Team : MEA

PhD student :  MOULIN Emeline

Thesis supervisors :  MALAGOLI Philippe ,  BALANDIER Philippe ,  SAUDREAU Marc

Dates : November 2024 - November 2027

Description

In forest ecosystems, the upper canopy plays a key role in regulating resource availability by intercepting part of the incoming light and precipitation while modulating humidity and temperature. It thereby shapes the stand’s microclimatic conditions, creating a stable buffering effect that contrasts with external climate conditions. In the context of climate change, marked by rising temperatures and increasing water deficits, this microclimatic modulation helps mitigate the impact of drought stress on vegetation.

These local microclimatic conditions strongly influence soil microbial activity, which is highly sensitive to temperature and moisture variations. Microbial activity governs biological processes that control nutrient availability for plants, thereby shaping competitive interactions among individuals. In response, trees adjust their architecture according to their resource acquisition or conservation strategies, influencing their spatial distribution. These structural dynamics, both horizontal and vertical, feed-back on local microclimate by modulating the distribution of light, water, and nutrients intercepted or mobilized within the forest ecosystem.

To deepen our understanding of the feedback between microclimate, stand structure, and resource availability, we propose to enhance the RReShar forest dynamics model, developed within the CAPSIS platform. RReShar currently simulates the sharing of light and water among individual trees. We aim to extend it by integrating temperature dynamics and nitrogen recycling processes, a resource still underrepresented in forest models. These improvements will allow us to assess the combined effects of climatic factors and resource availability across various spatial configurations, in order to anticipate forest adaptive capacities under future environmental conditions.