Climate-sensitive site index models for Norway

The present study aims to develop biologically sound and parsimonious site indexmodels for Norway to predict changes in site index(SI) under different climatic conditions. The models are constructed using data from the NorwegianNational Forest Inventoryand climate data from the Norwegianmeteorological institute. Site indexwas modeled using the potential modifier functional form, with a potential component (POT) depending on site quality classes and two modifier components (MOD): temperature and moisture. Each of these modifiers was based on a portfolio of candidate variables. The best model for spruce-dominated stands included temperature as modifier (R2 = 0.56). In the case of pine- and deciduous-dominated stands, the best models included both modifiers (R2 = 0.40 and 0.54 for temperature and moisture, respectively). We illustrate the use of the models by analyzing the possible shift in SI for year 2100 under one (RCP4.5) of the benchmark scenarios adopted by the IntergovernmentalPanel on Climate ...