Biomass allocation of individual birch trees along an environmental gradient,dr,gr,stip

Norway is committed to report emission by sources and removals by sinks of greenhouse gasses to the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol (KP). Carbon pools in forests are efficiently monitored by converting standard forestry measurements from inventory plots into biomass and carbon estimates. One of the main challenges for converting individual tree measurements into biomass is the sparse data availability for below-ground biomass. In Norway, downy birch is the dominant broadleaved tree species from sea level up to the tree-line. Within the productive forest regions downy and silver birch make up 14% of the county's total above-ground volume and approximately 25% of the forested area. In terms of the total biomass in Norway's forest, a minimum of 20% can be expected to be birch. It is well established that tree allometry and hence biomass components vary between tree species, tree sizes, site types, stand types and along environmental gradients. Norwegian c arbon reporting for below-ground birch biomass is currently based on a total sample size of 14 trees collected in a different geographic region with different climatic conditions. Inference about the total Norwegian below-ground birch biomass on these gro unds appears unsatisfactory. In this project we propose to describe the error and variation associated with existing birch biomass functions, develop new birch biomass functions, and to evaluate the effect of the results on the overall forest carbon bud get for Norway. The work will be organized in four work packages: (1) field sampling across an environmental gradient, (2) error estimation and error analysis for existing biomass equations, (3) development of new biomass functions, and (4) utilize Monte Carlo analysis to evaluation of the effect of uncertainty associated with below- and above-ground birch biomass estimates for Norway's forest carbon stock