KASHMEERA N.A.KASHMEERA N.A.II SEM MSc.ZOOLOGYII SEM MSc.ZOOLOGYROLL NO:37ROLL NO:37CHRIST COLLEGECHRIST COLLEGE
Term biome was coined by the Americanecologist Frederic Clements.“Largest land unit which is convinient torecognize” – Eugene.P.Odum.The chief character of a biome isdepicted by climax communities with theirdominant life forms.Biomes are grouping of ecosystems withsimilar environment and vegetationstructure.
“The planets lungs.Home to people andwildlife. Engines ofgreen economies.Forests are essentialto life on Earth ”
Forest biomes are characterised by thevegetation with densely growing trees havinga closed ,or nearly so,canopy cover.It include a complex assemblage ofdifferent kinds of biotic communities. The nature of soil,wind and air currentsdetermines the distribution of forestvegetation.
Normally ecologists recognize amoung forestcommunities such features as theirevergreen nature,whether deciduous or indeciduous,whether broad-leaved as in temperate forestsor needle-like as in conifers.On the basis of these features the forestbiomes of the world have been classified intofollowing –coniferous foresttropical foresttemperate forest
Tropical rain forests occur near the equator in Central andsouth America ,central and western Africa,southeastAsia,Malaya,Borneo,New guinea and NorthwestAustralia.In India the main areas of tropical forest are found in theAndaman and Nicobar Islands; the Western Ghats, and thegreater Assam region in the north-east.Tropical rain forests are amoung the most diversecommunities on earth.
One of the major characteristics of tropical forests is their distinctOne of the major characteristics of tropical forests is their distinctseasonality: winter is absent, and only two seasons are present (rainyseasonality: winter is absent, and only two seasons are present (rainyand 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 littleCanopy in tropical forests is multilayered and continuous, allowing littlelight 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 monthsthe average temperatures of the three warmest and three coldest monthsdo 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 differenttree 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 verticallystratified .
Tall trees are often covered withvinesvineslianaslianasepiphyticepiphyticorchidsorchidsbromeliadsbromeliads
Under the tall trees is a continuous evergreen carpet, the canopy layer, some 25to 35 meters tall.The lowest layer is an understorey of trees, shrubs, herbs like ferns and palmsPalms 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 areIsopods spiders planarians leeches.Isopods spiders planarians leeches.Snails millipedes centipedes scorpionsSnails millipedes centipedes scorpions
most common insectsmost common insectsHeteropterans orthopterans blattidsHeteropterans orthopterans blattidsMantids phasmids bees termitesMantids phasmids bees termitesantsants
common vertebratescommon vertebratesRhacophorus malabaricuschameleonsagamidsgeckoes
many species of snakesmany species of birds, social birds beingpredominant
Mammals with nocturnalMammals with nocturnaland arboreal habits areand arboreal habits aremost commonmost commonleopardsleopardsslothsslothsmonkeysmonkeysgiant flying squirrelsgiant flying squirrelsanteatersanteatersjungle catsjungle cats
• The temperate forest biomes are characterized by a moderateThe temperate forest biomes are characterized by a moderateclimate and broad-leaved deciduous trees,climate and broad-leaved deciduous trees,which shed their leaves in fall, are bare over winter and grow newwhich shed their leaves in fall, are bare over winter and grow newfoliage 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 cmwith 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 uniformIn these biomes the precipitation may be fairly uniformthroughout the year.throughout the year.• In India, at elevations of 2743.2m -3655.6m in Himalayas occurIn India, at elevations of 2743.2m -3655.6m in Himalayas occurtemperate vegetationtemperate 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 arethin and broad. The predominantgenera of this biome are:Maple CottonwoodMaple CottonwoodBeech Oak HickoryBeech Oak HickoryElm Cedar ChestnutElm Cedar Chestnut
Boreal forests or taigaBoreal forests or taiga• Boreal forests, or taiga, represent the largest terrestialbiome.• Occur between 50 and 60 degrees north latitudes,• boreal forests can be found in the broad belt of Eurasiaand North America.• Seasons are divided into short, moist, and moderatelywarm summers and long, cold, and dry winters.• The length of the growing season in boreal forests is 5months.• Temperature - very low.
• Precipitation is primarily in the form ofsnow, 40-100 cm annually.• Soil is thin, nutrient-poor, and acidic.• Canopy permits low light penetration, andas a result, understorey is limited.• Another characteristic feature of thisbiome is the presence of numerous lakes
• Flora consist mostly of cold-tolerantevergreen conifers with needle-like leaves,such as pine, fir, and spruce.
Mangroves are salt-tolerant plants of tropical andsubtropical intertidal regions of the world.The specific regions where these plants occur are termedas mangrove ecosystem.These are highly productive but extremely sensitive andfragile.Besides mangroves, the ecosystem also harbours otherplant and animal species.
The distribution of mangroves on Indian coastlines indicates thatthe Sundarban mangroves occupy very large area followed byAndaman-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 identifiedfrom these areas.According to a status report of the Government of Indiapublication, the total area of the mangroves in India, wasreckoned at about 6,740 km2.This covered about 7% of the world mangroves (Krishnamurthy,1987).But a recent Indian Remote Sensing Data (Nayak, 1993) showedthat 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 alongthe west coast.The East coast of India and the Andaman and Nicobar islands show ahigher species diversity as well as unique distribution of mangrove flora.The east coast is represented by 48 species belonging to 32 genera.
Since mangroves are transition ecosystems, they give refuge toSince mangroves are transition ecosystems, they give refuge toterrestrial, marine/brackish water as well as purely intertidalterrestrial, marine/brackish water as well as purely intertidalorganisms, making itself a richly diversed ecosystem.organisms, making itself a richly diversed ecosystem.The mangroves may play a special role as nursery habitat forThe mangroves may play a special role as nursery habitat forjuveniles of fish whose adults occupy other habitatsjuveniles of fish whose adults occupy other habitatsthe submerged mangroves roots, trunks, and branches providethe submerged mangroves roots, trunks, and branches provideniche for bacteria, fungi, macroalgae, and invertebrates.niche for bacteria, fungi, macroalgae, and invertebrates.The aerial roots, trunks, leaves and branches host other groups ofThe aerial roots, trunks, leaves and branches host other groups oforganisms.organisms.
A number of crab species live among theroots, on the trunks or even forage in thecanopy.Insects, reptiles, amphibians, birds andmammals thrive in the habitat and contributeto its unique character.The mangrove fauna could also be classifiedas a) Aquatic, b) Semi aquatic and c)Terrestrial.
Zooplankton - mostly includes crustacean larvaeInsects - Apis dorsata (rock bee) and Apis mellifera (European bee).Butterflies and mothsSalmona butterfly - SalvadoraHybloea puera -Avicennia marina
Molluscs and Crustaceans20 species of shellfish and 229 species of Crustaceans have been recordedMangrove Crab (Scylla cerata)Telescopium telescopium - an indicator species for mangroves
• Fish : Mangroves are the breeding and nursery grounds forseveral species of fish.• There are a total of 105 species of fish which are typicalmangrove dwellers in India.• Besides, many other species visit the mangrove environmentfrequently or occasionally.• Some common species are - scats, milk fish, mudskippers,mullets, cat fish, perches, etc.• Mud skippers. well adapted to alternating period of exposure toair and submersion and is frequently seen hopping along the mudat the waters edge
Reptiles•Estuarine or Saltwater Crocodile (Crocodylus porosus): This isthe largest crocodile found in India or in the world• Sea Turtles : Olive Ridley (Lepidochelys olivacea) is the mostcommon sea turtle in Indian waters. Large nesting sites are found inOdisha.• the Green Turtle (Chelonia mydas), the Leatherback turtle(Dermochelys coriacea)
• Water Monitor Lizard (Varanussalvator) : They are a major predator ofcrocodile and turtle eggs. Due tooverkilling and very long periods ofincubation (8-9 months) it has becomeendangered in India.
• Both aquatic as well as tree dwelling birds are commonly found inmangroves and associated areas• About 177 species of resident and migratory birds are found in themangrove forests.• The most common among these areBIRDSBIRDSKingfishers storksKingfishers storksherons sea eaglessea eagleskiteskites
•Flamingoes flock the exposed mud flats, duringthe low tides. They use mangrove environs asbreeding and feeding groundssand pipers Curlews duckssand pipers Curlews ducks
• Royal Bengal Tiger(Panthera tigris tigris) :one of the unique residentspecies of mangroves ofthe Sunderbans .• Dugong (Dugongdugong): the Sea Cow,though a frequentmangrove visitor, is not anexclusive mangrovedweller.• Otters : Otters are alsovisitors of mangroves andoften frequent them insearch of food and shelter
Crab eating macaqueCrab eating macaqueThe 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 dwellsThis monkey has adapted to the coastal environment and dwellsamongst the mangrove trees.amongst the mangrove trees.Another adaptation is its skill in catching crabs which helps it to surviveAnother adaptation is its skill in catching crabs which helps it to survivein the mangrove habitat.in the mangrove habitat.