There are two types of rainforests: the temperate and the tropical. At one time, Tropical rain forests covered 12% of the Earth’s land mass, but now it covers only 6%. The rainfall averaged yearly is about 90-460 inches a year. Rainforests on the equator have about 12 hour days all year around. The temperature averages around 80ºF and the humidity is high, ranging from 77% to 88%. There are four layers of the tropical rainforest, each built ontop of one another. The topmost layer is called the Emergent layer. Beginning at heights of 75 feet and reaching higher than 250 feet, the emergent layer has plentiful amounts of sunshine. The next layer, The canopy, is the large covering mass of leaves that stands 60-90 feet above the rainforest ground. About 90% of the photosynthesis in the entire rainforest occurs in the canopy. The canopy also accommodates the widest variety of animal species in the world. The next level is called the understory. Starting at the ground and including everything until 50 feet above ground level, the understory is dimly lit, making it hard for young canopy plants to grow. A diversity of plants live here; however they must accommodate for the lack of sunlight. Also, the most insects live in this layer. Scientists estimate that there are over 30 million species of insects alone in the tropical rainforest. Finally, there is the Forest floor. Here, there is very limited plant life, and only 1% of the total sunlight ever reaches the forest floor. The soil is very low in nutrients, unlike the early misconceptions of the tropical rainforest soil.
The Temperate rainforest covers very little of the total land mass of rainforests in the world and are found in temperate zones. On average, the temperate rainforest is cooler and it houses the largest and oldest trees in the world. The largest strip of remaining temperate rainforest lies on the coast from Alaska to Oregon. Others are located in southern South America, New Zealand, and Tasmania.
The Amazon Rainforest is the largest plot of tropical rainforest in the world. It contains the largest source of biodiversity and genetic variation. Located in Northern Brazil, the Amazon rainforest is about 2.5 million square miles, approximately the size of Europe. Just one acre of land might contain 180 different species. Many plants and insects here have been found to obtain special healing capabilities, such as curing cancer. About ¼ of the world’s medicine is found in this forest.
In the 1500’s, Portugal royal expeditions discovered valuable dyewood, also known as Brazilwood, in this large region of South America, leading to the formation of the country with the similar name, Brazil. Initial capitalism started when merchants traded this wood to Europeans and other items to native Indians. By the mid sixteenth century, sugar developed into the leading export and Brazil became a model of trading for the world. During the 1900’s, the Amazon Rainforest began to noticeably decrease in size. New towns and roads were built including Brazil’s eighth largest city, Manaus. It is estimated that in 1970 about 1% of the Amazon Rain Forest was deforested and the year 2000, 15%. In a thirty year time span, about 14% of the rainforest was consumed, approximately the size of France. However, the total amount of rainforest in the world is about the size of Europe, or 6.7% of the Earth’s land mass. In the 1990’s, Brazil’s government and many environmental organizations began working to protect the Amazon Rain Forest. They also provide education about how to earn profits from the rainforest without damaging it. Many people harvest nuts, fruits, rubber, and other products that grow naturally in the rainforest while logging and mining companies use and cut down the wood.