TRACES
National Projects
Project duration: 
Sep 2022 to Aug 2026


Increased drought in the context of climate warming will impact the structure, composition and functioning of the vegetation. The main objective of this project is to improve the ability to predict vegetation responses to drought stress and climate warming, taking into account different functional dimensions, intra- and interspecific variability of traits and their coordination at different scales. These issues will be addressed through global database analysis, community-level field sampling along environmental gradients and drought simulation experiments.

Introduction

Increased drought in the context of climate warming is expected to impact vegetation structure, composition and function in many regions, with important feedbacks on key ecosystem services, including climate regulation. Forecasting these changes under different climate change scenarios has become one of the main goals of contemporary research in ecology and conservation science. Functional traits (i.e. morphological, physiological or phenological features measurable at the individual level that impact demographic rates and fitness) provide a natural basis to predict vegetation responses to changes in the environment. However, most studies have found little variation in demography explained by commonly measured traits.

In agreement with recent developments in trait-based ecology, we posit here that the predictive capacity of traits could be improved by (i) measuring traits that are more closely connected to relevant physiological processes; (ii) considering trait coordination at the whole-plant level and the corresponding trait modules or syndromes, as well as the evolutionary constraints driving coordination; and (iii) accounting for the environmental context (e.g., exposure) and trait variability at different scales, including within-species. We argue that two key functional dimensions that are not usually considered in trait-based ecology but that are critical in understanding and predicting vegetation responses to climate warming are drought tolerance traits, including allocation and hydraulic architecture, and metabolomic features associated with both the primary and the secondary (specialized) metabolism.

Objectives

The main goal of this proposal to improve the capacity to predict vegetation responses to drought stress and climate warming, by accounting for different functional dimensions, trait variability and coordination at different scales. Specifically, we will address the following questions:

  1. How are traits belonging to different plant functional dimensions (coordinated across species and to what extent this coordination reflects evolutionary constraints?
  2. How does trait coordination differ among species from communities along an environmental gradient of water availability and how does it relate to their demography and biogeographical context?
  3. How does intraspecific trait coordination change along a gradient of water availability spanning the whole distribution of a species? Does it differ from coordination at higher levels of organization? How does it relate to performance under stress?

Actions

These questions will be addressed by three complementary approaches: the analyses of existing global databases, focusing on patterns across woody species (Work Package 1); a community-level study in dry shrublands along an environmental gradient of water availability (Work Package 2); and a common garden experiment including populations from the entire distribution range of a model species and their response to an experimental drought (Work Package 3).