Impacts of fructification on biomass production and correlated genetic effects in Norway spruce (Picea abies [L.] Karst.)
European Journal of Forest Research
Department of Forest and Wood Science, Faculty of AgriSciences Stellenbosch University, Private Bag X1, Matieland 7062, South Africa; Section of Forest Genetics, Technische Universität München, Weihenstephan Center of Life and Food Sciences, Am Hochanger 13, 85354 Freising, Germany
For the period 2003-2006, fructification of Norway spruce (Picea abies [L.] Karst.) was recorded at the Kranzberg forest site in Southern Germany by employing a crane with access to the canopy of more than 266 trees. For each tree, stem diameter and growth parameters were assessed annually as well as biomass of cones and seeds, number of seeds per cone, and proportions of empty seeds for a total of 371 trees with cone crop. Genotypes at 19 enzyme coding gene loci of 110 trees were included in the study of correlations between morphological and genetic traits. Re-scaling the observed values for a virtual pure Norway spruce stand of 1 ha, cone biomass including winged seeds (oven-dried at 38°C) varied between 706.8 kg/ha in 2006 (average value per tree was 3.6 kg) and values close to zero in 2005. Corresponding values for vegetative biomass increment of the coning trees in 2006 were 9,273.0 kg/ha and 10.8 kg/tree. A significant higher biomass investment was determined for dominant trees in terms of absolute cone mass as well as in terms of cone mass relative to vegetative biomass and fructification frequency. No trade-off effects in decreased vegetative biomass growth were found in the fructification year, compared to trees that did not grow cones. Although the dominant trees invested proportionally considerable biomass in cones, they showed no significant reduction in vegetative biomass growth. In the following year no decrease in vegetative growth was detected. Based on logistic regressions and homogeneity tests, respectively, significant genetic effect became evident with respect to the gene loci AAP-B and AAT-C concerning fructification probability in the year with maximum generative biomass investment. These and closely related loci also have been found to be indicative for growth and viability, respectively, in other species. © pringer-Verlag 2008.
biomass allocation; canopy architecture; fruit production; genotype; growth rate; logistics; parameterization; regression analysis; stem; tree; vegetation structure; Bavaria; Central Europe; Eurasia; Europe; Germany; Kranzberg Forest; Picea abies