Effects on ecosystem function –
Work package 4

Ecosystem functioning is a generic term, which can be defined as the interactions between living organisms and the physical environment, such as nutrients, soil development and water budgeting. As such, ecosystem functioning integrates the ecological function of individual species present in the system and will be affected by changes in species response, which is investigated in WP2 as well as by species composition and structure, which is investigated in WP3. In this context, the investigations in WP4 will integrate essentials of WP2 and WP3, and will include components of temporal changes in energy and carbon flow and nutrient cycling processes. Since several components of ecosystem functioning are important links between the system and the surrounding environment, detailed knowledge on the system functioning is therefore a prerequisite to understand and predict how perturbations to the system may affect the surrounding environment.

The overall objective of this work package is to identify effects of climatic perturbations and changes in seasonality and of frequencies of weather events on ecosystem functioning. The focus will be on internal cycling and transformation of the main nutrients and elements C, N and P, and external exchange of these nutrients.

The work will include two main types of activities:

• Measurements and analyses of the end results of integrated ecosystem processes in the experimental plots, such as C exchange between the ecosystem and the atmosphere, mobilization and allocation of nutrients to various ecosystem pools and the loss of C and nutrients from the plots.
   
  
• Determination of steps and processes controlling the C and nutrient cycles thus being important for the interpretation of the treatment effect, e.g. pathways and rates of internal transfers of C and nutrients within the ecosystem.