Reconsidering the concepts of ecological quality Achim Paetzold

“Ecological health is a nebulous concept that should be expunged from the vocabulary. Likewise, all synonymous terms are ridiculous in a scientific context.” Jill Lancaster (2000)

Ecological quality – why? Clear definitions of quality is needed for environmental legislation, e.g. WFD target for ecosystem management and restoration environmental impact assessment

Existing concepts Ecological / biological integrity WFD, Clean Water Act USA Ecosystem health Rio Declaration on Environment and Development 1992 Ecosystem goods and services Millennium Ecosystem Assessment (UNEP coordinated)

Ecological / biological integrity “ the capability of supporting and maintaining a balanced, integrated, adaptive community of organisms having species composition, diversity, and functional organization comparable to natural habitats of the region” (Karr & Dudley 1981)

“Natural” “Natural” can be defined as being without human influence human technology

agriculture wood wetland Integrity of created wetlands Biological integrity low high

agriculture wood wetland low high Integrity of created wetlands Biological integrity

Advantages defined target existing indicators (e.g. IBI) Problems characterisation of natural reference state is problematic long term and large scale changes of the environment world is dominated by humans Ecological integrity

Ecosystem health “ a healthy ecosystem is defined as being stable and sustainable, maintaining its organization and autonomy over time and its resilience to stress” (Haskell et al. 1992) Ecosystem health is defined by the lack of change in system organization and functioning.

Key attributes of ecosystem health (analogy to human health): Ecosystem health vigour (productivity) organization (biodiversity) ability to resist or recover from stress Rapport et al. (1998)

Ecological quality and society valuation no intrinsic optimum state of an ecosystem societal decision whether ecosystem state is good or bad society decides whether “naturalness” has primacy

Ecosystem services “ the conditions and processes through which ecosystems sustain and fulfil human life” Millennium Ecosystem Assessment (2003)

Valuation of ecosystem services valuation of ecosystem services are context dependent societal demands need to be integrated

Valuation of ecosystem services valuation of ecosystem services are context dependent societal demands need to be integrated status of an ecosystem service is the ratio of provision to demand Provision Demand Flood protection

Valuation of ecosystem services valuation of ecosystem services are context dependent societal demands need to be integrated status of an ecosystem service is the ratio of provision to demand Provision Demand Flood protection

Ecosystem services profile (ESP) provision demand

Ecosystem services provision demand ESP

agriculture wood ESP of created wetlands ESP

agriculture wood ESP of created wetlands ESP

agriculture wood ESP of created wetlands ESP

Challenges identify demands for ecosystem services (incl. future demands) develop indicators for ecosystem services define the scale / boundaries for assessment identify interdependencies among ecosystem services

Conclusions quality of an ecosystem is a societal judgement ecological quality can be defined by the overlap between ecosystem services provision and demand profile (ESP) ESP fosters integrative approach to ecosystem management

Defining ecosystem services Wetlands, infiltrationRetention of waterAvoidance of flood damage Instream productivity Water quality Physical habitat Water body Target fish population Adjacent landscape Recreational angling Ecosystem function/ component Ecosystem serviceBenefit

Resilience Resilience has been defined as rate at which a system approaches steady state after perturbation as the capacity of a system to absorb disturbance and reorganize while undergoing change so as to retain essentially the same function, structure, identity and feedbacks

Human valuation standards aspects of human utility respect or virtue (moral, religion) precaution

Provision Demand Flood protection Fish production Biodiversity Drinking water supply Interdependencies of ecosystem services