Publications

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 …

In recent years, the EU Commission has enacted various firefighting policies to combat and diminish the adverse effects of wildfires. The Mediterranean area has experienced an observable extension of its wildfire season, coupled with rapid shifts in fire-weather dynamics, resulting in exceptionally severe wildfire occurrences. As of 2022, the EU has recorded an approximate total burned area of 792,902 hectares, with forests accounting for 66% of this figure (Rodrigues et al., 2023). The main objective of this study is to anticipate extreme wildfire conditions by providing a synthetic product …

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 …

Armed conflicts and other types of violence are key drivers of human-induced landscape change. Since March 2011, Syria has been embroiled in a prolonged and devastating armed conflict causing immense human suffering and extensive destruction. As a result, over five million people have been forced to seek refuge outside the country’s borders, while more than six million have been internally displaced. This study focuses on examining the impact of this conflict on forest cover by identifying the drivers of forest change. To assess this change, Landsat and PALSAR imagery were used to …

Forests are exposed to changing climatic conditions reflected by increasing drought and heat waves that increase the risk of wildfire ignition and spread. Climatic variables such as rain and wind as well as vegetation structure, land configuration and forest management practices are all factors that determine the burning potential of wildfires. The assessment of emissions released by vegetation combustion is essential for determining greenhouse gases and air pollutants. The estimation of wildfire-related emissions depends on factors such as the type and fraction of fuel (i.e., live biomass, …

Background Lightning is the most common origin of natural fires, being strongly linked to specific synoptic conditions associated with atmospheric instability, such as dry thunderstorms; dry fuels are required for ignition to take place and for subsequent propagation. Aims The aim was to predict the daily probability of ignition by exploiting a large dataset of lightning and fire data to anticipate ignition over the entire Iberian Peninsula. Methods We trained and tested a machine learning model using lightning strikes (>17 million) in the period 2009–2015. For each lightning strike, we …

Lightning-caused fires are comparatively rare in Europe, but they may affect remote forested areas and result in large-scale burnings. One of the major hot-spots of lightning fires in Europe lies in Spain, with remarkable ignition counts in the northwest part of the country (el Bierzo) and along certain Mediterranean mountain ranges (Sistema Ibérico). These regions experience frequent thunderstorms and host dense vegetation communities that lead to high rates of natural fires (30% versus the 10% national average). Here we analyze a large and comprehensive record of hourly cloud-to-ground …

As large fires threaten human assets in Mediterranean areas, creating fire-adapted communities became a core long-term goal to cope with extreme wildfires. In addition to early detection and risk-monitoring tools, preemptive efforts are essential to reduce wildfire spread, prevent catastrophic losses, and help minimize casualties. However, despite extensive scientific development to predict potential fire impacts, the poor risk communication with landscape and urban planners is often a barrier to translating primary outcomes into operational projects. Comprehensive solutions for creating …

El cambio climático está provocando cambios en la intensidad y frecuencia de perturbaciones sobre los bosques (ej sequías, plagas, e incendios forestales) que pueden comprometer su conservación. Por ello, existe la urgencia en conocer como contribuyen a mejorar la resiliencia de los bosques factores como la gestión forestal o la composición de especies, aunque existen todavía pocos estudios que hayan investigado la resiliencia frente a plagas forestales. En este trabajo evaluamos la resistencia, recuperación y resiliencia (sensu LLORET al. 2011) a corto plazo de bosques mixtos de encinas y …

Los bosques de montaña suponen una fuente de servicios fundamental para gran parte de la población humana. Dada la suma importancia de estos espacios, su monitoreo y seguimiento se hace primordial. Nuevas tecnologías como los sensores LiDAR nos permiten analizar su estructura de forma sistemática y a diferentes escalas. El novedoso sensor LiDAR Global Ecosystem Dynamics Investigation (GEDI) nos ha permitido analizar la altura de la vegetación a escala regional en diversas cadenas montañosas europeas (Pirineos, Alpes, Cárpatos y Cáucaso), y relacionarla con la elevación y otras variables …

Many mountain regions in Europe have experienced massive migrations towards metropolitan areas, with far-reaching implications for societies and the environment, especially croplands and grasslands. In this work, we tailored a geospatial framework to envisage the probability of land abandonment in the Spanish Pyrenees at moderate spatial resolution. We predicted the likelihood of land abandonment combining machine learning algorithms, geospatial data and historical observations of land abandonment in the period 1980 to 2019. The model attained a high predictive performance (AUC = 0.85) at a …

Despite the abundant firefighting resources deployed to reinforce the fire exclusion policy, extreme events continue to cause substantial losses in Mediterranean regions. These catastrophic wildfires question the merely-reactive response, while science-based decision-making advocates for a paradigm shift towards a long-term solution to coexist with fire. Comprehensive management solutions integrate multiple efforts to minimize the number of escaped wildfires in fire ignition hotspots, restrict large fire spread across the landscape, and prevent losses to valued resources and assets. This study …

The transition zone between the Tellian and Saharan Atlas of the Tiaret region in Algeria is believed to be undergoing land degradation processes because of the increase in population needs, which causes a weakening of the biological potential and generates ecological and socio-economic imbalances. The lack of periodically acquired data on land cover is a major handicap to understand and diagnose the state of this transition zone. The goal of our work was to reconstruct past annual land cover changes in order to assess the best monitoring tools for the current and future situations. We used an …

La altura del arbolado es un excelente indicador de la productividad forestal, la biodiversidad y otras funciones del ecosistema. Sin embargo, se sabe poco acerca de cómo la elevación influye en la altura de la vegetación en las zonas de montaña, ya que tradicionalmente esta influencia ha sido analizada mediante muestreos en transectos. Recientemente, se ha llevado a cabo un estudio en el Pirineo concluyéndose que la altura de la vegetación disminuye de forma abrupta desde los 1623msnm; utilizándose la tecnología LiDAR como instrumento para mapear de forma continua la altura de la vegetación. …

Despite the need for preserving the carbon pools in fire-prone southern European landscapes, emission reductions from wildfire risk mitigation are still poorly understood. In this study, we estimated expected carbon emissions and carbon credits from fuel management projects ongoing in Catalonia (Spain). The planning areas encompass about 1000 km 2 and represent diverse fire regimes and Mediterranean forest ecosystems. We first modeled the burn probability assuming extreme weather conditions and historical fire ignition patterns. Stand-level wildfire exposure was then coupled with fuel …

Secondary succession (SS) is one of the main consequences of the abandonment of agricultural and forestry practices in rural areas, causing -among other processes- woody encroachment on former pastures and croplands. In this study we model and monitor the spatial evolution of SS over semi-natural grassland communities in the mountain range of the Pyrenees in Spain, during the last 36 years (1984-2019). Independent variables for ‘annual-based’ and ‘period-based’ modeling were drawn from a suite of Surface Reflectance Landsat images, LandTrendr (LT)-algorithm-adjusted images and LT outputs. …

Canopy height is an excellent indicator of forest productivity, biodiversity and other ecosystem functions. Yet, we know little about how elevation drives canopy height in mountain areas. Here we take advantage of an ambitious airborne LiDAR flight plan to assess the relationship between elevation and maximum forest canopy height, and discuss its implications for the monitoring of mountain forests’ responses to climate change. We characterized vegetation structure using Airborne Laser Scanning (ALS) data provided by the Spanish Geographic Institute. For each ALS return within forested areas, …

Wildfires in the Mediterranean are strongly tied to human activities. Given their particular link with humans, which act as both initiators and suppressors, wildfire hazard is highly sensitive to socioeconomic changes and patterns. Many researchers have prompted the perils of sustaining the current management policy, the so-called ‘total fire exclusion’. This policy, coupled to increasingly fire-prone weather conditions, may lead to more hazardous fires in the mid-long run. Under this framework, the irruption of the COVID-19 pandemic adds to the ongoing situation. Facing the lack of an …

Despite escalating expenditures in firefighting, extreme fire events continue to pose a major threat to ecosystem services and human communities in Mediterranean areas. Developing a safe and effective fire response is paramount to efficiently restrict fire spread, reduce negative effects to natural values, prevent residential housing losses, and avoid causalties. Though current fire policies in most countries demand full suppression, few studies have attempted to identify the strategic locations where firefighting efforts would likely contain catastrophic fire events. The success in containing …

Forest fires can change forest structure and composition, and low-density Airborne Laser Scanning (ALS) can be a valuable tool for evaluating post-fire vegetation response. The aim of this study is to analyze the structural diversity differences in Mediterranean Pinus halepensis Mill. forests affected by wildfires on different dates from 1986 to 2009. Several types of ALS metrics, such as the Light Detection and Ranging (LiDAR) Height Diversity Index (LHDI), the LiDAR Height Evenness Index (LHEI), and vertical and horizontal continuity of vegetation, as well as topographic metrics, were …

Las bajas temperaturas suponen un límite fisiológico para el desarrollo de la vegetación arbórea. Dicha limitación se hace máxima en el denominado treeline o límite superior del bosque, que se define como la cota a partir de la cual los árboles ya no son capaces de crecer en altura. Sin embargo, la limitación al crecimiento comienza a actuar a cotas muy inferiores. El modo en que el crecimiento en altura de la vegetación se ve condicionado a lo largo de gradientes altitudinales ha sido relativamente poco estudiado hasta la fecha. En primer lugar, la dificultad de acceso inherente a las zonas …

The present study proposes and exemplifies a methodology to estimate the carbon stock from aerial biomass.Essentially, the method combines field data from forest inventory to obtain site specific measurements of carbonstock, and airborne LiDAR (ALS) data to derive proxy variables of forest structure. We then model and patializecarbon predictions. First, we filtered forest inventory plots to retrieve those representing ‘pure’ forest stands, i.e. dominated by asingle species (above 80% of individuals belong to the same species). Next, carbon stock was calculated frombiomass estimations based on …