Large scale irrigation schemes and ecosystem services

Associate Professor Jamie Pittock,

Fenner School of Environment & Society

The Australian National University jamie.pittock@anu.edu.au

Ecosystem services categories:• Provisioning: products obtained from ecosystems,

including food, fresh water, and fuel.• Regulating: benefits derived from the regulation of

ecosystem processes, such as erosion control, storm protection, climate and water regulation.

• Cultural: non-material benefits obtained from ecosystems, including heritage, recreation and tourism.

• Supporting: services that are necessary for the production of all the other services, such as soil formation and retention, nutrient and water cycling.

Key points: the ecosystem services concept provides an analytic framework and a more common currency

Source: MEA 2003

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Millennium Ecosystem Assessment (2005):

• “Freshwater ecosystems tend to have the highest proportion of species threatened with extinction.”

• “The use of two ecosystem services - capture fisheries and freshwater - is now well beyond levels that can be sustained even at current demands, much less future ones.”

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Source: WWF Living Planet Report 2004

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‘Rebalancing’ between provisioning, regulating and cultural ecosystem services in agricultural and natural ecosystems

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(Gordon et al. 2010)

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Intensity of use and ecosystem services

Irrigation options?Irrigation options?A. Extensification / land sharingA. Extensification / land sharing

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Irrigation options?Irrigation options?B. Intensification / land sparingB. Intensification / land sparing

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Irrigation schemes as ecosystemsAustralian review for the National Water Commission:

1.Irrigation systems sustain a range of aquatic and semi-aquatic ecosystems.

2.Water-dependent ecosystems linked to irrigation have distinctive habitats.

3.Entrained wetlands may have important values that should be protected.

4.Threatened and listed species occur in irrigation areas.

5.Hydrological effects are complex and extensive.

6.The ecological benefits from water efficiency improvements should be realised.

7.Environmental values should be broad not narrow.

8.Investment in regional biodiversity and management is needed.

(Source: Beavis et al. 2010)

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But … a heretic’s view?1. All interventions have risks, costs and benefits

2. Too much emphasis on land, too little on freshwater ecosystems

3. Intensification is preferable to extensification

4. The non-crop biodiversity associated with irrigation systems are mainly pioneer species of lower conservation value

5. The balance of ecosystem services is a value judgment

6. Trade-offs should be decided transparently

Ecosystem services and revitalization of existing irrigation schemes?1. Environmental flows:

– Cap extraction based on thresholds of change– Use aquifer and off-river storages– Improve water quality and soil conservation

2. Restore connectivity:– Remove or modify instream barriers– Restore floodplain flows– Screen fish out of intakes

3. Land sparing

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Key questions?

• Revitalising existing LSIS by reducing harm (e.g. water pollution) or promoting additional services (e.g. fish)?

• Alternatively, better design of new LSIS?

• Extensification or intensification?

• Better, more transparent information for decisions on tradeoffs between ecosystem services?

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Some references:Beavis SG, Roberts J, Ellis DJ (2010) Water-dependent ecosystems: the consequences of irrigation infrastructure refurbishment. Waterlines report 33. National Water Commission, Canberra

Godfray H.C.J., Garnett T. (2014) Food security and sustainable intensification. Phil Trans R Soc B 369:20120273. doi:http://dx.doi.org/10.1098/rstb.2012.0273

Gordon LJ, Finlayson CM, Falkenmark M (2010) Managing water in agriculture for food production and other ecosystem services. Agricultural Water Management 97 (4):512-519

MEA (2005) (Millennium Ecosystem Assessment), Ecosystems and human well-being: wetlands and water synthesis. World Resources Institute, Washington DC

Pittock J, Hussey K, Dovers S (eds) (2015) Climate, energy and water. Cambridge University Press, Cambridge

WLE (undated) Groundwater and ecosystem services. A framework for managing smallholder groundwater-dependant agrarian socio-ecologies - applying an ecosystem service and resilience approach. CGIAR Research Program on Water, Land and Ecosystems, Colombo