3. Do you know what are forests? The word
forest is derived from the Latin word foris
meaning –outside the village boundary.It
refers to large tracts of land covered by
trees, shrubs , herbs and grasses, which also
supports a wide variety of life.Forests can
be broadly grouped into three categories:
tropical,temperate and coniferous.All the
three types support different kinds of flora
and fauna as they thrive in different
climatic conditions.
FOREST
4. Tropical evergreen forests are usually found in areas receiving
more than 200 cm of rainfall and having a temperature of 15 °C
to 30 °C and have annual humidity exceeding 77%. They occupy
about seven per cent of the Earth's land surface and harbour
more than half of the planet's terrestrial plants and animals.
Tropical evergreen forests are dense, multi-layered, and
harbour many types of plants and animals. The trees are
evergreen as there is no period of drought or frost. The canopy
tree species are mostly tall hardwoods with broad leaves that
release large quantities of water through transpiration, in a
cycle that is important in raising as much mineral nutrient
material as possible from the soil.
5. In India, evergreen forests are found on the eastern
and western slopes of the Western Ghats in such
states as Tamil Nad, Karnataka, Kerala and
Maharashtra. And also found in Assam, Arunachal
Pradesh, Meghalaya, Nagaland, Tripura, West Bengal
and Andaman and Nicobar Islands. They are also
found in the hills of Jaintia and Khasi. Some of the
trees found in Indian tropical forests are rosewood,
mahogany and ebony. Bamboo and reeds are also
common. Because of dense foliage competing for
light, little direct sunlight reaches the understory.
7. The tropical deciduous forest, also known as tropical dry
forest, vine thicket, and vine scrub is located at tropical and
subtropical latitudes. Though these forests occur in climates
that are warm year-round, and may receive several hundred
centimeters of rain per year, they have long dry seasons which
last several months and vary with geographic location. These
seasonal droughts have great impact on all living things in the
forest. Three tropical dry broadleaf forest ecoregions, the
East Deccan dry evergreen forests, the Sri Lanka dry-zone
dry evergreen forests, and the Southeastern Indochina dry
evergreen forests are characterized by evergreen trees.
8. Though less biologically diverse than rainforests, tropical dry
forests are home to a wide variety of wildlife including
monkeys, deer, large cats, parrots, various rodents, and ground
dwelling birds. Mammalian biomass tends to be higher in dry
forests than in rain forests, especially in Asian and African
dry forests. Many of these species display extraordinary
adaptations to the difficult climate.
This biome is alternately known as the tropical bane forest
biome or the tropical and subtropical deciduous forest biome.
Locally some of these forests are also called monsoon forests,
and they tend to merge into savannas.
10. Temperate evergreen forests are found largely in the temperate mid-
latitudes of Montane North America, Siberia, Canada, Australia, Africa
and Scandinavia. Broadleaf evergreen forests occur in particular in
eastern North America and in countries around the Mediterranean Basin,
such as Lebanon and Morocco. Many subtropical broadleaved evergreen
forests occur along the eastern margins of major land masses, e.g., in
southeastern United States, southern China and in southeastern Brazil.
Other examples include the wet temperate conifer forests of
northwestern North America.
Temperate evergreen forests are the regional climax vegetation,
commonly dominated by hardy trees that can deal with sandy, rocky, and
various other soils of poor quality. Most such communities also are subject
to intermittent fire, drought and cold. Coniferous temperate evergreen
forests are most frequently dominated by species in the families Pinaceae
and Cupressaceae
11. Broadleaf temperate evergreen forests include those in
which Fagaceae such as oaks are common, those in which
Nothofagaceae predominate, and the Eucalyptus forests
of the Southern Hemisphere. There also are assorted
temperate evergreen forests dominated by other families
of trees, such as Lauraceae in laurel forest.
Evergreen forests around the world are under threat of
logging, mining, oil and gas developments, pollution,
hydroelectric projects and other human developments
planned in these areas.
13. Temperate deciduous forests or temperate broad-leaf
forests are dominated by trees that lose their leaves each
year. They are found in areas with warm, moist summers and
mild winters. The three major areas of this forest type occur
in the Northern Hemisphere: eastern North America, eastern
Asia, and Europe. Smaller areas occur in Australasia and
southern South America. Examples of typical trees include
oak, maple, beech, and elm. The diversity of tree species is
higher in regions where the winter is milder, and also in
mountainous regions that provide an array of soil types and
microclimates.One of the world's great protected examples of
this forest type is found in Great Smoky Mountains National
Park.
TEMPERATE DECIDUOUS FORESTS
16. Coniferous forests are made up mainly of cone-bearing or
coniferous trees, such as spruces, hemlocks, pines and firs.
The leaves of these trees are either small and needle-like or
scale-like and most stay green all year around (evergreen). All
are softwoods able to survive cold termperatures and acidic
soil.Coniferous forests are found mainly in the northern
hemisphere, although some are found in the southern
hemisphere.
The northern coniferous forests are called taiga or boreal
forests. They cover vast areas of North America from the
Pacific to the Atlantic, and range across northern Europe,
Scandinavia, Russia and across Asia through Siberia and
Mongolia to northern China and northern Japan
17. Short summers and long winters-
Coniferous trees thrive where summers are short and cool and
winters long and harsh, with heavy snowfall that can last as
long as 6 months. The needle-like leaves have a waxy outer
coat which prevents water loss in freezing weather and the
branches are soft and flexible and usually point downwards, so
that snow slides off them. Larches are one example of a
coniferous tree found in some of the coldest regions.
Unusually for coniferous trees they are deciduous, that is
they shed their leaves in winter.
Coniferous trees such as cypresses, cedars and redwoods are
found in warmer regions.
