Integrated assessment of wetland services and values as a tool to analyse policy trade-offs and management options
A case study in the Daly and Mary River catchments, northern Australia
Supervising Scientist Report 198
de Groot R, Finlayson M, Verschuuren B, Ypma O & Zylstra M
Department of the Environment, Water, Heritage and the Arts, 2008
- SSR198 - Integrated assessment of wetland services and values as a tool to analyse policy trade-offs and management options:
A case study in the Daly and Mary River catchments, northern Australia (PDF - 1,650 KB) | (RTF - 8,300 KB)
About the report
In this report we present the results of a study carried out between May 2004 and May 2005 as a contribution to the Tropical Rivers Inventory and Assessment Project (TRIAP) of Australia’s Tropical Rivers Program. The aim was to provide a framework for the analysis of the ecosystem services provided by the wetland and riverine ecosystems of northern Australia. The analyses drew heavily on the conceptual framework provided by the Millennium Ecosystem Assessment (MA) where ecosystem services were defined as ‘the benefits people obtain from ecosystems’. These benefits include: provisioning services such as food and water; regulating services such as flood and disease control; cultural services such as spiritual, recreational, and cultural benefits; and supporting services such as nutrient cycling that maintain the conditions for life on earth. The term ‘ecosystem services’ is now broadly used to encompass what can also be referred to as ecosystem goods and services and/or ecosystem functions and, at times, also environmental services. For the purposes of this report – given that the study was undertaken using the recognised ‘function analysis framework’ – the terms ecosystem services and functions are considered to be interchangeable unless a distinction is made otherwise.
In accordance with the above, an assessment of the ecosystem services and values (ecological, socio-cultural and economic) of selected wetlands in northern Australia (with a focus on the Daly and Mary River catchments) was undertaken and the results incorporated into a practical framework and guidelines for integrated assessment and valuation of wetland services. Relevant policies and management strategies that address wetland functions and services in the Daly and Mary River catchments were analysed and trade-offs that contributed to the development of options for the sustainable ‘multi-functional use’ of the wetlands highlighted.
The assessment entailed consultation and active involvement with many stakeholders, such as governmental organisations, local associations and corporations, NGOs and community-based groups, and land-owners and managers to collect information and incorporate their views and respective interests. As this was a pilot study, the level of focus was primarily at the institutional level; more interviews would be needed to sufficiently quantify results on an individual basis, for example, for farming or Aboriginal communities. The benefits of this approach were multiple in that it enabled the collation and analysis of existing information that could be used to support existing conservation, natural resource management, and social initiatives within the study areas and identified information gaps. In this respect it was based on the outcomes and approaches suggested in the Millennium Ecosystem Assessment for undertaking social and ecosystem-based analyses in complex systems.
Results and conclusions
The following section provides an overview of the main results obtained through the application of the integrated assessment approach in the Daly and Mary River case studies.
1 - Main ecosystem services
Many ecosystem services derived from or provided by the wetlands were identified. The main services provided by the wetlands were: (1) Provisioning services: 1a) Carrier functions, including use of (wetland) space for, amongst other activities, agriculture (cattle, buffalo), horticulture, crocodile farming, aquaculture, and mining (eg sand, gold); 1b) Production functions: harvesting natural resources such as food (eg bush tucker), commercial and subsistence fishing, medicinal resources, raw materials, and ornamental resources (eg wood and leaves for handicraft); (2) Supporting services: including the provision of important habitat for wildlife and nursery areas for many taxa as well as soil formation and retention; (3) Regulating services: covering the critical role of ecological and biophysical processes such as climate regulation, water supply (for flora, fauna and human use), regulating runoff, erosion control, disturbance prevention, nutrient regulation and waste treatment (water quality regulation), and biological control; (4) Cultural and amenity services: including important non-material benefits such as aesthetic information, recreation and tourism (boating, fishing, wildlife viewing, etc), spiritual and historic information, cultural and artistic information, and use in science and education.
It was established that local communities and other stakeholders were highly dependent on Northern Territory wetlands in many ways. As it was not possible to deal equally with all the ecosystem services identified, especially those in the regulation category, these (such as climate and nutrient regulation) have not been discussed further.
2 - Ecological importance (value)
Both the Daly and Mary River catchments possess many wetlands of national importance that provide essential habitat for rare and endemic species, eg the freshwater whipray (Himantura chaophyra), bull shark (Carcharhinus leucas) and bamboo (Bambusa arnhemica), and provide seasonal habitat refuge for many residential and migratory species, including birds such as the little curlew (Numenius minutus) and the magpie goose (Anseranas semipalmata), and fish such as the barramundi (Lates calcarifer). The wetlands experience a markedly seasonal climate and flooding/drying regime and are extremely productive and support many plants and animals. The ecological value of the wetlands would qualify them for listing as ‘internationally important’ under the Ramsar Convention on Wetlands, as has occurred for the wetlands in nearby Kakadu National Park.
3 - Socio-cultural importance (value)
Human well-being and wetland ecosystems are inextricably connected through non-material and anthropocentric values and many stakeholders attach socio-cultural importance to the wetlands in the Northern Territory. In this study, a typology was developed to identify socio-cultural values, including cultural heritage, spiritual and existence values, inspiration and expression, knowledge, sense of place, aesthetic quality and recreation.
4 - Economic importance (value)
The current economic benefits provided by the main identified ecosystem services have been estimated at A$50.7 million for the Mary River catchment (approx A$450/ha) and A$82.4 million for the Daly River catchment (approx A$230/ha). These are relatively low figures compared to values found in literature for wetlands which on average are estimated at US$3000 (approx A$4000)1 per ha/year or more. This was due to several factors: (a) monetary values were estimated for only 10 of 27 possible ecosystem services, (b) only net-values have been used (gross values, including effects on labour and capital investments would be at least five times higher); and (c) in case several values were found for one service, the lowest figure was used. The four economically most important ecosystem services identified and estimated were: carbon sequestration: A$87 million (based on expressed willingness to pay preferences); water use: A$46 million (potential consumer surplus based on licensed consumption), agriculture/horticulture: A$26.5 million (producer surplus based on net benefit), and tourism: A$21 million (producer surplus based on visitor expenditures). Taking into account the conservative approach used during the valuation process, it can be safely stated that the true contribution of wetland services to the local community and the regional economy is much higher than the values shown.
5 - Trade-offs and competing interests
The economic values are based on assumed sustainable use levels and depend on the maintenance of the integrity of the wetlands. Since most ecosystem services are interdependent, maximising one service (eg pastoralism, mining, nature conservation) in isolation will most likely lead to the loss or reduced availability of others (eg fishing, recreation, cultural services). As a complete cost-benefit analysis would be necessary to ensure informed decision-making, the ecosystem services analysis framework was used to assess which services were utilised by which individuals or organisations and to what extent this led to competing interests. For example, regarding water supply, diverse stakeholders have competing interests. Some would prefer to see irrigation for agriculture given priority while others seek the maintenance of environmental and cultural ‘flows’ (eg protection of culturally significant sites that are at risk of being disturbed or damaged should there be a drop in the water table of the Daly River). Additionally, there is continued debate as to what extent any of the related economic, environmental or cultural values can be ‘traded-off’; the framework can be used to assess potential trade-off scenarios such as those mentioned above.
6 - Policy analysis
The policy analysis highlights both the sectoral and integrated effect of policies and institutions on the wetland services as well as providing a base for assessing consistency in policy. The analysis provided a broad picture of factors and conditions (in terms of policies, institutions and stakeholders) affecting the use of wetland services. The study indicated discrepancies between higher-level strategies and management practices that can help to make choices and set priorities for important management issues.
7 - Management implications
Assessing the implications of the ecosystem services approach for wetland management and planning requires synthesising the results of all components of the integrated framework (ie identifying and valuing wetland services and values, stakeholder interests and conflicts over services, and policy and institutional contexts). A key implication for management is that by explicitly stating the functions and values of wetland ecosystems and identifying where benefits are likely to accrue, it provides justification for specific management actions and proposals. By highlighting potential trade-offs, the decision-making process can become more transparent and encourage consensus and communication between stakeholder representatives and government agencies.
The integrated assessment also emphasises the need to manage in a precautionary and adaptive manner as well as effectively acknowledging the importance of the values that stakeholders attach to various ecosystem services. Differences in perception about the importance of management issues are related to the contrasting values stakeholders attach to wetland services – expressed or implied – and which may or may not be reflected in management plans. Generally, wetland services in each catchment were addressed by focusing efforts on mitigating a priority issue; for example, the control or reduction of weed infestations due to concerns over impacts on agricultural productivity and biodiversity (eg in the Mary River catchment), or the retention of culturally important activities, such as the customary harvest of wetland resources (eg in the Daly River catchment).
1 - Greater in-depth analysis of services and values
This pilot study provided an overview and framework for the analysis of wetlands services and values, but more quantitative data is needed on the individual services. In future studies, it would be useful to focus in more detail on a more restricted geographical area, eg sub-catchment level, rather than the two large catchments included in this study. This would make it more feasible to assess the perceptions of stakeholders at a more specific level (eg through questionnaires) and to provide more reliable locally-relevant data for decision makers. A balance between the interests and perceptions of individual stakeholders and institutional interest in managing across catchments or other large-scale land units may need to be considered.
Future research would also benefit from a more sequential application of the framework; that is, research for the individual components of the framework is arranged to allow steps relating to trade-off analysis and management implications to be synthesised and analysed on the basis of the results obtained in the earlier ecosystem services identification and valuation steps.
2 - Spatial analysis of ecosystem services to allow assessment of trade-offs in multi-functional use
Follow-up work should attempt to obtain better insight into the spatial distribution of the wetland services in order to allow more in-depth analysis of the possibilities and constraints for multi-functional use of the catchments. Ideally, a decision-support system should be developed to optimise trade-offs between conservation and (sustainable) use of wetland services, linking public participation (eg organisation of workshops or other forms of stakeholder involvement in the valuation and trade-off analysis) with geographical information (mapping) tools.
3 - More focused policy analysis
The present research has been able to provide a broad overview and baseline information particularly in representing the existing institutions, policies and stakeholders, and has identified the institutions responsible for the management of wetlands in the research areas, list of policies associated with the functions and their interactions, and the existing extent of stakeholders’ involvement in the catchment management. More detailed analysis is needed of individual issues or selected ecosystem services, or individual categories of policies to see how these affect and/or are affected by different factors at different scales (local scale, regional scale, national scale etc).
4 - Indicators for integrated management
The importance of indicators (ecological, socio-cultural and economic) cannot be under-estimated for integrated assessment. Whilst the value of indicators for adaptive management is recognised, there are few guidelines or case studies on how to identify and apply them. A more detailed analysis should aim to identify indicators for integrated natural resource management and link these to potential indicators for ecosystem services.
1 Using an exchange rate of 1 Australian dollar = 0.75 US dollars for the period of the study (2004/2005).