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Consequences of global warming on plant biochemistry in European shrublands
Within this project we now specifically want to investigate the effects of a warmer climate on the biochemistry of different shrubland plant species. Plant biochemistry plays a key role in ecosystem carbon and nitrogen cycling. Moreover, the biochemical quality of plant tissues determines plant susceptibility to attack from parasitic fungi as well as insect and mammalian herbivores. Plant growth in unpolluted shrubland ecosystems are normally limited by the nitrogen supply. Warming can increase photosynthetic activity and soil nitrogen mineralization rates and thus alter both the plant carbon and nitrogen supplies. Plants respond to an increased nitrogen supply with increased nitrogen uptake resulting in accumulation of nitrogen rich free amino acids and proteins in plant tissues. Nitrogen accumulation in plant tissues demands carbon (to synthesize amino acids and proteins), plant tissue concentrations of carbohydrates as well as carbon-based secondary compounds like phenolic compounds and condensed tannins may decrease if not the plant photosynthetic rate increase enough to compensate for the greater plant C demand. The objective with the planned study is to investigate changes in plant biochemistry of plant species included in the VULCAN experimental plots. The results will be evaluated in collaboration with other European researchers active in investigating other aspects of plant and soil ecology within the project.
The project will include a field trip during the 2003 vegetation period to visit the VULCAN project sites in Denmark, Netherlands and Wales to collect plant samples. The study will focus on these sites since the vegetation structure is similar, i.e. Calluna vulgaris dominated heath with ingrowth of the grass Deschampsia flexuosa. At the laboratory in Umeå the biochemical analysis of the plant material will take place. Specifically analysis of amino acids, proteins, soluble carbohydrates and phenolic compounds will be performed using HPLC (high performance liquid chromatography) and GC (gas chromatography) technique. The planned project is suitable for a student in biology, ecology or biochemistry.
Informationen om uppsatsförslag är hämtad från Nationella Exjobb-poolen.