SYSTEM HEALTH (SELF-TUITION ASSIGNMENT) Teacher Dr Yen Le, Department of Environmental Science, FNWI, RU Background A healthy ecosystem is active and dynamic (vigour), has sufficient counteractive capacity (resilience) and maintains its organisation over time (metastability) while allowing social and economic needs to be met by society (Vugteveen et al., 2006) This sounds rather abstract, but ‘vigour’, ‘resilience’ and ‘organisation’ can be reduced to measurable variables (indicators), which for the most part find origin in system ecology Also anthropogenic stress that arises from societal activities in the system can be quantified Objectives  Students can adequately discuss the development and meaning of the concept ‘Ecosystem Health’;  Students are able to indicate how the concept can be elaborated in measurable variables and are aware of the knowledge gaps that are present in the development of applications of the concept Instruction Thoroughly read the article by Vugteveen et al (2006) Next, define the terms below and then answer the posed questions For this assignment hours have been scheduled Spend at least hour on the definition of terms and the elaboration of the questions Terms Define the following terms: • Organisation • Resilience • Vigour • Condition indicator • Stressor indicator Questions Produce a short overview of the development of the concept of ‘Ecosystem Health’ based on existing definitions and their features Ecosystem Health and Biological Integrity are both normative concepts Suppose you are talking with two nature managers and both adhere to either one of these concepts Firstly, in what way you think that their visions will coincide or differ, and secondly what can be the consequences for management in practice? Illustrate your answer in relation to the management of a nature conservation area Write down (at least three of) the most important features, or parts of definition, for (River) Ecosystem Health How does River System Health (RSH) conceptually relate to River Ecosystem Health (REH)? Explain 5 What is meant by the ‘combined approach’ in relation to the measurement of River Ecosystem Health? Explain Explain how aspects of time and space (levels of scale) play a role in the application and interpretation of system indicators, for example in relation to the measurement of primary production in a river? Why is it generally easier to measure ‘stressor’ indicators than ‘condition’ indicators? Explain a What are the advantages and disadvantages of developing a single index (‘one value’) for Ecosystem Health? b What are the important issues that need to be considered when developing such an index? Explain Product Answers to the questions formulated above Discussion • What is the contribution of Ecosystem Health within the context of conservation and management of (eco)systems? • What are the most important knowledge gaps in quantifying Ecosystem Health? • What is the meaning of the assessment approach proposed by Vugteveen et al for quantifying the effects of anthropogenic stress on ecosystems? Literature Vugteveen, P., R.S.E.W Leuven, M.A.J Huijbregts & H.J.R Lenders, 2006 Redefinition and elaboration of river ecosystem health: perspectives for river management Hydrobiologia.565(1), 289-308