Economic growth and land use change: implications for global biodiversity.
This study examines whether land use change and biodiversity loss conform to an environmental Kuznets curve, a relationship in which certain environmental impacts increase then decrease with economic growth. The study draws on the experience of economic structural change to show that agricultural land use may follow this pattern. Also, a reduction in agricultural land use may allow forests and parks to expand (with positive implications for biodiversity). These predictions are tested on national-level land use data from 127 countries over the period 1965-1994. In the empirical analysis, the relationships of cropland, pasture, forests, and parks to per capita income and other socioeconomic variables are estimated. Results of two systems of simultaneous equations ' demonstrate a transition in land use, characterised by rapid agricultural land conversion in the initial stage of development, followed by a gradual reversion to forests (and an expansion of parks). Turning points in the Kuznets curve for agricultural land use, and in the inverse Kuznets curve for forests and parks, appear between $1000 and $1500 in per capita income. The pattern varies by geographic region, however, as shown in an analysis of ten regional groups of countries. The econometric analysis also produced insights into the impact of population density, agricultural yield, land ownership security, and trade. The general picture to emerge from these results is that economic development, and particularly improvement in agricultural productivity, are associated with a reduction in agricultural land use and an expansion of forests. Sixty-six countries in the sample have not reached the turning point in the land use transition, and thirty-six have past it. An appendix chapter contains a separate empirical analysis of the relationship between species extinction rates (a proxy for biodiversity) and economic growth. Drawing on biogeographic models of extinction that attribute species loss to habitat conversion, and the finding of a Kuznets curve for agricultural land use, the analysis tests the prediction that species extinction rates will rise and fall in the course of economic development. The empirical analysis focuses on the developed countries where records are best, and finds that extinction rates peak at a per capita income of around $3500 before declining. This indicates that the pattern of species extinction is consistent with the Kuznets curve for land use, though with a lag effect.
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