The Millennium Ecosystem Assessment (2003) provides definitions and descriptions of the characteristics of ecosystems and ecosystem services that should be used in the wise use of Ramsar wetlands. These definitions and concepts have been adopted by the National Framework (DEWHA 2008).
Within the Millennium Ecosystem Assessment (MEA), ecosystems are described as the complex of living communities (including human communities) and non-living environment (ecosystem components) interacting (through ecological processes) as a functional unit which provides a variety of benefits to people (ecosystem services). The sections below discuss key terms and concepts from the MEA and the National Framework used throughout the report. Specific definitions of these and other commonly used terms are contained in the Glossary in Section 7.
Wetland ecosystem processes are defined as the dynamic forces within the ecosystem between organisms, populations and the non-living environment. Interactions can be physical, chemical or biological. Examples include:
It is noted in the National Framework that some components may be viewed as both wetland components and wetland processes (for example, geomorphology, water quality).
The terms ‘benefits’ and ‘services’ are defined within the National Framework in the context of the ‘benefits that people receive from ecosystems’. The Millennium Ecosystem Assessment (2003) defines services as ‘provisioning, regulating, and cultural services that directly affect people, and supporting services which are needed to maintain these other services.’
The Millennium Ecosystem Assessment (2003) identifies four types of services:
provisioning services (products obtained from ecosystems) such as food and water
regulating services (benefits obtained from the regulation of ecosystem processes) such as regulation of floods, drought, land degradation, and disease
cultural services (non-material benefits through spiritual enrichment, cognitive development, reflection, recreation and aesthetic experiences) such as recreational, spiritual, religious and other non-material benefits, and
supporting services (those necessary for the production of all other services) such as soil formation, nutrient cycling and primary production.
Supporting services differ from provisioning, regulating, and cultural services in that their impacts on people are either indirect or occur over a very long time (Millennium Ecosystem Assessment 2003). In the context of this ECD, ecological values (attributes relating to biological diversity) represent supporting services. The ecological values of wetlands are of indirect benefit to people in maintaining biodiversity.
The National Framework notes that wetland ecosystem services and benefits are based on or underpinned by wetland components and processes and can be both of direct benefit to humans (for example, food for humans or livestock) or of indirect benefit (for example, wetland provides habitat for biota which contribute to biodiversity).
Figure 1 -2 from the National Framework document shows a generic conceptual model of the interaction between ecosystem processes, components and services/benefits for a wetland. In general terms, the model shows how wetland ecosystem processes interact with wetland components to generate a range of wetland services/benefits. These services/benefits can be broadly applicable to all wetlands ecosystems (such as primary productivity) or specific to a given site (for example, breeding habitat for an important bird species or population).
Guidelines under the Ramsar Convention favour the use of international or national biogeographic regions in the context of interpretation of Ramsar Nomination Criteria and other aspects of the Convention. Different biogeographic schemes apply to the site, depending on whether marine, terrestrial or freshwater environments are considered.
In this context, Kakadu National Park occurs within the following ‘biogeographic’ regions:
Division VIII - Timor Sea Drainage Division (Wildman, South Alligator; East Alligator basins) (refer Figure 1-3), and
Northern IMCRA Provincial Bioregion (IMCRA version 4, refer Figure 1-4).
Figure 1 2 Generic conceptual model showing interactions between wetland ecosystem processes, components and services/benefits (source: DEWHA 2008)
Figure 1 3 Australian drainage divisions, indicating the Timor Sea Drainage Division (number VIII) (source: Bureau of Meteorology undated)
Figure 1 4 IMCRA provincial bioregions, indicating the Northern Provincial Bioregion (number 25) (source: Commonwealth of Australia 2006)