Brown Calum, Murray-Rust Dave, van Vliet Jasper, Alam Shah Jamal, Verburg Peter H, Rounsevell Mark D
School of GeoSciences, University of Edinburgh, Edinburgh, EH8 9XP, United Kingdom.
Institute for Environmental Studies, VU University Amsterdam, Amsterdam, The Netherlands.
PLoS One. 2014 Dec 1;9(12):e114213. doi: 10.1371/journal.pone.0114213. eCollection 2014.
The globalisation of trade affects land use, food production and environments around the world. In principle, globalisation can maximise productivity and efficiency if competition prompts specialisation on the basis of productive capacity. In reality, however, such specialisation is often constrained by practical or political barriers, including those intended to ensure national or regional food security. These are likely to produce globally sub-optimal distributions of land uses. Both outcomes are subject to the responses of individual land managers to economic and environmental stimuli, and these responses are known to be variable and often (economically) irrational. We investigate the consequences of stylised food security policies and globalisation of agricultural markets on land use patterns under a variety of modelled forms of land manager behaviour, including variation in production levels, tenacity, land use intensity and multi-functionality. We find that a system entirely dedicated to regional food security is inferior to an entirely globalised system in terms of overall production levels, but that several forms of behaviour limit the difference between the two, and that variations in land use intensity and functionality can substantially increase the provision of food and other ecosystem services in both cases. We also find emergent behaviour that results in the abandonment of productive land, the slowing of rates of land use change and the fragmentation or, conversely, concentration of land uses following changes in demand levels.
贸易全球化影响着世界各地的土地利用、粮食生产和环境。原则上，如果竞争促使基于生产能力进行专业化，全球化可以使生产力和效率最大化。然而，在现实中，这种专业化往往受到实际或政治障碍的限制，包括那些旨在确保国家或地区粮食安全的障碍。这些障碍可能导致全球土地利用分布次优。这两种结果都取决于个体土地管理者对经济和环境刺激的反应，而且已知这些反应是可变的，并且往往（在经济上）是非理性的。我们研究了在各种模拟的土地管理者行为形式下，程式化的粮食安全政策和农业市场全球化对土地利用模式的影响，包括生产水平、韧性、土地利用强度和多功能性的变化。我们发现，就总体生产水平而言，一个完全致力于区域粮食安全的系统不如一个完全全球化的系统，但几种行为形式缩小了两者之间的差距，而且在这两种情况下，土地利用强度和功能的变化都可以大幅增加粮食和其他生态系统服务的供给。我们还发现了一些新出现的行为，这些行为导致生产性土地被弃用、土地利用变化速度放缓，以及需求水平变化后土地利用的碎片化或相反的集中化。
