Ecological Archives A022-040-A2

Geneviève S. Metson, Rebecca L. Hale, David M. Iwaniec, Elizabeth M. Cook, Jessica R. Corman, Christopher S. Galletti, and Daniel L. Childers. 2012. Phosphorus in Phoenix: a budget and spatial representation of phosphorus in an urban ecosystem. Eological Applications 22:705–721.

Appendix B (TABLE B1). Calculations, assumptions, and data sources used to spatially represent the phosphorus budget of Phoenix, Arizona, USA.

Category Area Unit Spatial Layer Source Generic calc for P Assumptions and Notes P stock (Gg/m²)
Mesic soil 47018 90m Pixels Mesic Residential class from 2005 Land Cover data  Buyantuyev (2007) Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
Mesic soil and vegetation were calculated from the mesic residential land cover in the 2005 CAP-LTER land cover dataset. Assumed equal distribution by dividing across land class area (in pixels) 2.10059 × 10-9
Mesic vegetation 47018 90m Pixels Mesic Residential class from 2005 Land Cover data  Buyantuyev (2007) Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
Mesic soil and vegetation were calculated from the mesic residential land cover in the 2005 CAP-LTER land cover dataset.  Assumed equal distribution by dividing across land class area (in pixels) 1.20784 × 10-9
Xeric soil 95386 90m Pixels Xeric Residential class from 2005 Land Cover data  Buyantuyev (2007) Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
Xeric soil and vegetation was based on the Xeric residential land cover class.  Assumed equal distribution by dividing across land class area (in pixels) 5.04772 × 10-9
Xeric vegetation 95386 90m Pixels Xeric Residential class from 2005 Land Cover data  Buyantuyev (2007) Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
Xeric soil and vegetation was based on the Xeric residential land cover class.  Assumed equal distribution by dividing across land class area (in pixels) 2.53680 × 10-9
Desert soil 3607694 90m Pixels Compacted soil land cover clas from 2005 Land Cover data; Desert land use from 2000 land Use data Buyantuyev (2007); Redman et al. (2005) Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
The desert land use class and compacted soil land cover class was used to create the spatial component for desert soil.  Assumed equal distribution by dividing across land class area (in pixels) 3.03387 × 10-9
Desert vegetation 88109 90m Pixels Vegetation land cover class from 2005 Land Cover data; Desert land use from 2000 Land Use data Buyantuyev (2007); Redman et al. (2005) Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
Desert vegetation was calculated from the desert land use class and vegetation land cover class.  Assumed equal distribution by dividing across land class area (in pixels) 5.85694 × 10-9
Agriculture vegetation (stock) 884 90m Pixels Only dairy from CAP-LTER study area USDA 2010 NASS Agricultural data Stock = P(stock)/pixel#,
No input or output
Assumed equal distribution by dividing across land class area (in pixels) of crops with woddy materials (tree (e.g., organges) and shrub crops(e.g., olives)) 9.77599 × 10-9
Urban non-residential vegetation 94879 90m Pixels Vegetation land cover class from2005 Land Cover data; Urban land use from 2000 Land use data Buyantuyev (2007); Redman et al. (2005) Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
Urban non-residential soil was based on the intersection of urban land use data and the vegetation land cover class.   Assumed equal distribution by dividing across land class area (in pixels) 1.82168 × 10-10
Urban soil 94879 90m Pixels Undisturbed and Compacted soil land cover class from 2005 Land Cover data; urban land use from 2000 land Use data Buyantuyev (2007); Redman et al. (2005) Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
Urban non-residential soil was based on the intersection of urban land use data and the vegetation land cover class.  Assumed equal distribution by dividing across land class area (in pixels) 5.20481 × 10-10
Agricultural soil 86095 90m Pixels Cultivated vegetation land cover class and Compacted soil (Prior Ag use) land cover class from 2005 Land Cover data 2005 Land Cover data (Buyantuyev 2007) Stock = P(stock)/pixel#,
No input or output
The agricultural soil was derived from the CAP-LTER land cover map by combining the cultivated vegetation class and the compacted soil (prior agriculture) class.  Assumed equal distribution by dividing across land class area (in pixels) 5.59244 × 10-9
People 788771 90m Pixels Area of CAP-LTER - Not uniformaly distributed, based on population per tract per pixel 2000 Census Tract data for Arizona Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
For humans, The phosphorus stock, output, and input numbers were first calculated on a per capita basis and then divided across the number of 90 m² pixels for each census tract in the study area. variable
Pets 788771 90m Pixels Area of CAP-LTER - Not uniformaly distributed, based on population per tract per pixel 2000 Census Tract data for Arizona Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
For pets, the P stock, output, and input was calculated on a per household basis and then divided similarly across 90 m pixels for each census tract area. variable
Atmosphere, gasoline emissions and natural deposition 788771 90m Pixels The entire CAP-LTER study area CAP-LTER study boundary Input = P(input)/pixel#,
no stock or output
Assumed equal distribution by dividing across land class area (in pixels) No stock
Dairy 8405 90m Pixels Only dairy from CAP-LTER study area Geocoded dairy farm data for Maricopa County Stock = P(stock)/pixel#,
Input = P(input)/pixel#,
Output = P(output)/pixel#
Dairy was derived from geocoding publicly available dairy farms and assuming an equal number of cows (2079) and an equal amount of pixels per farm.  Assumed equal distribution by dividing across land class area (in pixels) 2.79081 × 10-8
Agriculture vegetation 55078 90m Pixels Only agriculture from CAP-LTER study area USDA 2010 NASS Agricultural data Input = P(input)/pixel#,
Output = P(output)/pixel#,
no stock
Agriculture input and output was calculated from the those pixels that are identified to be cultivated within the CAP-LTER study area 9.77599 × 10-9
Asphalt 36822 90m Pixels Disturbed (asphalt) land cover class from 2005 Land Cover data  Buyantuyev (2007) Stock = P(stock)/pixel#,
No input or output
The asphalt land class was based on the disturbed (asphalt) land cover class.  Assumed equal distribution by dividing across land class area (in pixels) 2.43230 × 10-8
Stock         Stock = Impervious + Desert Vegetation + Mesic Vegetation + Xeric Vegetation + Urban Non-residential Soil + Agricultural Trees + Urban Non-residential Soil + Desert Soil + Mesic Soil + Xeric Soil + Agricultural Soil + Dairy + People + Pets Calculated by adding all rasters listed using the 'Plus' function in ArcGIS 9.3.  Smoothed using a 5 cell (pixel) mean focal statistics function in ArcGIS  
Input         Input = Desert Vegetation + Mesic Vegetation + Xeric Vegetation + Urban Non-residential Veg + Agricultural Trees + Dairy + People + Pets + Atmosphere + Agriculture Calculated by adding all rasters listed using the 'Plus' function in ArcGIS 9.3.   
Output         Output = Desert Vegetation + Mesic Vegetation + Xeric Vegetation + Urban Non-residential Veg + Agricultural Trees + Dairy + People + Pets + Agriculture Calculated by adding all rasters listed using the 'Plus' function in ArcGIS 9.3.   
Throughput         Input + Output Calculated by adding the input raster and output raster with the ArcGIS 9.3 'Plus' function.  Smoothed with a 5 cell radial filter in focal statistics (mean)  
Accumulation         Input - Output Calculated by subtracting the output from the input raster with the ArcGIS 9.3 'Plus' function.  Smoothed with a 5 cell radial filter in focal statistics (mean)  

Literature Cited

Buyantuyev, A. 2007. Land cover classification using enhanced Landsat Enhanced Mapper (ETM) data-2005. CAP LTER database

Redman, C., Hutchins, J., & Kunda, R. 2005. Landuse classification 2000. Land-use and land-cover change. Available via CAP LTER URL: http://caplter.asu.edu/home/products/datasetByIpa.jsp.

U.S. Census Bureau. 2000. 2000 Census Tracts for Arizona. Retrieved December 2010, from: http://caplter.asu.edu/data/.

United States Department of Agriculture and National Agricultural Statistics Service (USDA-NASS). 2010. 2010 Crop Layer Data Western States. Retrieved from: http://www.nass.usda.gov/research/Cropland/SARS1a.htm


[Back to A022-040]