On the functional role of tree species in two forest ecosystems

Ecosystems can be characterized in different ways depending on the point of view or the scientific background. Summarizing these views, one can describe ecosystems by their structure and metabolism. The species composition is part of the ecosystem structure. Moreover, ecosystem structures are detailed by biomass or soil and canopy architecture. Ecosystem metabolism represents the functional side. It can be described by primary production, nutrient retention, or control and use of water resources.