A model of shifting cultivation: can soil conservation reduce deforestation?
A model of shifting cultivation: can soil conservation reduce deforestation?
复制标题
轮耕模式：土壤保持可以减少森林砍伐吗？
DOI：
10.1111/j.1574-0862.2006.00152.x
复制
发表时间：
2006
影响因子：
4.1
通讯作者：
Yoshito Takasaki
中科院分区：
文献类型：
--
作者：
Yoshito Takasaki
轮作耕者不仅通过调整已经清理的土地上的土壤使用来管理土壤，比如在连续耕作中，而且还通过开垦森林来获得新的肥沃土壤。这项研究通过将森林砍伐模拟为私人农民对土壤的投资，考察了农场土壤保持和轮作耕作中森林砍伐之间的关键联系。更广泛地说，通过这样做，这项研究试图将文献中单独开发的森林砍伐和土壤保持模型结合起来。我们的政策目标是遏制热带森林砍伐--作为对全球公地的破坏--在轮作过程中因土地退化而造成的破坏，同时改善贫穷轮作的耕种者的福祉。我们的综合办法使我们能够对毁林和土地退化问题进行联合政策分析。我们考虑了三项增进福利的政策。首先是影响农业和非农收入机会的农业和非农业补贴。第二个是影响贴现率的财政和保有期政策。我们的问题是，森林砍伐和土壤肥力之间的联系是否会改变文献中常见的这两种标准宏观经济政策的结果。第三项政策(或计划)是影响已清理土地上土壤再生和侵蚀力的各种土壤保持措施。这篇文章考察了一个非常重要的问题，这个问题在以前的理论工作中很少受到关注：土壤保持能减少森林砍伐吗？这项研究证实了促进非农业活动的反砍伐森林的效果--这是在以前的研究中经常强调的一个发现--在轮作中。更重要的是，它还表明，改进各种土壤保持措施不仅阻碍轮作耕种者砍伐森林，而且往往对森林保护产生比促进非农业活动更大的影响。相反，农业价格补贴或技术进步会产生相反的结果，降低农民的贴现率或改善保有权保障会鼓励他们砍伐更多的森林，只是为了积累土壤。版权所有，2006年国际农业经济学家协会。
Shifting cultivators manage soil not only by adjusting soil use on already-cleared lands, as in continuous cultivation, but also by clearing forests to obtain new fertile soils. This study examines the crucial link between on-farm soil conservation and deforestation in shifting cultivation by modeling forest clearing as an investment in soil for a private farmer. More generally, by doing so the study attempts to integrate deforestation and soil conservation models which have been separately developed in the literature. Our policy goal is to arrest tropical deforestation-as destruction of global commons-caused by land degradation in shifting cultivation while improving the well-being of poor shifting cultivators. Our integrated approach enables joint policy analyses of deforestation and land degradation. Three welfare-enhancing policies are considered. The first is agricultural and nonagricultural subsidies affecting farm and nonfarm income opportunities. The second is fiscal and tenure policies affecting discount rates. Our question is whether the link between forest clearing and soil fertility alters the outcomes of these two standard macroeconomic policies commonly found in the literature. The third policy (or program) is various soil conservation measures affecting soil regeneration and erosivity on already-cleared lands. This article examines a very important question which has received little attention in previous theoretical works: can soil conservation reduce deforestation? This study confirms anti-deforestation effects of the promotion of nonfarming activities-a common and often emphasized finding in previous works-among shifting cultivators. More importantly, it also demonstrates that improving various soil conservation measures not only discourages forest clearing among shifting cultivators but also tends to have greater effects on forest protection than promoting nonfarming activities. Contrarily, agricultural price subsidy or technological progress gives rise to the opposite outcome, and lowering the farmer's discount rate or improving tenure security encourages him/her to clear more forests just to accumulate soil. Copyright 2006 International Association of Agricultural Economists.