LB 26-226 - Product-specific human appropriation of net primary production (HANPP) among US counties and its end uses

Human appropriation of net primary production (HANPP) has been developed in the 21st century as an ecological indicator that may supersede ecological footprint due to its spatial specificity, precise measurement of land use intensity, and potential to be tied to trade in biomass-based products, thus enabling a consumption-based analysis. Fusing publicly available data sources, this poster presents a product-specific, county-level analysis of HANPP harvested from crops, timber and grazing in the conterminous United States in the years 1997, 2002, 2007 and 2012, the most recent dates for which all necessary data are available. Total HANPP(harvest) was 716-834 megatonnes (MT), including 514-615 MT from crops, 105-148 MT from timber and 64-76 MT grazed. Of this total, 432-512 MT, 60-66 percent, was a harvested commodity while the remainder was straw and forest slash; 83-84 percent was above-ground HANPP. Mean HANPP density varied from 92-107 gCm-2yr-1 in the years studied. With net primary production (NPP) varying from 558-610 gCm-2yr-1, this is 15-17 percent of NPP; NPP(ecological) thus varied from 466-577 gCm-2yr-1, 83-85 percent of NPP. Among states, HANPP density varies from 7 gCm-2yr-1 in Nevada to 391 gCm-2yr-1 in Iowa and from 2% of NPP in Massachusetts to 53% in Iowa. Disaggregated analysis for 3101 counties shows even greater variation, from < 1 to 726 gCm-2yr-1 and delineates regions carrying similar HANPP signatures. Livestock feed commanded the largest proportion of HANPP but decreased from 395 (50%) to 305 MT (42%) of all HANPP and 320 to 240 MT (58–44%) of crop-based HANPP. The proportion allocated to exports was stable at 118–141 MT (17–18%) of total HANPP and 112–133 MT (21–23%) of crop-based HANPP. Biofiber decreased from 141 MT (18%) to 97 MT (13%) of all HANPP. Biofuel increased strongly from 11 MT to 98 MT, from 1% to 14% of all HANPP and 2% to 18% of crop-based HANPP, surpassing food and biofiber by 2012. Direct food commanded 89–105 MT, the lowest proportion at 12–13% of all HANPP, and 17–18% of crop-based HANPP. The highly fertile Midwest and the drought-prone Intermountain West stand out as regions where a very small percentage of biomass is allocated to direct human food.