Malin Broberg, PhD student
I study the impacts of elevated ozone and carbon dioxide on agricultural crops, using meta-analysis and dose-response relationships together with experimental studies. Elevated levels of tropospheric ozone and carbon dioxide may significantly influence crop yields and its quality, such as protein and mineral nutrient content, but also baking qualities. This project aims to aggregate experimental field data from the 1980’s until present, in order to estimate the overall effects. Dose-response relationships between ozone/carbon dioxide and different crop variables are derived to evaluate the sensitivity to these environmental factors. Crops of main concern are varieties of wheat and rice, with experiments covering growing conditions in Europe, Asia, Australia and North America.
Supervisors: Håkan Pleijel, Johan Uddling
Shubhangi Lamba, PhD student
There is a lot of uncertainty in the response of trees and entire forest ecosystems due to the increasing atmospheric CO2 concentration and climate change. Much of these uncertainties are due to poorly quantified, bidirectional climate-forest feedbacks. Investigating responses of specific forest ecosystem processes such as photosynthesis, respiration and tree-atmosphere exchange of CO2 and H2O in detail is important to estimate forest responses to and feedbacks on climate change.
My study deals with the response of boreal Norway spruce forest ecosystem processes such as photosynthesis, respiration and transpiration to increasing CO2 concentration and temperature. Effects of elevated CO2 and temperature on mature boreal spruce trees were studied in field experiments in which fluxes of both CO2 and water flux data are available at shoot as well as whole tree level. Responses of shoot photosynthesis, respiration, stomatal conductance and phenology are quantified and scaled up to whole tree level by using the MAESTRA model to assess the relative importance of different types of plant acclimation in a changing climate. My research also aims to introduce dynamic tree responses (i.e. tree acclimation) into the dynamic global vegetation model (DGVM) LPJ-GUESS.
Supervisors: Johan Uddling, Göran Wallin