Into the Depths of the Amazon
The Amazon's climate is heavily influenced by its tropical location. This gives it a warm temperature and plenty of rain.
About the Tropics
The tropics are a region that spans the globe along the equator. The Northern tropics (northern hemisphere) line is called the Tropic of Cancer at 23.5 degrees North latitude and the southern tropics (southern hemisphere) is called the Tropic of Capricorn at 23.5 degrees South latitude. In this region, the sun shines approximately the same amount of time every day and so there is little variation in temperatures. Some of the Amazon (basin, rainforest, and river) are located within the tropics. This is why the Amazonian forest, and many other forests across the world, is called a tropical rainforest. In the Amazon region, there are basically two seasons: a rainy season and a not-so-rainy season. In the rainy seasons, one can expect up to 60-180 inches. In the "dry" season, one can expect anywhere from 30 inches to 100 inches. Some spots along the basin average more or less than others. Generally, the north and south edges of the basin have less than the western edge.
At the fringes of the Tropics and past the tropics, the change in seasons is more visible. Universally throughout the Amazon, an average day is warm and humid. This type of climate is called a selva climate.
Influence of the Climate in the Past
The Amazon has a rich diversity of plants and animals. It is a haven for thousands of species of plants and animals. The reason the Amazon has great biodiversity is due to the last Ice Age which occurred approximately 2.5 million years ago. When large glacial ice masses encroached upon the continents, places like the Amazon rainforest became a refuge for creatures because year-round temperatures remained constant and the forest had warm weather, conditions hospitable for many plants and animals. Animals generally moved towards the tropics by locomotory means such arms or legs. Plants moved more slowly because the only way they could move is by seed dispersion. When plants disperse their seeds, they let them out all over. Seeds that were dispersed more closer to the tropics and the Amazon, had a better chance of surviving than those seeds that were dispersed away from the tropics.
Influence of the Climate in the Present
The major contribution the climate makes to the Amazon is the vast amount of precipitation, humidity, and warmth. Although it rains year-round, the Amazon has a "rainy" season. A vast majority of the precipitation falls during this period and it is enough to raise the levels of many rivers, flooding nearby forests and villages.
Flooding is a huge problem for residents who live around flood banks or otherwise close to the rivers since the all water from the surrounding highlands collects into the Amazon Basin. Resident have had to adapt to the large amounts of rain by making their houses on stilts so that if they are flooded, water passes below their houses. Many build houses on rafts so that the whole house rises during a flood and comes back down when the floods recede.
Flooding is also beneficial to some plants. Many plants have adapted to the seasonal flooding as a way to disperse seeds. Berries on certain trees ripen during the flood season and aquatic animals eat them and move on, helping to disperse the seeds in new locations along the banks of the river and other flood plains.
Influence of the Climate in the Future
In recent years, temperatures of the rainforest and surrounding waters have become abnormally warmer than usual. Many plants and animals have adapted to certain temperatures of the forest and water bodies. However, when the water becomes warmer, these plants and animals find it harder to survive in intolerable temperatures. If waters keep becoming warmer (Global changes coupled with human interference such CFC's) many species might move away from these areas or worse yet, become extinct. Animals have become extinct due to droughts. When not enough rain falls, the area becomes too dry to live in. For the golden frog, when less than normal rain fell, there were inadequate spaces to lay eggs and so many eggs that were laid in "dry" places did not survive.
Humans have a huge effect on the climate. Our CFC's are the cause of the ozone hole. We have, through our industrial might, unleashed carbon dioxide and methane, agents of global warming. Some also argue, the planet is going through climatic changes that have occurred periodically throughout the planet's history. Whatever the case may be, plants and animals will not be able to survive the global temperature increases as well as humans will. It might prove disastrous to biodiversity.
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