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Afforestation is an important mitigation strategy for climate change due to its carbon sequestration potential. Besides this favorable biogeochemical effect on global CO 2 concentrations, afforestation also affects the regional climate by changing the biogeophysical land surface characteristics. In this study, we investigate the effects of an idealized global CO 2 reduction to pre-industrial conditions by a Europe-wide afforestation experiment on the regional longwave radiation balance, starting in the year 1986 on a continent entirely covered with grassland. Results show that the impact of biogeophysical processes on the surface temperatures is much stronger than that of biogeochemical processes. Furthermore, biogeophysically induced changes of the surface temperatures, atmospheric temperatures, and moisture concentrations are as important for the regional longwave radiation balance as the global CO 2 reduction. While the outgoing longwave radiation is increased in winter, it is reduced in summer. In terms of annual total, a Europe-wide afforestation has a regional warming effect despite reduced CO 2 concentrations. Thus, even for an idealized reduction of the global CO 2 concentrations to pre-industrial levels, the European climate response to afforestation would still be dominated by its biogeophysical effects. [ABSTRACT FROM AUTHOR]

Afforestation is an important mitigation strategy to climate change due to its carbon sequestration potential. Besides this positive biogeochemical effect on global CO2 concentrations, afforestation also affects the regional climate by changing the biogeophysical land surface characteristics. In this study, we investigate the effects of an idealized global CO2 reduction to pre-industrial conditions by a Europe wide afforestation experiment on the regional longwave radiation balance, starting in the year 1986 from a continent entirely covered with grassland. Results show that the impact of biogeophysical processes on the surface temperatures is much stronger than of biogechemical processes. Furthermore, biogeophysically induced changes of the surface temperatures, atmospheric temperatures and moisture concentrations are as important for the regional greenhouse effect as the global CO2 reduction. While the greenhouse effect is strengthened in winter, it is weakened in summer. On annual total, a Europe-wide afforestation has a regional warming effect, despite reduced CO2 concentrations. Thus, even for an idealized reduction of the global CO2 concentrations to pre-industrial levels, the European climate response to afforestation would still be dominated by its biogeophysical effects. [ABSTRACT FROM AUTHOR]

Aim: Forest herbs might be unable to track shifts in habitat suitability due to rapid climate change and habitat fragmentation. In this study, we quantified the role of dispersal limitation and the potential mitigating effect of large‐scale reforestation on the redistribution of the herbaceous forest plant species Primula elatior under climate change. Location: Europe. Methods: High resolution (100 m) landscape‐scale and macro‐climatic variables were combined to predict range‐wide habitat suitability using Maxent. Dispersal limitation was modelled, based on isolation‐by‐resistance (IBR) principles through integration of circuit theory and genomic data, to assess patch accessibility and metapopulation stability under climate change. Large‐scale reforestation was evaluated as a potential mitigating strategy by incorporating a land use change scenario into the distribution and dispersal models. Results: Landscape‐scale variables contributed significantly to the distribution of P. elatior (78.33%) and to the accuracy of our model (AUC = 0.81). Isolation‐by‐resistance (R2cond =.92) was driven by land use (45.5%), distance from rivers (36.4%) and elevation (18.2%). It was estimated that 46.4 ± 13.9% (mean ± SD of climate change scenarios) of the total distribution area would be lost due to climate change by 2050 and an additional 15.6 ± 1.7% (mean ± SD) of the distribution would not be accessible through migration. The median latitude of the patch distribution shifted 183.2 ± 34.8 km (mean ± SD) northwards and 58.1 ± 9.3 km (mean ± SD) to more maritime regions. The patch accessibility was low in these regions and the metapopulation stability decreased considerably in the south of the distribution. Reforestation mitigated 54.1 ± 18.2% (mean ± SD) of the accessible distribution area loss and 49.5 ± 4.2% (mean ± SD) of the decrease in metapopulation stability. Main conclusion: To alleviate the loss of the accessible distribution area of P. elatior under climate change, it will be required to integrate climate mitigation strategies (RCP 2.6), range‐wide afforestation, restoration of ecological connectivity and focused assisted migration to newly available habitat. [ABSTRACT FROM AUTHOR]

In the context of the first phase of the Euro-CORDEX Flagship Plot Study (FPS) Land Use and Climate Across Scales (LUCAS), we investigate the afforestation impact on the seasonal cycle of soil temperature over the European continent with an ensemble of ten regional climate models (RCMs). For this purpose, each ensemble member performed two idealized land cover experiments in which Europe is covered either by forests or grasslands. The multi-model mean exhibits a reduction of the annual amplitude of soil temperature (AAST) over all European regions, although this not a robust feature among the models. In Mediterranean, the simulated AAST response to afforestation is between -4 K and +2 K while in Scandinavia the inter-model spread ranges from -7 K to +1 K. We then examine the role of changes in the annual amplitude of ground heat flux (AAGHF) and summer soil moisture content (SMC) in determining the effect of afforestation on AAST response. In contrast with the diverging results in AAST, all the models consistently indicate a widespread AAGHF decrease and summer SMC decline due to afforestation. The AAGHF changes effectively explain the largest part of the inter-model variance in AAST response in most regions, while the changes in summer SMC determine the sign of AAST response within a group of three simulations sharing the same land surface model. Finally, we pair FLUXNET sites to compare the simulated results with observation-based evidence of the impact of forest on soil temperature. In line with models, observations indicate a summer ground cooling in forested areas compared to open lands. The vast majority of models agree with the sign of the observed reduction in AAST, although with a large variation in the magnitude of changes. Overall, we aspire to emphasize the effects of afforestation on soil temperature profile with this study, given that changes in the seasonal cycle of soil temperature potentially perturb crucial biochemical processes. Such perturbations can be of societal relevance as afforestation is proposed as a climate change mitigation strategy. [ABSTRACT FROM AUTHOR]

• The nexus between forest-based climate mitigation and health is poorly researched. • This scoping review identified exposure pathways and health co-benefits from forests. • There is potential for synergies between forest management and health benefits. • Interdisciplinary efforts are required for advancement of research and understanding. Climate change is a pressing global challenge with profound implications for human health. Forest-based climate change mitigation strategies, such as afforestation, reforestation, and sustainable forest management, offer promising solutions to mitigate climate change and simultaneously yield substantial co-benefits for human health. The objective of this scoping review was to examine research trends related to the interdisciplinary nexus between forests as carbon sinks and human health co-benefits. We developed a conceptual framework model, supporting the inclusion of exposure pathways, such as recreational opportunities or aesthetic experiences, in the co-benefit context. We used a scoping review methodology to identify the proportion of European research on forest-based mitigation strategies that acknowledge the interconnection between mitigation strategies and human impacts. We also aimed to assess whether synergies and trade-offs between forest-based carbon sink capacity and human co-benefits has been analysed and quantified. From the initial 4,062 records retrieved, 349 reports analysed European forest management principles and factors related to climate change mitigation capacity. Of those, 97 studies acknowledged human co-benefits and 13 studies quantified the impacts on exposure pathways or health co-benefits and were included for full review. Our analysis demonstrates that there is potential for synergies related to optimising carbon sink capacity together with human co-benefits, but there is currently a lack of holistic research approaches assessing these interrelationships. We suggest enhanced interdisciplinary efforts, using for example multideterminant modelling approaches, to advance evidence and understanding of the forest and health nexus in the context of climate change mitigation. [ABSTRACT FROM AUTHOR]

• A RCM is used to study the effect of LCC on climate extremes in Europe. • LCC significantly changes the occurrence frequency and duration of extreme climate. • Increasing understanding of land cover change-climate interactions. • Findings are helpful in developing future land management strategies in Europe. Extremes in climate and weather can pose significant challenges to economy, ecosystems and human health. Changes in land cover are one of the drivers for variability in frequency and magnitude of extreme climate at regional and local levels. In this study, a regional climate model (COSMO-CLM v4.8) is used to simulate effects in climate extremes from two different idealized land cover change scenarios in Europe. These two simulations involve abrupt large-scale conversion of today forestland to herbaceous vegetation (deforestation), and of today cropland to evergreen needle-leave forest (afforestation). A control simulation with today land cover distribution is used to identify differences in extreme climate. We find significant changes in extreme climate in both deforestation and afforestation simulations, with seasonal and spatial differences. Deforestation causes a warmer summer (with higher annual maximum temperature) and a colder winter (with lower annual minimum temperature). Afforestation slightly increases the average intensity of the hot extremes, although with high spatial variability (a reduction is common in several locations), and mitigates cold extremes in winter. Changes in extreme indices show that deforestation increases both the frequency and duration of hot and cold extremes, while afforestation causes a lower frequency of extreme cold climate. The two simulations show opposing results in the number of frozen days, as they increase for deforestation and decrease for afforestation. A drier climate is found after deforestation, whereas a wetter climate is observed after afforestation. In general, deforestation and afforestation increase the frequency of hot extreme climate as they reduce the return period and increase the return level. Overall, our findings show the potential critical effects that land cover changes can have on climate extremes, and the possible synergies that land management strategies and planning can have for climate change mitigation and adaptation at a regional scale. [ABSTRACT FROM AUTHOR]

The extension of forest area is a globally accepted tool to offset CO 2 emissions from deforestation and the combustion of fossil fuels. The common assumption is that in addition to the perceived climate benefits increasing forest area will also support biodiversity, thus making afforestation a “win-win scenario”. Based on the existing scientific evidences, we show that joined climate and biodiversity benefits are strongly context-dependent and that the outcome of afforestation is often highly questionable. In Europe, grasslands managed at low intensity contribute substantially to biodiversity conservation and carbon storage. However, many of these grasslands have been lost due to abandonment and subsequent spontaneous succession towards woody vegetation, or due to land use intensification. Moreover, grasslands are the ecosystems most often deliberately afforested in the context of EU carbon-centered policies that may thus counteract biodiversity conservation programmes. By reviewing the main EU policies targeting forests and grasslands, we found a striking ambivalence between policies and funding schemes addressing grassland conservation on the one hand (e.g. Habitats Directive, green payments within the Common Agricultural Policy) and those supporting afforestation on the other (e.g. rural development funds). We suggest three measures towards a better harmonization of the European Union policies that target forest and grassland ecosystems: (1) promoting the alignment of the decisions taken across different policy sectors; (2) focusing on the whole range of ecosystem services and biodiversity issues rather than on carbon management only; (3) valuing systems managed at low-intensity for their multifunctionality. [ABSTRACT FROM AUTHOR]