Sparing land for nature: exploring the potential impact of changes in agricultural yield on the area needed for crop production
Sparing land for nature: exploring the potential impact of changes in agricultural yield on the area needed for crop production
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DOI：
10.1111/j.1365-2486.2005.001035.x
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发表时间：
2005-10-01
影响因子：
11.6
通讯作者：
Scharlemann, JPW
中科院分区：
文献类型：
--
作者：
Balmford, A;Green, RE;Scharlemann, JPW
如何在满足快速增长的粮食需求的同时将对自然的不利影响降至最低？文献中主要提出了两种截然不同的建议：野生动物友好型农业，即农场做法尽可能对野生动物无害（以降低产量为代价）；节约土地，即增加农业产量，从而减少将土地用于农业的压力（以减少农田上野生动物数量为代价）。本文讨论的是土地节约理念的一个重要方面——相对于其他变量，未来耕地需求对产量增加的合理变化的敏感性。我们重点关注 23 种最重要的粮食作物，利用粮食及农业组织 (FAO) 和联合国人口司 (UNPD) 的数据来预测 2050 年人口规模、饮食、产量和贸易的合理值，然后依次研究它们对满足发展中国家和发达国家 23 种作物需求所需面积的影响。我们的计算表明，到 2050 年，发展中国家这些作物的种植面积将需要大幅增加（根据中期预测增加 23%），平均产量的合理变化与人口规模或人均消费的变化对种植面积的影响同样大；在可预见的来自世界其他地区的粮食净进口变化的情况下，未来农田面积的变化要小得多。相比之下，到 2050 年，发达国家的耕地面积可能会略有减少（根据这 23 种作物的中间预测，耕地面积将减少 4%），并且对人口增长、饮食、产量或贸易变化的敏感度较低。节约土地理念的其他有争议的方面需要进一步审查，但这些结果证实了其潜在意义，并表明自然资源保护主义者应该像关注人口增长和人均消费上升一样关注未来的农业产量。
How can rapidly growing food demands be met with least adverse impact on nature? Two very different sorts of suggestions predominate in the literature: wildlife-friendly farming, whereby on-farm practices are made as benign to wildlife as possible (at the potential cost of decreasing yields); and land-sparing, in which farm yields are increased and pressure to convert land for agriculture thereby reduced (at the potential cost of decreasing wildlife populations on farmland). This paper is about one important aspect of the land-sparing idea - the sensitivity of future requirements for cropland to plausible variation in yield increases, relative to other variables. Focusing on the 23 most energetically important food crops, we use data from the Food and Agriculture Organisation (FAO) and the United Nations Population Division (UNPD) to project plausible values for 2050 for population size, diet, yield, and trade, and then look at their effect on the area needed to meet demand for the 23 crops, for the developing and developed worlds in turn. Our calculations suggest that across developing countries, the area under those crops will need to increase very considerably by 2050 (by 23% under intermediate projections), and that plausible variation in average yield has as much bearing on the extent of that expansion as does variation in population size or per capita consumption; future cropland area varies far less under foreseeable variation in the net import of food from the rest of the world. By contrast, cropland area in developed countries is likely to decrease slightly by 2050 (by 4% under intermediate projections for those 23 crops), and will be less sensitive to variation in population growth, diet, yield, or trade. Other contentious aspects of the land-sparing idea require further scrutiny, but these results confirm its potential significance and suggest that conservationists should be as concerned about future agricultural yields as they are about population growth and rising per capita consumption.