Exploring the economic, social and environmental prospects for commercial natural annual grasslands by performing a sensitivity analysis on a multidisciplinary integrated model

This paper presents an integrated modelling assessment that estimated the sensitivities of five endogenous factors in commercial rangelands, i.e. number of active farmers, profits, stocking rate, standing herbage biomass, and soil erosion, to the same percentage variation in 70 factors, including economic and climate drivers. The assessment utilised a system dynamics model (107 equations) which represents an area of extensive private farms, its farmers, the main local markets on which they trade, and key ecosystem services involved. The assessment procedure consisted in analysing the behaviours of 288,000 variants of this system during 300 years, each under a different economic and climate scenario. Our key findings were as follows: 1) It is likely that at least annual grasslands will suffer environmental degradation in the future, and that such degradation will be primarily caused by climate change, not by the increasing demand for livestock products; 2) Private farming systems provide social and economic security to farmers against the effects of climate change, especially in a scenario of rising prices of animal products. However, this research will remain incomplete until its methods and results can be contrasted with other similar assessments.