Christelle Hély

Christelle Hély
Ecole Pratique des Hautes Etudes | EPHE · UMR Institut des Sciences de l'Evolution - Montpellier (ISEM)

PhD in Environmental Sciences

About

135
Publications
22,307
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
3,742
Citations
Introduction
Additional affiliations
January 2012 - December 2014
Ecole Pratique des Hautes Etudes
Position
  • Professor (Full)

Publications

Publications (135)
Article
Full-text available
Exceptionally large areas burned in 2014 in central Northwest Territories (Canada), leading members of the Tłıchǫ First Nation to characterize this year as 'extreme'. Top-down climatic and bottom-up environmental drivers of fire behavior and areas burned in the boreal forest are relatively well understood, but not the drivers of extreme wildfire ye...
Article
Full-text available
Corsican biodiversity is threatened by both climate and disturbance-regime changes. Here, we simulate the future impacts of fires and discuss how integrated paleomodeling approaches can help assess future trends, in the context of the millennial-scale fire variability.
Article
Full-text available
In the Mediterranean basin, Corsica (French island) harbours among the best-preserved Mediterranean forest ecosystems. However, its high biodiversity could be threatened by the climate and disturbance-regime changes due to the global warming. This study aims (i) to estimate the future climate-related fire hazard in Corsica for the current century (...
Article
Full-text available
Sub-Saharan social-ecological systems are undergoing changes in environmental conditions, including modifications in rainfall pattern and biodiversity loss. Consequences of such changes depend on complex causal chains which call for integrated management strategies whose efficiency could benefit from ecosystem dynamic modeling. However, ecosystem m...
Preprint
Full-text available
Sub-Saharan social-ecological systems are undergoing changes in environmental conditions, including modifications in rainfall pattern and biodiversity loss. Consequences of such changes depend on complex causal chains which call for integrated management strategies whose efficiency could benefit from ecosystem dynamic modelling. However, ecosystem...
Poster
Full-text available
Very large wildfires (several thousand hectares) are increasingly frequent in the Northwest Territories (NWT), Canada, leading to exceptionally large areas burned during some years, such as in 2014. Crown fires spreading over very large areas affect socio-economic, cultural and traditional activities of human societies, including Indigenous peoples...
Article
In the context of global change, tropical forests are increasingly affected by fires. Understanding the ecological processes driving forest recovery in fire-modified landscapes is a critical issue. We analyzed spatial and temporal (8 years) changes in functional and phylogenetic composition of tree communities during forest post-fire recovery in an...
Preprint
Full-text available
In the Mediterranean basin, Corsica (French island) harbours among the best-preserved Mediterranean forest ecosystems and its high biodiversity could be threatened by the climate and disturbance-regime changes due to the global warming. This study aims i) to estimate the future climate-related fire hazard in Corsica for the current century (2020–21...
Preprint
Full-text available
The dynamics of ecosystems is of crucial importance. Various model-based approaches exist to understand and analyze their internal effects. In this paper, we model the space structure dynamics and ecological dynamics of meta-ecosystems using the formal technique of Graph Transformation (short GT). We build GT models to describe how a meta-ecosystem...
Preprint
Full-text available
In the Mediterranean basin, Corsica (French island) harbours among the best-preserved Mediterranean forest ecosystems. However, its high biodiversity could be threatened by the climate and disturbance-regime changes due to the global warming. This study aims (i) to estimate the future climate-related fire hazard in Corsica for the current century (...
Article
The north-central Canadian boreal forest experienced increased occurrence of large and severe wildfires caused by unusually warm temperatures and drought events during the last decade. It is, however, difficult to assess the exceptional nature of this recent wildfire activity, as few long-term records are available in the area. We analyzed macrosco...
Article
Aim Non‐climatic constraints on species northern range boundaries are often overlooked in attempts to predict climate‐induced range shifts. Here, we examined the effects of habitat availability and fire disturbance on the distribution of a species that transitions from being common to being found only in marginal populations at the northern boundar...
Article
Full-text available
Ecosystems are complex objects, simultaneously combining biotic, abiotic, and human components and processes. Ecologists still struggle to understand ecosystems, and one main method for achieving an understanding consists in computing potential surfaces based on physical dynamical systems. We argue in this conceptual paper that the foundations of t...
Article
Full-text available
Wildland fire is the most important disturbance in the boreal forests of eastern North America, shaping the floral composition, structure and spatial arrangement. Although the long-term evolution of the frequency and quantity of burned biomass in these forests can be estimated from paleo-ecological studies, we know little about the evolution of fir...
Article
Full-text available
Currently, indexes from the Fire Weather Index System (FWI) are used to predict the daily fire hazard, but there is no reliable index available in the Mediterranean region to be compared with paleofire records and check for their long-term reliability. In order to assess the past fire hazard and the fire-season length, based on data availability an...
Article
Full-text available
We evaluated the skills of different palaeofire reconstruction techniques to reconstruct the fire history of a boreal landscape (Russian Karelia) affected by surface fires. The analysis of dated lacustrine sediments from two nearby lakes was compared with independent dendrochronological dating of fire scars, methods which have rarely been used in c...
Article
Full-text available
In the Mediterranean region, Corsica represents one of the most important hotspots of biodiversity, partly due to the high number of endemics species. This region is also one of the most affected by forest fires worldwide. The present vegetation is adapted to a wide range of disturbance regimes, but a change in fire frequency or intensity in the fu...
Chapter
Dryland regions are climatically defined as having low annual precipitation and dry season periods that can span over several months and take place once or twice a year. Dryland ecosystems (e.g., grasslands, savannas, or dry forests) that experience recurrent fires often exhibit fire-adapted (or “pyrophytic”) vegetation (Trabaud 1981; Scholes 1997;...
Article
Full-text available
Identifying geochemical paleo‐proxies of vegetation type in watersheds could become a powerful tool for paleoecological studies of ecosystem dynamics, particularly when commonly used proxies, such as pollen grains, are not suitable. In order to identify new paleological proxies to distinguish ecosystem types in lake records, we investigated the dif...
Article
Full-text available
Context The Canadian boreal forest provides valuable ecosystem services that are regionally and globally significant. Despite its importance, the future of the Canadian boreal forest is highly uncertain because potential impacts of future climate change on ecosystem processes and biomass stocks are poorly understood. Objectives We investigate how...
Preprint
Full-text available
Context. The Canadian boreal forest provides valuable ecosystem services that are regionally and globally significant. Despite its importance, the future of the Canadian boreal forest is highly uncertain because potential impacts of future climate change on ecosystem processes and biomass stocks are poorly understood. Objectives. We investigate ho...
Chapter
Full-text available
As there are several types of fires, firefighters face different types of mitigation difficulties. They also face different situations potentially leading to entrapment. We suggest here ways to implement safer mitigation practises at both strategical and tactical levels. We analysed 103 firefighters’ entrapments described in both publications and i...
Article
Aim This study analyses the places and the scales at which the latitudinal diversity gradient (LDG) for vertebrate species holds or, conversely, fails. Although much empirical support for the LDG at a global scale exists, several marked departures have also been previously reported for some regions, scales and organisms. Here, we aim to test the ge...
Article
Full-text available
Wildland fires are the main natural disturbance shaping forest structure and composition in eastern boreal Canada. On average, more than 700 000 ha of forest burns annually and causes as much as CAD 2.9 million worth of damage. Although we know that occurrence of fires depends upon the coincidence of favourable conditions for fire ignition, propaga...
Article
This paper introduces dynamic configurational changes for patchy mosaics, parameterizable dilationand/or erosion processes of units in a vectorial landscape. Patchy-based models are rare although thisconceptual framework could yield insights to the functioning and dynamics of agricultural and naturallandscapes. Compared to common raster-based model...
Article
Full-text available
Wildland fires are the main natural disturbance shaping forest structure and composition in eastern boreal Canada. On average, more than 700 000 ha of forest burns annually, and causes as much as C$ 2.9 million worth of damage. Although we know that occurrence of fires depends upon the coincidence of favourable conditions for fire ignition, propaga...
Article
Full-text available
At the northernmost extent of the managed forest in Quebec, Canada, the boreal forest is currently undergoing an ecological transition between two forest ecosystems. Open lichen woodlands (LW) are spreading southward at the expense of more productive closed-canopy black spruce–moss forests (MF). The objective of this study was to investigate whethe...
Article
Full-text available
At the northernmost extent of the managed forest in Quebec, the boreal forest is currently undergoing an ecological transition between two forest ecosystems. Open lichen woodlands (LW) are spreading southward at the expense of more productive closed-canopy black spruce-moss forests (MF). The objective of this study was to investigate whether soil p...
Article
Full-text available
Global warming could increase climatic instability and large wildfire activity in circumboreal regions, potentially impairing both ecosystem functioning and human health. However, links between large wildfire events and climatic and/or meteorological conditions are still poorly understood, partly because few studies have covered a wide range of pas...
Article
Full-text available
Wildfire activity is projected to increase under global warming in many parts of the world. Knowledge of the role of these disturbances in shaping the composition of boreal forests is needed to better anticipate their future impacts. Here, we investigate the incidence of wildfire activity (burned biomass, frequency and size) on multi-millennia vege...
Article
Full-text available
In boreal ecosystems, wildfire severity (i.e., the extent of fire-related tree mortality) is affected by environmental conditions and fire intensity. A burned area usually includes tree patches that partially or entirely escaped fire. There are two types of post-fire residual patches: (1) patches that only escaped the last fire; and (2) patches wit...
Article
African herbaceous biomes will likely face drastic changes in the near future, due to climate change and pressures from increasing human activities. However, these biomes have been simulated only by dynamic global vegetation models and failing to include the diversity of C4 grasses has limited the accuracy of these models. Characterizing the floris...
Article
Full-text available
Human activities are historical ecological drivers, and we need to better understand their effects on ecosystems. In particular, they have been very important in the shaping of the Mediterranean biodiversity hotspot. Researchers and managers nonetheless lack knowledge concerning the impacts of their combinations and their current intensity on the s...
Article
Human activities are historical ecological drivers, and we need to better understand their effects on ecosystems. In particular, they have been very important in the shaping of the Mediterranean biodiversity hotspot. Researchers and managers nonetheless lack knowledge concerning the impacts of their combinations and their current intensity on the s...
Article
The aim of this study is to represent simultaneously changes in the spatial distribution of the Atlantic forest during the last 17,000 years. To characterize such changes, here we focused on three different forest physiognomies, evergreen, semi-deciduous, and Araucaria, and we provide a list of indicator taxa for each class retrieved from the origi...
Article
Full-text available
Climate, vegetation and humans act on biomass burning at different spatial and temporal scales. In this study, we used a dense network of sedimentary charcoal records from eastern Canada to reconstruct regional biomass burning history over the last 7000 years at the scale of four potential vegetation types: open coniferous forest/tundra, boreal con...
Article
In boreal forest ecosystems, wildfire severity (i.e. the extent of fire-related tree mortality) is affected by environmental conditions and fire intensity. A burned area usually includes tree patches that partially or entirely escaped fire, called ‘residual patches’. Although the occurrence of residual patches has been extensively documented, their...
Article
Full-text available
Landscape fires show large variability in the amount of biomass or fuel consumed per unit area burned. Fuel consumption (FC) depends on the biomass available to burn and the fraction of the biomass that is actually combusted, and can be combined with estimates of area burned to assess emissions. While burned area can be detected from space and esti...
Article
Full-text available
Wildfire has been recognized as one of the most ubiquitous disturbance agents to impact on natural environments. In this study, our main objective was to propose a modeling approach to investigate the potential impact of wildfire on biodiversity. The method is illustrated with an application example in New Caledonia where conservation and sustainab...
Presentation
Full-text available
Charcoal particles fossilized in two lakes in eastern Canadian boreal forest (Quebec) were used to infer fire history during the Holocene. Reconstructions of fire frequency are based on analysis of charcoals area and charcoals number records in time series. The comparisons of reconstructions before and after screening procedure suggest that the his...
Article
New Caledonia (NC) is a biodiversity hotspot sheltering terrestrial ecosystems of high ecological and conservation value including tropical dry forests, rainforests, and maquis. However, uncontrolled bushfires threaten this exceptional biodiversity. A science-based fire management policy could reduce the impact of unwanted fires and help facing cli...
Article
Full-text available
Landscape fires show large variability in the amount of biomass or fuel consumed per unit area burned. These fuel consumption (FC) rates depend on the biomass available to burn and the fraction of the biomass that is actually combusted, and can be combined with estimates of area burned to assess emissions. While burned area can be detected from spa...
Article
Fire frequency is expected to increase in boreal forests over the next century owing to climate change. In Quebec (Canada), the location of the northern limit of commercial forests (c. 51 °N) was established in 2000 taking into account mainly forest productivity and fire risk. The location of the limit is currently under debate and is being re-eval...
Article
Full-text available
Although past climate change is well documented in West Africa through instrumental records, modeling activities, and paleo-data, little is known about regional-scale ecosystem vulnerability and long-term impacts of climate on plant distribution and biodiversity. Here we use paleohydrological and paleobotanical data to discuss the relation between...
Article
Burned areas in boreal mixedwood forests usually include tree patches that partially or entirely escaped fire. Some of these post-fire residual stands – called fire refuges – can escape several consecutive fires due to particular microsite conditions. Despite their potential importance as biodiversity hotspots, the long-term forest dynamics of fire...