Global Conservation Priorities Research Articles

Global patterns in endemicity and vulnerability of soil fungi.

Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here, we examined endemicity patterns, global change vulnerability and conservation priority areas for functional groups of soil fungi based on six global surveys using a high-resolution, long-read metabarcoding approach. We found that the endemicity of all fungi and most functional groups peaks in tropical habitats, including Amazonia, Yucatan, West-Central Africa, Sri Lanka, and New Caledonia, with a negligible island effect compared with plants and animals. We also found that fungi are predominantly vulnerable to drought, heat and land-cover change, particularly in dry tropical regions with high human population density. Fungal conservation areas of highest priority include herbaceous wetlands, tropical forests, and woodlands. We stress that more attention should be focused on the conservation of fungi, especially root symbiotic arbuscular mycorrhizal and ectomycorrhizal fungi in tropical regions as well as unicellular early-diverging groups and macrofungi in general. Given the low overlap between the endemicity of fungi and macroorganisms, but high conservation needs in both groups, detailed analyses on distribution and conservation requirements are warranted for other microorganisms and soil organisms.

Mapping global conservation priorities and habitat vulnerabilities for cave-dwelling bats in a changing world

Research and media attention is disproportionately focused on taxa and ecosystems perceived as charismatic, while other equally diverse systems such as caves and subterranean ecosystems are often neglected in biodiversity assessments and prioritisations. Highlighting the urgent need for protection, an especially large fraction of cave endemic species may be undescribed. Yet these more challenging systems are also vulnerable, with karsts for example losing a considerable proportion of their area each year. Bats are keystone to cave ecosystems making them potential surrogates to understand cave diversity patterns and identify conservation priorities. On a global scale, almost half (48 %) of known bat species use caves for parts of their life histories, with 32 % endemic to a single country, and 15 % currently threatened. We combined global analysis of cave bats from the IUCN spatial data with site-specific analysis of 1930 bat caves from 46 countries to develop global priorities for the conservation of the most vulnerable subterranean ecosystems. Globally, 28 % of caves showed high bat diversity and were highly threatened. The highest regional concentration of conservation priority caves was in the Palearctic and tropical regions (except the Afrotropical, which requires more intensive cave data sampling). Our results further highlight the importance of prioritising bat caves by incorporating locally collected data and optimising parameter selection (i.e., appropriate landscape features and threats). Finally, to protect and conserve these ecosystems it is crucial that we use frameworks such as this to identify priorities in species and habitat-level and map vulnerable underground habitats with the highest biodiversity and distinctiveness.

Functional connectivity of the world’s protected areas

Global policies call for connecting protected areas (PAs) to conserve the flow of animals and genes across changing landscapes, yet whether global PA networks currently support animal movement—and where connectivity conservation is most critical—remain largely unknown. In this study, we map the functional connectivity of the world’s terrestrial PAs and quantify national PA connectivity through the lens of moving mammals. We find that mitigating the human footprint may improve connectivity more than adding new PAs, although both strategies together maximize benefits. The most globally important areas of concentrated mammal movement remain unprotected, with 71% of these overlapping with global biodiversity priority areas and 6% occurring on land with moderate to high human modification. Conservation and restoration of critical connectivity areas could safeguard PA connectivity while supporting other global conservation priorities.

Evaluation of Protected Areas in Côte d’Ivoire and Ghana, West Africa, Using a Remote Sensing-Based Approach

This study assesses the representation of defined ecoregions, slope profiles, and species richness of threatened mammals in the International Union for Conservation of Nature (IUCN)-listed protected areas in Ghana and Côte d’Ivoire. It also evaluates the exposure of protected area categories to the cumulative degree of human modification and their vulnerability to future agricultural expansion. Spatial gap and statistical analyses were performed using quantitative data from publicly available online global databases. Analyses indicated key conservation priorities for both countries: (1) to increase the protection of the Guinean forest–savanna mosaic, West Sudanian savanna, and Eastern Guinean forests, especially of the Eastern Guinean forests’ ecoregion associated with the Guinean forests of the West Africa biodiversity hotspot; (2) to increase the protected area coverage of flat lands and low slopes; and (3) to enhance the size and connectivity of existing protected areas, including restoring degraded habitats. The study emphasizes that improving the ability of tropical protected areas to conserve nature and mitigate anthropogenic threats should be a global conservation priority. Improving the data quality and detail within the World Database on Protected Areas and ground-truthing them are recommended urgently to support accurate and informative assessments.

Global challenges and priorities for interventions addressing illegal harvest, use and trade of marine turtles

AbstractWorldwide, conservation initiatives have attempted to curb illegal harvest, use and trade of marine turtles at least since the 1950s. Despite some declines in local trade and consumption, these illegal activities are still often reported as a key threat to marine turtle populations. Reassessing and refining global conservation priorities for marine turtles allows us to formulate evidence-based strategies and effective interventions to address this threat. We surveyed a total of 103 marine turtle conservation researchers and practitioners globally to understand how conservation efforts can be better allocated to curb illegal harvest, use and trade. We explored the characteristics of these illegal activities, conservation priorities, challenges and lessons learnt. According to participants’ perceptions, progress has been achieved, but illegal harvest, use and trade remain pressing threats globally. Current challenges to addressing illegal activities relate to fisheries management, enforcement and legislation. Recommended priority actions include law and penalty enforcement, enhancing environmental literacy, awareness and stakeholder participation, and improving local conservation leadership and onshore/maritime management based on research. Based on participants' perceptions, we identify priorities for marine turtle conservation interventions that aim to curb illegal harvest, use and trade. Given the challenges of obtaining reliable information on sensitive topics such as illegal harvest, use and trade, further work should seek to validate our findings through empirical research. Further work could also seek to comprehend better how expert elicitation in conservation is influenced by individual experience, perspectives and goals.

Madagascar Terrestrial Camera Survey Database 2021: A collation of protected forest camera surveys from 2007-2021.

Madagascar is a threatened global biodiversity hotspot and conservation priority, yet we lack broad-scale surveys to assess biodiversity across space and time. To fill this gap, we collated camera trap surveys, capturing species occurrences within Madagascar into a single standardized database. This data set includes nine distinct protected areas of Madagascar and encompasses 13 subprojects, 38 camera arrays, and 1156 sampling units (independent camera site per survey) within two important biodiversity eco-regions: western dry deciduous forest and eastern humid rainforest. Camera surveys were conducted from June 2007 to January 2021. The final data set includes 17 unique families of mammals (Bovidae, Canidae, Cheirogaleidae, Daubentoniidae, Equidae, Eupleridae, Felidae, Hominidae, Indriidae, Lemuridae, Lepilemuridae, Muridae, Nesomyidae, Pteropodidae, Soricidae, Suidae, Tenrecidae) comprising 45 species and 27 unique families of birds (Accipitridae, Acrocephalidae, Alcedinidae, Bernieridae, Brachypteraciidae, Caprimulgidae, Cisticolidae, Columbidae, Coraciidae, Corvidae, Cuculidae, Dicruridae, Mesitornithidae, Monarchidae, Motacillidae, Muscicapidae, Numididae, Phasianidae, Rallidae, Sarothruridae, Strigidae, Sturnidae, Sulidae, Threskiornithidae, Upupidae, Vangidae, Zosteropidae) comprising 58 species. Images were processed and verified by individual project data set creators and camera operation and species tables were then collated. The final product represents the first broad-scale freely available standardized formal faunal database for Madagascar. Data are available through this publication and at DOI: 10.5281/zenodo.5801806. These data will be useful for examining species-level and community-level trends in occurrence across space or time within Madagascar and globally, evaluating native and invasive species dynamics, and will aid in determining species conservation status and planning for at-risk species. There are no copyright restrictions; please cite this paper when using the data for publication.

Effects of future climate change on the forests of Madagascar

AbstractGlobal climate change is continuing to occur at an alarming rate. In addition to increases in global weather extremes, melting of polar ice caps, and subsequent sea level rises, climate change is known to directly impact the life cycles and ecologies of many animals and plants. While climate change is projected to result in substantial geographic range and habitat contractions for many species in future, the effects of climate change on many habitats of conservation concern remain poorly understood. In this study, we investigated how future climate change is projected to impact the occurrence and distribution of four major forest types of Madagascar, a global biodiversity hotspot and conservation priority, over the next 60 years. We also compared how climate change effects vary among the four forest types under a “mitigation” climate forecast and under a “business‐as‐usual” trajectory. As expected, our models suggest that future climate change will affect the distribution of the four forest types under both trajectories, and forest occurrence is likely to decrease if mean temperatures, temperature seasonality, and precipitation rates increase as predicted. The exception is that forest gain is predicted to occur in the northwest of Madagascar, resulting in a small increase in transitional forest area under the “business‐as‐usual” climate change trajectory. Our study highlights that unmitigated climate change will have a negative impact on Madagascar's forests during the period up to the year 2080, and climate change therefore needs to be mitigated. Madagascar remains a global conservation priority, and urgent conservation action and protective legislation are required to safeguard the future of its native forest.

Cage transplant experiment shows weak transport effect on relative abundance of fish community composition as revealed by eDNA metabarcoding

Protection of freshwater fish diversity is a global conservation priority in face of its alarming decline in the last decades. A crucial step to protect freshwater fish diversity is the production of prompt and precise evaluation of community composition and spatial distribution. Metabarcoding of environmental DNA (eDNA metabarcoding) generally surpasses traditional methods for documenting diversity and community composition in aquatic environments. Nevertheless, empirical evidence evaluating how eDNA transportation in water affect community composition and structure via eDNA metabarcoding data remains scarce. Using a brown trout (Salmo trutta) cage transplant experiment in the St. Lawrence River (Canada), a large fluvial system, we tested the detection and relative abundance of species’ eDNA along 15 sampling locations. We detected brown trout eDNA in five localities up to 5,000 m from the cage, but only one sampling location situated 10 m downstream and in the direct line of the cage was affected at the community composition level. This locality showed a relative abundance of brown trout eDNA of 13.1%, while the four others showed a relative abundance under 1.0%. K-means cluster analysis confirmed the impact of brown trout eDNA on community composition by separating this locality from all others. Based on species loading of a redundancy analysis, we showed that this different k-means group was associated with the high relative abundance of brown trout. No evidence of transport effect of brown trout eDNA on fish community composition was observed in any other sampling locations. Together, our results support the view that eDNA metabarcoding can be both a conveyor belt of biodiversity information and a precise tool to study the composition and structure of fish communities in river.

Land Vulnerability, Risk Zoning, and Ecological Protection in the Protection Forest of Pagaibamba (Peru)

The protection of natural areas is considered an essential strategy for environment conservation. The objective of this work was to determine the level of vulnerability, considering the characterization and identification of the risk zones and ecological protection of the Pagaibamba Protection Forest (PPF, Peru). To determine the vulnerable areas, Landsat ETM satellite images, topographic, geological, ecological, and vegetation cover maps were used. Geological, physiographic, edaphological, vegetation cover, and land use potential characteristics, were analyzed. Three Ecological Protection and Risk Zones were identified, with the largest extension of the PPF corresponding to lands of very high and high vulnerability and high ecological risk, which include >85% of Protected Natural Areas (PNA) and 54% of the Buffer Zone (BZ). Moderate risk areas represent 30% of the Buffer Zone (BZ) and 13% of the PNA, and the low-risk areas (represent 15% of the BZ and 2% of the PNA). Biogeographically, the PPF was related to the Cloudy Montane Forests Ecoregion of the Andes Mountains, standing out the Tropical Montane Cloud Forest (TMCF) and the Tropical Lower Montane Cloud Forest (TLMCF). These forests are a global conservation priority due to their great biodiversity, high level of endemicity of flora and fauna, and the crucial hydrological function they fulfill.

Using publicly available data to conduct rapid assessments of extinction risk

AbstractThe IUCN Red List plays a key role in setting global conservation priorities and is populated via rigorous, time‐intensive assessments. Here, we test rapid preliminary assessments of plant extinction risk using one Red List metric: Extent of Occurrence (EOO). We developed REBA (Rapid EOO‐Based Assessment) to harvest and clean data from the Global Biodiversity Information Facility, calculate each species' EOO and assign EOO‐based Red List categories. We validated REBA classifications against 1671 North American plant species already on the Red List and found ~87% overlap between REBA’s classifications and the IUCN’s. However, REBA’s false‐negative rate for species outside the Least Concern category was substantial (~68%). To elucidate factors that might drive such a high rate of under‐classification, we used hierarchical Bayesian models to show that certain plant types (e.g., Geophytes) and threats (e.g., Invasive and Other Problematic Species, Genes, and Diseases) increased the probability of under‐classification. While REBA requires further refinement, it has yielded valuable insight into how preliminary assessment methodologies may become more effective.

Seasonal variations in the plant diet of the Chinese Monal revealed by fecal DNA metabarcoding analysis

The Chinese Monal (Lophophorus lhuysii) is an alpine-obligate galliform species of global conservation priority. It has been listed as a first class protected wildlife species in China, requiring conservation actions during the 14th Five-Year Plan period. However, the diet composition of Chinese Monal and its seasonal variations have rarely been studied, constraining the effective conservation of the species. Here, we investigated the plant diet composition of the Chinese Monal and its seasonal variations using a DNA metabarcoding approach on fecal samples. We collected 190 fecal samples of the Chinese Monals from the central Qionglai Mountains located in China, and analyzed the plant diet of this species using a DNA metabarcoding approach. Taxonomic profiling of higher plants in the fecal samples was performed using the second internal transcribed spacer (ITS2) amplicon. Downstream analyses, including rarefaction curves, nonmetric multidimensional scaling (NMDS) and permutational multivariate analysis of variance (PERMANOVA), were used to explore the seasonal variations in diet composition. The Chinese Monal foraged a wide range of plant recipes composed of 35 families and 83 genera throughout the year, with Brassicaceae, Apiaceae, and Poaceae as the dominant families, and Cardamine as the dominant genus. The species consumed plants from 62 genera from 28 families during the breeding season (n ​= ​81) and 66 genera from 31 families during the non-breeding season (n ​= ​109). Further, the plant diet composition significantly varied between the breeding and non-breeding seasons, especially for the frequency of occurrence and relative read abundances at genus level. Our study analyzed the plant diet of the Chinese Monal at a high resolution for the first time, and the results revealed that the seasonal variations in its plant diet composition was adapted to plant phenology and foraging strategy. Fritillaria species, a previously confirmed important food resource for the Chinese Monal, were not detected in any fecal samples, potentially due to overharvesting of Fritillaria bulbs for Traditional Chinese Medicine. Therefore, we highly recommend further restriction of herb gathering in Chinese Monal habitats to facilitate the conservation of this endangered species. Altogether, our study enriches essential ecological information for the Chinese Monal and also provides insights into conservation management for this endangered species.

Ecological dependencies make remote reef fish communities most vulnerable to coral loss

Ecosystems face both local hazards, such as over-exploitation, and global hazards, such as climate change. Since the impact of local hazards attenuates with distance from humans, local extinction risk should decrease with remoteness, making faraway areas safe havens for biodiversity. However, isolation and reduced anthropogenic disturbance may increase ecological specialization in remote communities, and hence their vulnerability to secondary effects of diversity loss propagating through networks of interacting species. We show this to be true for reef fish communities across the globe. An increase in fish-coral dependency with the distance of coral reefs from human settlements, paired with the far-reaching impacts of global hazards, increases the risk of fish species loss, counteracting the benefits of remoteness. Hotspots of fish risk from fish-coral dependency are distinct from those caused by direct human impacts, increasing the number of risk hotspots by ~30% globally. These findings might apply to other ecosystems on Earth and depict a world where no place, no matter how remote, is safe for biodiversity, calling for a reconsideration of global conservation priorities.

Transcending capitalism growth strategies for biodiversity conservation.

The unlimited economic growth that fuels capitalism's metabolism has profoundly transformed a large portion of Earth. The resulting environmental destruction has led to an unprecedented rate of biodiversity loss. Following large-scale losses of habitats and species, it was recognized that biodiversity is crucial to maintaining functional ecosystems. We sought to continue the debate on the contradictions between economic growth and biodiversity in the conservation science literature and thus invite scholars to engage in reversing the biodiversity crisis through acknowledging the impacts of economic growth. In the 1970s, a global agenda was set to develop different milestones related to sustainable development, including green-blue economic growth, which despite not specifically addressing biodiversity reinforced the idea that economic development based on profit is compatible with the planet's ecology. Only after biodiversity loss captured the attention of environmental sciences researchers in the early 2000s was a global biodiversity agenda implemented. The agenda highlights biodiversity conservation as a major international challenge and recognizes that the main drivers of biodiversity loss derive from economic activities. The post-2000 biodiversity agendas, including the 2030 Agenda for Sustainable Development and the post-2020 Convention on Biological Diversity Global Strategy Framework, do not consider the negative impacts of growth-oriented strategies on biodiversity. As a result, global biodiversity conservation priorities are governed by the economic value of biodiversity and its assumed contribution to people's welfare. A large body of empirical evidence shows that unlimited economic growth is the main driver of biodiversity loss in the Anthropocene; thus, we strongly argue for sustainable degrowth and a fundamental shift in societal values. An equitable downscaling of the physical economy can improve ecological conditions, thus reducing biodiversity loss and consequently enhancing human well-being.

Existing approaches and future directions to link macroecology, macroevolution and conservation prioritization

Due to increasing human transformation of virtually all habitats on Earth, setting global priorities for conservation is essential. The emerging disciplines of macroecology and macroevolution (MEE) can provide a global perspective and information for such prioritization but remain relatively separated from conservation prioritization, partly because MEE researchers are unaware of the requirements for effective conservation prioritization and existing approaches implementing these. Indeed, existing approaches for conservation prioritization at large scale are scattered across literature. Here, we systematically review this literature and provide a guideline for researchers in MEE as to which of approaches might be suitable for their needs. From >11 000 scientific publications, we identified 134 methods suitable for commonly used MEE data and geographic scale. Furthermore, we use a ‘trait matrix' to identify families of similar approaches and to design a guideline to select the most suitable method, given a user‐defined set of data and analysis scope. The guidelines are freely available via the conserveR R‐package (<https://github.com/azizka/conserveR>). Finally, we used our review to identify increasing scalability, continuous monitoring and the integration of molecular, remote sensing and animal movement data as key areas for future impacts of MEE in conservation prioritization. We anticipate that our review can serve as a guide to MEE researchers interested in linking their data to conservation as well as for conservation scientists interested in using MEE approaches.

An integrative synthesis to global amphibian conservation priorities.

Human activities are driving many species to the brink of extinction, and the current distribution of protected areas only weakly alleviates pressure on threatened species. This discrepancy reflects the presence of protected areas on lands available instead of the ecological, evolutionary, or conservation values of species present. Habitat loss consequently continues to impact threatened species, as illustrated by geographic patterns of biodiversity loss for amphibians. Given the need to better align the boundaries of protected areas with at-risk biodiversity, we assessed the importance of various factors for identifying global and biome-level conservation priority areas, specifically for amphibians. We identified, mapped, and ranked areas of critical conservation importance for all amphibian species on earth using a new integrative tool that scores the urgency of conserving each species and location based on a combination of species characteristics and ecoregion-level human impacts. Our integrative approach is novel in that it accounts for likely threats to Data Deficient species, considers the irreplaceability of unique species that are phylogenetically isolated, and addresses the localized conservation implications of species endemicity and projected future human impacts to an ecoregion. For comparison, we also mapped and ranked amphibian biodiversity using species richness and an Evolutionarily Distinct and Globally Endangered (EDGE) score proxy. Our integrative approach predicted key regions for amphibian conservation that were not apparent when using a simple species richness or EDGE score proxy-based approach. Furthermore, by scaling conservation priority scores relative to biome, we identified several temperate and xeric regions of crucial yet overlooked conservation importance for amphibians. Until global amphibian diversity is thoroughly catalogued, we recommend using our integrative scoring approach to set geographic priorities for amphibian habitat protection, while acknowledging that this approach may be complemented by others (e.g., EDGE scores). Our study provides an avenue for avoiding common pitfalls of more simplistic species richness-based approaches for conservation planning, and can be used to improve the future design of protected areas.

Plastic contamination of a Galapagos Island (Ecuador) and the relative risks to native marine species

Ecuador's Galapagos Islands and their unique biodiversity are a global conservation priority. We explored the presence, composition and environmental drivers of plastic contamination across the marine ecosystem at an island scale, investigated uptake in marine invertebrates and designed a systematic priority scoring analysis to identify the most vulnerable vertebrate species. Beach contamination varied by site (macroplastic 0–0.66 items·m−2, microplastics 0–448.8 particles·m−2 or 0–74.6 particles·kg−1), with high plastic accumulation on east-facing beaches that are influenced by the Humboldt Current. Local littering and waste management leakages accounted for just 2% of macroplastic. Microplastics (including anthropogenic cellulosics) were ubiquitous but in low concentrations in benthic sediments (6.7–86.7 particles·kg−1) and surface seawater (0.04–0.89 particles·m−3), with elevated concentrations in the harbour suggesting some local input. Microplastics were present in all seven marine invertebrate species examined, found in 52% of individuals (n = 123) confirming uptake of microplastics in the Galapagos marine food web. Priority scoring analysis combining species distribution information, IUCN Red List conservation status and literature evidence of harm from entanglement and ingestion of plastics in similar species identified 27 marine vertebrates in need of urgent, targeted monitoring and mitigation including pinnipeds, seabirds, turtles and sharks.

Maximizing the effectiveness of national commitments to protected area expansion for conserving biodiversity and ecosystem carbon under climate change.

Global commitments to protected area expansion should prioritize opportunities to protect climate refugia and ecosystems which store high levels of irrecoverable carbon, as key components of an effective response to biodiversity loss and climate change. The United States and Canada are responsible for one‐sixth of global greenhouse gas emissions but hold extensive natural ecosystems that store globally significant above‐ and below‐ground carbon. Canada has initiated a process of protected area network expansion in concert with efforts at reconciliation with Indigenous Peoples, and acknowledged nature‐based solutions as a key aspect of climate change mitigation. The US, although not a party to global biodiversity conventions, has recently committed to protecting 30% of its extent by 2030 and achieving the UNFCCC Paris Agreement's mitigation targets. The opportunities afforded by these dual biodiversity conservation and climate commitments require coordinated national and regional policies to ensure that new protected areas maximize biodiversity‐focused adaptation and nature‐based mitigation opportunities. We address how global commitments can best inform national policy initiatives which build on existing agency mandates for regional planning and species conservation. Previous analyses of global conservation priorities under climate change have been tenuously linked to policy contexts of individual nations and have lacked information on refugia due to limitations of globally available datasets. Comparison and synthesis of predictions from a range of recently developed refugia metrics allow such data to inform planning despite substantial uncertainty arising from contrasting model assumptions and inputs. A case study for endangered species planning for old‐forest‐associated species in the US Pacific Northwest demonstrates how regional planning can be nested hierarchically within national biodiversity‐focused adaptation and nature‐based mitigation strategies which integrate refugia, connectivity, and ecosystem carbon metrics to holistically evaluate the role of different land designations and where carbon mitigation and protection of biodiversity's resilience to climate change can be aligned.

Evaluating suitability of land for forest landscape restoration: A case study of Three Gorges Reservoir, China

Restoring degraded lands is now a global priority for conservation, and world leaders even made positive commitments to do so as part of the Bonn Challenge. Forest Landscape Restoration, which focuses on improving ecological functioning, biodiversity conservation and human livelihoods was introduced to meet these restoration goals. However, the restoration can be carried out only after a series of evaluations. One such evaluation is that of land for its suitability for forest landscape restoration and has become the basis for successful restoration of forest landscapes. A land suitability assessment method for forest landscape restoration is therefore fundamental. This study introduces a matter-element model-based methodology to assess land suitability for forest landscape restoration. The case study was evaluated in terms of altitude, slope, aspect, soil depth, soil type, and nutrient status of soil, all of which greatly influence the type of vegetation and plant growth. The results showed that the main factors influencing forest restoration in Zigui were altitude, slope, and soil depth. Roughly 100 km2 are suitable for restoration in Zigui County, accounting for about 60% of the theoretical recoverable area, a little more than one-third of which consists of slopes steeper than 25° and approximately 16% consists of slopes between 15° and 25°. The area under low quality forest land is a little over 40 km2, that under low quality garden land is roughly 15 km2, and that under sloping cultivated land is 40 km2. Evaluating the suitability of land for restoration can serve as a basis for forest-restoration projects and structural adjustments in shelter forests in this fragile area. Specifically, this method of evaluation can be replicated on different spatial and temporal scales and represents a new framework for evaluating the suitability of land for restoration of forests in other regions as well.

Tree size and crown structure explain the presence of cavities required by wildlife in cool-temperate forests of South America

Maintenance of tree cavity supply is a global conservation priority for forest wildlife, which requires understanding the ecology and population dynamics of cavity-bearing trees. Explaining the occurrence of cavities in trees is particularly important in ecosystems where most secondary cavity-users (SCUs) are critically dependent on the slow formation of cavities by wood-decay processes. Our main objectives were (1) to explain the distribution of decay cavities in trees according to their individual attributes and, (2) to quantify the relative importance of each individual tree attribute to determine the presence of decay cavities. We focused on medium and large decay cavities (smallest entrance dimension ≥ 5 cm), which can limit populations of management-sensitive SCUs. We measured forest attributes and inspected cavities in trees (n = 860) and snags (n = 93) in six 0.5 ha plots from old- and second-growth Nothofagus dombeyi forest stands. We used generalised linear mixed-effects models (GLMM) to analyse the distribution of decay cavities in trees using data on their presence/absence, based on several tree individual attributes, across different sites. We applied an information-theoretical and multi-model inference approach to quantify the strength of alternative sets of hypotheses/models. We used model averaging, which allows estimating coefficients and making inferences that account for model and parameter uncertainty. Diameter at breast height (DBH), crown damage and decay, crown ratio (crown length • trunk length−1) and woodpecker foraging signs were important to explain the presence/absence of decay cavities in trees. Diameter at breast height, woodpecker foraging signs and a moderate-high crown damage and decay were positively related with decay cavity presence. The presence of medium and large decay cavities was also positively related with DBH, but trees with low crown ratios had relatively low probabilities of presenting these cavities, even with DBHs > 150 cm. Trees with DBHs smaller than 50 cm had very low probabilities (<0.25–0.30) to present decay cavities, while the probability of trees presenting decay cavities of medium and large sizes was very low for trees with diameters < 100 cm, even for trees with high crown ratios. Our results point out that conservation of large diameter trees with high crown ratios is important to maintain the supply of decay cavities required by management-sensitive SCUs in these forests. As these keystone structures are globally threatened by climate change induced disturbances (e.g. fires, droughts), they should be maintained/restored through forest management (e.g. retention of keystone structures) to achieve cavity-using wildlife habitat conservation in the long-term.

Southeast Asia as One of World’s Primary Sources of Biotic Recolonization Following Anthropocene Extinctions

The plight of Southeast Asia’s animals, plants and ecosystems in the face of unsustainable exploitation and habitat destruction has been illustrated in several recent studies, despite often falling outside the global discourse on global conservation priorities. Here, we collate biogeographic and phylogenetic information to argue that this beleaguered region is one of world’s primary macrorefugia, and possibly its best chance of regaining its natural biodiversity distribution patterns after the current Anthropocene upheaval. The region uniquely combines top diversity values in (a) ancient lineage diversity and (b) cosmopolitan lineage diversity, suggesting that it has acted in the past as a biodiversity museum and source of global colonization. This is at least partly due to the interplay between latitudinal diversity gradients and continental connectivity patterns. However, the peak values in South China/North Indochina for cosmopolitan tetrapods and their sister lineages suggest that a key feature is also the availability of diverse climatic conditions. In particular, the north-south orientation of the mountain ranges here has allowed for rapid recolonization within the region following past climatic changes, resulting in high survival values and overall exceptional relict lineage diversity. From this starting point, global colonization occurred on multiple occasions. It is hoped that, with urgent action, the region can once again fulfill this function.