Climate change is a growing global concern and is predicted to increase the intensity and frequency of extreme weather events, such as drought. Soil microorganisms play a central role in the cycling of carbon and nutrients in forest ecosystems, being their activity highly dependent on water availability. Thus, drought imposes challenges to microbial life in soils, and it is still unknown how drought affects important microbial functions such as soil carbon storage and nutrient provision to plants. In this project we aim at studying how soil microorganisms cope with drought under different forest management practices.
Objectives
This project aims to understand how forest drought affects soil microbial resistance (ability to function in dry soil) and resilience (ability to recover after soil is rewet) to drought, and the consequences this has for the microbial contribution to C and nutrient cycling. We will set up experimental sites with rain-exclusion shelters ina forest ecosystem, and we will simulate seasonal drought along with rewetting events in situ. In addition, we will explore how different management practices (thinning, clear-cutting, residue return treatments, etc) modulate microbial responses drought and rain events. We will evaluate the microbial performance to deliver ecosystem functions and sensitivity to drought by resolving responses in growth and respiration, as well as associated soil characteristics in different management treatments. By combining the effect of drought in soil and in their microbial communities we will determine how climate change impact soil microbial communities and their processes such as CO2 emission, along with the potential for C storage in forest soils. The project is open to adjustments according to your interest within the topic, with the possibility to match your research interests.
Methodology:
- Determine bacterial and fungal growth rates by isotope tracing
- Estimate soil respiration using both gas chromatography and continuous soil fluxes
- Learn how to assess micrometereological assessments of soil moisture and temperature.
- Determine soil characteristic including soil moisture, C, N, pH, organic matter etc.
- Assess microbial community composition
Skills and techniques acquired:
- Design and manage a field experiment with focus on rain and drought simulations
- Learn about how soil moisture and link it to microbial community responses
- Assess the soil carbon budget during drought and rain cycles
- Develop problem-solving strategies and explore various approaches related to running a field
and lab experiment - Search and compile relevant literature within the topic
- Data treatment and statistical analysis of environmental data to interpret patterns of
microbial drought responses
Application process:
If you are interested, please contact: Margarida Soares margarida.soares@biol.lu.se and/or Johannes Rousk johannes.rousk@biol.lu.se