Forest management is crucial for climate change mitigation, particularly in Mediterranean forests, which serve as significant carbon pools but face increasing climate threats. This study assesses the impact of different forest management strategies on the carbon balance of Mediterranean forests in Catalonia (NE Spain) under two climate scenarios (RCP 4.5 and RCP 8.5). We simulate forest dynamics over 100 years and apply a Life Cycle Assessment approach to quantify carbon fluxes associated with four contrasting management strategies: (i) Business-as-usual, (ii) Promotion of wood energy, (iii) Carbon storage, and (iv) Ecohydrological-based management. Our results indicate that management strongly influences the carbon balance, often outweighing the effect of climate change. The carbon storage scenario exhibited the highest net sequestration due to extended rotations and the production of long-lived wood products, while the Promotion of wood energy scenario led to higher emissions, resulting in carbon losses in low-productivity Pinus nigra forests. Manufacturing dominated emissions (50–75%), while forest growth accounted for most uptake (77%). Our findings indicate that climate-smart forestry in Mediterranean landscapes should prioritize strategies that balance productivity, resilience, and carbon storage. Ecohydrological management stands out as a scalable pathway for the fragmented private forests typical of the region, while carbon-storage practices may be selectively applied in productive and well-protected stands.

In Mediterranean forests, the increasing frequency of high severity fires poses a challenge to current landscape management. In addition, these areas are experiencing a generalized process of landscape homogenization leading to a major risk of large fires. In this context, it is important to understand how wildfires (e.g. fire severity) influence changes in landscape heterogeneity. Our objectives were (1) to evaluate how pre-fire landscape conditions influence the post-fire dynamics of landscape heterogeneity both in terms of composition and configuration and (2) to understand how variability in fire severity affects changes in the structural heterogeneity of landscapes. We analyzed 225 landscapes within 45 fire perimeters that occurred between 2002 and 2004 in Spain. We used a novel land cover database and fire severity data to assess post-fire landscape heterogeneity dynamics. Landscapes with higher pre-fire diversity values were more stable (in both composition and configuration) than more homogeneous landscapes. Additionally, we identified a significant interaction between fire severity and pre-fire landscape configuration. This interaction showed that high variations in fire severity decreased the size of small and medium pre-fire patches but increased the size of larger pre-fire patches. This work provides valuable insights into the effects of fire on mid-term (11–13 years after fire) landscape configuration and composition. The results highlight the importance of fire severity variability. They emphasize the need to consider the role of fire in landscape management, as this could help reduce the vulnerability of Mediterranean forests.

Aims Rapid revegetation of burnt forest is essential for recovering ecosystem functioning, especially in the context of climate change-driven shifts in fire regime. This study aimed to provide a comprehensive understanding of how abiotic factors (topography, fire behaviour) and biotic factors (pre-fire forest characteristics, plant reproductive strategies, land-use trajectories) influence the recovery of Pinus halepensis forests, identifying regeneration vulnerabilities that could inform management practices.Location A P. halepensis forest burnt in 2019 (4000 ha) in NE Iberian Peninsula.Methods We established 72 sampling sites within the burnt forest, covering gradients of pre-fire canopy cover (PCC), topography, fire severity and land-use history. At each site, we recorded the abundance of P. halepensis seedlings within a 100-m2 plot. We also conducted a floristic inventory of all associated woody species along two parallel 20-m transects to assess woody species cover, richness and distribution. Woody species were classified based on their post-fire reproductive strategies (obligate seeding, facultative resprouting and resprouting) to explore the relationship between functional characteristics and plant distribution along the studied gradients.Results Northern exposures enhanced the abundance of P. halepensis, whereas coexisting woody species cover was higher on southern ones, probably due to the contribution of obligate seeders, as fire-responsive reproductive traits vary along the north-south gradient. PCC boosted pine regeneration and species richness, while high fire severity reduced both cover and richness of woody species, likely due to damage to reproductive structures.Conclusions We show that the drivers of post-fire regeneration influence in different and even divergent ways the vegetation components considered (canopy and shrub layer), as in the case of aspect. From a management perspective, post-fire forest interventions should be tailored to restoration objectives and to the post-fire vegetation communities that better respond to them.

In this work we showcase the in-progress results from the FirePATHS project (PID2020-116556RA-I00). The project aims to assess the evolution of fire danger under different emission and forest management scenarios through the explicit interaction of the climate-vegetation-fire system. For this purpose, a methodological framework combining different simulation models of the elements of this system is proposed. The core of the process lies in the modeling of vegetation dynamics at stand scale according to different trajectories of climatic evolution to characterize the state and typology of fuels and the subsequent simulation of potential fire behavior during the 21st century.We analyzed a set of 114 Pinus halepensis plots, surveyed in the field during 2017; 68 plots burned during the summer of 1994 and 46 unburned control stands. We used the medfate model to simulate forest functioning and dynamics, which provides the necessary fuel model parameters to be entered into fire behavior models (Fuel Characteristics Classification System, implemented in medfate as well). The combination of these two approaches provides time-varying estimates of fire behavior metrics (e.g., flame length or rate of spread). The simulation was conducted under SSP climate scenarios (SSP 126, 245, 370 and 585) depicting different levels of climate warming, vegetation dynamics and, hence, fire danger. Likewise, we devised a set of forest management prescriptions aimed at reducing climate vulnerability of tree communities and reducing extreme wildfire potentials. A baseline scenario with no management was also assessed.We observed very contrasting trajectories between burned and control stands, with the first leading to increasing fuel loads, except in SSP 585. Fire potentials depicted a significant increase in surface fire behavior, with adaptive and mitigation management being able to mitigate it to some extent.

Recent shifts in fire regimes challenge recovery of forest ecosystems. In Catalonia, Spain, the capacity of Pinus nigra to persist has been affected by recent high severity fires. To understand the biophysical conditions that support P. nigra recovery after high severity fire, we investigate the main biophysical drivers—seed availability, community interactions, water, and nutritional constraints—affecting post-fire regeneration patterns in Catalonia. We identified fire refugia and calculated the distance-weighted refugia density (DWD) across four fire footprints to represent the seed source abundance. We surveyed abundance of regeneration and shrub cover on 270 sites. We tested identical statistical models for “inside” and “outside” fire refugia, to assess the role of fire refugia and main biophysical drivers on post-fire regeneration. The DWD had a positive effect on post-fire P. nigra recovery, with a stronger effect outside refugia than inside. Inside fire refugia, canopy trees had a sheltering effect on post-fire regeneration, reducing negative effects of heat load, particularly at higher aridity plots. Presence of Rubus spp. broadleaf shrubs enhanced the abundance of regeneration both inside and outside refugia. Total shrubs cover negatively impacted regeneration inside refugia and sites with greater aridity outside refugia but exerted a facilitative effect on P. nigra regeneration outside of fire refugia at sites with lower heat load. Seed source abundance is an integral driver of post-fire regeneration however, biophysical site conditions are important filters that amplify or diminish regeneration. This ecological information can be used to tailor post-fire management goals for forest recovery.

Mountain forests face important threats from global change and spatio-temporal variation in tree height can help to monitor these effects. In this study, we used the Global Ecosystem Dynamics Investigation space-borne laser sensor to examine the relationship between maximum tree height and elevation, and the role of climate, in the main European mountain ranges. We found a piecewise relationship between elevation and maximum tree height in all mountain ranges, supporting the existence of a common breakpoint that marks the beginning of tree development limitations. Temperature and precipitation were identified as the most important drivers of tree height variation. Additionally, we predicted significant upward displacement of the breakpoint for the period 2080-2100 under climate change scenarios, potentially increasing the area without growth limitations for trees. These findings contribute to understanding the impacts of global warming on mountain forest ecosystems and provide insights for their monitoring and management.

Competition can intensify the struggle for resources among plants, affecting forest growth and dynamics. The intensity and mode of competition - asymmetric vs. symmetric - can change along environmental gradients and with time, impacting the response of plants to their environment, but this is seldom explicitly considered in management plans. In this study, we aim to (i) disentangle the main environmental and tree-related factors that affect post-fire Pinus halepensis sapling growth; (ii) determine which mode of competition characterizes the species post-fire regeneration; and (iii) elucidate if the mode of competition changes with time, and along climatic gradients. We sampled 148 P. halepensis saplings located in 15 sites affected by wildfires between 1987 and 2013 in Catalonia (NE Spain). We measured their radial growth at the base, and we identified their competitive environment by locating and measuring all the trees in a 3-meter-radius from our target saplings. We modelled the effect of tree size, age, climate, and competitive environment on the post-fire regeneration growth following the neighborhood theory of forest dynamics and using model comparison and information criteria to address our research questions. We used a modification from the Hegyi index to determine the prevalence of symmetric vs. asymmetric competition, and we assessed the support for models in which competition was allowed to vary with age and precipitation. The best model showed that competition, precipitation, age, and target size influenced the radial growth of P. halepensis post-fire regeneration (Akaike weight 0.66, R2 = 0.52). We found evidence that P. halepensis mode of competition is generally asymmetric but can change along a precipitation gradient: it shifts from asymmetric in drier sites to almost fully symmetrical as precipitation increases. Our findings have implications for the management of post-fire P. halepensis stands, enabling the adaptation of silvicultural prescriptions to the climatic environment. In a context of increasing water scarcity, adaptive silviculture is fundamental to foster the resilience of pinewoods to future climatic and disturbance regimes.

Spatial and temporal variation in functional traits allows trees to adjust to shifting environmental conditions such as water stress. However, the change of traits, both mean and variances, along water availability gradients and across growing seasons, as well as their covariation with tree performance, have been rarely assessed. We examined intraspecific trait variation in coexisting evergreen (Quercus ilex ssp. ilex and Q. ilex ssp. ballota) and deciduous (Quercus faginea and Quercus humilis) Mediterranean oaks along a wide water availability gradient in northeastern Spain during six years. We measured leaf area (LA), shoot twig mass (Sm), leaf mass per area (LMA) and the ratio of shoot twig to leaf biomass (Sm:Lm). We characterized tree performance through basal area increment (BAI) and drought resilience indices. Higher variation was found within individuals than between individuals across populations and years. Within species, we found trait adjustments toward more conservative water -use (low LA and Sm and high LMA) with increasing drier conditions. Intraspecific trait variation was constrained by water availability, particularly on the deciduous species. In Q. ilex, trait variance of LMA positively covaried with annual BAI, whereas variance of LA, Sm and Sm:Lm was positively related to resistance and resilience against the severe 2012 drought in deciduous oaks. Our results support a tradeoff between the ability to tolerate drought and the capacity to cope with unpredictable changes in the environment through increased intraspecific trait variation, which may have implications on tree performance in the face of increased extreme events.

In the climate-vulnerable Mediterranean basin, the severity and frequency of disturbances such as windthrows, droughts and fires are intensifying. Forests are generally resilient, but struggle to adapt to abrupt changes, which can impact their functionality and service provision. Various forest management alternatives aim to reduce forest vulnerability to disturbances, but few studies have evaluated the impact of management alternatives on multiple disturbances and service provision simultaneously. We aimed at filling this gap by conducting simulations of forest dynamics between 2020 and 2100 for 261 pine-dominated forest plots in Catalonia (NE Spain), under two emissions scenarios (RCP4.5 and RCP8.5) and four management scenarios (business-as-usual, promotion of bioenergy, maximum carbon storage, and ecohydrological forest management). We used the annual simulated output of forest structure and composition and future climatic projections to produce annual estimates of six ecosystem services, and we determined the annual potential impact on forests of the three main abiotic disturbances in the Mediterranean region: fire, droughts, and windstorms. We also evaluated trade-offs and synergies between disturbance impact and the provision of ecosystem services. Our simulations predicted a greater influence of management over climate scenario on the potential impact caused by all disturbances. The business-as-usual scenario consistently predicted higher impacts than the other three management scenarios, regardless of the disturbance considered or the climate scenario (fire impact 175% higher, drought impact 300%; wind impact 130%). The other three management scenarios showed similar patterns in predicted impact, but differences among them increased under more severe climate conditions. In general, there was a positive correlation between the impact by the three disturbance agents, particularly drought and fire (Pearson's r = 0.69). We observed that the provision of some services is highly correlated to disturbance impacts, suggesting that, under certain management schemes, service provision may be compromised due to abiotic disturbance impacts. Our work supports the need for an "adaptation-first" model in which the promotion of forest adaptation is placed at the core of forest management as the only way to ensure forest persistence and the delivery of services.

Background: Understanding the role of species identity in interactions among individuals is crucial for assessing the productivity and stability of mixed forests over time. However, there is limited knowledge concerning the variation in competitive effect and response of different species along climatic gradients. In this study, we investigated the importance of climate, tree size, and competition on the growth of three tree species: spruce (Picea abies), fir (Abies alba), and beech (Fagus sylvatica), and examined their competitive response and effect along a climatic gradient. Methods: We selected 39 plots distributed across the European mountains with records of the position and growth of 5,759 individuals. For each target species, models relating tree growth to tree size, climate and competition were proposed. Competition was modelled using a neighbourhood competition index that considered the effects of inter- and intraspecific competition on target trees. Competitive responses and effects were related to climate. Likelihood methods and information theory were used to select the best model. Results: Our findings revealed that competition had a greater impact on target species growth than tree size or climate. Climate did influence the competitive effects of neighbouring species, but it did not affect the target species' response to competition. The strength of competitive effects varied along the gradient, contingent on the identity of the interacting species. When the target species exhibited an intermediate competitive effect relative to neighbouring species, both higher inter- than intraspecific competitive effects and competition reduction occurred along the gradient. Notably, species competitive effects were most pronounced when the target species’ growth was at its peak and weakest when growing conditions were far from their maximum. Conclusions: Climate modulates the effects of competition from neighbouring trees on the target tree and not the susceptibility of the target tree to competition. The modelling approach should be useful in future research to expand our knowledge of how competition modulates forest communities across environmental gradients.

Reproductive traits influence plant auto-successional dynamics in post-fire regeneration. Obligate seeding species rely on their seedbank and on the climatic conditions following the fire to ensure a successful recovery, defining the window of opportunity for seedling emergence. In the Mediterranean basin, emergence opportunities generally begin with autumnal rains. However, climate change-induced increases in temperature and drought could jeopardise the regeneration capacity of seeding species by causing temporal shifts in emergence opportunities or by modifying wildfire seasonality. This study aimed to explore the impact of experimentally induced climate change on regeneration dynamics of Aleppo pine (Pinus halepensis), a serotinous Mediterranean obligate seeder. In March 2021, we set up an 18-month climate change simulation experiment with 15 open-top chambers (OTC), each paired with a control subplot (CON) on top of Aleppo pines that were naturally regenerating after a stand-replacing wildfire in SW Catalonia (June 2019). We tagged 178 young Aleppo pine recruits in OTC and CON subplots (98 and 81 respectively), classified according to their initial size, to periodically measure height growth and survival throughout the experiment duration. Furthermore, Aleppo pine seeds were seasonally sown (7900 total seeds) in 10 subplot pairs between May 2021 and April 2022, to monthly monitor temporal patterns of seedling emergence and survival. We found that OTCs reduced overall emergence rates and caused the loss of the autumnal window of opportunity for the emergence of Aleppo pine seedlings. Furthermore, seedlings which emerged within OTCs faced higher mortality rates in all seasons, with only 1% of seedlings surviving compared with 21.1% of seedlings in control plots. The OTC-induced conditions were also detrimental to the survival of recruited seedlings, especially those with a smaller initial size, although no significant effects of temperature increase were found on growth. Synthesis. Climate change is likely to interfere with the post-fire regeneration dynamics of obligate seeders by shortening the temporal window of opportunities for emergence and by enhancing the bottleneck effects throughout the recruitment process in the early phases of pine demographic recovery. Altogether, it could threaten post-fire regeneration by increasing the hazard of a demographic collapse of Aleppo pine. Les caracter & iacute;stiques reproductives de les plantes condicionen la din & agrave;mica de la seva regeneraci & oacute; post incendi. La germinaci & oacute; de les esp & egrave;cies 'germinadores obligades' dep & egrave;n de la viabilitat del banc de llavors i de les condicions clim & agrave;tiques de despr & eacute;s del foc, que defineixen la finestra d'oportunitat per la germinaci & oacute;. A la zona mediterr & agrave;nia, aquesta finestra d'oportunitat, en general, es dona amb les primeres pluges tardorenques. El canvi clim & agrave;tic amena & ccedil;a la capacitat de regenerar de les germinadores, ja que comporta increments de temperatures i sequeres que poden causar modificacions temporals en la finestra d'oportunitat per la germinaci & oacute; i en l'estacionalitat dels incendis. L'objectiu del present estudi & eacute;s avaluar com el canvi clim & agrave;tic, indu & iuml;t experimentalment, afecta la din & agrave;mica de regeneraci & oacute; del pi blanc (Pinus halepensis), una esp & egrave;cie serotina i germinadora obligada de l'& agrave;rea mediterr & agrave;nia. El mar & ccedil; del 2021 es va installar un dispositiu experimental en una & agrave;rea que havia estat afectada per un incendi el juny del 2019 al sud oest de Catalunya. Durant 18 mesos es van simular condicions de canvi clim & agrave;tic en pl & agrave;ntules de regenerat de pi utilitzant 15 Open Top Chambers (OTC), cada una aparellada amb una parcella de control (CON). Es van identificar 179 pl & agrave;ntules de Pinus halepensis regenerant a les OTC i a les parcelles CON (98 i 81 respectivament). El regenerat present es va classificar en funci & oacute; de la seva al & ccedil;ada inicial per peri & ograve;dicament fer un seguiment del creixement i de la superviv & egrave;ncia. Amb l'objectiu de monitorar el patr & oacute; temporal de germinaci & oacute; i superviv & egrave;ncia, entre el maig del 2021 i l'abril del 2022, es van sembrar llavors de pi blanc peri & ograve;dicament (en total 7900 llavors) en 10 OTC i en 10 parcelles CON. S'ha observat que les OTC redueixen les taxes d'emerg & egrave;ncia globals i provoquen la p & egrave;rdua de la finestra d'oportunitat tardorenca per a l'emerg & egrave;ncia de pl & agrave;ntules de pi blanc. A m & eacute;s, les pl & agrave;ntules germinades dins de les OTC presenten taxes de mortalitat m & eacute;s altes en totes les estacions, amb nom & eacute;s un 1% de pl & agrave;ntules supervivents en comparaci & oacute; amb el 21,1% de les pl & agrave;ntules a les parcelles CON. Les condicions generades per les OTC tamb & eacute; han tingut efectes perjudicials per a la superviv & egrave;ncia del regenerat present, especialment pel de mides m & eacute;s petites, tot i aix & iacute; no s'han observat efectes significatius de l'augment de la temperatura en el creixement. En resum, & eacute;s provable que el canvi clim & agrave;tic interfereixi amb la din & agrave;mica de regeneraci & oacute; post-incendi de les esp & egrave;cies germinadores obligades, escur & ccedil;ant la finestra temporal d'oportunitat per a la germinaci & oacute; i potenciant els efectes de coll d'ampolla durant el proc & eacute;s d'establiment en les primeres fases de regeneraci & oacute; del pi blanc. Aix & ograve; pot amena & ccedil;ar la regeneraci & oacute; post-incendi incrementant el risc d'un col.lapse demogr & agrave;fic d'aquesta esp & egrave;cie. Climate change is likely to interfere with the post-fire regeneration dynamics of obligate seeders by shortening the temporal window of opportunities for emergence and by enhancing the bottleneck effects throughout the recruitment process in the early phases of pine demographic recovery. Altogether, it could threaten post-fire regeneration by increasing the hazard of a demographic collapse of Aleppo pine.image

The dataset associated with this paper comprises GEDI 2A data collected from 2019/05/01 to 2020/09/03, along with ancillary data (NASADEM & WorldClim) at the footprint level. Additionally, footprints are filtered by elevation ranging from 800 meters above sea level to the maximum elevation calculated for each mountain range (please see Methods / GEDI Dataset subsection). Each file encompasses the described data for a specific mountain range (specified in the filename) and is presented as a *.RData file. Data ready for modelling and plotting.

Quercus robur/Quercus petraea and Pinus sylvestris are light demanding, drought resistant wide spread European tree species occupying a similar ecological niche on mesotrophic xeric and mesic sites. Increasing drought and heat-spells will decrease their growth, but growth reductions depend on the timing of drought within a year, site characteristics, and inter- and intraspecific competition.In this study we analysed tree ring series of 1589 trees growing on 36 triplets installed across Europe, spanning a gradient of mean annual temperatures from 5.5°C to 11.5°C. Tree ring data were analysed using a generalized additive model with random effects for triplet, year and tree level and a random slope for age, explaining 87 % of the variation of diameter increment.High values for potential evapotranspiration in spring and autumn, indicating warm temperatures, positively and non-linearly influenced diameter increment of both species, while the effect in June was linear and negative. Across Europe, June was the most influential month for tree growth. Further, tree growth declined with age and local density and increased with social position.Modelled random patterns showed no large scale trend, when plotted per site and year indicating highly site specific shifts in competitive advantages.

Process-based models and empirical modelling techniques are frequently used to (i) explore the sensitivity of tree growth to environmental variables, and (ii) predict the future growth of trees and forest stands under climate change scenarios. However, modelling approaches substantially influence predictions of the sensitivity of trees to environmen-tal factors. Here, we used tree-ring width (TRW) data from 1630 beech trees from a network of 70 plots established across European mountains to build empirical predictive growth models using various modelling approaches. In addi-tion, we used 3-PG and Biome-BGCMuSo process-based models to compare growth predictions with derived empirical models. Results revealed similar prediction errors (RMSE) across models ranging between 3.71 and 7.54 cm2 of basal area increment (BAI). The models explained most of the variability in BAI ranging from 54 % to 87 %. Selected explan-atory variables (despite being statistically highly significant) and the pattern of the growth sensitivity differed between models substantially. We identified only five factors with the same effect and the same sensitivity pattern in all empir-ical models: tree DBH, competition index, elevation, Gini index of DBH, and soil silt content. However, the sensitivity to most of the climate variables was low and inconsistent among the empirical models. Both empirical and process -based models suggest that beech in European mountains will, on average, likely experience better growth conditions under both 4.5 and 8.5 RCP scenarios. The process-based models indicated that beech may grow better across European mountains by 1.05 to 1.4 times in warmer conditions. The empirical models identified several drivers of tree growth that are not included in the current process-based models (e.g., different nutrients) but may have a sub-stantial effect on final results, particularly if they are limiting factors. Hence, future development of process-based models may build upon our findings to increase their ability to correctly capture ecosystem dynamics.

Purpose of Review Forests support most global terrestrial biodiversity and contribute to the livelihood of billions of people, but these and other benefits are in jeopardy due to global change. This leads to questions, such as how to address the challenges of global change in forest management, given the lack of knowledge and deep uncertainty about future developments. In addition, many of the impediments to implement adaptation strategies are unknown. Recent Findings Here, we present an overview of results from a global survey of 754 forestry professionals (370 researchers and educators, 227 practicing foresters, 37 policymakers, 64 administrators, and 56 with other or unspecified roles) from 61 countries across 6 continents who were interested in global change issues. These professionals were asked about their opinion regarding three different adaptation strategies: resist , adapt , and transform . Most respondents agreed that the majority of global change factors will negatively influence the ability of forests to provide desired ecosystem services. Similarly, they agreed about major challenges when implementing adaptation strategies and specifically whether our current knowledge base is sufficient. These concerns were not limited to ecological aspects, but respondents also highlighted the need for a better appreciation of social/political and economic barriers, especially regarding transformation strategies. In addition, the response patterns, including differences due to economic status, highlight the importance of developing and evaluating adaptation strategies in a local social–ecological context. Summary Our study demonstrates a widespread perception on the part of forestry professionals around the world, especially among researchers and practitioners, that many global change factors will affect sustainable forest management negatively, resulting in the need for active silvicultural adaption. The results also suggest potential barriers to different adaptation strategies, particularly a relative lack of information and social acceptance for transform strategies. Further, this study highlights the importance of social and political factors and the need to understand the general public’s values regarding adaptation strategies as well as how the influence of public opinion is perceived by forest managers.

Background Climate change is altering the fire regime and compromising the post-fire recovery of vegetation worldwide. To understand the factors influencing post-fire vegetation cover restoration, we calculated the recovery of vegetation in 200,000 hectares of western Mediterranean forest burned by 268 wildfires over a 27-year period (1988–2015). We used time series of the Tasseled Cap Transformation Brightness (TCTB) spectral transformation over Landsat imagery to calculate vegetation recovery. Then, we quantified the importance of the main drivers of post-fire vegetation recovery (climate, fire severity, and topography) along an aridity gradient (semi-arid, sub-humid, and humid) using Random Forest models. Results In most models (99.7%), drought duration was the most important factor, negatively affecting post-fire recovery especially in the extremes of the aridity gradient. Fire severity was the second most important factor for vegetation cover recovery, with its effect varying along the aridity gradient: there was a positive relationship between fire severity and recovery in sub-humid and humid areas, while semi-arid areas showed the opposite pattern. Topographic variables were the least important driver and had a marginal effect on post-fire recovery. Additionally, semi-arid areas exhibited a low mean recovery rate, indicating limitations in the short-term recovery after a fire. Conclusions Our study highlights the key role that drought duration plays in the recovery of vegetation after wildfires in the Mediterranean basin and, particularly, in forests located in climatically extreme areas. The results suggest that the predicted increase in drought duration coupled with a higher frequency and intensity of large fires may modify the structure and composition of Mediterranean forest ecosystems. Our analysis provides relevant information to evaluate and design adaptive management strategies in post-fire recovery hotspots of Mediterranean forest ecosystems.

Given the rising frequency of drought events, close-to-nature principles appear to be a suitable management option for promoting more adapted forests by increasing diversity and vitality (e.g., enhancing tree growth), while preserving soil moisture. In this study, we evaluate individual tree growth from selected trees (including future crop trees) and soil moisture responses to close-to-nature silvicultural treatments in sub-humid Mediterranean mixed forests in Catalonia (Northeastern Spain). We relied on 18 permanent sample plots (i.e., 9 pairedplots: managed / control) representing a competition intensity gradient and different forest types (dominated by either Quercus ilex, Castanea sativa, Quercus pubescens/petraea, Pinus pinea and Pinus sylvestris). From them, 8 plots were subject to intense monitoring in terms of intra-annual tree radial growth, monitored by manual band dendrometers, and hourly soil water content. Basal area increment, and annual and seasonal (May, June, July) radial increment rates were computed as a proxy of tree growth for all plots and for those plots with dendrometers, respectively. We conducted Spearman correlation analyses between tree growth, competition intensity, soil water content and climatic variables to detect significant relations between forest management and variables of interest (e.g., basal area increment, radial increment rates, soil water content). To investigate further into the effect of this silviculture on tree growth, we used mixed-effects models using as predictors variables related to competition intensity and forest management (dummy variable) in combination with monthly soil water content variables. We observed that basal area increment and radial increment rates had a positive (albeit weak) correlation with forest management, while competition intensity had a negative correlation with both variables. The models were not capable of detecting clear species-specific tree growth responses to competition. Compared to control plots, on average, the treatments boosted soil water content by about a 10% in managed plots in Q. ilex, P. sylvestris and P. pinea stands, and this increase was particularly significant during the growing season. Moreover, the best-fitted model predicted seasonal radial increment rates using not only forest management and competition variables, but also monthly soil water content factors. Our results suggest that close-tonature-forest management may reduce the vulnerability to drought by increasing tree vitality and soil moisture, at least in the short term (<3 years).

Abstract Mountain forests face significant threats from global change and spatio-temporal variation in tree height can help to monitor these effects. While tree height is typically measured through field inventories, remote sensing can provide accurate and extensive forest structure data. In this study, we used the Global Ecosystem Dynamics Investigation space-borne laser sensor (GEDI) to examine the relationship between maximum tree height and elevation, temperature, and precipitation in the main European mountain ranges. We found a non-linear relationship between elevation and maximum tree height in all mountain ranges, supporting the existence of a common breakpoint that marks the beginning of the tree development limitation. Temperature and precipitation were identified as the most important drivers of tree height variation. Additionally, we predicted significant upward displacement of the breakpoint under climate change scenarios, potentially increasing the area without growth limitations for trees. However, the displacement of the breakpoint may not align with the movement of the treeline, impacting on alpine ecosystems. These findings contribute to understanding the impacts of global warming on mountain forest ecosystems and provide insights for their monitoring and managing.

El gestor forestal se enfrenta al desafío de tener que adaptar sus prácticas a un contexto de creciente incertidumbre ambiental, motivado por el cambio climático y las alteraciones en los regímenes de perturbaciones. El artículo repasa brevemente el concepto de gestión forestal adaptativa y las fases que componen este tipo de procesos. A continuación, identifica algunas líneas estratégicas de actuación a las que puede acogerse el gestor forestal para promover la progresiva adaptación de las masas al cambio climático y reforzar su resiliencia. Finalmente, remarca la importancia de monitorear adecuadamente la respuesta de las masas a los tratamientos ejecutados para poder evaluar, en base a ello, su pertinencia para la consecución de los objetivos perseguidos. Además, aboga por continuar estableciendo nuevas parcelas de seguimiento y ensayos y exprimir el potencial de las nuevas tecnologías y de los avances existentes en materia de análisis de datos y modelización para el ajuste y mejora de la práctica selvícola y de la planificación forestal.

Mediterranean forests and fire regimes are closely intertwined. Global change is likely to alter both forest dynamics and wildfire activity, ultimately threatening the provision of ecosystem services and posing greater risks to society. In this paper we evaluate future wildfire behavior by coupling climate projections with simulation models of forest dynamics and wildfire hazard. To do so, we explore different forest management scenarios reflecting different narratives related to EU forestry (promotion of carbon stocks, reduction of water vulnerability, biomass production and business-as-usual) under the RCP 4.5 and RCP 8.5 climate pathways in the period 2020-2100. We used as a study model pure submediterranean Pinus nigra forests of central Catalonia (NE Spain). Forest dynamics were simulated from the 3rd National Forest Inventory (143 stands) using SORTIE-nd software based on climate projections under RCPs 4.5 and 8.5. The climate products were also used to estimate fuel moisture conditions (both live and dead) and wind speed. Fuel parameters and fire behavior were then simulated, selecting crown fire initiation potential and rate of spread as key indicators. The results revealed consistent trade-offs between forest dynamics, climate and wildfire. Despite the clear influence exerted by climate, forest management modulates fire behavior, resulting in different trends depending on the climatic pathway. In general, the maintenance of current practices would result in the highest rates of crown fire activity, while management for water vulnerability reduction is postulated as the best alternative to surmount the increasingly hazardous conditions envisaged in RCP 8.5.