Leader: John-André Henden, UiT
We will explore how climate variation and change in combination with harvesting and other management actions impinge on food web interactions and multiple ecosystem functions for the three focal ecosystems.
Our approach will be 1) empirical/statistical, utilizing the extensive data available from the three ecosystems, and 2) theoretical, to simulate situations beyond our data (e.g., different climate change scenarios and alternative harvest control rules; 53).
In our empirical/statistical approach we will apply ‘hierarchical dynamic models’ (aka structural equation and state-space models; e.g., 54) that handle different sources of stochasticity and uncertainty and explicitly model the relative strength of direct and indirect (cascading) inter-specific interactions (e.g., Box 3) and multiple driver (i.e., climate and harvesting) effect chains in the ecosystem. We will use multi-trophic level datasets available from the three ecosystems to fit hierarchical dynamic models to analyse associations and causal relationships (i.e., dynamical relationships) between drivers and ecological variables, and to test specific hypotheses about the presence or absence of relationships and trade-offs between potentially linked ecosystem functions/services (54, 55).
Finally, we will use simulated data with known interactions and changes to assess the ability of the chosen analytical framework from WP1-4 to detect/predict changes as well as to assess the data/effort needed to detect potential effects of climate change and/or management actions on the ecosystem. Such simulations will also use the input from managers/stakeholders with respect to different Harvest Control Rules in a Management Strategy Evaluation (cf. WP6).