1. `-- Twin Cities Household Ecosystem Project Lawrence A. Baker, Cinzia Fissore, , Sarah Hobbie, Kristen Nelson,, University of Minnesota Jennifer King and Joe McFadden UC-Santa Barbara Support: NSF Biocomplexity Projects EAR-0322065 and CHN 0709581
2. Why study households? 1. In post-industrial cities, large fractions of C, N, and P fluxes move through households 2. Household choices are flexible, especially over time 3. Understanding household fluxes could be used to develop environmental policies 4. Households are discrete, meaningful units, and easy to study
3. TCHEP Goal: “Seamless, transdisciplinary model of urban biogeochemistry that links the biophysical and social components …” Inputs Carbon - natural gas, gasoline, food, jet fuel, paper, etc. N and P - human and pet food, fertilizer, etc. Outputs Carbon - CO 2 , garbage, sewage N and P - lawn runoff, sewage, garbage 2. What demographic and behavioral factors control consumption? 1. What are the “fluxes” of C, N, and P, and how does this vary among households? 3. How are environmental behavior messages processed through social networks?
4. Turf Inputs Compartments Outputs Transportation (household vehicles, air, mass transit) Fuel (C org ), Atmospheric N 2 Emissions (CO 2 , NO x ) Household energy (heating, cooling, appliances) Humans Food C org, N org P org Exported garbage C org , N org , P org Wastewater (C org , P org , N org PO 4 3- , NH 4 + ) Respiration (CO 2 ) Atmospheric CO 2 ; fertilizer (N org , NH 4 , NO 3 ) Soil (root zone) Trees External compost (C org , N org , P org ) Pets Export to street (runoff + leaves) (C org , P org , N org PO 4 3- , NH 4 + , NO 3 - ) Paper and plastics Paper and plastics (C org , N org ) Denitrification (N 2 , N 2 O, NO 2 ) Export to vadose zone and aquifer (NO 3 - , PO 4 3- ) Carbon, nitrogen, and phosphorus movement through households (Baker et al. 2007)
5. Individual choice: Theory of Planned Behavior Azjen and Fishbein (many papers) ATTITUDES TOWARD BEHAVIOR SUBJECTIVE SOCIAL NORMS PERCEIVED BEHAVIORAL CONTROL INTENT TO BEHAVE BEHAVIOR DECISION BEHAVIORAL BELIEFS (KNOWLEDGE) NORMATIVE BELIEFS CONTROL BELIEFS How this might be used: - Identify the key motivations - Identify constraints toward changing behavior - Identify method for providing information
10. Full-scale TCHEP: Hybrid approach Mail survey ~ 80 multi-part questions 22 pages 30-40 minutes Household energy records (permission from respondents) GIS parcel data Ground-based vegetation survey (400 homes) UFORE model Lawn model Household Flux Calculator CO 2 emissions N and P fluxes
14. atm. deposition grass removal soil leaching, runoff, denitrification leaves removal fertilizers pets wood Kg N household -1 yr -1 Average landscape N fluxes INPUTS OUTPUTS ACCUMULATION
15. INPUTS OUTPUTS ACCUMULATION grass wood leaves leaf removal leaf decomposition heterotrophic respiration wood soil Kg C household -1 yr -1 Average landscape C fluxes
16. 1:1 Cumulative frequency for household vehicle travel Cum. C cum. % C Cumulative % Vehicles C emissions 25 55 50 78 75 93 100 100
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18. Broader impacts: pollution management Source reduction for urban stormwater Baker et al., Storm Water Magazine, Nov. 2007 Lawn runoff Leaf input
19. 3 or more fertilizer applications,+ mulching Steep slope, low infiltration soil The Nowak disproportionality idea applied to lawn nutrient export High nutrient export Site characteristics Site behaviors (TCHEP survey) Baker et al., 2008, Cities and the Environment