ecology forest

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ECOLOGY : PART 1 FORESTS

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Page 1: Ecology forest

ECOLOGY :

PART 1 – FORESTS

Page 2: Ecology forest

Ecology

(from Greek: οἶκος, "house", or "environment"; -λογία,

"study of" [A]) is the scientific analysis and study of

interactions among organisms and their environment. It

is an interdisciplinary field that includes biology,

geography and Earth science.

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Flora (forests) and fauna(animals) are one of the renewable resources of

our country. The flora of India is diverse. It is estimated that our country

possesses 45,000 different species of plants. This is the widest range of

diverse plants found in any country in the world. Nearly 5000 species are

found exclusively in India. We can subdivide the forests of India into five

classes. They are:

1. Tropical Rain Forests (Ever green forests)

2. Tropical Deciduous Forests

3. Thorn and Scrub Forests

4. Tidal Forests (Mangrove Forests)

5. Mountain Forests

Forest in india

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Distribution of forest cover

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1. Tropical Rainforests (Ever Green Forests):

These forests grow in areas having a rainfall of more than 200 cms.

These are found in the mountain ranges of North-eastern India, in

the western slopes of the Western Ghats, along the foot-hills of the

Himalayas and in the Andaman and Nicobar Islands. The trees of

these forests don’t shed their leaves in any season of the year. They

always looks green. So they are called ‘Evergreen Forests’. Trees

like Ablus, Mahogany, ebony, rosewood, sisham (Dalbergia Sissoo),

Sandalwood (Santalum album) grow in these forests. The trees are

tall and form a dense canopy overhead. Trees of these forests

reaches up to a height of 60 meters or even more.

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2. Tropical Deciduous Forests: • Deciduous forests are called Monsoon Forests. This is because they form

the natural cover almost all over India particularly between regions of 200

and 75 cms of rainfall. This forest- cover accounts for more than half of

the total forest area of India. They are very Important from economic point

of view.

•They are called ‘deciduous forests’ because the trees of these forests

shed their leaves in the dry season of the year.

•Trees like Teak (Tectona gradis), Sal(Shorea rabusta), Sandalwood

(Santalum album), Shisham (Dalbergia sissoo), Hurra (Terminalia chebula),

Khair(Acacia catechu), Bamboo and Cane grow in these forests.

•These forests are confined to north-eastern India, eastern slopes of the

Western Ghats, the Eastern Ghats, Chhotnagpur Plateau, Orissa,

Chhatisgarh and Madhya Pradesh.

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3. THE THORN AND SCRUB FORESTS:

These are confined to areas with a rainfall of less than 75cms. It spreads over

north-western part of the country from Saurashtra in the south to Punjab plains in

the north.

It is found in parts of Rajasthan, Punjab, Uttar Pradesh, Madhya Pradesh, Haryana

and also in parts of south India. Kikar, babul, khair, acacia, munj and sawai grass

are found in these forests. These forest areas are being converted into residential

areas due to population pressure. Thorn and cactus are found in western Punjab

and western Rajasthan where the rainfall is less than 50 cms.

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4. TIDAL FORESTS:

The tidal areas along the coast of India particularly the lowlands and river-mouths

of the eastern coast is covered with mangrove forests. Mangrove trees can

survive both in fresh and saline water- the major characteristic of the tidal areas.

Sundari is a well-known mangrove tree. It is after the name of this tree that the

name sundarban has been given to the vast tidal mangrove forests of the Ganga-

Brahmaputra delta in West Bengal. Due to the abundance of Hental trees, the

mangrove forests of the Mahanadi-Brahmani mouth are called ‘Hentalban’. It is

also called ‘The Little Sundarbans’.

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5. MOUNTAIN FORESTS (ALTITUDINAL ZONES OF VEGETATION IN

MOUNTAINOUS REGIONS OF INDIA):

•Altitude is an important factor in the distribution of vegetation in the

mountainous regions because of the decrease of temperature with the increase

of altitude.

•The Himalayas are covered with all types of vegetation starting with tropical

rain forests in the foothills to tundra vegetation on the peaks. Due to the hot

and humid climate, siwaliks, the foothills of the Himalayas are covered with

tropical rain forests and moist deciduous flora. Sal is the most important and

dominant species. It is then succeeded by wet hill forest between 1000 and

2000 meters. Evergreen broad leave oaks, chestnuts and apple trees are

common trees in these altitudes.

•Further up between 1600 and 3300 meters above sea level, pine, cedar,

spruce and silver fir are found which are some of the most important species in

these altitudes. These forests are the coniferous forests of the temperate

regions of the world found in these altitudes of the Himalayas.

• Temperate coniferous forests is succeeded by Alpine Forests which is found

generally at altitudes between 2750 to 3600 meters above sea level. These

forests are covered with species like silver firs, pines, birches and junipers.

Above 3600 meters above sea level, Alpine Forests give way to Alpine

Grasslands. The peaks of the Himalayas are covered with perpetual snow.

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