Forest ecosystem

Presentation by

Jhansirani.R AP/ECE

Forest ecosystem

• These ecosystem have dominance of trees with herbs, shrubs, climbers, lichens, 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

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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)

Jhansirani.R AP/ECE

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.,

Jhansirani.R AP/ECE

Jhansirani.R AP/ECE

Jhansirani.R AP/ECE

Tropical rain forests distribution

Jhansirani.R AP/ECE

Tropical rain forests

• Different types and layers of plants and animals in tropical rain forest

• Emergent layer: topmost layer of the tallest broad-leaf trees

• Canopy: top branches of shorter trees form an umbrella like cover.

• Understory: lies below the canopy with still smaller trees.

• Lianas: some woody climbers which grow on the tree trunks

Jhansirani.R AP/ECE

Jhansirani.R AP/ECE

Kapok tree

• Emergent layer:

The trees up here are much more windblown than the trees of shorter layers. 

Canopy trees

lianas

• Liana plants are vines that can grow up to 3000 ft in length.

Tropical rain forests

• Epiphytes: these plants are attached to the trunks or branches of big trees and they take up water and nutrients falling from above.

• Eg: orchids

• Orchids have special types of leaves to capture and hold water.

• Orchids have bright colors and attract insects such as wasps, bees, moths and butterflies.

• Some large epiphytes can hold 4lts of water.

• That is the reason for variety of birds, insects, animals like monkeys have their natural homes in these forests. (plate II)

Jhansirani.R AP/ECE

Tropical rain forests

• Understory: they receive very dim sunlight• They develop dark green leaves with high

chlorophyll content so that they can use diffused sunlight for photosynthesis. Jhansirani.R AP/ECE

Tropical rain forests

• Shrub layer: This is the layer that grows between the smaller trees of the understory and the forest floor. This layer is made up of ferns and small shrubs.

• They receive less sunlight.

• Ground layer (or) forest floor: it receives almost no sunlight and almost dark .

Jhansirani.R AP/ECE

Tropical rain forests

• 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. Jhansirani.R AP/ECE

• Flowers of forest are very large, colorful, fragnent & attractive which helps in pollination

• E.g. Rafflesia arnoldi

• 7Kg weight• Smells like rotten

meet

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Tropical rain forest• Silent valley in Kerala is the only rain

forest in India• Forest provides us timber, fuel wood,

drugs, resins, gums etc.,• Unfortunately cutting down of these

forests will lead to only scattered segments of such forests in next 30-40 yrs

• Thus losing the rich biodiversity and ecological uses of forests.

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Tropical deciduous forest

• They are found little away from the equator• It has warm climate the year around• Rain occurs only during monsoon• Large part of the year remains dry• Different types of deciduous trees are found.• Trees lose their leaves during dry season.• Deciduous means "falling off at maturity"• E.g.:  Maple, Oaks, Elm, Aspen, and Birch,

Jhansirani.R AP/ECE

Tropical deciduous forest

TROPICAL SCRUB FOREST

• They are found in area where the dry season is even longer

• Small deciduous trees and shrubs are found here

• Trees are small and drought resistance• Mostly has spines and thorns• Animals like great Indian bustard and

blackbuck are found here.

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TROPICAL SCRUB FOREST

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

Jhansirani.R AP/ECE

Jhansirani.R AP/ECE

Temperate rain forest

• They are found in temperate areas with adequate rainfall

• They are dominant by coniferous trees

• E.g. pines, firs, redwoods etc.,• Also consist of evergreen broad leaf trees

like Olive, holly, eucalyptus, etc.,• Cougar, black bears, elk, giant

panda are found here.

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TEMPERATE RAIN FORESTS

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.

BOREAL FORESTS

Terrestrial biome

Jhansirani.R AP/ECE

Jhansirani.R AP/ECE