Janzen D H
Science. 1973 Dec 21;182(4118):1212-9. doi: 10.1126/science.182.4118.1212.
I have listed some of the ways in which the lowland tropics are not such a warm and wonderful place for the farmer, some of the reasons why it may be unreasonable to expect him to cope with the problems, and some of the ways in which the temperate zones make his task more difficult. The tropics are very close to being a tragedy of the commons on a global scale (69, 103), and it is the temperate zone's shepherds and sheep who are among the greatest offenders (31). Given that the temperate zones have some limited amount of resources with which they are willing to repay the tropics, how can these resources best be spent? The first answer, without doubt, is education, and the incorporation of what is already known about the tropics into that education. Second should be the generation of secure psychological and physical resources for governments that show they are enthusiastic about the development of an SYTA. Third should be support of intensive research needed to generate the set of site-specific rules for specific, clearly identified SYTA's. The subject matter of youths' cultural programming is presumably determined by what they will need during the rest of their lives. A major component of this programming should be the teaching of the socioeconomic rules of a sustained-yield, nonexpanding economy, tuned to the concept of living within the carrying capacity of the country's or region's resources. Incorporating such a process into tropical school systems will cause a major upheaval, if for no other reason than that it will involve an evaluation of the country's resources, what standard of living is to be accepted by those living on them, and who is presently harvesting them. Of even greater impact, it will have to evaluate resources in terms of their ability to raise the standard of living by Y amount for X proportion of the people in the region, rather than in terms of their cash value on the world market. For such a change to be technologically successful, it will require a great deal of pantropical information exchange. This information exchange will cost a great deal of resource, not only in travel funds and support of on-site study, but in insurance policies for the countries that are willing to take the risk of trying to change from an exploitative agroecosystem to an SYTA. For such an experiment to be sociologically successful, it will require a complete change in tropical educational systems, from emphasizing descriptions of events as they now stand, to emphasizing analysis of why things happen the way they do. This will also be very expensive, not only in retreading the technology and mind-sets of current teaching programs, but in gathering the facts on why the tropics have met their current fate. There is a surfeit of biological and agricultural reports dealing with ecological experiments and generalities which suggest that such and such will be the outcome if such and such form of resource harvest is attempted. It is clear that human desiderata regarding a particular site are often radically different from the needs of the "average" wild animals and plants that formed the basis for such experiments and generalities. A finely tuned SYTA will come close to providing a unique solution for each region. The generalities that will rule it are highly stochastic. The more tropical the region, the more evenly weighted the suboutcomes will be, and thus the more likely each region will be to have a unique overall outcome. For example, it is easy to imagine four different parts of the tropics, each with the same kind of soil and the same climate, with four different, successful SYTA's, one based on paddy rice, one on shelterwood forestry, one on tourism, and one on shifting maize culture. A regional experiment station working holistically toward an SYTA is potentially one of the best solutions available. As currently structured, however, almost all tropical experiment stations are inadequate for such a mission. Most commonly they are structured around a single export crop such as coffee, sugar, rubber, cotton, cacao, or tea. A major portion of their budgets comes directly or indirectly from the industry concerned. This industry can hardly be expected to wish to see its production integrated with a sustained-yield system that charges real costs for its materials. When an experiment station is centered around a major food crop, such as rice or maize, the goal becomes one of maximizing production per acre rather than per unit of resource spent; this goal may often be translated into one of generating more people. More general experiment stations tend to be established in the most productive regions of the country and, therefore, receive the most funding. Such regions (islands, intermediate elevations, areas with severe dry seasons) need experiment stations the least because they can often be successfully farmed with only slightly modified temperate zone technologies and philosophies. The administrators of tropical experiment stations often regard their job as a hardship post and tend to orient their research toward the hand that feeds them, which is certainly not the farming communities in which they have been placed. The tropics do not need more hard cash for tractors; they need a program that will show when, where, and how hand care should be replaced with draft animals, and draft animals with tractors. The tropics do not need more randomly gathered, esoteric or applied agricultural research: they need a means to integrate what is already known into the process of developing SYTA's. The tropics do not need more food as much as a means of evaluating the resources they have and generating social systems that will maximize the standard of living possible with those resources, whatever the size. The tropics need a realistic set of expectations.
我已经列举了一些原因,说明低地热带地区对农民而言并非温暖宜人之地,解释了为何期望农民独自应对这些问题可能不合理,还阐述了温带地区使农民的任务变得更加艰巨的一些方式。热带地区在全球范围内几乎就是一场公地悲剧(69, 103),而温带地区的牧民和羊群是罪魁祸首之一(31)。鉴于温带地区愿意用一些有限的资源来回报热带地区,那么这些资源该如何才能得到最佳利用呢?毫无疑问,首要答案是教育,以及将已有的关于热带地区的知识融入教育之中。其次是为那些表现出对可持续热带农业发展充满热情的政府,创造稳定的心理和物质资源。第三是支持开展深入研究,以制定针对特定、明确界定的可持续热带农业的因地制宜的规则。青少年文化规划的主题大概是由他们余生所需来决定的。这个规划的一个主要组成部分应该是教授可持续产量、非扩张型经济的社会经济规则,使其与在国家或地区资源承载能力范围内生活的理念相契合。将这样一个过程纳入热带地区的学校系统将会引发重大变革,原因之一在于这将涉及对国家资源的评估、依靠这些资源生活的人们应接受何种生活水平,以及目前谁在收获这些资源。影响更为重大的是,它必须根据资源提高该地区X比例人口生活水平Y幅度的能力来评估资源,而不是依据其在世界市场上的现金价值。要使这种变革在技术上取得成功,将需要大量的泛热带信息交流。这种信息交流不仅在差旅费和实地研究支持方面会耗费大量资源,而且对于那些愿意冒险从掠夺性农业生态系统转变为可持续热带农业的国家来说,还需要购买保险。要使这样的试验在社会学上取得成功,就需要对热带教育系统进行彻底变革,从目前强调对事件的描述,转变为强调分析事情为何如此发展。这同样会非常昂贵,不仅要重新调整当前教学项目的技术和思维模式,还要收集关于热带地区为何陷入当前困境的事实。有大量关于生态实验和一般性结论的生物学和农业报告,这些报告表明,如果尝试某种资源收获形式,将会产生这样那样的结果。显然,人类对于特定地区的需求往往与构成此类实验和一般性结论基础的“普通”野生动物和植物的需求截然不同。一个精心调整的可持续热带农业将接近为每个地区提供独特的解决方案。支配它的一般性结论具有高度的随机性。地区越靠近热带,子结果的权重就越均匀,因此每个地区就越有可能产生独特的总体结果。例如,很容易想象热带地区的四个不同部分,每个部分有着相同的土壤和气候,却有着四个不同且成功的可持续热带农业模式,一个基于水稻种植,一个基于择伐林业,一个基于旅游业,还有一个基于轮作玉米种植。一个全面致力于可持续热带农业的地区实验站可能是现有的最佳解决方案之一。然而,按照目前的架构,几乎所有热带实验站都无法胜任这样的任务。最常见的情况是,它们围绕单一的出口作物构建,如咖啡、糖、橡胶、棉花、可可或茶叶。它们预算的很大一部分直接或间接来自相关产业。几乎不能指望这个产业希望看到其生产与一个为其原材料收取实际成本的可持续产量系统相结合。当一个实验站以主要粮食作物如水稻或玉米为核心时,目标就变成了每英亩产量最大化,而不是每单位投入资源的产量最大化;这个目标往往可能转化为增加人口数量。更综合的实验站往往建在一个国家生产力最高的地区,因此获得的资金也最多。这些地区(岛屿、中等海拔地区、有严重旱季的地区)最不需要实验站,因为仅通过对温带地区技术和理念稍作调整,它们通常就能成功进行农业生产。热带实验站的管理人员常常将他们的工作视为艰苦岗位,并且倾向于将研究方向指向养活他们的那只手,而这肯定不是他们所在地区的农业社区。热带地区并不需要更多购买拖拉机的现金;它们需要一个能表明何时、何地以及如何用役畜取代人力,再用拖拉机取代役畜操作的方案。热带地区并不需要更多随机收集的、深奥的或应用型农业研究:它们需要一种方法,将已有的知识融入到可持续热带农业的发展过程中。热带地区并不需要更多的食物,而是需要一种评估其现有资源并建立社会系统的方法,以便在无论资源规模大小情况下,都能最大限度地提高生活水平。热带地区需要一套现实的期望。