| environ. |
tropical rain forest The most valuable and the richest ecosystem on Earth. It plays a critical part in the Earth's life support systems and house 50%, and possibly as much as 90%, of all the species on Earth. It is a key storehouse of foods, oils and minerals, and a source of ingredients that make up a range of medical treatments. It also represents home and livelihood for many people. However, more than half of the rainforests have disappeared, chopped down for valuable tropical hardwoods, or cleared to provide areas for cattle grazing or human habitation. The forests play an important part in climate patterns, and deforestation is thought to be responsible for 18% of global warming. Furthermore, as they disappear there is also an albedo effect - a damaging increase in the sunlight reflected - which affects wind and rainfall patterns (地球上最有价值和最丰富的生态系统，它是地球的生命支持系统的一个重要组成部分，它拥有地球上50%、可能达到90%这么多的物种。它是食品、油和矿物的主要仓库，是一系列医疗用品的配料成分的来源。它也是很多人赖以生存的物质基础。然而，超过半数的热带雨林已消失，宝贵的热带硬木被砍伐或被清除以提供空地来放牧或人类居住。森林在气候模式中发挥着重要的作用，森林的砍伐被认为要为18％的全球变暖负责。此外，它们的消失也会带来反照率效应，反射的阳光会破坏性地增加，这会影响风和降雨的模式。) |
