Ecological memory of extreme drought events in soil microbial communities

Introduction

Current global changes are increasing the frequency and intensity of extreme drought events, with severe consequences for ecosystems. Recent evidence of ecological memory formation upon recurrent disturbances — defined as the capacity of past events to influence current ecosystem responses — challenges our ability to simulate future ecosystem responses to drought. Yet an important question remains: is ecological memory a fundamental feature regulating how ecosystem functioning responds to extreme climatic events?

Project Aim

EcoMEMO aims at filling this large knowledge gap, with a focus on soil microbial communities, for which I previously showed ecological memory of drought. Soil microbes regulate important biogeochemical processes for carbon and nutrient cycling. They also possess an enormous taxonomic and functional diversity which allows for potential short-term adaptation.

Methodology

By embracing new approaches to study microbial ecology under drought conditions and new experimental facilities targeted to test ecological memory under realistic climate scenarios, I aim to quantify the importance of ecological memory of drought and identify its mechanisms. All this makes EcoMEMO potentially ground-breaking towards our understanding of soil microbial community response to climate change.

Hypotheses

My overarching hypothesis is that ecological memory is a common phenomenon in soil microbial communities, attenuating negative effects of extreme drought on the processes they mediate. I also hypothesize that microbial community transition to alternative stable states during exposure to extreme drought underpins the positive effect on biogeochemical cycling.

Research Goals

Combining soil biogeochemistry, molecular ecology, and mathematics, I will:

• Quantify ecological memory across ecosystems and its consequence for soil processes.
• Assess legacies of previous drought events within soil biotic and abiotic properties.
• Identify features of soil microbial community dynamics underpinning ecological memory formation.