Forest | Types | Environment |
A forest is a large area which is dominated by trees. Hundreds of more precise definitions are used throughout the world for forests, incorporating factors such as density of a tree, height of a tree, land used by trees, legal standing and ecological function. According to the widely used Food and Agriculture Organization definition, forests covered 4 billion hectares which is 15 million square miles or approximately 30 percent of the world’s land area in 2006.
The very first known forests on Earth arose in the Late Devonian which is approximately 380 million years ago, with the evolution of Archaeopteryx. Archaeopteryx was a plant that was both tree-like and fern-like, growing to 10 meters which is approximately 33 ft in height. Archaeopteryx quickly spread throughout the world, from the equator to sub-polar latitudes, archaeopteryx formed the first forest by being the first known species to cast shade due to its fronds and forming soil from its roots. Archaeopteryx was deciduous, dropping its fronds onto the forest floor. The shade, soil, and forest duff from the dropped fronds created the first forest. The shed organic matter altered the freshwater environment, slowing it down and providing food. This promoted freshwater fish.
The Forests account for 75% of the gross primary productivity of the Earth’s biosphere, and contain 80% of the Earth’s plant biomass. Forest ecosystems can be found in all regions capable of sustaining the growth of tree, at altitudes up to the line of tree, except where natural fire frequency or where the environment has been altered by human activity. The latitudes 10° north and south of the equator are mostly covered in tropical rain forests, and the latitudes between 53°N and 67°N have Borealis forest. As a general rule, forests dominated by broad-leaf forests are more species-rich than those dominated by conifer, montage, or needle-leaf forests, although exceptions exist. Forests sometimes contain many tree species within a small area as in tropical rain and temperate deciduous forests, or relatively few species over large areas. For instance, taiga and arid montage coniferous forests. Forests are often home of many animals and plant species, and biomass per unit area is high compared to other vegetation communities. Approximately all of this biomass occurs below ground in the root systems and as partially decomposed plant detritus. The woody component of a forests contains ligning, which is relatively slow to decompose compared with other organic materials such as cellulose or carbohydrate etc.
Types of Forests:
There are different types of forests which spread across the globe.
TROPICAL RAIN FOREST:
The tropical rain forests contain the greatest diversity of species of all biomass on earth. They are found around the equator, between 23.5 degrees North latitude and 23.5 degrees South latitude.
TEMPERATE CONIFEROUS FOREST:
Temperate coniferous forests are typically found in coastal areas with mild winters and heavy rainfall or in in-land mountainous areas with mild climates. Examples of where these forests are found are Pacific Northwestern United States and Canada, southwestern South America, Southern Japan, New Zealand and small parts of northwestern Europe
This is the northern most forest type and is found between 50 and 60 degrees N latitude. Boreal forests are found in Canada, northern Asia, Siberia and Scandinavia (Denmark, Norway, Sweden and Finland). About two-thirds of the world’s boreal forests are found in Scandinavia.
1.TEMPERATE DECIDUOUS FOREST:
These forests are located in Eastern United States and Canada, Western Europe and parts of Russia, China and Japan.