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Aim: Much research has focused on the separate and combined effects of habitat and geography on species communities, both in mainland and island ecosystems. However, few studies have looked into the differences among communities inhabiting different island habitats. Here we aim to determine the contributions of habitat filtering and dispersal to the differences in taxonomic structure of island communities across geographic scales. Location: Sixty plots in two habitats (forest and dry habitat) across eight islands of the Macaronesian archipelagos of the Azores, Madeira, Canary Islands and Cabo Verde. Taxon: Spiders (Araneae). Methods: We generated community data by using the optimised and standardised COBRA sampling protocols. We tested the differences in three beta diversity metrics ( βTotal, βReplacement and βRichness) for each habitat and dispersal category separately, across geographic scales through nested non-parametric PerMANOVA. We tested if dispersal and habitat influenced differences between the communities of the same area by applying a PERMDISP to βreplacement, and using the distances in linear mixed models. We tested the effects of habitat and dispersal on species relative abundances (SADs) and rarity by building Gambin models for each community and dispersal group separately. Results: Communities grouped according to archipelago and habitat, in terms of taxonomic similarity. In general, β diversity increased with geographic scale, and was greater in dry habitats. βReplacement among communities of the same region was greater in dry habitats than in forests, and this difference was stronger for rare ballooners. Dry habitat communities showed more species with low abundances (rare species) at different spatial scales. Main conclusions: Our findings reveal that habitat type does not only condition the processes behind community assembly but also the scale at which they occur. Indeed, our findings are highly relevant for theories on across and within island community assembly as well as for biodiversity conservation., Field work was supported by two projects: 1) the ERA-Net Net-Biome research framework, Canary Islands Government ACIISI grants SE-12/02 (PO), SE-12/03 (JCC), SE-12/04 (BE), co-financed by FEDER, Portuguese FCT-NETBIOME grant 0003/2011 (PB); and 2) FCT MACDIV – FCT PTDC/BIABIC/0054/2014. Open Access was financed by the project UID/BIA/00329/2020. The National Parks of Terceira and Pico (Azores), the Instituto das Florestas e da Conservação da Natureza (Madeira), the Cabildos of Tenerife and La Gomera, Garajonay National Park (La Gomera) as well as the Cabo Verde Government provided permits for specimen collection in protected areas. IRA was funded by national funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., under the Norma Transitória DL57/2016/CP1375/CT0003.

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The JRC PESETA IV study shows that ecosystems, people and economies in the EU will face major impacts from climate change if we do not urgently mitigate greenhouse gas emissions or adapt to climate change. The burden of climate change shows a clear north-south divide, with southern regions in Europe much more impacted, through the effects of extreme heat, water scarcity, drought, forest fires and agriculture losses. Limiting global warming to well below 2°C would considerably reduce climate change impacts in Europe. Adaptation to climate change would further minimize unavoidable impacts in a cost-effective manner, with considerable co-benefits from nature-based solutions., JRC.C.6-Economics of Climate Change, Energy and Transport

European forests provide a set of fundamental services that contribute to climate change mitigation and human well-being. At the same time, forests are vulnerable systems because the long life-span of trees limits the possibility of rapid adaptation to drastic environmental changes. Climate-driven disturbances in forests, such as fires, windstorms and insect outbreaks, are expected to rise drastically under global warming. As a result, key forest services, such as carbon sequestration and supply of wood materials, could be seriously affected in the near future. Despite the relevance and urgency of the issue, little is known about the vulnerability of European forests to multiple climate-related hazards and the adaptation benefits of alternative forest management strategies. To fill this knowledge gap we investigated the susceptibility of European forests when exposed to a given natural disturbance under different forest management scenarios. For this purpose, we assessed forest vulnerability by integrating in a data-driven framework satellite observations, national forest inventories, land surface climatic data and records of disturbances over the 2000-2017 period. The integration of these data streams is meant to capture the key drivers of vulnerability and to quantify, for the first time, the vulnerability of European forests to fires, windstorms and insect outbreaks in a systematic and spatially explicit manner. We point out that, the term vulnerability is used in this study to express to what degree a forest ecosystem is affected when exposed to a given disturbance. In order to derive risk estimates, vulnerability estimates should be integrated with hazard and exposure components, according to typical impact assessment frameworks. Results of this analyses show that in average at Europe level forest vulnerability to windstorms appears the disturbance with larger biomass loss both in relative and absolute terms (~38%, ~17 t ha-1) compared to fires (~24%, ~12.5 t ha-1) and insect outbreaks (~21%, ~9 t ha-1). Substantial spatial variations in vulnerability emerge and depict generally higher values in norther and Mediterranean regions. Overall, forest structural properties play a larger control on the vulnerability of European forests to natural disturbances compared to climate and landscape features. However, increases in temperature and changes in precipitation patterns occurred over the last two decades, have contributed substantially to make European forests more vulnerable to natural disturbances. We found that these changes in climate led to a limited increase in vulnerability at Europe for fires and windstorms and to a strong increase for insect outbreaks. However, contrasting regional trends emerging over Europe mask relevant temporal changes in vulnerability occurring at local scale. When analyses of single disturbances are combined together, results show that large part of the European forests are substantially vulnerable to at least one natural disturbance and that many of the areas more vulnerable have been subject to an amplification of vulnerability over the observational period due to changes in climate. Reducing tree age and tree density appear effective forest management strategies to reduce the vulnerability of European forests to climate-driven disturbances. The magnitude of the potential benefits appears strongly dependent on local environmental conditions. Previous assessments of future climate risks to European forests, based on catalogues of disturbances collected at country level, have showed that damage from fires, windstorms and insect outbreaks is likely to increase further in coming decades. Such intensification could offset the impact of land-based strategies aiming to increase the forest carbon sink. However, the country scale approach used in such studies do not allow to explore in detail the underlying physical processes and to elaborate adaptation strategies at appropriate local scales. It is therefore fundamental to elaborate new modelling approaches that address in explicit manner the high spatial and temporal variability of forest disturbances. In this respect, machine learning approaches and the increasing availability of multi-platform satellite observations of land surface in combination with high regional climate model simulations, represent valuable opportunities to appraise the impact of forest disturbances at a spatial and temporal resolution relevant for forest management strategies. This explorative study represents a first step towards such integrated framework., JRC.D.1-Bio-economy

During intense heatwaves in June and July 2019, all-time temperature records were broken in many locations in Europe. These events are projected to happen more frequently and become more intense with climate change. Projections show that the number of citizens in the EU and UK exposed to heatwaves will grow from 10 million/year (average 1981-2010) to nearly 300 million/year, or more than half the EU population, in a scenario with 3°C global average warming by the end of this century. In case of no adaptation this could result in 96,000 fatalities/year from extreme heat, compared to 2,750 annual deaths at present. Curbing global warming to 1.5°C would limit mortality from extreme heat to around 30,000 fatalities/year. The rise in exposure to and projected fatalities from extreme heat is most pronounced in southern Europe. Milder winters will reduce significantly exposure to and fatalities from extreme cold, nearly 10-fold with 3°C global average warming by the end of this century., JRC.E.1-Disaster Risk Management

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