CAMPUS-S – The model of ground layer vegetation populations in forest ecosystems and their contribution to the dynamics of carbon and nitrogen. II. Parameterization, validation and simulation experiments

Abstract This study presents an example of the parameterization and validation of the CAMPUS-S model for the dwarf shrubs of the genus Vaccinium, and the results of computational experiments showing the applicability of the model. A quantitative analysis of the population dynamics of dwarf shrubs, their productivity and contribution to the carbon and nitrogen cycling in forest ecosystems was carried out. The CAMPUS-S model takes the morphology, ontogenesis (developmental stages) and physiological features of modeled species into account, both in undisturbed environmental conditions and under external natural and anthropogenic impacts, including climate change. The validation of the model was based on the independent field data and showed a high reliability of the results. Our simulation experiments showed that species-specific properties of dwarf shrubs, such as their structural and functional organization, flexibility of ontogenesis, and tolerance to a range of environmental factors, determine the resistance of populations to different kinds of disturbances, the speed of occupation of the territory and the ability to hold it. We demonstrated that dwarf shrubs have an important contribution to the carbon and nitrogen cycles of boreal forest ecosystems via above- and belowground litter production.