Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Characterizing global livestock production systems with the HANPP framework

Auteur : Krulis, Anna-Maria

Université de soutenance : Alpen-Adria-Universität Klagenfurt

Grade : Magistra der Naturwissenschaften (Mag. rer. nat) 2015

Résumé partiel
Global ruminant farming is connected to severe terrestrial colonization processes. Human society alters the Earth’s surface to achieve favourable agro-ecological conditions and thereby also intervenes with global biochemical cycles. In this study the concept of Human Appropriation of Net Primary Production (HANPP), a socio-ecological indicator, is used to assess the land use intensity associated with global ruminant farming. This methodological framework enables to characterize Global Livestock Production Systems (GLPS) by accounting for both biomass harvested to farm ruminants, and also productivity changes resulting from land conversion processes. Grazing land provides biomass, which mostly gets directly grazed by ruminants. Feeds grown on cropland experience increased significance as the intensification of animal production progresses. By combining spatial-explicit datasets on global terrestrial aboveground productivity, land use and feed demand estimates, this study develops profiles of land use intensity connected to different global ruminant production systems. This allows to draw conclusions about the pressure ruminant farming inflicts upon nature. In the year 2000 global ruminant production systems are responsible for aHANPP flows of 4,5 Pg C/yr. This corresponds to 27% of aNPPpot on areas used for forage and food production. A large amount of 2,9 Pg C/yr is associated with land used as grazing area. 2,4 Pg C/yr or 85% are directly grazed by ruminants and an additional 15% of aHANPP on grazing areas is caused by productivity changes due to land conversion processes. Ruminant farming activities on cropland areas result in aHANPP flows of 1,6 Pg C/yr, whereat 97% occur due to biomass harvest and 3% result as aHANPPluc. aHANPP of traded cropland feeds plays a marginal role and amounts to 0,08 Pg C/yr, which corresponds to only 5% of total cropland aHANPP. Productivity changes due to land conversion processes and yields on grazing land as well as cropland, ruminant diets and feed use efficiency are identified as most important factors influencing aHANPP flows

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