Modeling response of N addition on C and N allocation in Scandinavian Norway spruce stands

• Published in: Ecosystems (New York) 2005-06, Vol.8 (4), p.373-381
• Main Authors: Salih, N, Agren, G.I, Hallbacken, L
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Biomass; Boreal forests; Carbon; Climate effects; Climate models; climatic factors; equations; Fertilization; fertilizer application; Fertilizers; Forest ecosystems; Forest growth; forest stands; Forests; Fundamental and applied biological sciences. Psychology; General aspects; Limiting factors; mathematical models; Nitrogen; nitrogen fertilizers; nutrient availability; Picea abies; Pine trees; Plant litter; Productivity; Retention; Sedimentation & deposition; simulation models; Soil air; Synecology; Terrestrial ecosystems; Trees
• ISSN: 1432-9840; 1435-0629
• DOI: 10.1007/s10021-003-0103-6

Because nitrogen is considered to be the major growth-limiting element in boreal forests, the increasing nitrogen availability from deposition should lead to increasing growth. We have tested this assumption by simulating, with a simple model, carbon and nitrogen development in seven long-term fertilization experiments in three Nordic countries. The only differences between sites in the model are climate, the ambient nitrogen deposition, nitrogen fertilization regimes, and the initial conditions at the start of the experiment. The model simulates the observed stand development well as long as nitrogen remains the limiting factor. The simulated retention of deposited nitrogen is in general low (less than 50%), whereas retention of fertilizer nitrogen is higher. This seems to imply that the higher production in the fertilized stands will not be maintained once the fertilization is stopped. The model results also indicate that the major effect of climate on site productivity is through soil processes, not tree physiology.