People in Ecosystems/Watershed
Integration (PEWI):
A dynamic land-use and ecosystem
service tradeoffs assessment tool
Why PEWI?
• How agriculture can produce outcomes that
society desires
• How we can learn
– Complex social-ecological relationships
– Ecosystem service tradeoffs
• How we can facilitate urban-rural dialogue
An analogy
• The analogy of a sandbox is a
great way to think about PEWI
• Why a sandbox?
Friends and a sandbox
The right tools and a design
The finished product…until
Create something new
What if there were a virtual “sandbox” to explore humans,
land use, and ecosystem service in a watershed?
PEWI is that sandbox
• Fun, simple, and accurate
• Explore land uses and ecosystem services
without technical expertise or the costs of
experimenting in the real world
Introduce PEWI
• Models how changes in land use and management result
in tradeoffs in the levels of ecosystem services outcomes
in a fictional Iowa agricultural watershed
Introduce PEWI
• Models how changes in land use and management result
in tradeoffs in the levels of ecosystem services outcomes
in a fictional Iowa agricultural watershed
4 concepts:
1. Land use and management
2. Watershed
3. Tradeoffs
4. Ecosystem Services
1. Land uses and management
2. What is a watershed?
When water hits land, runoff drains to a
stream, lake, or larger waterway.
A watershed is the area of land where all of
the water that is under it or drains off of it
goes into the same place.
3. What are ecosystem services?
Ecosystem services are “the benefits people
obtain from ecosystems. These 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”
(UNEP, Millennium Assessment Reports).
Ecosystem services are “the conditions and
processes through which natural ecosystems,
and the species that make them up, sustain
and fulfil human life” (Daily, 1997).
Provisioning Services
Food
Fresh Water
Fuel Wood
Fiber
Biochemicals
Genetic Resources
Regulating
Services
Cultural
Services
Climate regulation
Disease regulation
Water regulation
Water purification
Pollination
Spiritual & religious
Recreation
Ecotourism
Aesthetic
Inspirational
Educational
Sense of place
Cultural heritage
Supporting Services
Biodiversity & Ecosystem Functions
Nutrient Cycling | Evolution | Soil Formation | Spatial Structure | Primary Production
Modified, with additions, from the Millennium Assessment
4. Tradeoffs among ecosystem services
Adapted from Foley et al. (2005).
Photos from Iowa DNR (left), USDA NRCS (middle), and Sarah Hirsh (right)
www.nrem.iastate.edu/pewi
PEWI land uses
PEWI physical feature maps
Behind the scenes
• 7 modules in PE/WI  16 ES indicators
– Biodiversity
– Game Wildlife
– Carbon Sequestration
– Nitrate
– Phosphorus
– Erosion & Sedimentation
– Yield
PEWI results
PEWI results
User designs
Compare two designs
Check PEWI out online
• PEWI Companion Website
– http://www.nrem.iastate.edu/pewi
• PEWI App
– http://www.nrem.iastate.edu/pewi/app
• Iowa State University Project Leaders
– Prof. Lisa Schulte Moore lschulte@iastate.edu
– Prof. John Tyndall jtyndall@iastate.edu
– Carrie Chennault carriemc@iastate.edu