Thomas Berg Hasper

Doktorand

Tel: 031-786 2670
Mobile: +46 (0)73 995 1065
Fax: +46 31 786 2560
e-post: thomas.hasper@bioenv.gu.se
Personal homepage: www.thomashasper.wordpress.com

Research

PhD student in plant ecophysiology, studying plant adaptations and responses to carbon dioxide (CO₂) variations

Preliminary project title:
Understanding the stomata response to carbon dioxide (CO₂):
A physiological and evolutionary approach

The world’s forests influence climate through physical, chemical, and biological processes that affect planetary energetics, the hydrologic cycle and atmospheric composition, and they are now under tremendous pressure from global climate change. Anthropogenic climate change can be amplified or damped by these complex and nonlinear forest–atmosphere interactions, like when increasing concentrations of atmospheric carbon dioxide (CO₂) and tropospheric ozone (O₃) affect tree physiology and structure, and hence forest feedbacks on climate. The impact of atmospheric CO₂ and tropospheric O₃ on trees are a major concern for large areas of global forests. Both greenhouse gases are known to influence physiological functions in plants by affecting the stomatal conductance (g_s). An increase in atmospheric CO₂ is expected to reduce stomatal conductance, possibly affecting forest carbon and water balance (evapotranspiration). Furthermore, according to several models, rising atmospheric CO₂ may alleviate the toxicological impacts of concurrently rising tropospheric O₃ during the present century if higher CO₂ is accompanied by lower stomatal conductance (g_s).

Several studies involving CO₂ and O₃ gases and stomatal conductance have already been made. However, once stomatal conductance (g_s) is not only regulated by these gases, other parameters like precipitation and air temperature should be taken in account in future experiments. One of the objectives of my project is to measure stomatal behaviour of Spruce and Eucalyptus trees grown at different CO₂ concentrations and temperature. Furthermore, for a broader range of species, I want to look at the evolutionary and environmental basis of the stomatal CO₂ response and its possible adaptation and to acclimation of the stomatal response to elevated concentrations.

Understanding the stomatal response to carbon dioxide (CO2): a physiological and evolutionary approach
Presentation September 2011