Medical Health Articles

Human Land Use Restricts Ecological Services

In-depth studies of how human land use is having an ever greater impact on ecosystems over a period of three centuries are being carried out for the first time. This project, funded by the Austrian Science Fund FWF, investigates on a global level how the transition from an agrarian to an industrial society has affected ecosystems. Knowledge about past processes will be used to model and assess possible consequences of growing biomass demand and land use for global sustainability.

The enormous demand for land for human use is leaving our planet’secosystems with less and less room to survive. Through their land use,humans today are already consuming over 20 percent of the Earth’s naturalbiomass production, thereby robbing ecosystems of their most importantenergy source.

The intensity of land use is heavily dependent on population density, asresearchers from the Institute of Social Ecology at the University ofKlagenfurt have already identified in a previous project. Yet other factorscomplicate the picture, as shown by the example of industrialised countries.While a richer diet with a high share of meat in these countries is drivingthe extension of land use, technological progress is a counteracting forceand reduces the spatial imprint. The researchers are now looking to resolvethis conundrum in a follow-up project. Studying temporal dynamics will helpthem to determine both the socio-economic and natural factors that lead tohuman dominance over ecosystems and to identify potential consequences ofthis dominance.

HUMAN LAND DOMINANCE

The intensity of human land use and its impact on the biosphere can bedetermined using the HANPP indicator. This measures human appropriation ofnet primary production. Net primary production is the biomass that primaryproducers, mainly plants, produce after deduction of their own cellrespiration and which is therefore available as energy input for ecosystemseach year. As project leader Prof. Haberl explains: “In order to determinethe factors for human land dominance, we create a global HANPP timeline thatextends from the 18th to the 20th centuries. This database will not onlyallow us to analyse how the transition from an agrarian to an industrialsociety has impacted on ecosystems - i.e. what proportion of the net primaryproduction of natural ecosystems has been lost through human activity. Wewill also be able to examine which changes in natural and socio-economicsystems have resulted in changes to HANPP. At a socio-economic level, forexample, the key parameters include rising prosperity and agriculturaltechnology. But natural limitations such as soil properties or the climateare also included in the analysis.”

RESTRICTED SERVICE

Beyond creating an understanding of major factors that cause changes inHANPP, an assessment of the possible consequences for global sustainabilityis a major goal of the project. For the first time, this project establishesa link between the production of biomaterials and the services provided bynature, as project team member Dr. Karlheinz Erb explains: “We support thehypothesis that intensive human land use changes ecosystems’ productivityand their resilience and that it restricts their ability to provide otherecosystem services. It is therefore debatable whether, under changingconditions, ecosystems are still able to absorb waste and emissions to theextent they have in the past.” The researchers also address changes in theavailability of biomass, in global water, carbon and nitrogen flows, and inthe volume of carbon that plants store worldwide as long-term consequencesand are testing the hypothesis that HANPP is a relevant factor for loss inbiodiversity.

This FWF project shows how important it is to consider humans’ landdominance, an area that has until now been little researched, in the contextof sustainable development strategies. The researchers are urging inparticular that the already high pressure on ecosystems reflected in thecurrent HANPP value should not be intensified by over-ambitious plans forreplacing fossil energy with biomass energy.

Image and text will be available online from Monday, 21st July 2008, 09.00a.m. CET onwards: here

Scientific Contact:
Prof. Helmut Haberl
University of Klagenfurt
Institute of Social Ecology
Schottenfeldgasse 29
1070 Wien
Austria
http://www.uni-klu.ac.at

Source:
Austrian Science Fund FWF:
Mag. Stefan Bernhardt
Haus der Forschung
Sensengasse 1
1090 Wien
Austria
http://www.fwf.ac.at

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