Quantifying and mapping the human appropriation of net primary production in earth's terrestrial ecosystems

TLDR

Human appropriation of net primary production (HANPP) quantifies the aggregate impact of land use on yearly biomass availability, highlighting human domination of the biosphere, while land use reshapes terrestrial surfaces, altering biogeochemical cycles and ecosystem service provision. The study aims to comprehensively assess and map global HANPP, quantifying land‑use impacts on ecosystems and illustrating spatial patterns of human domination. Authors employ vegetation modeling, agricultural and forestry statistics, GIS land‑use and land‑cover data, and soil‑degradation information to generate maps of human‑induced changes in trophic energy flows across ecosystems.

Abstract

Human appropriation of net primary production (HANPP), the aggregate impact of land use on biomass available each year in ecosystems, is a prominent measure of the human domination of the biosphere. We present a comprehensive assessment of global HANPP based on vegetation modeling, agricultural and forestry statistics, and geographical information systems data on land use, land cover, and soil degradation that localizes human impact on ecosystems. We found an aggregate global HANPP value of 15.6 Pg C/yr or 23.8% of potential net primary productivity, of which 53% was contributed by harvest, 40% by land-use-induced productivity changes, and 7% by human-induced fires. This is a remarkable impact on the biosphere caused by just one species. We present maps quantifying human-induced changes in trophic energy flows in ecosystems that illustrate spatial patterns in the human domination of ecosystems, thus emphasizing land use as a pervasive factor of global importance. Land use transforms earth's terrestrial surface, resulting in changes in biogeochemical cycles and in the ability of ecosystems to deliver services critical to human well being. The results suggest that large-scale schemes to substitute biomass for fossil fuels should be viewed cautiously because massive additional pressures on ecosystems might result from increased biomass harvest.