Assessing the cross-scale impact of 50 years of agricultural transformation in Argentina

Given the increasing number of actors related to farming that make decisions at different scales (plot, farm, region, etc.), knowledge about patterns and processes that behave hierarchically is increasingly needed. This is necessary in countries like Argentina, where cultivation expanded at increasing pace during the last 50 years over an area of 1.47 million km2. Relying on different sources of existing data, the purpose of this work was to assess the cross-scale dependence of patterns and processes related to the expansion of cultivation in Argentina. The study involved indicators of (i) carbon, nitrogen and phosphorous stocks, (ii) energy productivity, fossil energy consumption, C, N and P balances, water consumption and greenhouse gases fluxes, and (iii) impacts related to pesticide contamination, habitat intervention and soil erosion. Three scales involving (i) regions, (ii) macro-regions and (iii) the whole country were analyzed. Principal Components, Correlation and Regression Analysis were used to identify and quantify meaningful relationships between the different scales. The expansion of annual crops affected C–N–P stocks significantly at the regional scale, whereas it influenced energy and matter flows, and contamination across all scales. This finding explains conflictive responses to land use and management when different scales are considered and shows that scale dependency needs to be considered when their effects on the environment are explored and quantified.

► A scale-dependence approach is key to explain functional variations across scales.
► Relations between cultivation and fluxes in agroecosystems weaken at increasingly larger scales.
► Decision makers must learn about the scales at which pattern and processes are relevant.