Responses of plant communities to climate change – biotic interactions
The climate is changing. Human activities cause increased emissions of green house gasses, particularly CO2. Elevated atmospheric CO2 increases the green house effect, which will lead to elevated global temperatures and altered precipitation pattern. In the future ecosystems are therefore facing simultaneous changes in three factors; elevated atmospheric CO2, elevated temperature and altered precipitation patterns. These are key factors regulating biological processes. Climatic changes will therefore affect natural ecosystems. The CLIMAITE project includes a large scale climate manipulation experiment where the three factors can be studied alone and in combination.
The present PhD-project will focus on plant responses to climate change. Climate change including extreme weather events and changes in seasonal patterns will affect the spatial and temporal distribution of plant species, growth rates and consequently changes in community structure depending on the vulnerability of species. Especially during the regeneration phase, plants are more or less sensitive to climatic stress as warmer and drier climate will inhibit germination and establishment of certain species. Regeneration studies in plants are therefore important for long term assessment of plant adaptation to climate change. Further, especially the elevated CO2 will increase root exudation and root growth with increased belowground competition for resources with cascading effects. Changes in plant tissue chemistry as well as changes in tissue chemistry associated with changes in plant abundance are foreseen and will be a determining factor for long term impact on the turn-over and storage of organic material in the soil and thereby for the overall carbon balance.
Within permanent vegetation plots, the plant community composition has been and will be assessed. The effect of treatments on plant root chemistry and root exudation will be analyzed by spectral analysis and wet chemistry and plant resource allocation will be determined using stable isotopes. Regeneration can be studied in the experimental plots supported by studies in phytotrons under controlled climate conditions. However, depending on the qualification of the candidate, the focus of the PhD-project will be adjusted in collaboration with scientific and statistical supervisors.
The present PhD-project will be carried out in a unique experimental field site in semi natural terrestrial ecosystem established in 2004 with realistic manipulations of CO2, temperature and water alone and in combinations. Each of these factors directly affects biological processes and there is increasing evidence that the combined effects of these changes will be very complex and include strong interactions between factors.
The research will take advantage of novel research tools including field scale ecosystem manipulations, growth chambers and stable isotope techniques.
Senior Scientist Inger Kappel Schmidt, Forest&Landscape (F&L), Division of Forest and Landscape Ecology, KU-LIFE
Phd student is employed on the project.
Involved people and partners
The PhD-project will be part of the Danish VKR Centre of Excellence CLIMAITE “Research Centre on Biological Effects of Climate Change” (www.climaite.dk).
The project will also benefit from the EU-funded network of climate change experiments INCREASE “An Integrated Network on Climate Research Activities on Shrubland Ecosystems” (www.increase-infrastructure.eu) coordinated by Inger Kappel Schmidt.