02774nas a2200229   4500008004100000022001400041245006200055210006100117260028800178300001600466490000700482520184200489653001602331653001702347653001702364653001502381100002202396700003002418700002102448700002002469856005502489       2009                        eng d  a1365-248600aDo increases in agricultural yield spare land for nature?0 aDo increases in agricultural yield spare land for nature  aInstitute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK; Conservation Science Group, Department of Zoology, University of Cambridge, Downing St, Cambridge CB2 3EJ, UK; Smithsonian Tropical Research Institute, Apartado 0843-03bBlackwell PublishingcJuly  a1716–17260 v153 aFeeding a rapidly expanding human population will require a large increase in the supply of agricultural products during the coming decades. This may lead to the transformation of many landscapes from natural vegetation cover to agricultural land use, unless increases in crop yields reduce the need for new farmland. Here, we assess the evidence that past increases in agricultural yield have spared land for wild nature. We investigated the relationship between the change in the combined energy yield of the 23 most energetically important food crops over the period 197920131999 and the change in per capita cropland area for 124 countries over the same period. Per capita area of the 23 staple crops tended to decrease in developing countries where large yield increases occurred. However, this was counteracted by a tendency for the area used to grow crops other than staples to increase in the countries where staple crop yields increased. There remained a weak tendency in developing countries for the per capita area of all cropland to decline as staple crop yield increased, a pattern that was most evident in developing countries with the highest per capita food supplies. In developed countries, there was no evidence that higher staple crop yields were associated with decreases in per capita cropland area. This may be because high agricultural subsidies in developed countries override any land-sparing pattern that might otherwise occur. Declines in the area of natural forest were smaller in countries where the yield of staple crops increased most, when the negative effects of human population increases on forest area were controlled for. Our results show that land-sparing is a weak process that occurs under a limited set of circumstances, but that it can have positive outcomes for the conservation of wild nature.10aagriculture10abiodiversity10aconservation10awilderness1 aEwers, Robert, M.1 aScharlemann, Jörn, P. W.1 aBalmford, Andrew1 aGreen, Rhys, E.  uhttp://dx.doi.org/10.1111/j.1365-2486.2009.01849.x