About
114
Publications
42,270
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
7,363
Citations
Introduction
Skills and Expertise
Publications
Publications (114)
European forests are being shaped by active human use and management, and by harvesting of wood in particular. Yet, our understanding of how forests are harvested across Europe is limited, as the real harvest regimes are not well described by currently available data. Here, we analyse recent harvests, as observed in permanent plots of forest invent...
Competition between individuals is a key process that drives tree growth and survival in forests. Ecological theories predict that the effect of competition should be weaker in stressful environments. However, quantitative studies have failed to reach a consensus on the direction of the interaction between climate and competition. In this study, we...
Species distribution models are key to evaluate how climate change threatens European forests and tree species distributions. However, current models struggle to integrate ecophysiological processes. Mechanistic models are complex and have high parameter requirements. Some correlative species distribution models have tried to include traits but so...
Increasing water stress is emerging as a global phenomenon, and is anticipated to have a marked impact on forest function. The role of tree functional strategies is pivotal in regulating forest fitness and their ability to cope with water stress. However, how the functional strategies found at the tree or species level scale up to characterise fore...
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...
Although climate change is expected to drive tree species toward colder and wetter regions of their distribution, broadscale empirical evidence is lacking. One possibility is that past and present human activities in forests obscure or alter the effects of climate. Here, using data from more than two million monitored trees from 73 widely distribut...
Climate change effects on tree reproduction are poorly understood, even though the resilience of populations relies on sufficient regeneration to balance increasing rates of mortality. Forest‐forming tree species often mast, i.e. reproduce through synchronised year‐to‐year variation in seed production, which improves pollination and reduces seed pr...
Key message
In European mountain forests, the growth of silver fir ( Abies alba Mill.), sycamore maple ( Acer pseudoplatanus L.), European beech ( Fagus sylvatica L.) and Norway spruce ( Picea abies (L.) H. Karst.) seedlings is more strongly affected by ungulate browsing than by elevation. But, the constraint exerted by ungulates, in particular the...
Intraspecific variability (IV) has been proposed as a new track to explain species coexistence. Previous studies generally assumed that IV results from intrinsic differences between conspecifics that widen species’ fundamental niches and blur differences among species, thus impeding stable coexistence, but also slowing down the rate of competitive...
Tree species composition is known to influence forest productivity, but its effect on forest resilience to disturbances such as storms remains largely unexplored. Furthermore, climate is likely to influence forest resilience directly but also to influence the effect of tree species composition on resilience. In Europe, storm‐induced tree mortality...
Key message
Metabarcoding analysis of soil fungal communities in French mountain forests revealed that harvesting intensity, time since last harvest and former land use had no effect on fungal community composition compared to key abiotic factors. Low-intensity management in these uneven-aged mountain forests therefore has limited effects on soil f...
Understanding how species abundances are driven by biotic interactions along environmental gradients is a fundamental question in ecology. For abundances at competitive equilibria in Central European forests, a classical ecological theory formulated by Ellenberg (1963) predicts that beech ( Fagus sylvatica L.) outcompetes other tree species within...
Climate change is expected to drive species towards colder and wetter regions of their distribution with alternative processes such as forest management having the potential to alter species displacements. Here, using data from more than two million monitored trees from 73 widely-distributed species, we quantify changes in tree species abundance ac...
The functioning and structure of most European forests are actively shaped by intensive human use. Harvesting of wood is one of the key processes of forest management, making it a crucial element to include in any large-scale analysis of forest ecosystems. Yet, our understanding of how forests are harvested across Europe is limited, as the true har...
Forest stand densities are increasing in the boreal and temperate biomes, suggesting that tree‐tree competition is intensifying. Anticipating the consequences of this intensified competition is difficult because competition‐induced mortality may depend not only on the occurrence of extreme climatic events such as drought, but also on stand composit...
In forest communities, light competition is a key process for community assembly. Species' differences in seedling and sapling tolerance to shade cast by overstory trees is thought to determine species composition at late-successional stages. Most forests are distant from these late-successional equilibria, impeding a formal evaluation of their pot...
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...
Intraspecific variability (IV) has been proposed to explain species coexistence in diverse communities. Assuming, sometimes implicitly, that conspecific individuals can perform differently in the same environment and that IV increases niche overlap, previous studies have found contrasting results regarding the effect of IV on species coexistence. W...
Aim
Our understanding of the mechanisms that maintain forest diversity under changing climate can benefit from knowledge about traits that are closely linked to fitness. We tested whether the link between traits and seed number and seed size is consistent with two hypotheses, termed the leaf economics spectrum and the plant size syndrome, or whethe...
With climate change, natural disturbances such as storm or fire are reshuffled, inducing pervasive shifts in forest dynamics. To predict how it will impact forest structure and composition, it is crucial to understand how tree species differ in their sensitivity to disturbances. In this study, we investigated how functional traits and species mean...
Aim
Linking local population dynamics and species distributions is crucial to predicting the impacts of climate change. Although many studies focus on the mean fitness of populations, theory shows that species distributions can be shaped by demographic stochasticity or population resilience. Here, we examine how mean fitness (measured by invasion r...
Aim: Linking local population dynamics and species distributions is critical to predicting the impacts of climate change.
While many studies focus on the mean fitness of populations, theory shows that species distributions can be shaped by demographic
stochasticity or population resilience. Here we examine how mean fitness (measured by invasion rat...
Ecological theory aims to understand how and why species differences allow competitors to coexist, but explanations remain inconsistent with data. Tightly constrained parameter tradeoffs needed for coexistence in models contrast with evidence that forests can support high diversity and be invaded repeatedly by species that lack specialized tradeoff...
The role of intraspecific variability (IV) in shaping community dynamics has been intensively discussed over the past decade and modeling studies have played an important role in that respect. However, a major, but often implicit, assumption typically made by these studies, that IV can be represented by independent random draws around species-speci...
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...
Recent climate warming has fueled interest into climate‐driven range shifts of tree species. A common approach to detect range shifts is to compare the divergent occurrences between juvenile and adult trees along environmental gradients using static data. Divergent occurrences between life stages can, however, also be caused by ontogenetic effects....
Significance
Suitable habitats for forest trees may be shifting fast with recent climate change. Studies tracking the shift in suitable habitat for forests have been inconclusive, in part because responses in tree fecundity and seedling establishment can diverge. Analysis of both components at a continental scale reveals a poleward migration of nor...
Aim
The population processes that drive tree species distribution are still widely debated. We test the hypotheses that metapopulation processes of colonization and extinction are linked to predictions of species distribution models.
Location
Europe: Spain, France, Germany, Finland and Sweden.
Taxon
Angiosperms and Gymnosperms.
Methods
For 17 tr...
Despite its importance for forest regeneration, food webs, and human economies, changes in tree fecundity with tree size and age remain largely unknown. The allometric increase with tree diameter assumed in ecological models would substantially overestimate seed contributions from large trees if fecundity eventually declines with size. Current esti...
There is an urgent need to synthesize the state of our knowledge on plant responses to climate. The availability of open-access data provide opportunities to examine quantitative generalizations regarding which biomes and species are most responsive to climate drivers. Here, we synthesize time series of structured population models from 162 populat...
A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-22025-2
Indirect climate effects on tree fecundity that come through variation in size and growth (climate-condition interactions) are not currently part of models used to predict future forests. Trends in species abundances predicted from meta-analyses and species distribution models will be misleading if they depend on the conditions of individuals. Here...
Species range limits are thought to result from a decline in demographic performance at range edges. However, recent studies reporting contradictory patterns in species demographic performance at their edges cast doubt on our ability to predict climate change demographic impacts. To understand these inconsistent demographic responses, we need to sh...
To mitigate and adapt to climate change, there is an urgent need to synthesize the state of our knowledge on plant responses to climate. The availability of open-access data, combined with our understanding of plant physiology and life history theory provide opportunities to examine quantitative generalizations regarding which biomes and species ar...
Over the coming decades, the predicted increase in frequency and intensity of extreme events such as droughts is likely to have a strong effect on forest functioning. Recent studies have shown that species mixing may buffer the temporal variability of productivity. However, most studies have focused on temporal stability of productivity, while spec...
Species range limits are thought to result from a decline in demographic performance at range edges. However, recent studies reporting contradictory patterns in species demographic performance at their edges cast doubt on our ability to predict climate change demographic impacts. To understand these inconsistent demographic responses at the edges,...
For decades, ecologists have investigated the effects of tree species diversity on tree productivity at different scales and with different approaches ranging from observational to experimental study designs. Using data from five European national forest inventories (16,773 plots), six tree species diversity experiments (584 plots), and six network...
Aim
Processes driving current tree species distribution are still largely debated. Attempts to relate species distribution and population demography metrics have shown mixed results. In this context, we would like to test the hypotheses that the metapopulation processes of colonization and extinction are linked to species distribution models.
Loca...
Size inequality has been considered a key feature of plant population structure with impacts on ecosystem functions. In forest ecosystems, studies examining the relationship between tree size inequality and stand productivity have produced mixed outcomes. These studies found positive, neutral or negative relationships and discussed how this could b...
Key message
In tree communities, tree size inequality reduces productivity and interacts with tree shade tolerance to modulate stand productivity, with a higher productivity in stands where shade-intolerant species dominate shade-tolerant species in size.
Context
Positive diversity–productivity relationships have been reported in different plant c...
Key message
A better transfer to managers of studies examining the functional role of tree species diversity would be achieved by explicitly addressing two missing links: the effect of management interventions on coexistence mechanisms and the relationships between coexistence mechanisms and ecosystem functions.
Context
Plant species diversity has...
Humans require multiple services from ecosystems, but it is largely unknown whether trade-offs between ecosystem functions prevent the realisation of high ecosystem multifunctionality across spatial scales. Here, we combined a comprehensive dataset (28 ecosystem functions measured on 209 forest plots) with a forest inventory dataset (105,316 plots)...
Damage due to wind storms and droughts are increasing in many temperate forest, yet little is known about the long-term roles of these key climatic factors in forest dynamics and in the carbon budget. The objective of this study was to estimate individual and coupled effects of droughts and wind-storms on adult tree mortality across a 31-year perio...
We present repeated tree measurement data from 63 permanent plots in mountain forests in France. Plot elevations range from 800 (lower limit of the montane belt) to 1942 m a.s.l (subalpine belt). Forests mainly consist of pure or mixed stands dominated by European beech (Fagus sylvatica), Silver fir (Abies alba) and Norway spruce (Picea abies), in...
Ce livret vient en complément du premier livret sur les idées reçues sur les risques naturels en montagne, paru en 2013. Il aborde la question des idées reçues sur le changement climatique en montagne, sur la base de connaissances acquises dans les projets de recherche du centre Irstea de Grenoble. Les risques en montagne vont-ils augmenter ou au c...
Alexander et al. [1] made two really important points about species range boundaries. First, we still know very little about which boundaries are set by competition rather than by direct effects of temperature or other environmental variables. Second, reliable knowledge about this can come only from field experiments, transplanting species beyond t...
Plant structural diversity is usually considered as beneficial for ecosystem functioning. For instance, numerous studies have reported positive species diversity-productivity relationships in plant communities. However, other aspects of structural diversity such as individual size inequality have been far less investigated. In forests, tree size in...
Description of the French National Geographic Agency data and climatic data.
(PDF)
P-values from the models for the ten species.
(PDF)
Comparison of different analysis methods: lm vs. nls.
(PDF)
Ecologists have limited understanding of how geographic variation in forest biomass arises from differences in growth and mortality at continental to global scales. Using forest inventories from across North America, we partitioned continental-scale variation in biomass growth and mortality rates of 49 tree species groups into (1) species-independe...
Phenotypic traits and their associated trade-offs have been shown to have globally consistent effects on individual plant physiological functions, but how these effects scale up to influence competition, a key driver of community assembly in terrestrial vegetation, has remained unclear. Here we use growth data from more than 3 million trees in over...
Investigating how interactions among plants depend on environmental conditions is key to understand and predict plant communities’ response to climate change. However, while many studies have shown how direct interactions change along climatic gradients, indirect interactions have received far less attention. In this study, we aim at contributing t...
Understanding the long‐term impacts of invasive mammalian browsers and granivores in mixed forests is difficult due to the many processes potentially affecting the demography of long‐lived trees. We constructed individual‐based spatially explicit simulation models of two mixed conifer–angiosperm forests, growing on soils of contrasting phosphorus (...
Hutchinson defined species' realized niche as the set of environmental conditions in which populations can persist in the presence of competitors. In terms of demography, the realized niche corresponds to the environments where the intrinsic growth rate ( r ) of populations is positive. Observed species occurrences should reflect the realized niche...
Uneven-aged forests are usually characterized by high size inequality of trees within stands. This dimension of heterogeneity has often been left out of the diversity-productivity debate which has mainly focused on species diversity. Our study aimed to bring quantitative answers to what effects size inequality has on the basal area production of pu...
Climate change is expected to increase the magnitude and the frequency of extreme climatic events such as droughts. Better understanding how plant communities will respond to these droughts is a major challenge. We expect the response to be a shift in functional trait values resulting from both species turnover and intraspecific trait variability,...
1 Climate change is expected to increase the magnitude and the frequency of extreme climatic events such as droughts. Better understanding how plant communities will respond to these droughts is a major challenge. We expect the response to be a shift in functional trait values resulting from both species turnover and intraspecific trait variability...
1.The importance of competition has been defined as the impact or role of competition relative to the total impact of the environment, and the intensity of competition is its absolute impact. Understanding the distinction has been proposed as key in reconciling long-running ecological debates.
2.An index of competition importance, Cimp, has been u...
Climate scenarios suggest that current forest stands will face radically different temperature and precipitation conditions in the future. Developing future strategies for forest management in the face of uncertain and highly variable forecasts of future site conditions is a great challenge. Here we have analyzed transnational case studies dealing...
Global warming is predicted to dramatically alter communities' composition through differential colonization abilities, such as between sessile plants and their mobile herbivores. Novel interactions between previously non‐overlapping species may, however, also be mediated by altered plants' responses to herbivore attack.
Syndromes of plant defences...
Context
There is strong interest in sustainable forest management systems that preserve characteristics of forests close to naturalness. Assessing the effectiveness of these systems is difficult because defining “natural” baselines from which impacts are estimated is challenging and because the influence of harvesting can have complex interactions...