Post-doct (M/F) - Advancing a mechanistic framework for climate–soil interactions in plant species distribution models

Job Description

Missions

Plant species distribution models (SDMs) are an important tool for predicting the impacts of climate change on communities and ecosystems, but their accuracy depends on how well they reflect factors that ultimately drive plant fitness, including resource uptake, stress tolerance, and species interactions. A case in point is optimal partitioning theory (OPT), a dominant paradigm of plant resource allocation that describes the ability of plants to adjust root-shoot allocation in response to resource deficiencies above- and belowground. OPT leads to resource colimitation of plant growth under many conditions. For example, increasing light availability or growing season duration increases annual carbon gain, which improves a plant's ability to harvest nutrients through greater belowground investment, and vice-versa. This suggests that climate and soil factors should commonly interact to drive plant fitness and potential shifts in specific range positions (e.g., margins or center) under a changing climate, yet correlative-based SDMs lack a formal method for incorporating such extensions of plant functional theory.

One prediction of OPT is that plants occur across a broader range of edaphic conditions in more energy-rich habitats, through compensation processes. For example, in sites of higher actual evapotranspiration (AET) where water and energy are more available, individuals should be able to withstand a larger array of soil-based stressors, including low nutrient availability from extremely acidic or basic soils. In correlative-based SDMs, this would emerge as interactions between climate (AET) and soil factors like pH, and explain why some species appear to have greater edaphic specialization in the colder or drier parts of their distribution. Differences in growth potential across species may also be important; for example, greater overall carbon gain by non-native, invasive species may allow them to inhabit a greater range of soil conditions under the same climate conditions as native species. Competitive or facilitative interactions will further modify these patterns, in ways that may be predictable from allocation theory.

Activity

This postdoctoral project will use existing databases of plant species occurrences (e.g., the European Vegetation Archive, U.S. Forest Inventory and Analysis program, sPlotOpen) along with geospatial soil and climate data to apply resource colimitation theory in the refinement of correlative-based species distribution models. The project will involve statistical, computational, and theoretical components, including:
- derivation of environmental covariates that best reflect resource uptake processes above- and belowground;
- development of SDM modeling structures that best reflect plant use of multiple resources (e.g., interactive vs. substitutable resources);
- testing the application of resource colimitation theory to SDMs across species of contrasting ecology (e.g., native vs. nonnative species, different growth forms and nutrient acquisition strategies, continuous traits reflecting growth potential such as leaf economics and genome size);
- and comparing climate-based SDM projections assuming single and multiple resource limitation.

Your Profil

Skills

Required
- PhD in plant ecology, spatial ecology, landscape ecology, vegetation science, or related fields
- fluent in written and spoken English
- demonstrated facility with spatial and statistical analyses in R or Python

Desired
- evidence of strong computational skills and large dataset analysis
- experience with hierarchical Bayesian modeling
- expert knowledge of plant functional ecology
- fluency in written and spoken French

Your Work Environment

The project is based at the EDYSAN laboratory at Universite of Picardie Jules Verne in Amiens, France.
EDYSAN – Ecology and DYnamics of ANthropized Systems is a research lab of the French CNRS and Jules Verne University of Picardy (UMR CNRS 7058). It conducts research on the response of forest ecosystems to various driving forces, including climate changes, land-use changes, biological invasions, fragmentation and human activities, with a special focus on plant communities. The approaches range from molecular analyses of the (holo)genome to remote sensing analyses at a global scale, through individuals, ecosystems and landscapes. The lab groups ca. 80 persons, including researchers and the technical staff.
Professor Jason Fridley at EDYSAN will support a one-year postdoctoral project to refine plant SDMs to more formally incorporate optimal partitioning theory using existing databases. A potential outcome is to improve the predictive accuracy of correlative-based SDMs at species' range margins where soil dependencies may be a significant barrier to effective SDM application.

Compensation and benefits

Compensation

3041,58€

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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