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"液体"森林
 缅甸的渔民. (Photo by R. Glsco)
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写 Rhett Butler. 翻译 Che Fei
07/12/2007
雨林河流对人们的重要性
热带河流对雨林的生态已起着很重要的作用, 对于森林中的各种生物和不在森林中的人们来说也很重要. 在欧洲人到来之前,沿着主要的水路形成了无序的文明和小社会，这些水路成为了交通和通讯的一种手段, 也是人们进行贸易的通道、鱼类和淡水的源泉.然而,由于它们的位置沿着主要的河流，这样的住区首先消失了,既有战争的直接影响，也有欧洲疾病传播的间接影响.
今天,大的热带河流仍然是重要形式的运输基础设施，对交通和通讯提供了便利可靠的 条件.主要的河流港口象伊基托斯、秘鲁、马瑙斯和巴西是贸易中心，在这些地方，森林产品与外界的货物进行交换。通常通往这些港口的通道被周围的森林所隔离，只能通过水路和空运.例如，没有路可通往伊基托斯，所有的建筑材料、汽车和其他的必需品必须船运到城市.
除了为商业贸易和通讯提供便利外，热带河流也是蛋白的主要来源地，其主要是鱼类.然而在一些地方, 渔民说在较小区域进行捕捞将要收费.河流也为城市居民提供服务，每次洪季都会使土壤更加丰饶，还能冲刷走城市居民扔进河里的大量的废物和污染物质.
热带鱼类是许多城市居民的主要收入来源, 尤其在有着约3000多种鱼类的亚马逊河.在温带地区水族馆商店看到的很多鱼都是从巴西和秘鲁进口的.
湖
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亚马逊河上的小船, 1999年于巴西 
秘鲁亚马逊河段
秘鲁雨林中蜿蜒河流的鸟瞰图.如果从近处看，两条牛轭湖明显位于图象的中心.一条比另一条暗的多,但它们都是与河流的主干道相隔离的. |
低地森林中绝大多数天然湖是牛轭湖.牛轭湖形似新月形，由河流改变流向而形成.在低地雨林，象主要是松软淤积土的亚马逊部分地区，由于侵蚀作用和沉积物的沉积作用，蜿蜒的河流也在逐渐发生着变化.当河流的弯曲处变得很曲折以至于主河道变成了一条新的较直的航线，使得离的越远的地方越是弯曲.随着时间的流逝，牛轭湖离主河道越来越远.水流不断淤塞，水况也发生着变化.
秘鲁亚马逊河段牛轭湖的轮廓图
牛轭湖的特征取决于它的"年龄"."年轻的"的牛轭湖可被河流冲刷掉，尤其在洪水季节.比起那些老湖，这些湖往往有点浑浊(不清澈)，而且酸性要小.
牛轭湖是许多鱼类和水生动物的主要栖息地.很多大家熟知的热带水族馆鱼种专门生活在牛轭湖里，同时这里也是南美大水獭的主要栖息地.
雨林里也存在"自立"湖,但数量上没有热带河流那么多.比如牛轭湖，随着植被慢慢的腐烂分解，湖水变的酸性更强了.
马达加斯加岛Lac Alaotra湖的"死亡"
复习题:
- 为什么亚马逊河对当地人是很重要的？
- 什么是牛轭湖?
[打印版]
续: 热带河流、湖泊所面临的威胁
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