27-11-2012, 02:16 PM
Forest ecosystem
Forest Ecosystem.ppt (Size: 2.07 MB / Downloads: 65)
These are ecosystems which have dominance of trees with herbs, shrubs, climbers, algae, variety of wild animals, birds.
Forest are found in undisturbed area
Receives moderate to high rain fall
Usually occurs as a stable climax community
Types of forest
Depending on the prevailing climatic conditions forest can be of various types
Tropical rain forests
Tropical deciduous forests
Tropical scrub forests
Temperate rain forests
Temperate deciduous forests
Evergreen coniferous forests (boreal forests)
Tropical rain forests
Evergreen broadleaf forests found near the equator.
High humidity, high temperature, high rainfall favours the growth of trees.
All throughout the year climate remains more or less uniform.
Richest in biodiversity
Different forms of life occupy special areas within different layers and spaces of the ecosystem depending upon their food, sunlight, water, nutrient etc.,
Animals present in various layers
Emergent layer: eagles, toucans etc.,
Canopy: snakes, tree frogs, bats, birds, insects.
Monkeys, toads, snakes, chameleons keep moving up and down in sunny and darker layers.
Ground layer: termites, fungi, mushroom
Warm temperature and high moisture facilitates rapid break down of dropped leaves, twigs etc., releasing nutrients.
These nutrients are immediately taken by mycorrhizal roots of trees.
Temperate deciduous forests
They are found in areas with moderate temperature
There is marked seasonality with long summer
Winter is cold but not too severe
Abundant rainfall throughout the year
The major trees includes Broad leaf deciduous trees
They shed their leaves every year.
E.g.: oak, hickory, magnolia, poplar etc..,
white-tailed deer, raccoons, beaver, red fox are found here
Evergreen coniferous forests (Boreal )
They are found south of arctic tundra
Here winters are long, cold and dry. Sunlight is available for few hours only
In summer the temperature is mild, sun shine is for long hours but the season is short
Trees includes pines, spruce, fir, cedar etc.,
They have tiny needle shaped leaves having waxy coating for withstanding cold and drought.
Soil is frozen during winter and the leaves fall on the forest floor & cover the nutrient poor soil
These soil are acidic and prevent other plants from growing.
Species diversity is rather low here.
woodland caribou, American black bear, grizzly bear, and wolverine.