| title: | Age-related changes in needle N concentration, N partitioning and photosynthesis of Norway spruce (Picea abies) |
|---|---|
| reg no: | ETF6462 |
| project type: | Estonian Science Foundation research grant |
| status: | accepted |
| institution: | University of Tartu |
| head of project: | Ebe Merilo |
| duration: | 01.01.2005 - 31.12.2008 |
| description: | Age-related decline in needle photosynthetic rate will be analysed using modern concepts of leaf nitrogen partitioning. The study is important, because experimental species Norway spruce is one of the most widespread tree species in Estonia and Europe and nutrient (mainly N) deficiency is one of the most important factors limiting growth in boreal forests. Nutrient limitation has also been associated with decline in net primary production during forest ageing. The aims of the study are 1. to measure chemical (N and chlorophyll content) and photosynthetic parameters of sun and shade needles (current, 1- and 2-year old needles) in relation to tree age and 2. to determine nitrogen partitioning between photosynthetic and non-photosynthetic fractions and to detect the potential links between age-related changes in needle N partitioning and photosynthetic capacity. The main hypothesis of the study claims that needle light-saturated photosyntetic rate and maximum carboxylation rate decline as trees age and this decline is associated with either reduced needle nitrogen concentration or with higher investment of needle nitrogen into non-photosynthetic fractions. Needle N and chlorophyll concentrations and photosynthetic parameters (light-saturated photosynthesis, maximum carboxylation rate and potential electron transport rate) will be determined in current, 1- and 2-year-old needles from trees of different age. The study area is spruce-birch forest, where ten plots ranging from fresh clear-cut to mature forest have been identified. N partitioning between different photosynthetic functions (carboxylation, bioenergetics associated with electron transport and light harvesting) will be calculated according to the model presented by Niinemets & Tenhunen (1997). The fraction of non-photosynthetic nitrogen and temporal changes in non-photosynthetic nitrogen will also be estimated. The results of the study will be published in international journals. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Ebe Merilo | University of Tartu | researcher | |
| 2. | Ingmar Tulva | University of Tartu | PhD student | |