An assessment of the state of conservation planning in Europe.

Expanding and managing current habitat and species protection measures is at the heart of the European biodiversity strategy. A structured approach is needed to gain insights into such issues is systematic conservation planning, which uses techniques from decision theory to identify places and actions that contribute most effectively to policy objectives given a set of constraints. Yet culturally and historically determined European landscapes make the implementation of any conservation plans challenging, requiring an analysis of synergies and trade-offs before implementation. In this work, we review the scientific literature for evidence of previous conservation planning approaches, highlighting recent advances and success stories. We find that the conceptual characteristics of European conservation planning studies likely reduced their potential in contributing to better-informed decisions. We outline pathways towards improving the uptake of decision theory and multi-criteria conservation planning at various scales, particularly highlighting the need for (a) open data and intuitive tools, (b) the integration of biodiversity-focused conservation planning with multiple objectives, (c) accounting of dynamic ecological processes and functions, and (d) better facilitation of entry-points and co-design practices of conservation planning scenarios with stakeholders. By adopting and improving these practices, European conservation planning might become more actionable and adaptable towards implementable policy outcomes. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.

Carrion ecology in inland aquatic ecosystems: a systematic review.

Carrion ecology, i.e. the decomposition and recycling of dead animals, has traditionally been neglected as a key process in ecosystem functioning. Similarly, despite the large threats that inland aquatic ecosystems (hereafter, aquatic ecosystems) face, the scientific literature is still largely biased towards terrestrial ecosystems. However, there has been an increasing number of studies on carrion ecology in aquatic ecosystems in the last two decades, highlighting their key role in nutrient recirculation and disease control. Thus, a global assessment of the ecological role of scavengers and carrion in aquatic ecosystems is timely. Here, we systematically reviewed scientific articles on carrion ecology in aquatic ecosystems to describe current knowledge, identify research gaps, and promote future studies that will deepen our understanding in this field. We found 206 relevant studies, which were highly biased towards North America, especially in lotic ecosystems, covering short time periods, and overlooking seasonality, a crucial factor in scavenging dynamics. Despite the low number of studies on scavenger assemblages, we recorded 55 orders of invertebrates from 179 families, with Diptera and Coleoptera being the most frequent orders. For vertebrates, we recorded 114 species from 40 families, with birds and mammals being the most common. Our results emphasise the significance of scavengers in stabilising food webs and facilitating nutrient cycling within aquatic ecosystems. Studies were strongly biased towards the assessment of the ecosystem effects of carrion, particularly of salmon carcasses in North America. The second most common research topic was the foraging ecology of vertebrates, which was mostly evaluated through sporadic observations of carrion in the diet. Articles assessing scavenger assemblages were scarce, and only a limited number of these studies evaluated carrion consumption patterns, which serve as a proxy for the role of scavengers in the ecosystem. The ecological functions performed by carrion and scavengers in aquatic ecosystems were diverse. The main ecological functions were carrion as food source and the role of scavengers in nutrient cycling, which appeared in 52.4% (N = 108) and 46.1% (N = 95) of publications, respectively. Ecosystem threats associated with carrion ecology were also identified, the most common being water eutrophication and carrion as source of pathogens (2.4%; N = 5 each). Regarding the effects of carrion on ecosystems, we found studies spanning all ecosystem components (N = 85), from soil or the water column to terrestrial vertebrates, with a particular focus on aquatic invertebrates and fish. Most of these articles found positive effects of carrion on ecosystems (e.g. higher species richness, abundance or fitness; 84.7%; N = 72), while a minority found negative effects, changes in community composition, or even no effects. Enhancing our understanding of scavengers and carrion in aquatic ecosystems is crucial to assessing their current and future roles amidst global change, mainly for water-land nutrient transport, due to changes in the amount and speed of nutrient movement, and for disease control and impact mitigation, due to the predicted increase in occurrence and magnitude of mortality events in aquatic ecosystems.

Detecting management gaps for biodiversity conservation: An integrated assessment.

The latest report on the state of nature in Europe (2013-2018) shows that biodiversity is declining at an alarming rate, with most protected species and habitats in poor condition. Despite an increasing volume of collected biodiversity information, urgent action is needed to integrate biodiversity data and knowledge to improve conservation efforts. We conducted a study in Catalonia (NE Spain), where we collected management measures implemented between 2013 and 2018, including allocation, budget, pressures aimed, and habitats/species potentially benefiting. We integrated information on pressures and habitats/species with the measures to identify non-spatial management gaps. Then, we integrated the spatially explicit information to determine the spatial management gap, identifying geographical areas where species/habitats are under pressure without registered measures. We demonstrated the importance of integrating existing information. Our findings revealed that resources were often not distributed adequately across species/habitats, with biases towards certain taxa being a common issue. The non-spatial management gap analysis identified taxonomic groups, especially plants and mollusks with the wider management gaps. We also identified threatened areas, especially in the northeast of the region with the larger spatial management gaps. These results could guide priority objectives to optimize conservation efforts. Integrating different information sources provided a broader view of the challenges that conservation science is facing nowadays. Our study offers a path toward bending the curve of biodiversity loss by providing an integrative framework that could optimize the use of the available information and help narrow the knowing-doing gap. In the context of the EU, this example demonstrates how information can be used to promote some environmental policy instruments, such as the Prioritized Action Frameworks (PAFs). Additionally, our findings highlight the importance of supporting decision-making with systematic assessments to identify deficiencies in the conservation process, reduce the loss of critical ecosystems and species, and avoid biases among taxa.

Mapping drivers of change for biodiversity risk assessment to target conservation actions: Human frequentation in protected areas.

Mapping the drivers of change that pose negative pressures or threats to biodiversity can help to identify where biodiversity is most threatened and can be used to determine priority sites to target conservation actions. Overlapping drivers of change maps with distribution maps of sensitive species provides valuable information to identify where and when it would be better to target actions to minimize the risk. The overall aim of this study was to develop a methodology for the integration of risk mapping associated with high human frequentation to guide conservation actions in two case study: the Kentish plover (Charadrius alexandrinus) and Posidonia meadows (Posidonia oceanica), both sensitive to human frequentation. To achieve this, we used two types of geolocated mobile phone information from the STRAVA platform: mapped paths and roads number of visitors at hourly precisions and a sporting activities heatmap representative of a wider period, together with species ecological information and complementary human frequentation data. The final, monthly risk maps identified the areas for Kentish plover with null, low, moderate, high, very high risk attributed to different aspects of the breeding biology of the species, nests, nestlings, and adults. The risk thresholds for nests are lower than for nestlings and adults, thought nestlings were generally less sensitive to human frequentation than adults. Visitors number ranges between 250 and 700 approximately suppose a moderate risk for the three assessed periods, and more than 1200 visitors appeared to prevent the nesting of the species completely. The final risk maps for Posidonia meadows determine the areas with low, moderate, hight and very high risk for human marine activities. Human frequentation values in this case study are scaled between 0 and 1, the results shows that values above 0.1 imply a high risk for the species. Both types of information can be used to target concrete, spatially explicit actions to minimize the risk caused by human frequentation. Furthermore, the first case study would allow to adapt the target actions to the species breeding phenology. The proposed risk assessment workflow is flexible and may be adjusted to match the available information and eventually could be adapted to other conservation objectives arising from different threats. In addition, data gathered from mobile mobility applications show great potential to accurately identify human frequentation, both spatially and temporally.

Niche dynamics along two centuries of multiple crayfish invasions.

The realised ecological niches of species may change in response to dynamic abiotic and biotic environments, particularly under fast global change. To fully understand the dynamics of niche features and their drivers, it is essential to have a long-term view of species distributions and the factors that may have influenced them. Here, we analysed the distribution and niche dynamics of the Italian crayfish (Austropotamobius fulcisianus) in the Iberian Peninsula over the past 200 years. The Italian crayfish was introduced to Spain in the 16th century, and spread due to multiple stocking events until the 1970s, when two North American crayfish (red swamp crayfish Procambarus clarkii, and signal crayfish Pacifastacus leniusculus) were introduced. Both North American species are carriers of a pathogen (Aphanomyces astaci, the causal agent of crayfish plague) lethal to the Italian crayfish. We hypothesised that the realised niche of the Italian crayfish, both in breadth and in position, has changed over time following changes in its range. The distribution of the Italian crayfish expanded from the mid-19th century until the mid-20th century, in association with an enlargement of its realised niched, mostly towards less abrupt and more coastal-influenced areas. After the introduction of the North American crayfishes, the collapse of the Italian crayfish involved a niche shift towards rough terrains in mountain areas. North American crayfish have eventually occupied most of the Italian crayfish's niche space, with the few no-coexistence areas being relegated to the most abrupt and high-elevation territories. Our historical approach allowed us to document and understand the highly dynamic distribution and niche of the Italian crayfish in the presence of invader counterparts, and to explore the environmental conditions under which their coexistence is minimised.

A horizon scan exercise for aquatic invasive alien species in Iberian inland waters.

As the number of introduced species keeps increasing unabatedly, identifying and prioritising current and potential Invasive Alien Species (IAS) has become essential to manage them. Horizon Scanning (HS), defined as an exploration of potential threats, is considered a fundamental component of IAS management. By combining scientific knowledge on taxa with expert opinion, we identified the most relevant aquatic IAS in the Iberian Peninsula, i.e., those with the greatest geographic extent (or probability of introduction), severe ecological, economic and human health impacts, greatest difficulty and acceptability of management. We highlighted the 126 most relevant IAS already present in Iberian inland waters (i.e., Concern list) and 89 with a high probability of being introduced in the near future (i.e., Alert list), of which 24 and 10 IAS, respectively, were considered as a management priority after receiving the highest scores in the expert assessment (i.e., top-ranked IAS). In both lists, aquatic IAS belonging to the four thematic groups (plants, freshwater invertebrates, estuarine invertebrates, and vertebrates) were identified as having been introduced through various pathways from different regions of the world and classified according to their main functional feeding groups. Also, the latest update of the list of IAS of Union concern pursuant to Regulation (EU) No 1143/2014 includes only 12 top-ranked IAS identified for the Iberian Peninsula, while the national lists incorporate the vast majority of them. This fact underlines the great importance of taxa prioritisation exercises at biogeographical scales as a step prior to risk analyses and their inclusion in national lists. This HS provides a robust assessment and a cost-effective strategy for decision-makers and stakeholders to prioritise the use of limited resources for IAS prevention and management. Although applied at a transnational level in a European biodiversity hotspot, this approach is designed for potential application at any geographical or administrative scale, including the continental one.

Identifying freshwater priority areas for cross-taxa interactions.

Information about biotic interactions (e.g. competition, predation, parasitism, diseases, mutualism, allelopathy) is fundamental to better understand species distribution and abundance, ecosystem functioning, and ultimately guide conservation efforts. However, conservation planning often overlooks these important interactions. Here, we aim to demonstrate a new framework to include biotic interactions into Marxan. For that, we use freshwater mussels and fish interaction (as mussels rely on fishes to complete their life cycle) in the Douro River basin (Iberian Peninsula) as a case study. While doing that, we also test the importance of including biotic interactions into conservation planning exercises, by running spatial prioritisation analysis considering either: 1) only the target species (freshwater mussels); 2) freshwater mussels and their obligatory hosts (freshwater fishes); 3) freshwater mussels, fishes and their interactions. With this framework we found that biotic interactions tend to be underrepresented when the data on both freshwater mussels and fishes is not simultaneously included in the spatial prioritisation. Overall, the priority areas selected across all scenarios are mostly located in the western part of the Douro River basin, where most freshwater mussels and fishes still occur. Given the low overlap of priority areas identified here and the current Natura 2000 network, our approach may be useful for establishing (or enlarging) protected areas, especially in light of the EU Biodiversity Strategy for 2030. Also, this work may provide guidance for future habitat restoration and management of main threats to freshwater biodiversity.

Boosting freshwater fish conservation with high-resolution distribution mapping across a large territory.

The lack of high-resolution distribution maps for freshwater species across large extents fundamentally challenges biodiversity conservation worldwide. We devised a simple framework to delineate the distributions of freshwater fishes in a high-resolution drainage map based on stacked species distribution models and expert information. We applied this framework to the entire Chinese freshwater fish fauna (>1600 species) to examine high-resolution biodiversity patterns and reveal potential conflicts between freshwater biodiversity and anthropogenic disturbances. The correlations between spatial patterns of biodiversity facets (species richness, endemicity, and phylogenetic diversity) were all significant (r = 0.43-0.98, p < 0.001). Areas with high values of different biodiversity facets overlapped with anthropogenic disturbances. Existing protected areas (PAs), covering 22% of China's territory, protected 25-29% of fish habitats, 16-23% of species, and 30-31% of priority conservation areas. Moreover, 6-21% of the species were completely unprotected. These results suggest the need for extending the network of PAs to ensure the conservation of China's freshwater fishes and the goods and services they provide. Specifically, middle to low reaches of large rivers and their associated lakes from northeast to southwest China hosted the most diverse species assemblages and thus should be the target of future expansions of the network of PAs. More generally, our framework, which can be used to draw high-resolution freshwater biodiversity maps combining species occurrence data and expert knowledge on species distribution, provides an efficient way to design PAs regardless of the ecosystem, taxonomic group, or region considered.

Potenciación de la conservación de peces de agua dulce con mapeos de distribución de alta resolución a lo largo de un territorio extenso Resumen La falta de mapas de distribución en alta resolución para las especies de agua dulce en grandes extensiones es un reto importante para la conservación mundial de la biodiversidad. Diseñamos un marco simple para delinear la distribución de los peces de agua dulce en un mapa de drenaje en alta resolución basado en los modelos apilados de la distribución de las especies y la información de expertos. Aplicamos este marco a toda la ictiofauna de agua dulce en China (>1600 especies) para analizar los patrones en alta resolución de la biodiversidad y revelar los conflictos potenciales entre la biodiversidad de agua dulce y las perturbaciones antropogénicas. Todas las correlaciones entre los patrones espaciales de las facetas de la biodiversidad (riqueza de especies, endemismo y diversidad filogenética) fueron importantes (r = 0.43-0.98, p < 0.001). Las áreas con valores altos de diferentes facetas de la biodiversidad se traslaparon con las perturbaciones antropogénicas. Las áreas protegidas existentes que actualmente cubren el 22% del territorio de China, protegen 25-2% del hábitat de los peces, 16-23% de las especies y 30-31% de las áreas de conservación prioritarias. Además, 6-21% de las especies se encontraban totalmente desprotegidas. Estos resultados sugieren que se necesita extender la red de áreas protegidas para asegurar la conservación de los peces de agua dulce de China y los bienes y servicios que proporcionan. En concreto, los niveles medio a bajo de los grandes ríos y sus lagos asociados del noreste al suroeste de China albergaron los ensambles de especies más diversos y por lo tanto deberían ser el objetivo de las futuras expansiones de la red de áreas protegidas. De forma más generalizada, nuestro marco, el cual puede usarse para trazar mapas en alta resolución de la biodiversidad de agua dulce al combinar los datos de presencia de las especies y el conocimiento de los expertos sobre su distribución, proporciona un método eficiente para diseñar las áreas protegidas sin importar el ecosistema, región o grupo taxonómico considerado.

Climate- and fire-smart landscape scenarios call for redesigning protection regimes to achieve multiple management goals.

Integrated management of biodiversity and ecosystem services (ES) in heterogeneous landscapes requires considering the potential trade-offs between conflicting objectives. The UNESCO's Biosphere Reserve zoning scheme is a suitable context to address these trade-offs by considering multiple management zones that aim to minimise conflicts between management objectives. Moreover, in Mediterranean ecosystems, management and planning also needs to consider drivers of landscape dynamics such as wildfires and traditional farming and forestry practices that have historically shaped landscapes and the biodiversity they host. In this study, we applied a conservation planning approach to prioritise the allocation of management zones under future landscape and climate scenarios. We tested different landscape management scenarios reflecting the outcomes of climate-smart and fire-smart policies. We projected the expected landscape dynamics and associated changes on the distribution of 207 vertebrate species, 4 ES and fire hazard under each scenario. We used Marxan with Zones to allocate three management zones, replicating the Biosphere Reserves zoning scheme ("Core area", "Buffer zone" and "Transition area") to address the various management objectives within the Biosphere Reserve. Our results show that to promote ES supply and biodiversity conservation, while also minimising fire hazard, the reserve will need to: i) Redefine its zoning, especially regarding Core Areas, which need a considerable expansion to help mitigate changes in biodiversity and accommodate ES supply under expected changes in climate and species distribution. ii) Revisit current management policies that will result in encroached landscapes prone to high intensity, uncontrollable wildfires with the potential to heavily damage ecosystems and compromise the supply of ES. Our results support that both climate- and fire-smart policies in the Meseta Ibérica can help develop multifunctional landscapes that help mitigate and adapt to climate change and ensure the best possible maintenance of biodiversity and ES supply under uncertain future climate conditions.

Ecological relevance of non-perennial rivers for the conservation of terrestrial and aquatic communities.

River conservation efforts traditionally focus on perennial watercourses (i.e., those that do not dry) and their associated aquatic biodiversity. However, most of the global river network is not perennial and thus supports both aquatic and terrestrial biodiversity. We assessed the conservation value of nonperennial rivers and streams (NPRS) in one of Europe's driest regions based on aquatic (macroinvertebrates, diatoms) and terrestrial (riparian plants, birds, and carabid beetles) community data. We mapped the distribution of taxa at 90 locations and across wide environmental gradients. Using the systematic planning tool Marxan, we identified priority conservation sites under 2 scenarios: aquatic taxa alone or aquatic and terrestrial taxa together. We explored how environmental factors (runoff, flow intermittence, elevation, salinity, anthropogenic impact) influenced Marxan's site selection frequency. The NPRS were selected more frequently (over 13% on average) than perennial rivers when both aquatic and terrestrial taxa were considered, suggesting that NPRS have a high conservation value at the catchment scale. We detected an underrepresentation of terrestrial taxa (8.4-10.6% terrestrial vs. 0.5-1.1% aquatic taxa were unrepresented in most Marxan solutions) when priority sites were identified based exclusively on aquatic biodiversity, which points to a low surrogacy value of aquatic taxa for terrestrial taxa. Runoff explained site selection when focusing on aquatic taxa (all best-fitting models included runoff, r2  = 0.26-0.27), whereas elevation, salinity, and flow intermittence were more important when considering both groups. In both cases, site selection frequency declined as anthropogenic impact increased. Our results highlight the need to integrate terrestrial and aquatic communities when identifying priority areas for conservation in catchments with NPRS. This is key to overcoming drawbacks of traditional assessments based only on aquatic taxa and to ensure the conservation of NPRS, especially as NPRS become more prevalent worldwide due to climate change and increasing water demands.

Los esfuerzos de conservación fluvial se enfocan tradicionalmente en los cauces permanentes (aquellos que no se secan) y la biodiversidad acuática asociada. Sin embargo, la mayor parte de la red hidrográfica mundial no es permanente, por lo que sustenta biodiversidad tanto acuática como terrestre. Evaluamos el valor de conservación de los ríos y arroyos no permanentes (RANP) en una de las regiones más secas de Europa con datos de comunidades acuáticas (macroinvertebrados, diatomeas) y terrestres (escarabajos carábidos). Mapeamos la distribución de los taxones en 90 localidades que cubren gradientes ambientales amplios. Con la herramienta de planificación sistemática Marxan identificamos los sitios prioritarios de conservación bajo dos escenarios: considerando sólo los taxones acuáticos o los taxones acuáticos y terrestres juntos. Exploramos cómo los factores ambientales (escorrentía, intermitencia del caudal, altitud, salinidad, impacto antropogénico) influyeron sobre la frecuencia de selección de sitio de Marxan. Los RANP fueron seleccionados con mayor frecuencia (más del 13% en promedio) que los ríos permanentes cuando consideramos los taxones acuáticos y terrestres, lo que sugiere que los RANP tienen un valor elevado de conservación a escala de cuenca. Detectamos que los taxones terrestres estaban infrarrepresentados (8.4-10.6% taxones terrestres vs. 0.5-1.1% acuáticos no tuvieron representación en la mayoría de las soluciones de Marxan) cuando los sitios prioritarios para la conservación se identificaban exclusivamente con la biodiversidad acuática, lo que indica que los taxones acuáticos tienen un reducido valor indicador para los taxones terrestres. La escorrentía determinó la selección de sitios cuando se basó en los taxones acuáticos (los mejores modelos incluyeron la escorrentía, r2 = 0.26-0.27), mientras que la altitud, la salinidad y la intermitencia del caudal fueron más importantes cuando se consideraron ambos grupos. En ambos casos, la frecuencia de selección disminuyó conforme se incrementó el impacto antropogénico. Nuestros resultados resaltan la necesidad de integrar las comunidades terrestres y acuáticas a la identificación de las áreas prioritarias para la conservación de la biodiversidad en cuencas con RANP. Lo anterior es importante para superar las evaluaciones tradicionales basadas solamente en los taxones acuáticos y para garantizar la conservación de los RANP, especialmente ahora que estos son cada vez más frecuentes a nivel mundial debido al cambio climático y a la creciente demanda de agua.

Multi-objective forest restoration planning in Costa Rica: Balancing landscape connectivity and ecosystem service provisioning with sustainable development.

Degradation, fragmentation, and loss of tropical forests has exponentially increased in the last decades leading to unprecedented rates of species extinctions and loss of ecosystems functions and services. Forest restoration is key to recover ecosystems health and achieve the UN Sustainable Development Goals. However, restoring forests at the landscape scale presents many challenges, since it requires balancing conservation goals and economic development. In this study, we used a spatial planning tool (Marxan) to identify priority areas for restoration satisfying multiple objectives across a biological corridor in Costa Rica. Biological corridors are critical conservation instruments promoting forest connectivity while acknowledging human presence. Increasing forest connectivity requires restoration initiatives that will likely conflict with other land uses, some of them of high national economic importance. Our restoration plan sought to maximize the provision of forest-related services (i.e., seed dispersal, tourism and carbon storage) while minimizing the impact on current land uses and thus avoiding potential conflicts. We quantified seed dispersal and tourism services (birdwatching potential) using species distribution models. We used the carbon sequestration model of InVEST to quantify carbon storage potential. We tested different restoration scenarios that differed in whether land opportunity costs of current uses were considered or not when identifying potential restoration areas, or how these costs were estimated. We showed how a landscape-scale forest restoration plan accounting for only forest connectivity and ecosystem service provision capacity can greatly differ from a plan that considers the potential impacts on local livelihoods. Spatial planning tools can assist at designing cost-effective landscape-scale forest restoration plans, identifying priority areas where forest restoration can maximize ecosystem provision and increase forest connectivity. Special care must be paid to the use of adequate estimates of opportunity cost, to avoid potential conflicts between restoration goals and other legitimate land uses.

A global agenda for advancing freshwater biodiversity research.

Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.

Tree planting: A double-edged sword to fight climate change in an era of megafires.

Climate regulation strategies based on forest restoration could pose an increase in fire risk, especially under drier and warmer conditions over large regions of Europe, impacting climate, the environment and human health. Climate-smarter options, such as wetlands restoration or recovery of grassland, that provide similar benefits for climate but also develop less flammable landscape is a more suitable option for these regions in Europe and elsewhere facing similar challenges.

The future for Mediterranean wetlands: 50 key issues and 50 important conservation research questions.

Wetlands are critically important for biodiversity and human wellbeing, but face a range of challenges. This is especially true in the Mediterranean region, where wetlands support endemic and threatened species and remain integral to human societies, but have been severely degraded in recent decades. Here, in order to raise awareness of future challenges and opportunities for Mediterranean wetlands, and to inform proactive research and management, we identified (a) 50 key issues that might affect Mediterranean wetlands between 2020 and 2050, and (b) 50 important research questions that, if answered, would have the greatest impact on the conservation of Mediterranean wetlands between 2020 and 2050. We gathered ideas through an online survey and review of recent literature. A diverse assessment panel prioritised ideas through an iterative, anonymised, Delphi-like process of scoring, voting and discussion. The prioritised issues included some that are already well known but likely to have a large impact on Mediterranean wetlands in the next 30 years (e.g. the accumulation of dams and reservoirs, plastic pollution and weak governance), and some that are currently overlooked in the context of Mediterranean wetlands (e.g. increasing desalination capacity and development of antimicrobial resistance). Questions largely focused on how best to carry out conservation interventions, or understanding the impacts of threats to inform conservation decision-making. This analysis will support research, policy and practice related to environmental conservation and sustainable development in the Mediterranean, and provides a model for similar analyses elsewhere in the world. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10113-020-01743-1.

An accessible optimisation method for barrier removal planning in stream networks.

Barriers associated to human infrastructure are a widespread impact in freshwater ecosystems worldwide, disrupting connectivity along river networks and key processes. Restoration of connectivity has risen in the last decade, with thousands of dams, weirs and culverts removed. Spatial optimisation methods can help inform decision on what barriers to remove to maximise gain in connectivity under limited budgets. However, current optimisation approaches rely on programming skills that are not easily accessible to stakeholders, which restrict the use of these methods. We demonstrate how Marxan, a publicly available tool, can be used to prioritise the allocation of barrier removal projects. We mapped the distribution of >900 barriers in the Tagus River (Iberian Peninsula) and 29 freshwater fish species with different movement abilities and needs. We assessed the passability of each barrier by all species and relative removal cost. We then identified priority barriers for removal to increase connectivity of populations of all species simultaneously. We tested two alternative scenarios: i) locking out barriers assesses as non-removable for their high strategic value or removal cost and ii) making all barriers available for removal. We found that connectivity recovery targets could be achieved by removing a small proportion of barriers, and avoiding large infrastructure. However, for some species, large recovery targets could only be achieved by removing some of these large infrastructures at high increases in cost. We also found some spatial differences in the recovery value of particular barriers for improving upstream and downstream connectivity. Our study demonstrates how to use a robust optimisation approach in an accessible tool, to address the complexity of prioritisation exercises commonly faced by stakeholders when deciding where to invest in barrier removal projects. This will improve decision-making for river connectivity restoration through a transparent, reproducible, and better-informed approach than traditional opportunistic or ranking-based approaches.

Fire and biodiversity in the Anthropocene.

Fire has been a source of global biodiversity for millions of years. However, interactions with anthropogenic drivers such as climate change, land use, and invasive species are changing the nature of fire activity and its impacts. We review how such changes are threatening species with extinction and transforming terrestrial ecosystems. Conservation of Earth's biological diversity will be achieved only by recognizing and responding to the critical role of fire. In the Anthropocene, this requires that conservation planning explicitly includes the combined effects of human activities and fire regimes. Improved forecasts for biodiversity must also integrate the connections among people, fire, and ecosystems. Such integration provides an opportunity for new actions that could revolutionize how society sustains biodiversity in a time of changing fire activity.

Realising the potential of Natura 2000 to achieve EU conservation goals as 2020 approaches.

In the last decades the EU has made substantial efforts implementing conservation strategies to halt biodiversity loss. However, little improvement has been reported. Given the proximity of the 2020 landmark set by the EU Biodiversity Strategy and the Convention for Biological Diversity, alternatives to reduce this conservation gap and prospect future strategies must be assessed urgently. Here, we explore how the current Natura 2000 could be used to enhance management of terrestrial and freshwater threatened vertebrates. We identified Natura 2000 sites to increase the coverage of threatened species as target species under two alternative scenarios: a policy-driven approach including only threatened vertebrates listed in the Directives; and a conservation-driven approach, including all the remaining threatened vertebrates. We show that representation of threatened vertebrates in Natura 2000 could be improved by updating lists of target species in less than 1% and 3% of sites in the policy-driven and conservation-driven scenarios, respectively. We highlight the strength of Natura 2000, with sites that complement each other and could contribute to achieving more ambitious conservation targets under future strategies. Prioritisation exercises like this could help realise the potential of this network and enhance the management of threatened species and improve current gaps.