Guillermo Gea-Izquierdo

• PhD
• ICIFOR-INIA

• In this study, we used a canopy photosynthesis model which describes changes in photosynthetic capacity with slow temperature-dependent acclimations. • A flux-partitioning algorithm was applied to fit the photosynthesis model to net ecosystem exchange data for 12 evergreen coniferous forests from northern temperate and boreal regions. • The model...

Forests modify their productivity, composition, and distribution in response to global change. We studied the radial growth trends of the Western Mediterranean oak Quercus pyrenaica over the last two centuries to analyze whether trees exhibited instability in productivity in response to climatic changes. Trees were sampled to build annual growth ch...

Climatic drivers limit several important physiological processes involved in ecosystem carbon dynamics including gross primary productivity (GPP) and carbon allocation in vegetation. Climatic variability limits these two processes differently. We developed an existing mechanistic model to analyse photosynthesis and variability in carbon allocation...

Forest performance is challenged by climate change but higher atmospheric [CO2 ] (ca ) could help trees mitigate the negative effect of enhanced water stress. Forest projections using data-assimilation with mechanistic models are a valuable tool to assess forest performance. Firstly, we used dendrochronological data from 12 Mediterranean tree speci...

Forest disturbances such as drought, fire and logging affect the forest carbon dynamics and the terrestrial carbon sink. Forest mortality after disturbances creates uncertainties that need to be accounted for to understand forest dynamics and their associated C‐sink. We combined data from permanent resampling plots and biomass oriented dendroecolog...

Trees' functional strategies to cope with extreme drought are essential under climate change. In a mixed Mediterranean forest, we analyzed the functional strategy in response to drought of four co‐occurring species ( Pinus pinea , Pinus pinaster , Juniperus oxycedrus, and Quercus ilex ) during two years. Specifically, we assessed functional traits...

In the Mediterranean region, a reduction of annual precipitation and a longer and drier summer season are expected with climate change by the end of the century eventually endangering forest survival. To cope with such rapid change, trees may modulate their morpho-anatomical and physiological traits. In the present study, we focused on the variatio...

Recent climate and societal changes have increased wildfire activity and prolonged the fire season in many regions of the world. The precision of fire seasonality analysis from tree-ring records can be improved by complementing the subjectively determined intra-ring position of fire scars with more precise studies of wood formation. With this aim,...

Severe droughts limit tree growth and forest productivity worldwide, a phenomenon which is expected to aggravate over the next decades. However, how drought intensity and climatic conditions before and after drought events modulate tree growth resilience remains unclear, especially when considering the range-wide phenotypic variability of a tree sp...

Forests are threatened globally by increased recurrence and intensity of hot droughts. Functionally close coexisting species may exhibit differences in drought-vulnerability large enough to cause niche differentiation and affect forest dynamics. The effect of rising atmospheric [CO2], which could partly alleviate the negative effects of drought, ma...

Forests are threatened globally by increased recurrence and intensity of hot droughts. Functionally close coexisting species may exhibit differences in drought-vulnerability large enough to cause niche differentiation and affect forest dynamics. The effect of rising atmospheric [CO2], which could partly alleviate the negative effects of drought, ma...

PREMISE: Maternal effects have been demonstrated to affect offspring performance in many organisms and, in plants, seeds are important mediators of these effects. Some woody plant species maintain long-lasting canopy seed banks as an adaptation to wildfires. Importantly, these seeds stored in serotinous cones are produced by the mother plant under...

Differential vulnerability to drought of two Mediterranean conifers under current and future CO2 concentrations

Global change challenges ecosystems in xeric locations transformed by intensive human use. Resilience to drought of relict Mediterranean Quercus pyrenaica populations in the southern Iberian Peninsula was analyzed in relation to historical records of land use, combining dendroecological growth of adult trees and greenness (EVI) as proxies for secon...

Drought-induced tree decline and accelerated mortality under global change threaten forests worldwide. Identifying environmental and structural factors driving tree mortality of species with different ecology is essential to understand forest dynamics. We compared three coniferous species and trees with different health status (i.e. healthy, declin...

Many oak stands (Quercus spp.) have been managed as coppices for firewood production for centuries in the Mediterranean area. After the abandonment of firewood production during the 1980s, current management practices attempt to convert coppices into coppices-with-standards through thinning and promoting forest regeneration via sexual reproduction....

European beech is a temperate species with peripheral populations in the Mediterranean mountains. These Mediterranean beech forests have often been interpreted as climatic relicts. However, the use of this term does not always seem appropriate because their recent post-glacial expansion in the Iberian Peninsula makes it difficult to disentangle the...

Most information on the ecology of oak-dominated forests in Europe comes from forests altered for centuries because remnants of old-growth forests are rare. Disturbance and recruitment regimes in old-growth forests provide information on forest dynamics and their effects on long-term carbon storage. In an old-growth Quercus petraea forest in northw...

Forest decline under environmental stress is expressed by regeneration failure and accelerated mortality in all ontogenic stages at the population level. Characterizing functional traits and mechanisms that best capture species decline and mortality is essential to assess forest dynamics. We analysed sensitivity to increasing water stress in two sp...

Increase in abiotic and biotic stress driven by global change threatens forest ecosystems and challenges understanding of mechanisms producing mortality. Phytophthora spp. like P. cinnamomi (PHYCI) are among the most lethal pathogens for many woody species including Quercus spp. Dynamics of biotic agents and their hosts are complex and influenced b...

Tree species have good tolerance to a range of environmental conditions, though their ability to respond and persist to environmental changes is dramatically reduced at the rear-edge distribution limits. At those edges, gene flow conferring adaptation is impaired due to lack of populations at lower latitudes. Thus, trees mainly rely on phenotypic c...

Severe droughts have the potential to reduce forest productivity and trigger tree mortality. Most trees face several drought events during their life and therefore resilience to dry conditions may be crucial to long-term survival. We assessed how growth resilience to severe droughts, including its components resistance and recovery, is related to t...

This article can be accessed from: https://authors.elsevier.com/a/1ZHPSB8cckPwP

The extent to which water availability can be used to predict the enlargement and final dimensions of xylem conduits remains an open issue. We reconstructed the time course of tracheid enlargement in Pinus sylvestris trees in central Spain by repeated measurements of tracheid diameter on microcores sampled weekly during a 2 yr period. We analyzed t...

Evergreen oak woodlands in the Western Mediterranean exploited as agrosilvopastoral systems have often been considered as a sustainability paradigm. Yet, these ecosystems show profound symptoms of degradation with widespread tree decline and increased mortality, making them a paradigmatic example of overexploited eco- systems threatened by global c...

Tree mortality is a key driver of forest dynamics and its occurrence is projected to increase in the future due to climate change. Despite recent advances in our understanding of the physiological mechanisms leading to death, we still lack robust indicators of mortality risk that could be applied at the individual tree scale. Here, we build on a pr...

In Mediterranean mountains, Pinus sylvestris L. is expected to be displaced under a warming climate by more drought-tolerant species such as the sub-Mediterranean Quercus pyrenaica Willd. Understanding how environmental factors drive tree physiology and phenology is, therefore, essential to assess the effect of changing climatic conditions on the p...

The Tambora eruption (1815 AD) was one of the major eruptions of the last two millennia and has no equivalents over the last two centuries. Here, we collected an extensive network of early meteorological time series, climate simulation data and numerous, well-replicated proxy records from Eastern Canada to analyze the strength and the persistence o...

Understanding the complex interactions of competition, climate warming-induced drought stress, and photosynthetic productivity on the radial growth of trees is central to linking climate change impacts on tree growth, stand structure and in general, forest productivity. Using a mixed modeling approach, a stand-level photosynthetic production model,...

Olive tree pruning, as one of the most abundant lignocellulosic residues in Mediterranean countries, has been evaluated as a source of sugars for fuel and chemicals production. A mild acid pretreatment has been combined with a fungal pretreatment using either two endophytes ( Ulocladium sp. and Hormonema sp.) or a saprophyte ( Trametes sp. I-62). T...

A better understanding of the coupling between photosynthesis and carbon allocation in the boreal forest, together with its associated environmental factors and mechanistic rules, is crucial to accurately predict boreal forest carbon stocks and fluxes, which are significant components of the global carbon budget. Here, we adapted the MAIDEN ecophys...

Climatic scenarios for the Mediterranean region forecast increasing frequency and intensity of drought events. Consequently, a reduction in Pinus sylvestris L. distribution range is projected within the region, with this species being outcompeted at lower elevations by more drought-tolerant taxa such as Quercus pyrenaica Willd. The functional respo...

Overlaid to a general reduction of European beech and sessile oak tree growth over the recent decades in the Mediterranean Basin, tree-ring records from western Mediterranean populations display a stronger growth decrease than eastern populations. We investigate here to what extent the impact of sustained atmospheric circulation patterns in summert...

Old-growth forests, particularly those located at the interface between different bioregions, are unevaluable sources of long-term vegetation dynamics and historical stand response to natural and anthropogenic disturbance. Although old-growth forest are scarce, the information gathered studying them may assist forest ecosystem restoration and manag...

A better understanding of the coupling between photosynthesis and carbon allocation in the boreal forest, with implicated environmental factors and mechanistic rules, is crucial to accurately predict boreal forest carbon stocks and fluxes, which are significant components of the global carbon budget. Here we adapted the MAIDEN ecophysiological fore...

Supplementary Material file includes weight losses during fungal, alkali extraction and acid hydrolysis pretreatments (Table S1), and evolution of sugar production during enzymatic hydrolysis (Figure S1).

Tree mortality is a key factor influencing forest functions and dynamics, but our understanding of the mechanisms leading to mortality and the associated changes in tree growth rates are still limited. We compiled a new pan-continental tree-ring width database from sites where both dead and living trees were sampled (2,970 dead and 4,224 living tre...

1.Climate change scenarios forecast rising temperatures for the Mediterranean region, which could enhance vulnerability to drought stress in forest ecosystems. The long-term effects of climate forcing on tree performance can be, however, modulated by other environmental factors, such as competition and rising atmospheric CO2 concentrations. 2.We a...

European beech Fagus sylvatica L. represents one of the most commercially and ecologically important forest tree species in Europe. The study of climate-growth relationships may provide relevant information to assist projections of future species' distribution as well as forest management strategies. In this study, 9 European beech stands were sele...

Key message The premature leaf withering in Quercus subpyrenaica during the especially dry summers of 2011 and 2012 is interpreted as a mechanism for protecting the stem from xylem cavitation. Abstract The Mediterranean basin has been proposed as an area especially vulnerable to the effect of global climate change, with a greater probability of ext...

Plant-plant interactions influence how forests cope with climate and contribute to modulate species response to future climate scenarios. We analysed the functional relationships between growth, climate and competition for Pinus sylvestris, Quercus pyrenaica and Quercus faginea to investigate how stand competition modifies forest sensitivity to cli...

A drier climate together with intense management can be detrimental for species when they are found at their xeric limit. We analyzed the dynamics of Pinus syl-vestris in Central Spain in relation to colonization by more drought-tolerant Quercus pyrenaica. The studied forest presents high biodiversity and is one of the last stands relict from a wid...

Climatic drivers limit several important physiological processes involved in ecosystem carbon dynamics including gross primary productivity (GPP) and carbon allocation in vegetation. Climatic variability limits these two processes differently. We developed an existing mechanistic model to analyse photosynthesis and variability in carbon allocation...

Ecosystem productivity estimated with a model calibrated with eddy-covariance data was related to tree-ring growth of two different boreal conifers along a latitudinal gradient. The relationship between ecosystem productivity and growth changed with species and site. Greater photosynthesis in spring and summer increased annual anomalies of radial g...

Pruning allows knot-free timber to be obtained, thereby increasing the value of the highest-value wood products. However, the effect of pruning on growth is under discussion, and knowledge about the tree response to the simultaneous development of thinning and pruning is scarce. The objective of this study was to analyze the effect of the interacti...

Dendrochronology (i.e., the study of annually dated tree-ring time series) has proved to be a powerful technique to understand tree-growth. This paper intends to show the interest of using ecophysiological modeling not only to understand and predict tree-growth (dendroecology) but also to reconstruct past climates (dendroclimatology). Process model...

Growth projections using ecological models fitted to data collected along climatic gradients can help to understand how forests will respond to climate change. Stem growth of two Mediterranean oaks was predicted using nonlinear multiplicative models as a function of precipitation and minimum temperature of the hydrological year fitted to dendrochro...

Climatic scenarios for the Mediterranean Region forecast increasing frequency and intensity of drought events. We analyzed how Pinus sylvestris modifies its cambial phenology and intra-annual growth under enhanced drought conditions. For this purpose, a rainfall exclusion experiment was applied in 2012 to trees located in the lower elevation limit...

A key issue for sustainable management of oak woodlands is understanding the complex overstory-understory relationships that influence ecosystem productivity and stability. Oak removal is traditionally practiced in Californian ranches and Spanish oak dehesas to increase forage for grazing, but the response of the understory, and subsequently of the...

Climate is one determinant of the distribution and structure of California oak woodlands and Spanish dehesas. We summarize studies conducted in the two regions that use different methodologies to investigate the influence of climate on the distribution of oak species in California and on the development of dehesa silvopastoral systems in Spain. Res...

El patrimonio forestal del sur de España se encuentra amenazado por el cambio global. En ese contexto, destaca la importancia de evaluar la vulnerabilidad de las masas forestales y sus respuestas al clima. En este trabajo se estudió una cronología de Pinus pinea en Huelva, con el fin de estudiar cómo varía su productividad en relación con el clima....

We present two chronologies of dead and weakened Quercus ilex trees from declining open woodlands of Southern Andalusia and discuss climate's implication in the current widespread mortality in these ecosystems. Basal area increments were used to find out periods of growth decline preceding death. Absent rings became frequent since the 1970s, coinci...

Plasticity of xylem architecture can be a species specific strategy to reduce vul-nerability to climate change. To study how the evergreen shrub Erica arborea regulates its xylem at different time scales as a response to climatic variability, we compared time series of annual xylem traits such as ring-width (growth), vessel size (hydraulic diameter...

In this study, the effect of density on poplar short-rotation forestry plantations was analyzed in the context of maximizing biomass production under Mediterranean conditions. Data from 12 experimental sites in Spain with densities ranging from 6666 to 33,333 cuttings·ha−1 were used. At the end of the first year, biomass production from the differe...

Global change challenges forest adaptability at the distributional limit of species. We studied ring-porous Quercus canariensis Willd. xylem traits to analyze how they adjust to spatio-temporal variability in climate. Trees were sampled along altitudinal transects, and annual time series of radial growth (ring width (RW)) and several earlywood vess...

We analyzed tree rings over the past 100 years to understand the response of Quercus ilex L. to climate change at four different sites along a temperature gradient in a highly anthropogenically transformed ecosystem. To test the hypothesis of a climate change related decrease in productivity at warmer sites, we discuss the effect of historical mana...

Using the small-scale gradients in light and fertility imposed by the presence of trees on Mediterranean open oak woodlands, we studied differences in the ecology, floristic diversity and species composition of an annual grassland, and modeled plant relationships with soil properties and radiation using generalized linear models. The strong intra-a...

– • In this study we analyzed heterogeneity in nutrient cycling induced by trees in Mediterranean annual grasslands, comparing years of higher and lower than average precipitation and analyzing the effects of two different solar radiation scenarios. – • Organic matter and consequently upper soil N, K, Ca and Mg were significantly greater in th...

• We present the longest tree-ring chronology (141 y) of Quercus ilex L. (holm oak), and discuss the species climate-growth relationships and the influence of stand density on tree sensitivity to climate. • Similarly to Quercus suber L., the most influential climatic variables upon holm oak growth were late spring and early summer precipitation, wh...

In this paper, we present a new approach, based on a mixed model procedure, to quantify the tree-ring-based growth-climate relationship of trembling aspen along a latitudinal gradient from 46 to 54 °N in eastern Canada. This approach allows breaking down the growth response into general intersite and local climatic responses, and analyzing variatio...

Analysis of plant competition is a major issue in ecology and forestry, as it influences plant growth and plant-environment interactions. Competition is expected to be lower in the sparse tree stratum of open woodlands and agroforestry systems than in closed forests. We have analyzed competition in open woodlands of Quercus ilex in the Iberian Peni...

Black pine (Pinus nigra Arn.) is a pan-Mediterranean species of high ecological importance and one of the most important timber species in the area. We compare several site dependent height–age models for the species in three regions along its natural distribution area in Spain. The best model was a generalized algebraic difference approach (GADA)...

Changing biotic and abiotic stress mediate in plant–plant interactions resulting in positive to neutral or negative effects, and these effects can change with gradients of stress or through plant dynamics. Here we studied the variability in annual grass production and composition induced by gradients of intercepted light by trees in years of contra...

Despite Quercus ilex L. being one of the most widespread tree species in the Mediterranean basin, there are no growth models in the literature for this species. In this study, we compare age-dependent and age-independent dynamic diameter growth models and discuss the concept of dominance in open stands. A posteriori dominance was determined to fit...

Acorn production is one of the most important products in silvopastoral systems in the Mediterranean region. In the present study we carried out two preliminary trials to analyze the distribution of production over time and the effect of pruning. The objective was to develop tools to manage this valuable resource within these systems. In the first...

We present a review on the state-of-the-art of fruit prodution in Western Iberia woodlands («dehesas»), and particularly in Q. ilex (holm oak) «dehesas». This threatened ecosystem is of very high ecological and economical importance. Quercus sp. fruits (acorns) are essential for wildlife, and for pig fattening in «dehesas». In the first part of thi...

Iberian wild rabbit numbers have decreased in the last decades. The management implemented to recover rabbit populations includes several techniques, one of the most common being the construction of artificial rabbit warrens. To optimally distribute the artificial warrens in the field it is essential to understand natural warren microhabitat. Few s...

To achieve sustainability of a forest system it is necessary to apply appropriate silvicultural management, including preservation measures. The characterization of the status and development of the harvested stands, as well as the timber potential of the unmanaged ones, is necessary to achieve a sustainable forest management. In southern Patagonia...

La dehesa de encinas (Quercus ilex L.) del Oeste peninsular es una sistema agrosilvopastoral de origen antrópico el cual, pese a poseer un gran interés ecológico y económico, aún encierra múltiples interrogantes. La sociedad actual exige que la gestión de los espacios naturales se realice de modo sostenible, para lo cual es necesario adquirir un am...