All About Water

The Taiga Ecosystem

The taiga, or boreal forest, is an ecosystem found across the northern regions of North America and Eurasia. It covers much of Canada and extends down into the northwestern United States. In Europe, Scandinavia and much of Russia is covered with boreal forest. Large cities including Moscow and Toronto are found in the southernmost part of the taiga, but farther north it is mostly unpopulated by humans. The taiga is composed of coniferous trees in an almost continuous belt. Boreal forest grows over areas that were once covered by glaciers and still retain some patchy areas of permafrost. Winter in the taiga is long and harsh, with temperatures dipping as low as -90 degrees Fahrenheit. The winter can last up to six months. The summer season is brief, comprising only about fifty to one hundred frost-free days. The taiga has little annual precipitation, only about fifteen to twenty inches, but its climate is humid because of low evaporation.

Plant Life in the Taiga

Taiga woodland soil is rocky, acidic and low in nutrients. The primary vegetation in the boreal forest is coniferous, needle-leaf trees. In North America, the dominant species of coniferous trees are fir and spruce. In Scandinavia and throughout Russia, the Scots pine is usually dominant. Deciduous trees and shrubs are also common, including alder, birch and aspen.

Coniferous forest is well adapted to difficult growing conditions. Needles remain green year-round, which means that the trees don’t need to expend energy by growing new leaves every year. The needles also limit water loss through transpiration, allowing evergreen trees to stay alive even when the ground is frozen and water from the soil is difficult to come by. The shape of the branches allows snow to slide off rather than build up and cause the branches to break.

Animal Life in the Taiga

The boreal forest is home to a wide variety of animal life, including predatory mammals like lynxes, bobcats, bears, and weasels; small herbivores like snowshoe hares, lemmings, and voles; and large herbivores like elk and moose.

Many birds in the taiga, such as wood warblers, are migratory and leave after the warmer season. Seed-eating birds like finches and omnivores like ravens make their home in the tundra year-round. Animals that live year-round in the taiga must adapt. Some hibernate through the coldest part of the season. Others produce an extra layer of fur or feathers to help them survive. Some animals change color to help them blend in with their snowy surroundings.

Water Pollution in the Taiga

Long ago, the taiga was covered by glaciers. When they receded, they left huge gouges and depressions. When it rains, the depressions fill, and lakes and bogs form. The bogs and ponds are a great breeding ground for insects, which help support the migratory bird populations.

Some areas of the taiga are at risk of deforestation caused by acid rain. Russia has a number of plants which smelt nickel, aluminum and lead. These plants emit chemicals into the atmosphere, which causes acid rain to form. Some rivers in the taiga are also at risk, due to the damage caused by the timber industry. Logs sink and cause flooding. When areas of the forest are cut clear, the topsoil erodes into the rivers and streams.

For more information on water and biomes, check out Role of Water in Ecosystems and Biomes

Rainforests are some of the most incredible ecosystems on Earth. They contain unique structures which allow for massive amounts of growth in both plant and animal life. Many plants and animals on Earth can only live in the rainforest. Even though many of these plants give oxygen to the world and offer potential cures for cancer, the rainforests are being destroyed at an alarming rate.

Features of the Rainforest

While there are many rainforests in different areas of the world, all rainforests have certain features in common. To be classified as a rainforest, an area must have a large amount of rainfall per year. Most rainforests experience between 68 to 78 inches of rainfall annually. Usually a rainforest is divided into four layers. The emergent layer is the top layer, followed by the canopy, the understory, and the forest floor, which receives about 2% of the rainforest’s sunlight.

Plants and Animals of the Rainforest

The rainforest is a lush and fertile environment, so fertile in fact that there are still many types of plants and animals that remain undiscovered by humans. No one knows exactly how many species of plants and animals are in the rainforest, but estimates indicate that 40-75% of all life on Earth can be found somewhere in the rainforest. Most plant and animal life is found in the canopy layer due to the rich and moist conditions and ample sunlight. Since the understory and forest floor layers receive so little sunlight, only low light plants can grow in these layers. The emergent layer is usually too hot to sustain much life.

Even though the rainforest is very fertile, the soil is not. Most plants that grow at the lower level only have their roots in the top layer of soil, as the lower levels are filled with mineral deposits and rapid bacterial decay. Plants on the lower layers tend to rely on the decomposing plant and animal life on the top layers of soil for nutrients.

The Importance of the Rainforest

Even though the rainforest only covers about 6% of the planet, it plays many crucial roles not only to the survival of humans, but also to the survival of all life on Earth.

Rainforests contain numerous plants in condensed areas, allowing for the production of massive amounts of the world’s oxygen.  In fact, the Amazon rainforest alone  is responsible for about 20% of the oxygen created on Earth. Rainforests also take in a huge amount of carbon dioxide each year. Both processes are crucial to life on Earth.

The rainforest also holds many different medicines that can only be found in the rainforest. Somewhere around 70% of the 3000 plants that are effective against cancer are found in tropical rainforests around the world.

Even with all of these benefits, the rainforest is still being destroyed. Estimates indicate that about one and a half acres of tropical rainforest is being destroyed for its wood each second. Oil spills, toxic byproducts, and other man-made contaminates are also poisoning the waters of the rainforest, killing many plants and animals. While rainforests cover only 6% of our Earth now, they used to cover 14%. Scientists predict that we could see the end of the tropical rainforest within 40 years. This would be an unspeakable blow to the plants, animals and well-being of Earth.

For more information on water and biomes, check out Role of Water in Ecosystems and Biomes