Josep Maria Espelta

• Phd in Ecology
• Senior Researcher at Centre for Research on Ecology and Forestry Applications

The UN Decade on Ecosystem Restoration and the Kunming-Montreal Global Biodiversity Framework aim to restore 30% of degraded ecosystems. Both the IPCC and IPBES highlight the crucial role of ecosystem restoration in addressing the interconnected crises of climate change and biodiversity loss. One key restoration strategy is rewilding, which enhance...

Forced migration has recently emerged as a deforestation driver in refugee camps, while reforestation offers a solution to restore these degraded ecosystems. The arrival of one million refugees to Kutupalong camp (southeastern Bangladesh), the world's largest refugee camp, led to significant forest losses after migrant influx, where restoration eff...

Context Forest scientists are challenged to identify and propose evidence-based silvicultural options to mitigate the impacts of drought events induced by climate change. For example, it has been suggested that thinning increases soil water availability for individual trees by reducing stand density and stand-level transpiration. Many studies have...

Second-growth forest establishment over abandoned agricultural lands has been envisaged as a nature-based solution to reduce atmospheric CO2 through carbon sequestration. However, we still have a very limited knowledge about the climate sensitivity of these second-growth forests in comparison to forests with a more continuous land-use history. Here...

The addition of biochar as a soil amendment has great potential for ecological restoration and long-term carbon (C) storage. However, few studies have evaluated the functional trait responses of tree seedlings to increasing application rates of biochar and almost no information is available for tropical dry forests (TDF). Here, we conducted a green...

With ongoing global warming, increasing water deficits promote physiological stress on forest ecosystems with negative impacts on tree growth, vitality, and survival. How individual tree species will react to increased drought stress is therefore a key research question to address for carbon accounting and the development of climate change mitigati...

The fundamental trade‐off between current and future reproduction has long been considered to result in a tendency for species that can grow large to begin reproduction at a larger size. Due to the prolonged time required to reach maturity, estimates of tree maturation size remain very rare and we lack a global view on the generality and the shape...

My poster shows the meta-analysis on thinning effects on drought-related mortality. I received the Best Poster Award in the theme Task Force Monitoring Global Mortality Patterns and Trends at the IUFRO World Congress 2024

Resilience is commonly addressed when dealing with the sustainable planning and management of social–ecological systems, but we lack a unified framework for its quantitative assessment and application. We present an operational resilience framework (ORF) based on recognizing and relating several elements: system variables (e.g., ecosystem services)...

Global climate change is increasing the frequency and severity of drought events that cause tree mortality worldwide, particularly in temperate and Mediterranean regions. Researchers have extensively studied the impact of such drought events on forest growth and tree mortality. However, knowledge on the aftermath of such mortality on habitat provis...

The addition of biochar as a soil amendment has great potential for ecological restoration and long-term carbon (C) storage. However, few studies have evaluated the functional trait responses of tree seedlings to increasing application rates of biochar and almost no information is available for tropical dry forests (TDF). Here, we conducted a green...

Under increasing human‐related threats to forests, many studies suggest that increasing tree species diversity may boost forest resilience by enhancing the range of species' responses to disturbances. However, it remains unclear whether passive or active forest management strategies should be applied to increase tree diversity. This issue would ben...

Drought episodes have become more frequent and intense because of global climate change, resulting in widespread tree mortality. Although extensive research has focused on drought as a driver of forest decay, little is known about how it shapes the structure and complexity of a forest. Tree-related microhabitats (TreMs), a widely used proxy for pot...

Natural forest expansion (NFE), that is, the establishment of secondary forest on non-forested land through natural succession, has substantially contributed to the widespread expansion of forests in Europe over the last few decades. So far, EU policies have largely neglected the potential of NFE for meeting policy objectives on restoration. Synthe...

The benefits of masting (volatile, quasi-synchronous seed production at lagged intervals) include satiation of seed predators, but these benefits come with a cost to mutualist pollen and seed dispersers. If the evolution of masting represents a balance between these benefits and costs, we expect mast avoidance in species that are heavily reliant on...

The periodic production of large seed crops, or masting, is a widespread phenomenon in perennial plants. This behavior can enhance the reproductive efficiency of plants, leading to increased fitness, and produce ripple effects on food webs. While variability from year to year is a defining characteristic of masting, the methods used to quantify thi...

Fires are recurrent in moist tropical savannas, but in recent decades, Neotropical forests have become more affected due to the increased frequency of fires and the extent of burned areas. Currently, there is still limited knowledge on whether and how these disturbance events generate changes in taxonomic and functional diversity that can ultimatel...

Tropical Andes are one of the most important biodiversity hotspots on earth, yet our understanding on how their biotas have responded to Quaternary climatic oscillations is extraordinarily limited and the alternative models proposed to explain their demographic dynamics have been seldom formally evaluated. Here, we test the hypothesis that the inte...

Animal‐mediated seed dispersal is envisaged as a key process to promote forest restoration success. Yet, we lack a comprehensive knowledge of the contribution of intrinsic and extrinsic factors which directly and indirectly influence this process and, ultimately, restoration outcomes. Here, we reviewed 157 articles to identify the most relevant int...

Wood formation during the growing season is shaped by the intra-annual variability of climatic conditions. In the Mediterranean, the cambial activity is seasonally constrained by winter low temperature and summer drought, resulting in bimodal growth patterns. Although bimodal growth is an ecologically important adaptation of woody species to season...

Climate change is increasing the occurrence of drought episodes. Many studies have focused on the effects of drought on tree growth and mortality while less emphasis has been devoted to the role of decaying trees and deadwood on the provision of (dendro)habitats (Hd) and resources available for associated forest species (birds, small mammals and in...

The frequency and intensity of natural disturbances such as infestations by forest insect pests are expected to increase under a scenario of climate change. Thus, tools for monitoring the impact of these disturbance events at large spatial scales are required, together with appropriate management practices for enhancing the ability of forest ecosys...

Woody vegetation spread over former croplands in Europe has created new unexploited habitats for forest organisms. Their ability to colonise them and thrive depends on life‐history traits including fecundity, dormancy and dispersal ability. The effects of these traits on species distribution, abundance and community assembly have been extensively s...

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 espe...

The influence of the ancient landscape configuration and the land use legacies on forest cover change has been thoroughly investigated in temperate and tropical forests while it remains barely explored at high-latitudinal regions. This study explores the landscape drivers leading forest cover changes and their influence on current forest attributes...

The relationships that control seed production in trees are fundamental to understanding the evolution of forest species and their capacity to recover from increasing losses to drought, fire, and harvest. A synthesis of fecundity data from 714 species worldwide allowed us to examine hypotheses that are central to quantifying reproduction, a foundat...

Lack of tree fecundity data across climatic gradients precludes the analysis of how seed supply contributes to global variation in forest regeneration and biotic interactions responsible for biodiversity. A global synthesis of raw seedproduction data shows a 250‐fold increase in seed abundance from cold‐dry to warm‐wet climates, driven primarily by...

This study analyzes the spatio-temporal dynamics of the drivers of forest expansion in the Iberian Peninsula for the periods 1987–2002–2017 through a 185 km-wide north–south Landsat scene transect. The analysis has considered a variety of biogeographical regions [0–3500 m.a.s.l, annual rainfalls 150–2200 mm] and 30 explanatory variables. A rigorous...

Aims Although tropical dry forests are among the most degraded and fragmented biomes in the world, we still only have a poor understanding of their basic ecological features and conservation status, particularly in the Neotropics. Here, we assess the diversity, composition, structure, and conservation value of tropical dry forests in a highly fragm...

Abstract Environmental conditions and the spatial arrangement of habitats are thought to play a major role in shaping community assembly during habitat construction and may be key in establishing time lags between habitat establishment and species colonization (colonization credits), and between local species extinction and habitat loss (extinction...

Key messageThe dioecious tree species Juniperus thurifera L. is undergoing a spontaneous process of forest expansion in southwest Europe. We investigated how growth, climate sensitivity, and wood density varied simultaneously between sexes and among stages of expansion while accounting for the variability of forest structure. We found few sex-based...

Farmland abandonment has been a widespread land-use change in the Iberian Peninsula since the second half of the 20th century, leading to the establishment of secondary forests across the region. In this study, we aimed to address changes in the recent (1985–2014) emergence patterns of these forests and examine how environmental factors affected th...

In Europe, forest area is increasing. These recently established forests can be classified into regenerating after disturbances or expanding into agricultural areas after abandonment. We used European Space Agency land cover maps and MODIS data to investigate which socioenvironmental drivers influenced recent forest expansion and regeneration in Eu...

Forests have expanded across Europe over the last centuries as a consequence of farmland (agricultural and pasture) abandonment. Agricultural practices usually increase soil fertility and reduce the diversity and abundance of ectomycorrhizal (ECM) fungi, essential mutualists of many woody species in temperate and Mediterranean forests. The recovery...

Context The current expansion of forests in Europe is expected to be affected by transient colonization credits (i.e. species deficits compared to long-established forests), especially due to plant species with limited dispersal ability. Objectives We aimed to disentangle the role of forest connectivity and climatic aridity in the assembly of wood...

Forest regrowth following farmland (agriculture and pasture) abandonment has been positively associated with a number of processes including the regulation of hydrological cycling, the enhancement of soil functioning and an increase in forest productivity and carbon (C) sequestration. Although these changes in ecosystem functioning post‐farmland ab...

Citation: Peñuelas, J.; Germain, J.; Álvarez, E.; Aparicio, E.; Arús, P.; Basnou, C.; Blanché, C.; Bonada, N.; Canals, P.; Capodiferro, M.; et al.

In peri-urban regions, the establishment of new forest patches can be affected by specific community assembly rules driving species extinction debts and colonization credits. This might result in species surpluses or deficits and shifts in species composition along forest establishment, whose association with human-driven landscape transformation r...

1. European forests are expanding and becoming denser following the widespread abandonment of farmland and rural areas. Spontaneous forest regrowth provides a cost-effective opportunity to restore ecosystems, enhance multifunctionality and sustainability and mitigate climate change. Yet, little is known about the goods and services that such forest...

Annually variable and synchronous seed production, or masting, is often correlated with environmental factors and in oaks involves differential pollination success that depends on phenological synchrony in flowering. The synchronization of phenology of flowering was thought to be driven by temperature during flowering (micro-climatic hypothesis). W...

Since the mid‐20th Century, Europe has experienced an unprecedented forest expansion associated with the abandonment of rural landscapes. Secondary forests may provide relevant ecosystem services such as landscape defragmentation, biodiversity conservation, control of hydrological cycling and carbon sequestration. Secondary forests may benefit from...

In his recent communication on our original paper 1,2 , D. Kelly, claiming that nutrient scarcity cannot select for masting behaviour in plants, initiated a fruitful discussion on traditionally settled hypotheses about the evolution of reproductive behaviour in plants. In his commentary, Kelly raises support for a contrasting hypothesis explaining...

Background and aims In a range of plant species, the distribution of individual mean fecundity is skewed and dominated by a few highly fecund individuals. Larger plants produce greater seed crops, but the exact nature of the relationship between size and reproductive patterns are poorly understood. This is especially clear in plants that reproduce...

Background and aims: In a range of plant species, the distribution of individual mean fecundity is skewed and dominated by a few highly fecund individuals. Larger plants produce greater seed crops, but the exact nature of the relationship between size and reproductive patterns are poorly understood. This is especially clear in plants that reproduc...

Key message Insect herbivory in novel Quercus ilex L. forests is a highly context- and scale-dependent process. We show that forest composition, tree height and fine-scale spatial location, as well as tree genetic relatedness and ontogeny, can all influence herbivore activity at local to landscape scale. ContextUnderstanding the intrinsic and extri...

Recent afforestation in Europe might involve deep changes on landscape composition and configuration. We show that afforestation promotes defragmentation of pre-existing forests and new patch proliferation, in forest-dominated and non-forest-dominated landscapes respectively, while it is not associated to decreasing landscape diversity. These proce...

Key message During the past decades, a multitude of oak stands have spontaneously established across the pine-dominated landscapes of the French Landes de Gascogne. Yet their future performance under modern climate change is unknown. We show that coppiced, dominant trees are most prepared to cope with drought episodes, displaying higher basal area...

Recruitment is a primary determinant of the long‐term dynamics of plant populations in changing environments. However, little information is known about the effects of anthropogenic environmental changes on reproductive ecology of trees. We evaluated the impact of experimentally induced 18 yr of drought on reproduction of three contrasting forest t...

The Andean forest is a high diversity ecosystem. These forests are negatively affected by anthropogenic pressures that have greatly increased wildfires. Wildfires may increase species susceptibility to other disturbances like insect pests. Little is known of these ecosystems, their responses to wildfires, or their interactions with other disturbanc...

Forest restoration is an effective tool to mitigate climate change, but its implementation in highly diverse and threatened tropical dry forests (TDFs) is particularly challenging due to the hostile environment. Intraspecific trait variability (ITV) in response to these constraints may be very informative for predicting the potential for species ac...

Masting-temporally variable seed production with high spatial synchrony-is a pervasive strategy in wind-pollinated trees that is hypothesized to be vulnerable to climate change due to its correlation with variability in abiotic conditions. Recent work suggests that aging may also have strong effects on seed production patterns of trees, but this po...

Mast seeding is one of the most intriguing reproductive traits in nature. Despite its potential drawbacks in terms of fitness, the widespread existence of this phenomenon suggests that it should have evolutionary advantages under certain circumstances. Using a global dataset of seed production time series for 219 plant species from all of the conti...

Europe is undergoing significant forest expansion due to the abandonment of rural areas driven by economic and demographic changes. Recently established forests provide key ecosystem services such as habitat provision and increased carbon stocks. However, we lack understanding of whether past land use might alter their resilience to climate change...

We provide the first known quantitative analysis of land cover change for the whole of the Catalan Countries and for some especially well-studied areas in particular (Catalonia, and the province and metropolitan area of Barcelona), considering various periods of time between 1956 and 2015. The study was performed on the basis of the main cartograph...

Host-parasite specificity constitutes one of the main speciation engines in phytophagous insects. The isolation of populations and its temporal persistence may promote local adaptations at the intra-specific level, in the same way that local extinctions and intense gene-flow among populations eliminate them. These adaptations may be the stage previ...

The predation and dispersal of seeds by scatter-hoarding animals is one of the most studied processes in the context of animaleplant interactions. Seed management by these animals has been traditionally approached at the population level: the patterns documented in the field are assumed to be similar for all individuals of the population and the va...

Many plant species present inter-annual cycles of seed production (mast seeding), with synchronized high seed production across populations in some years. Weather is believed to be centrally involved in triggering masting. The links between meteorological conditions and seeding are well-recognized for some species, but in others consistent correlat...

Synchronized and variable reproduction by perennial plants, called mast seeding, is a major reproductive strategy of trees. The need to accumulate sufficient resources after depletion following fruiting (resource budget), the efficiency of mass flowering for outcross pollination (pollen coupling), or the external factors preventing reproduction (en...

Background and aims: The ability of plants to allocate energy to resistance against herbivores changes with abiotic conditions and thus may vary along geographical clines, with important consequences for plant communities. Seed size is a plant trait potentially influencing plant tolerance to endoparasites, and seed size often varies across latitude...

The spatial heterogeneity of resource availability is a major driver of biodiversity patterns. Some environmental conditions and resources are characterized by large-scale patterns of variation within the landscape. Clumped local discontinuities or discrete elements also increase spatial heterogeneity, promoting local ‘biodiversity hot spots’ by mo...

Synchrony between seed growth and oogenesis are suggested to largely shape trophic breadth of seed-feeding insects and ultimately contribute to their co-existence by means of resource partitioning or in the time when infestation occurs. Here we investigated: i) the role of seed phenology and sexual maturation of females in the host specificity of s...

Variation in seed availability shapes plant communities, and is strongly affected by seed predation. In some plant species, temporal variation in seed production is especially high and synchronized over large areas which is called mast seeding. One selective advantage of this phenomenon is predator satiation which posits that masting helps escape s...

Species introduced to habitats outside their native range often escape control by their natural enemies. Besides competing with native species, an alien species might also affect the native herbivores by introducing a new source of different quality food. Here, we describe the case of northern red oak (Quercus rubra) invasion in Europe. We collecte...

This case study illustrates the equivalency analysis for estimating ex post environmental damage and appropriate compensatory remediation following a severe wildfire caused by a power line in a forest protected under the European Union Habitats Directive (HD). The study addresses long-term environmental damage (e.g., over several decades) by a larg...

Aim Landscape attributes can determine plant–animal interactions via effects on the identity and abundance of the involved species. As most studies have been conducted in a context of habitat loss and fragmentation, we know very little about interaction assembly in new habitats from a landscape approach. This study aimed to test the effect of fores...

Oak forests can naturally regenerate from seed or from sprouts. Both strategies result in the establishment of a tree layer, but they involve a crucial difference: i.e. regeneration from seeds affects population genetics while sprouting assures the recovery of biomass after a disturbance but it does not involve sexual reproduction. In addition the...

p>Para este estudio se han analizado las variables fenológicas, morfológicas y ecofisiológicas de 4 especies de Quercus sp que se encuentran en el Paisaje Terrestre Protegido Miraflor de Miraflor-Moropotente (Estelí, Nicaragua), en invierno (estación seca) y en verano (estación húmeda). Cada especie presenta un diferente rango altitudinal de distri...

Herbivore foraging is influenced by spatial and seasonal changes in the production of leaves and fruits. To understand how herbivores respond to these changes, it is necessary to identify their habitat preferences and how they use the vegetation available. In the Neotropical region, one of the largest terrestrial herbivores is the lowland tapir ( T...

Thinning is recommended in overstocked thickets to improve forest structure and reduce high-intensity stand replacing fires. Many studies have outlined the benefits of thinning for forest growth and reproduction but effectiveness in fire intensity needs more attention. Moreover, the effect that slash generated by thinning may have on fire behavior...

Phenological, morphological and ecophysiological variables were analyzed in winter (dry season) and in summer (wet season) for 4 species of Quercus sp. living in the Miraflor-Moropotente Natural Park, Estelì, Nicaragua. Each species has a slightly different altitudinal range of distribution in the studied area, and for each species two populations...

Masting is the highly variable production of synchronized seed crops, and is a common reproductive strategy in plants. Weather has been long recognized as centrally involved in driving seed production in masting plants. However, the theory behind mechanisms connecting weather and seeding variation has only recently been developed, and still lacks e...

Mast seeding, the extremely variable and synchronized production of fruits, is a common reproductive behavior in plants. Weather is centrally involved in driving masting. Yet, it is often claimed that it cannot be the sole proximate cause of masting because weather is less variable than fruit production and because the shape of their distributions...

Oak forests can naturally regenerate from seed or from sprouts. Both strategies result in the establishment of a tree layer, but they involve a crucial difference: i.e. regeneration from seeds affects population genetics while sprouting assures the recovery of biomass after a disturbance but it does not involve sexual reproduction. In addition the...

Over the last decades there have been a considerable number of deforestation studies in Latin America reporting lower rates compared with other regions; although these studies are either regional or local and do not allow the comparison of the intraregional variability present among countries or forest types. Here, we present the results obtained f...