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Reference : UMR7058-JONLEN-001
Workplace : AMIENS
Date of publication : Tuesday, October 01, 2019
Scientific Responsible name : Jonathan Lenoir, Ronan Marrec et Guillaume Decocq
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 6 January 2020
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
Modelling forest microclimate and the redistribution of forest-dwelling species under anthropogenic climate change
Species distribution models (SDMs), the toolbox to project biodiversity redistribution under anthropogenic climate change, are based on ambiant-air temperature (i.e. macroclimate) but fail to capture the local variability of microclimatic conditions. Yet, these local variations can lead to huge differences between apparent temperatures near the ground (i.e. the temperature conditions experienced by living organisms in their habitats) and air-temperatures measured by meteorological weather stations. This is especially true in the understory of forest ecosystems, which are decoupled from exterior climatic fluctuations and where management practices will have a prominent role in mediating the processes underlying microclimate. Very recent progress has been made to interpolate microclimate at very fine spatial resolution by combining in-situ microclimate measurements with fine-grained environmental variables derived from remotely sensed images such as light detection and ranging (LiDAR) images. However, these fine-grained spatial interpolations are not dynamic over time and unlikely to reflect the long-term dynamic of climate but rather the weather conditions that prevailed during the year the microclimatic data where recorded. Did sub-canopy temperature conditions increased as much as the warming trend observed in several networks of weather stations during the last decades? How forest-dwelling species are responding to long-term changes in microclimatic conditions below the forest canopy? The project entitled “IMPRINT” (Impacts of Microclimatic Processes on foRest bIodiversity redistributioN under macroclimaTic warming) led by Jonathan Lenoir aim at providing answers to these research questions, by combining: (i) in-situ microclimate measurements (both temperature and humidity near the ground); (ii) high-resolution LiDAR images; and most important (iii) long-term synoptic data from a network of permanent weather stations installed close to forest ecosystems (RENECOFOR: http://www1.onf.fr/renecofor). In the framework of IMPRINT, the PhD candidate will set up and coordinate two national networks of in-situ forest microclimate measurements. The first network, level I sites, aims at capturing the entire macroclimatic gradient covered by deciduous temperate forest in France. The successful candidate will be able to rely on an existing network (RENECOFOR) of 102 long-term (since 1995) permanent plots, which are not yet equipped with miniature data loggers. The second network, level II sites, aims at capturing the variability in forest microclimatic conditions due to forest management practices, ranging from very open forest stands to very dense and closed forest stands. To reach this aim, the PhD candidate will install a network of 60 permanent plots along a gradient of canopy closure within each of three large forests in France (FD de l'Aigoual, FD de Blois, FD de Mormal), dominated by oak and beech and managed by the French National Forest Service (ONF). Each plot will be equipped with miniature data loggers to record microclimatic conditions every hour. Forest inventory surveys as well as floristic surveys and arthropod surveys will be performed throughout the PhD thesis. Based on the data collected in the field, the PhD candidate will model forest microclimatic conditions over time and its impact on the redistribution of forest-dwelling species under anthropogenic climate change.
We are opening a 3-yr PhD position at the interface between forest ecology and climatology. The PhD candidate will be based within the research unit « Ecologie et Dynamique des Systèmes Anthjropisés » (EDYSAN, CNRS, Université de Picardie Jules Verne, Amiens, France; https://www.u-picardie.fr/edysan/). EDYSAN is a young research unit which research focuses on the impact of global change drivers (climate change, land-use changes and biological invasions) on forest ecosystems and agricultural landscapes. The PhD candidate will be supervised by Jonathan Lenoir (full researcher at CNRS), Ronan Marrec (assistant professor at Jules Verne University of Picardy) and Guillaume Decocq (full professor at Jules Verne University of Picardy), in close collaboration with Emilie Gallet-Moron (GIS engineer at Jules Verne university of Picardy), Fabien Spicher (assistant engineer at Jules Verne University of Picardy) and Vincent le Roux (assistant professor at Jules Verne University of Picardy). At a national level, the PhD candidate will benefit scientific and technical supports from Sylvie Durrieu (full researcher at IRSTEA Montpellier) and Samuel Alleaume (research engineer at IRSTEA Montpellier), both experts in remote sensing technologies (i.e. airborne and terrestrial LiDAR). At the international level, the PhD candidate will have the opportunity to interact with several close collaborators, including: Pieter De Frenne from Gent University (Belgium); Jonas Lembrechts From Antwerp University (Belgium); Kristoffer Hylander from Stockhom University (Sweden); and Miska Luoto from the University of Helsinki (Finland).
The PhD candidate should have a driving licence and preferably have her/his own car. Indeed, there will be numerous field trips to the forest sites, some located very far from the lab in Amiens. All field trip expenses (i.e. travel, food and accommodation expenses) as well as any participation to workshops and conferences throughout the PhD thesis duration will be covered by the research budget, which is funded by the French National Research Agency (ANR).
Constraints and risks
The PhD thesis will be funded by the French National Research Agency (ANR).
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