Upload
bridget-montgomery
View
218
Download
0
Tags:
Embed Size (px)
Citation preview
Large scale irrigation schemes and ecosystem services
Associate Professor Jamie Pittock,
Fenner School of Environment & Society
The Australian National University [email protected]
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
2
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.”
3
Source: WWF Living Planet Report 2004
Bo
ttle
Be
nd
, N
SW
, 2
00
9 (
c) J
Pitt
ock
‘Rebalancing’ between provisioning, regulating and cultural ecosystem services in agricultural and natural ecosystems
4
(Gordon et al. 2010)
5
Intensity of use and ecosystem services
Irrigation options?Irrigation options?A. Extensification / land sharingA. Extensification / land sharing
IRR
IGA
TIO
NEXT.EXT.
Irrigation options?Irrigation options?B. Intensification / land sparingB. Intensification / land sparing
RREESSOOUUCCEESS
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)
8
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
10
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?
11
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