forest biomes - kashmeera

KASHMEERA N.A.KASHMEERA N.A.

II SEM MSc.ZOOLOGYII SEM MSc.ZOOLOGY

ROLL NO:37ROLL NO:37

CHRIST COLLEGECHRIST COLLEGE

Term biome was coined by the American ecologist Frederic Clements.

“Largest land unit which is convinient to recognize” – Eugene.P.Odum.

The chief character of a biome is depicted by climax communities with their dominant life forms.

Biomes are grouping of ecosystems with similar environment and vegetation structure.

Tropical rain forests Grasslands Deserts ChapparalsTropical rain forests Grasslands Deserts Chapparals

Temperate deciduous Boreal forests Tundras SavannaTemperate deciduous Boreal forests Tundras Savanna

forestsforests

“The planet's lungs. Home to people and wildlife. Engines of green economies. Forests are essential to life on Earth ”

Forest biomes are characterised by the vegetation with densely growing trees having a closed ,or nearly so,canopy cover.

It include a complex assemblage of different kinds of biotic communities.

The nature of soil,wind and air currents determines the distribution of forest vegetation.

Normally ecologists recognize amoung forest communities such features as their

evergreen nature,whether deciduous or indeciduous,whether broad-leaved as in temperate forests or needle-like as in conifers.

On the basis of these features the forest biomes of the world have been classified into following – coniferous forest tropical forest temperate forest

Tropical rain forests occur near the equator in Central and south America ,central and western Africa ,southeastAsia,Malaya,Borneo,New guinea and Northwest Australia.

In India the main areas of tropical forest are found in the Andaman and Nicobar Islands; the Western Ghats, and the greater Assam region in the north-east.

Tropical rain forests are amoung the most diverse communities on earth.

One of the major characteristics of tropical forests is their distinct One of the major characteristics of tropical forests is their distinct seasonality: winter is absent, and only two seasons are present (rainy seasonality: winter is absent, and only two seasons are present (rainy and dry).and dry).

The length of daylight is 12 hours and varies little.The length of daylight is 12 hours and varies little.

Canopy in tropical forests is multilayered and continuous, allowing little Canopy in tropical forests is multilayered and continuous, allowing little light penetration.light penetration.

Humidity - high and constant. Humidity - high and constant.

Temperature is on average 20-25° C and varies little throughout the year: Temperature is on average 20-25° C and varies little throughout the year: the average temperatures of the three warmest and three coldest months the average temperatures of the three warmest and three coldest months do not differ by more than 5 degrees.do not differ by more than 5 degrees.

Annual rainfall – 200 to 225 cm.Annual rainfall – 200 to 225 cm.

High rate of leaching makes soil useless for agricultural purpose.High rate of leaching makes soil useless for agricultural purpose.

Flora is highly diverse: one square kilometer may contain as many as 100 different tree species.

Trees are 25-35 m tall, with buttressed trunks and shallow roots, mostly evergreen, moderate size, leathery dark green leaves.

The extremely dense vegetation of the tropical rainforests remains vertically stratified .

Tall trees are often covered with

vinesvines

lianaslianas

epiphytic epiphytic orchidsorchids

bromeliadsbromeliads

Under the tall trees is a continuous evergreen carpet, the canopy layer, some 25 to 35 meters tall.

The lowest layer is an understorey of trees, shrubs, herbs like ferns and palms

Palms fernsPalms ferns

Invertebrate density and abundance are very high in tropical rainforests,Invertebrate density and abundance are very high in tropical rainforests, The common invertebrates of these forests areThe common invertebrates of these forests are

Isopods spiders planarians leeches. Isopods spiders planarians leeches.

Snails millipedes centipedes scorpionsSnails millipedes centipedes scorpions

most common insectsmost common insects

Heteropterans orthopterans blattidsHeteropterans orthopterans blattids

Mantids phasmids bees termitesMantids phasmids bees termites

ants ants

common vertebratescommon vertebrates

Rhacophorus malabaricus

chameleons

agamids

geckoes

many species of snakes

many species of birds, social birds being predominant

Mammals with nocturnalMammals with nocturnaland arboreal habits are and arboreal habits are most common most common

leopardsleopards

slothssloths

monkeysmonkeysgiant flying squirrelsgiant flying squirrels

anteatersanteaters

jungle catsjungle cats

Major ground dwelling Major ground dwelling mammalsmammals

tigertiger

elephantelephant

samber deersamber deer

muntjacmuntjac

gaurgaur

spotted deerspotted deer

swamp deerswamp deer

• The temperate forest biomes are characterized by a moderate The temperate forest biomes are characterized by a moderate climate and broad-leaved deciduous trees, climate and broad-leaved deciduous trees,

which shed their leaves in fall, are bare over winter and grow new which shed their leaves in fall, are bare over winter and grow new foliage in the spring. foliage in the spring.

• These forests are the characteristics of North America, Europe, These forests are the characteristics of North America, Europe, Eastern Asia, Chile, part of Australia and Japan, Eastern Asia, Chile, part of Australia and Japan,

• with an annual rainfall of 75—150 cm with an annual rainfall of 75—150 cm

• temperature of 10—20°C. temperature of 10—20°C.

• In these biomes the precipitation may be fairly uniform In these biomes the precipitation may be fairly uniform throughout the year. throughout the year.

• In India, at elevations of 2743.2m -3655.6m in Himalayas occur In India, at elevations of 2743.2m -3655.6m in Himalayas occur temperate vegetation temperate vegetation

• Soils of temperate forests are podozolic and fairly deep.Soils of temperate forests are podozolic and fairly deep.

Trees are quite tall—about 40—50m in height and their leaves are thin and broad. The predominantgenera of this biome are:

Maple CottonwoodMaple Cottonwood

Beech Oak HickoryBeech Oak Hickory

Elm Cedar ChestnutElm Cedar Chestnut

undergrowth ofundergrowth ofscrubby rhododendrons.scrubby rhododendrons.

vinesvines

Lichen,mossLichen,moss

Millipedes Coleoptera OrthopteraMillipedes Coleoptera Orthoptera

SnailsSnails

Cricket frog salamanders snakesCricket frog salamanders snakes

Frill-necked lizardsFrill-necked lizards

Hawks woodpeckersHawks woodpeckers

Horned owlHorned owl

Gray fox Bob catGray fox Bob cat

SkunkSkunk

Racoon Moose Black bearRacoon Moose Black bear

Boreal forestsBoreal forests

Boreal forests or taigaBoreal forests or taiga

• Boreal forests, or taiga, represent the largest terrestial biome.

• Occur between 50 and 60 degrees north latitudes,• boreal forests can be found in the broad belt of Eurasia

and North America. • Seasons are divided into short, moist, and moderately

warm summers and long, cold, and dry winters. • The length of the growing season in boreal forests is 5

months.• Temperature - very low.

• Precipitation is primarily in the form of snow, 40-100 cm annually.

• Soil is thin, nutrient-poor, and acidic.

• Canopy permits low light penetration, and as a result, understorey is limited.

• Another characteristic feature of this biome is the presence of numerous lakes

• Flora consist mostly of cold-tolerant evergreen conifers with needle-like leaves, such as pine, fir, and spruce.

• Fauna include woodpeckers, hawks, owls,moose, bear, weasel, lynx, fox, wolf, deer, hares, chipmunks, shrews, and bats

Mangroves are salt-tolerant plants of tropical and subtropical intertidal regions of the world.

The specific regions where these plants occur are termed as 'mangrove ecosystem'.

These are highly productive but extremely sensitive and fragile.

Besides mangroves, the ecosystem also harbours other plant and animal species.

The distribution of mangroves on Indian coastlines indicates that the Sundarban mangroves occupy very large area followed by Andaman-Nicobar Islands and Gulf of Kachch in Gujarat.

Rest of the mangrove ecosystems is comparatively smaller.

Over 1600 plant and 3700 animal species have been identified from these areas.

According to a status report of the Government of India publication, the total area of the mangroves in India, was reckoned at about 6,740 km2.

This covered about 7% of the world mangroves (Krishnamurthy, 1987).

But a recent Indian Remote Sensing Data (Nayak, 1993) showed that the total area of the mangroves decreased to 4,474 km2

The floral diversity of mangroves in India is great.

The Indian mangroves are represented by approximately 59 species (inclusive of some mangrove associates) from 29 families.

Of the 59 species, 34 species belonging to 21 families are present along the west coast.

The East coast of India and the Andaman and Nicobar islands show a higher species diversity as well as unique distribution of mangrove flora.

The east coast is represented by 48 species belonging to 32 genera.

Rhizophora apiculata (Red Mangrove):

Rhizophora mucronata (Red Mangrove):

Avicennia marina

Avicennia officinalis:

Acanthus ilicifolius

Since mangroves are transition ecosystems, they give refuge to Since mangroves are transition ecosystems, they give refuge to terrestrial, marine/brackish water as well as purely intertidal terrestrial, marine/brackish water as well as purely intertidal organisms, making itself a richly diversed ecosystem. organisms, making itself a richly diversed ecosystem.

The mangroves may play a special role as nursery habitat for The mangroves may play a special role as nursery habitat for juveniles of fish whose adults occupy other habitats juveniles of fish whose adults occupy other habitats

the submerged mangroves roots, trunks, and branches provide the submerged mangroves roots, trunks, and branches provide niche for bacteria, fungi, macroalgae, and invertebrates. niche for bacteria, fungi, macroalgae, and invertebrates.

The aerial roots, trunks, leaves and branches host other groups of The aerial roots, trunks, leaves and branches host other groups of organisms. organisms.

A number of crab species live among the roots, on the trunks or even forage in the canopy.

Insects, reptiles, amphibians, birds and mammals thrive in the habitat and contribute to its unique character.

The mangrove fauna could also be classified as a) Aquatic, b) Semi aquatic and c) Terrestrial.

Zooplankton - mostly includes crustacean larvae

Insects - Apis dorsata (rock bee) and Apis mellifera (European bee).

Butterflies and moths

Salmona butterfly - Salvadora

Hybloea puera -Avicennia marina

Molluscs and Crustaceans20 species of shellfish and 229 species of Crustaceans have been recorded

Mangrove Crab (Scylla cerata)

Telescopium telescopium - an indicator species for mangroves

• Fish : Mangroves are the breeding and nursery grounds for several species of fish.

• There are a total of 105 species of fish which are typical mangrove dwellers in India.

• Besides, many other species visit the mangrove environment frequently or occasionally.

• Some common species are - scats, milk fish, mudskippers, mullets, cat fish, perches, etc.

• Mud skippers. well adapted to alternating period of exposure to air and submersion and is frequently seen hopping along the mud at the water's edge

Reptiles•

Estuarine or Saltwater Crocodile (Crocodylus porosus): This is the largest crocodile found in India or in the world

• Sea Turtles : Olive Ridley (Lepidochelys olivacea) is the most common sea turtle in Indian waters. Large nesting sites are found in Odisha.

• the Green Turtle (Chelonia mydas), the Leatherback turtle (Dermochelys coriacea)

• Water Monitor Lizard (Varanus salvator) : They are a major predator of crocodile and turtle eggs. Due to overkilling and very long periods of incubation (8-9 months) it has become endangered in India.

• Both aquatic as well as tree dwelling birds are commonly found in mangroves and associated areas

• About 177 species of resident and migratory birds are found in the mangrove forests.

• The most common among these are

BIRDSBIRDS

Kingfishers storksKingfishers storks

herons sea eaglessea eagles

kiteskites

•Flamingoes flock the exposed mud flats, during the low tides. They use mangrove environs as breeding and feeding grounds

sand pipers Curlews duckssand pipers Curlews ducks

• Royal Bengal Tiger (Panthera tigris tigris) : one of the unique resident species of mangroves of the Sunderbans .

• Dugong (Dugong dugong): the Sea Cow, though a frequent mangrove visitor, is not an exclusive mangrove dweller.

• Otters : Otters are also visitors of mangroves and often frequent them in search of food and shelter

Crab eating macaqueCrab eating macaque

The crab eating macaque is an endangered species of monkey.The crab eating macaque is an endangered species of monkey.

In India it is found only in the Andaman and Nicobar islands. In India it is found only in the Andaman and Nicobar islands.

This monkey has adapted to the coastal environment and dwells This monkey has adapted to the coastal environment and dwells amongst the mangrove trees. amongst the mangrove trees.

Another adaptation is its skill in catching crabs which helps it to survive Another adaptation is its skill in catching crabs which helps it to survive in the mangrove habitat.in the mangrove habitat.

In 2000, the tropical forests in our world looked something like this:

© WWF / IAASA

If we did nothing, and carried on depleting our forests at the rate we do today, then by 2100, here's what we'd be left with:

Forests: What future do we want?Forests: What future do we want?