversity of +0.14%, 95% confidence interval -0.10% to +0.39%). As biodiversity continues to decline from human impacts, it is increasingly imperative to minimize negative impacts when possible. We therefore suggest policy and the permitting process be changed to promote the adoption of NI.

Genomic evidence for demographic fluctuations, genetic burdens and adaptive divergence in fourfinger threadfin Eleutheronema rhadinum

Declining populations and bottlenecks lead to the accumulation of deleterious mutations in fish populations. These processes also trigger genetic purging, which is a key genetic factor in reducing the deleterious burdens and increasing population viability. However, there is a lack of empirical evidence on the interaction between demographic history and the genome-wide pattern of deleterious variations. Here, we generated genome resequencing data of Eleutheronema rhadinum from China and Thailand, representing the major distribution of the species' southern regions. E. rhadinum had exceptionally low genome-wide variability and experienced dramatic population expansions followed by continuous declines. The geographical divergence, which occurred ~ 23,000 years ago, shaped different demographic trajectories and generated different regional patterns of deleterious mutations in China and Thailand populations. Several lines of evidence revealed that this geographical pattern of deleterious mutation was driven by the purging of highly deleterious mutations. We showed that purifying selection had inbreeding-associated fitness costs and was more efficient against missense mutations in the Thailand population, which had the lowest genetic burden of homozygous deleterious mutations. Multiple evolutionarily conserved protein domains were disrupted by the loss-of-function mutations, posing a high probability of gene functionality elimination. Moreover, thermal and salinity genes (Trpm3, Nek4, Gtf2f2, Cldn14) were identified in genomic divergence regions of E. rhadinum among China and Thailand populations. Our findings highlight the importance of demographic history factors shaping the geographical patterns of deleterious mutations. The results serve to deepen our understanding of the adaptive evolution and divergence of E. rhadinum with implications for other marine fish.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42995-024-00276-4.

Bending the curve of global freshwater biodiversity loss: what are the prospects?

Freshwater biodiversity conservation has received substantial attention in the scientific literature and is finally being recognized in policy frameworks such as the Global Biodiversity Framework and its associated targets for 2030. This is important progress. Nonetheless, freshwater species continue to be confronted with high levels of imperilment and widespread ecosystem degradation. An Emergency Recovery Plan (ERP) proposed in 2020 comprises six measures intended to "bend the curve" of freshwater biodiversity loss, if they are widely adopted and adequately supported. We review evidence suggesting that the combined intensity of persistent and emerging threats to freshwater biodiversity has become so serious that current and projected efforts to preserve, protect and restore inland-water ecosystems may be insufficient to avert substantial biodiversity losses in the coming decades. In particular, climate change, with its complex and harmful impacts, will frustrate attempts to prevent biodiversity losses from freshwater ecosystems already affected by multiple threats. Interactions among these threats will limit recovery of populations and exacerbate declines resulting in local or even global extinctions, especially among low-viability populations in degraded or fragmented ecosystems. In addition to impediments represented by climate change, we identify several other areas where the absolute scarcity of fresh water, inadequate scientific information or predictive capacity, and a widespread failure to mitigate anthropogenic stressors, are liable to set limits on the recovery of freshwater biodiversity. Implementation of the ERP rapidly and at scale through many widely dispersed local actions focused on regions of high freshwater biodiversity and intense threat, together with an intensification of ex-situ conservation efforts, will be necessary to preserve native freshwater biodiversity during an increasingly uncertain climatic future in which poorly understood, emergent and interacting threats have become more influential. But implementation of the ERP must be accompanied by measures that will improve water, energy and food security for humans - without further compromising the condition of freshwater ecosystems. Unfortunately, the inadequate political implementation of policies to arrest widely recognized environmental challenges such as climate change do not inspire confidence about the possible success of the ERP. In many parts of the world, the Anthropocene future seems certain to include extended periods with an absolute scarcity of uncontaminated surface runoff that will inevitably be appropriated by humans. Unless there is a step-change in societal awareness of - and commitment to - the conservation of freshwater biodiversity, together with necessary actions to arrest climate change, implementation of established methods for protecting freshwater biodiversity may not bend the curve enough to prevent continued ecosystem degradation and species loss.

Vegetation-climate feedbacks across scales

Vegetation is often viewed as a consequence of long-term climate conditions. However, vegetation itself plays a fundamental role in shaping Earth's climate by regulating the energy, water, and biogeochemical cycles across terrestrial landscapes. It exerts influence by consuming water resources through transpiration and interception, lowering atmospheric CO2 concentration, altering surface roughness, and controlling net radiation and its partitioning into sensible and latent heat fluxes. This influence propagates through the atmosphere, from microclimate scales to the entire atmospheric boundary layer, subsequently impacting large-scale circulation and the global transport of heat and moisture. Understanding the feedbacks between vegetation and atmosphere across multiple scales is crucial for predicting the influence of land use and land cover changes, and for accurately representing these processes in climate models. This review discusses the biophysical and biogeochemical mechanisms through which vegetation modulates climate across spatial and temporal scales. Particularly, we evaluate the influence of vegetation on circulation patterns, precipitation, and temperature, considering both long-term trends and extreme events, such as droughts and heatwaves. Our goal is to highlight the state of science and review recent studies that may help advance our collective understanding of vegetation feedbacks and the role they play in climate.

Distribution of Population Sizes in Metapopulations of Threatened Organisms-Implications for Conservation of Orchids

Species are disappearing worldwide, and it is likely that the rate of their disappearance will increase. The most important factors responsible for this are assumed to be changes in climate and land use. To determine the probability of extinction of a given species, it must be viewed as a metapopulation composed of many populations. In plants, seeds are spread by wind or water (passive dispersers), unlike active dispersers, which can actively look for a suitable site of their species. Thus, while active dispersers can locate a suitable site, passive dispersers often fail to arrive at a suitable site. The following question arises: is it better for the survival of a metapopulation of passive dispersers to concentrate on conserving a few large populations, each of which will produce many propagules, or on many small populations, each of which will produce only few propagules? Here, we address the question of which of these strategies will maximize the likelihood of the survival of such a metapopulation, using orchids as a model. We concluded that small populations should be preferentially preserved. Small populations are more numerous and more likely to occur more widely in the region studied and therefore a larger proportion of the seeds they produce is more likely to land in suitable habitats than that produced by the fewer large populations. For conservation, there is a possibility to extend the results to other taxa. However, this must be carried out with caution and must consider the taxon in question.

Land use influences the faecal glucocorticoid metabolites of multiple species across trophic levels

Human landscape modification is amongst the greatest drivers of biodiversity loss. Measuring faecal glucocorticoid metabolites (FGM) in wildlife is of great value to measure the impact of human activities on local biodiversity because FGM offer a non-invasive way of measuring an animal's response to changes in its environment in the form of adrenocortical activity. Here, we measure the concentration of FGM in three native Australian mammal species belonging to different trophic levels: the Tasmanian devil (Sarcophilus harrisii) and the spotted-tailed quoll (Dasyurus maculatus), both carnivores, and an omnivore that is primarily an arboreal folivore, the brushtail possum (Trichosurus vulpecula), and compare the FGM concentrations across three major land uses: agricultural, plantation and National Parks. We find that land use influences the FGM concentration in all three species and that general patterns emerge in FGM concentrations across multiple species and trophic levels in relation to land use. Specifically, plantation landscapes are associated with the lowest median and range of variation of FGM concentration in all species with several plausible explanations depending on the species. Our results suggest that measuring FGM in multiple species can offer a time- and cost-efficient snapshot of how different animals experience the same environment, potentially simplifying FGM interpretation. This study is the first to apply a community approach to understand how multiple species of different trophic levels respond collectively, and separately, to different land use types.

Domestication During Restoration: Unintentional Selection During Eight Generations of Wild Seed Propagation Reduces Herkogamy, Dichogamy and Heterozygosity in Clarkia pulchella

Seed production on native seed farms has increased to meet the rising demand for plant material for restoration. Although these propagation efforts are necessary for restoration, cultivating wild populations may also result in unintentional selection and elicit evolutionary changes that mimic crop domestication, essentially turning these efforts into artificial domestication experiments. Here, we investigated whether phenotypic and genomic changes associated with domestication occurred in the wildflower Clarkia pulchella Pursh (Onagraceae) by comparing the wild source populations to the farmed population after eight generations of cultivation. At the phenotypic level, the farmed population shifted towards a floral morphology associated with self-pollination, with a significant decrease in both dichogamy and herkogamy. At the genomic level, > 6500 SNPs revealed that mean expected heterozygosity of the farmed population was significantly lower than the wild populations, despite the fact that the farmed population originated from a pool of multiple wild populations. Both the shift towards a selfing phenotype and the loss of diversity are expected consequences of domestication, although the phenotypic shifts in particular occurred much more rapidly than has been observed for other domestication traits. We discuss these results in the context of plant domestication and the implications for retaining the genetic integrity of wild populations during the process of seed production for restoration.

Spatial distribution of tree-related microhabitats in a primeval mountain forest: From natural patterns to landscape planning and forest management recommendations

Tree-related Microhabitats (TreMs) are essential for sustaining forest biodiversity. Although TreMs represent ephemeral resources that are spread across the landscape, their spatial distribution within temperate forests remains poorly understood. To address this knowledge gap, we conducted a study on 90 sample plots (0.05 ha each) located in a primeval mountain European beech Fagus sylvatica-dominated forest (Bieszczady Mountains, Carpathians). We explored the TreM profile with its link to habitat characteristics and described the spatial distribution of TreM indices. We identified 61 TreM types, with a mean richness of 19.7 ± 4.9 SD TreM types per plot, a mean density of 740.7 ± 292.5 SD TreM-bearing trees ha-1 and a mean TreM diversity of 1.2 ± 0.1 SD. The diameter and living status of trees (living vs dead standing tree) were correlated with TreM richness on an individual tree. The stand structure, i.e. density and/or basal area of living and/or dead standing trees, and topographic conditions, i.e. slope exposure, were correlated with the TreM richness, density and diversity recorded on a study plot. We found no relationship between TreM richness, density and diversity and the presence of canopy gaps, which indicates that the influence of small-scale disturbances on the TreM profile is limited. However, our analysis revealed a clustered spatial pattern of TreM indices, with TreM-rich habitat patches (hot-spots) covering ~20 % of the forest. A moderate TreM richness, density and diversity dominated ~60 % of the forest, while TreM-poor habitat patches (cold-spots) covered ~20 %. Based on our findings, we advise the transfer of knowledge on the spatial distribution of TreMs from primeval to managed forests and advocate the '2:6:2' triad rule: to allocate 20 % of forests as strictly protected areas, to dedicate 60 % to low-intensity forest management with the retention of large living trees and all dead standing trees, and to use the remaining 20 % for intensive timber production. To ensure the continuance of the majority of TreM types, ≥55 living trees ha-1 >60 cm in diameter should be retained. Such an approach will maintain a rich and diverse TreM assemblage across a broad spatial scale, which in turn will support biodiversity conservation and ecosystem restoration in secondary or managed forests.

Evaluating historical changes in a mussel bed community in northern California

Marine foundation species are increasingly impacted by anthropogenic stressors, driving a loss of diversity within these critical habitats. Prior studies suggest that species diversity within mussel beds has declined precipitously in southern California, USA, but it is unclear whether a similar loss has occurred farther north. Here, we resurvey a mussel bed community in northern California first sampled in 1941 to evaluate changes in diversity after 78 years. More broadly, we explore the value and potential challenges of using imperfect historical data to assess community changes. Our 2019 survey documented 90 species/taxa across 10 phyla. The majority of species (~ 72%) were common to all replicate plots, suggesting that variation in species diversity over small spatial scales was unlikely to mask temporal changes. In contrast to results from southern California, we observed no decline in species diversity between timepoints. However, there were shifts in species composition, with an increase in the abundance of southern species and a decrease in northern species, consistent with warming observed at a nearby shoreline site. Overall, our findings are an encouraging sign for the health of this mussel bed community in northern California and illustrate how non-traditional data can contribute to assessments of long-term ecological change.

Does Reproductive Success in Orchids Affect the Evolution of Their Number of Flowers?

Species are disappearing worldwide, and changes in climate and land use are commonly assumed to be the most important causes. Organisms are counteracting the negative effects of environmental factors on their survival by evolving various defence strategies, which positively affect their fitness. Here, the question addressed is: can evolution shape these defence strategies so that they positively affect the fitness of an organism? This question is complex and depends on the taxa and environmental factors. Therefore, here, only a special case of this question is studied in deceptive species of orchids: reproductive success (RS, ratio of the number of fruits to the number of flowers produced by a plant during the whole season), a commonly used measure of fitness is used to develop a model describing how RS affects the number of flowers, n, of a plant. This model predicts that: (i) the resulting relationship between RS and n is a positively skewed parabola, (ii) the distribution of the numbers of individuals with a specific number (n) of flowers, NI(n), also resembles a parabola and is also positively skewed, and that (iii) the peak of the distribution of NI is to the left of the peak of RS. A large set of data is presented that supports these predictions. If the data set is small, the concave positively skewed parabolic RS-n dependence is obscured by other factors.

Bending the curve of biodiversity loss requires a 'satnav' for nature

Georgina Mace proposed bending the curve of biodiversity loss as a fitting ambition for the Convention on Biological Diversity. The new Global Biodiversity Monitoring Framework (GBMF) may increase the chances of meeting the goals and targets in the Kunming-Montreal Global Biodiversity Framework (KMGBF), which requires bending the curve. To meet the outcome goals of KMGBF, the GBMF should support adaptive policy responses to the state of biodiversity, which in turn requires a 'satnav' for nature. The twin pillars of such a satnav are (i) models to predict expected future outcomes of today's choices; and (ii) rapid feedback from monitoring to enable course corrections and model improvement. These same elements will also empower organizations to ensure that their actions are truly nature-positive, but they are not yet written into the GBMF. Without a satnav, society will effectively have to try to find its way to the outcome goals by looking in the rear-view mirror that the current headline indicators provide. Drawing contrasts and parallels with climate modelling, I discuss challenges for indicators, models, data and research culture that must be overcome if we are to bend the curve, and suggest ways forward.This article is part of the discussion meeting issue 'Bending the curve towards nature recovery: building on Georgina Mace's legacy for a biodiverse future'.

The trophic distribution of biomass in ecosystems with co-occurring wildlife and livestock

Trophic interactions regulate populations, but anthropogenic processes influence primary productivity and consumption by both herbivore and carnivore species. Trophic ecology studies often focus on natural systems such as protected areas, even though livestock globally comprise the majority of terrestrial vertebrate biomass. Here we explore spatial and temporal patterns in the distribution of biomass between plants, and large herbivores and carnivores (> 10 kg) in Norwegian rangelands, including both wildlife and livestock. We find high spatial variation in the relationship between plant and herbivore biomass, with both positive and negative divergence in observed biomass from expectations based on primary productivity. Meanwhile, despite recent partial recoveries in carnivore densities across Norway, carnivore biomass is still lower than expected based on herbivore biomass, even if livestock are excluded from the estimation. Our study highlights how temporal trends in both herbivores and carnivores reflect policy development. The role of livestock husbandry and wildlife management is thus key in determining realised biomass distributions in anthropogenically influenced ecosystems.