PHYTOGEOGRAPHIC ZONES OF INDIA
PHYTOGEOGRAPHIC REGIONS OF INDIA
1. North-West Himalayas 2. Indo-Gangetic Plain 3. Eastern Himalayas 4. Assam
5. Central India 6. Arid Zone
7. Northern Western Ghats and West Coast
and West Coast
8. Southern Western Ghats, West coast and Lakshadweep 9. Deccan
10. Eastern Ghats and Coromandel coast
11. Andaman and Nicobar islands FLORA OF INDIA, INTRODUCTORY
VOLUME, PART 1 (1996) BSI.
1. NORTH-WEST HIMALAYAS
Comprises the states of Jammu &Kashmir, Himachal Pradesh and Western Uttar Pradesh (now Uttarakhand).
Rodgers and Panwar (1988) divided
Rodgers and Panwar (1988) divided
Himalayas into two zones (a) Trans Himalaya and (b) Himalayas.
Under these two zones there are five biotic provinces
(a) Tibetan (b) North-West Himalayas (c) West Himalayas (d) Central Himalayas and (e) East Himalayas
Mountain ranges to the west of 77O E---- Mountain ranges to the west of 77 E----
Western region (Kashmir, Punjab and Himachal Pradesh)
---between 77O & 84O E Central region
---beyond 84O E Eastern region
W E S T E R
H I M
A L A
C E N
T H
I M
A
E A S
H I M
77O 84O
R N
A Y A S
T R A L
A L A Y A S
S T E R N
M A
L A Y A S
Altitudinal Climatic Zones
(i) Submontane (Tropical and Sub tropical) zone
This area extends from nearly 300 to 1500 m in Siwalik ranges and adjoining areas.
Forests are tropical and subtropical.
Dominant species are Cedrela toona (toon), Dalbergia sissoo (shisham) and Shorea robusta (Sal).
Open areas are occupied by Acacia catechu (Khair or Kattha),
Open areas are occupied by Acacia catechu (Khair or Kattha), Butea monosperma (dhak), Ziziphus sp. (jhar beri etc.) and Euphorbia royleana.
Pinus roxburghii occurs in upper regions of this zone (ii) Temperate zone
Altitude range from 1500-3500 m
Common components are Pinus wallichiana, and Cedrus deodara
At higher altitudes Aesculus indica, Abies pindrow and Taxus baccata.
At still higher altitudes occur Betula utilis and species of Salix and Rhododendron
(iii) Alpine Zone
Altitudinal range: 3500-4500 m
3500 m is tree limit or tree line in western Himalayas, therefore, Alpine zone begins beyond the tree line.
Alpine zone begins beyond the tree line.
Dominated by dwarf bushy shrubs such as Salix, Lonicera, Cassiope and Juniperus.
Alpine meadows dominated by species of Potentilla, Iris, Saxifraga, Primula, Euphrasia, Pedicularis, Geranium and Polygonum.
2. INDO-GANGETIC PLAIN
Cover South-East Punjab below Satluj and Beas rivers, plains of Haryana, plains of Uttar Pradesh and Bihar in between himalayas in the north and Vindhyas and Rajmahal hills on the south.
Inclusion of west Bengal and Sundarbans in this region is controversial.
Roughly divided in to (a) moist dry western part
(b) relatively humid Bihar and West Bengal and (c) deltoid (b) relatively humid Bihar and West Bengal and (c) deltoid Sundarbans.
Rainfall ranges from 70 cm in western parts to more than 150 cm in west Bengal.
Vegetation ranges from moist tropical forests to dry deciduous forests.
Roy (1996) recognized five forest types in Indo-Gangetic Plains.
(i) Sal forests: Common in northern belt. Up to 90% of vegetation consists of Shorea robusta . Best quality of sal forests occur in north Kheri.
(ii) Mixed forests: Occur in in terai close to foothills of Nepal (relatively moist), along Bundelkhand, Kaimore Hills (Mixed deciduous and Dry thorn type)
deciduous and Dry thorn type)
In relatively moist type characteristic species are Premna scandens, Mallotus repandus, Clematis cadmia and Alangium begoniifolium etc.
In relatively drier type characteristic species are Balanites aegyptiaca, Ziziphus xylocarpus, Z. nummularia, Acacia
leucophloea, Butea monosperma and Capparis aphylla etc.
(iii) Swamp forests: Occur in water-logged swampy areas.
Characteristic species are Syzygium cumini, Trewia nudiflora,
Ficus glomerata, Litsaea polyantha, Barringtonia acutangula and Rosa involucrata etc.
(iv) Alluvial forests: Occur along the banks of rivers and are frequently flooded.
frequently flooded.
Most characteristic species is Tamarix dioica along with Saccharum spontaneum (Kans).
On older soil (either due to elevation or due to changed course of the river) tree species like Bombax ceiba, Acacia catechu,
Dalbergia sissoo and Lannea coromandelica gradually appear.
(v) Mnagrove forests of Sunderbans: Typically an evergreen forest
on tidal muddy flats.
Remains permanently wet with salt water submergence from every tide.
Trees of moderate height.
Common species are Heritiera fomes, Rhizophora spp.,
Avicennia alba, Sonneratia apetala and species of Xylocarpus and Ceriops.
3. EASTERN HIMALAYAS
This region covers Darjeeling and Sikkim and extends in the east to Arunachal Pradesh
Most Humid tract of Himalayas.
Characterized by higher rainfall, less snow and higher mean temperature as compared
to western Himalayas.
Altitudinal climatic zones extend about
300-500 meter higher than western Himalayas 300-500 meter higher than western Himalayas
Like western Himalayas there are following three altitudinal climatic zones.
This region has higher proportion of tropical elements ( about 250 tree species) and more species of Rhododendron and Quercus.
(i) Submontane (tropical and subtropical) zone
Extends from foothills to 1800 m and has tropical semi-evergreen and deciduous forests dominated by Shorea robusta.
Other common species belong to the genera Bauhinia, Anthocephalus, Lagerstroemia, Bombax and Bambusa.
(ii) Temperate (Montane zone)
Extends from 1800 to 3800 m.
Forests dominated by Quercus, Michelia and Eugenia etc. in lower areas.
At higher altitudes Cryptomeria, Juniperus and Rhododendron are common. Among bamboos Arundinaria is also found here.
(iii) Alpine zone (iii) Alpine zone
Extends from 3800 to 5000 m.
Among common plants are dwarf shrubs of Juniperus and Rhododendron. Among herbaceous plants are species of
Polygonum, Potentilla, Gentiana and Anemone.
WESTERN HIMALAYAS EASTERN HIMALAYAS
4500 m
3800 m 5000 m
Alpine
Dwarf shrubs of Juniperusand
Rhododendron;herbaceous species :Polygonum, Potentilla, Gentiana and Anemone.
Permanent ice and snow
Dwarf shrubs: Salix, Lonicera, Cassiope and Juniperus.
Herbs: Potentilla, Iris, Saxifraga, Primula, Euphrasia, Pedicularis, Geranium andPolygonum.
Permanent ice and snow
1500 m
3500 m
1800 m
Sub-montane Temperate
Cedrela toona, Dalbergia sissoo, Shorea robusta Acacia catechu, Butea monosperma, Ziziphus sp., Euphorbia royleana (in open areas)
Pinus longifolia, P. roxburghii
Dominated by Shorea robusta, other species include Bauhinia, Anthocephalus, Lagerstroemia, Bombaxand
Bambusa
Quercus, Michelia, Eugenia, Pyrus, and Echinocarpus etc.
Cryptomeria, Juniperus, Picea
spinulosa, Abies, Larix, Tsuga griffithii, T. brunoniana, Rhododendron
and Arundinaria Populus, Rhododendron, Betula, Quercus,
Pyrus, Pinus excelsa, Taxus, Picea, Abies and Cupressus etc.
4. ASSAM
This north-eastern region has very heavy rainfall, up to 1000 cm in Cherapunji.
The vegetation is dominated by evergreen tree species of Dipterocarpus, Shorea, Ficus Mesua etc.
Bamboos, ferns and orchids (world’s highest concentration) are also very common.
Takhtajan considered these forests as ‘Cradle
Takhtajan considered these forests as ‘Cradle of Angiosperms’ because of rich representation
of primitive taxa such as members of Magnoliaceae, Winteraceae, Annonaceae and many vessel-less genera.
In hilly areas species of Pinus, Betula and Rhododendron are common.
Wild tea (Camellia sinensis var. assamica)was discovered in
upper Brahmaputra valley (Lakhimpur & Sibsagar districts) by Robert Bruce in 1823.
5. CENTRAL INDIA
Almost synchronizes with the political boundaries of Madhya Pradesh.
Lies between Gangetic plain in the north and Deccan peninsula in the south (18O N – 26O N latitudes and 74O E- 85O E longitudes).
Vindhyas and Satpura ranges, running from north-east to south-west with Nrmada valley between them.
between them.
Rainfall 700-2000 mm.
FOREST TYPES:
Two major forest types:
1. Tropical forests
(a) Northern tropical semi-evergreen forests
Dense and richest in species composition
but not very extensive. Ferns and orchids abundant.
Important trees:
Shorea robusta, Terminalia alata, Pterocarpus marsupium, Stereospermum chelonoides, and Dalbergia paniculata etc.
(b). Tropical moist deciduous forest:
Occur on lower hill slopes-and ravines in eastern, central and southern Madhya Pradesh and adjoining western regions of Orissa.
Average annual rainfall about 1500 mm.
Ferns and orchids found in moist areas.
Important tree species Shorea robusta, Terminalia alata, T. bellirica, T. chebula, Pterocarpus marsupium, Dalbergia paniculata, Lannea coromandelica, and Bombax ceiba etc.
ceiba etc.
C. Tropical dry deciduous forests:
Mostly found in areas with low rising hills, flat countries or plateaus receiving average annual rainfall between 850-1300 mm and long dry periods of nearly six months (February to July).
Found in the northern, western and central western Madhya Pradesh.
Ferns and orchids absent.
Important tree species are Terminalia elliptica, T. bellirica, T. chebula, Tectona grandis, Bombax ceiba, Madhuca longifolia var. latifolia, Garuga pinnata, Soymida febrifuga etc.
D. Tropical thorn forests:
Species poor forests found on shallow and poor soils.
Rainfall between 700-1000 mm.
Confined to a small area in the plains and low hills of the north-west border of Morena and in the south-west corner of West Nimar.
Important trees are Acacia nilotica ssp. indica, A. leucophloea, A. catechu, Aegle marmelos, Cordia obliqua etc.
2. Montane subtropical forests:
Occur in small patches on hill tops above 1200 m in places like Pachmarhi and Bailadila in Madhya Pradesh. Rainfall sufficiently high but the soil can not and Bailadila in Madhya Pradesh. Rainfall sufficiently high but the soil can not retain moisture.
Important tree species are Michelia champaca, Syzygium cumini, Manilkara hexandra, Salix tetrasperma, Litsea monopetala, and Dillenia indica and tree ferns like Cyathea gigantea and C. spinulosa etc.
6. ARID ZONE
In India the Western arid Zone encompasses vast areas of western Rajasthan, western Gujarat, south-western Punjab and Haryana.
Total area about 2,85,600 sq. km.
Arid area in Rajasthan about 62% of total area of the state.
Punjab 5%
Haryana 4%
Gujarat 20%
This zone includes Delhi too.
This zone includes Delhi too.
Rainfall ranges between 403.2 mm in Bhatinda (Punjab) to 322.2 mm in Kutch (Gujarat). 79% to 96% of total rainfall is received during monsoons and 1-12%
in winters.
In Rajasthan mean maximum temperature ranges between 40.5O-43OC and mean minimum temperature 23.8O – 25.5OC.
Based on edaphic factors the vegetation of western Rajasthan is of following types a. Sand dunes and interdunal areas: About 58% of western Rajasthan is
covered with dunes. Common species on dunes are Calligonum polygponoids, Calotropis procera, Capparis decidua and Lycium barbatum.
Vegetation is more luxuriant in interdunal areas. Common species are Acacia jacquemontii, Prosopis cineraria, Salvadora oleioides, Tecomella undulata etc.
b. Sandy and hummocky plains: Calligonum polygponoids, Calotropis procera, Capparis decidua and and Ziziphus nummularia.
c. Gravelly/rocky plains: Calligonum polygponoids, Calotropis procera, Capparis decidua and Maytenus emarginatus.
d. Isolated hills and rock outcrops: Most characteristic plant of this
vegetation type is cactiform Euphorbia caducifolia, other species are Commiphora wightii, Grewia tenax, and Maytenus emarginatus.
e. Saline habitats: Important species are Chenopodium album, Cressa e. Saline habitats: Important species are Chenopodium album, Cressa cretica, and Haloxylon salicornicum etc.
In the Rann od Kutch Artocnemon indicum, Peplidium maritimum, Salicornia brachiaria and Sesuvium portulacastrum etc.
7. NORTHERN WESTERN GHATS AND WEST COAST
The west coast runs for about 1600 km and borders the Arabian sea. It is limited by Cambay in the north and by Kanyakumari in the south.
The coastal region between Tapi (Tapti) basin and Goa (about 750 km long) is termed as North-western coast or North-western Ghats.
The remaining part between Goa and Kanyakumari is termed as south –western ghats. Also known as is termed as south –western ghats. Also known as
‘Sahyadris’ in Maharashtra.
Mean annual temperature varies from 20O C -24O C.
Mean annual rainfall ranges between 2359 mm to 7450 mm.
Vegetation types:
a. Sandy sea shores: Aleuropus lagopoides, Cressa cretica, Hyphaene dichotoma, Pandanus tectorius
b. Mangrove vegetation: Avicennia marina, Rhizophora mucronata, Sonneratia alba, Acanthus ilicifolius,
Kandelia candel and Lumnitzera racemosa etc.
Scrub forests: Occur along foothills and lower elevations. Important species are Maytenus senegalensis, Acacia chundra, A. nilotica, and Capparis divaricata etc.
Dry deciduous forests: Occur at relatively higher elevations. Important species Tectona grandis, Albizi odoratissima, Bauhinia racemosa and Bombax ceiba etc.
Tropical moist deciduous forests: Usually found along hill slopes. Important species are Albizia chinensis, Canthium dicoccum, Catunaregum spinosa, Macaranga peltata etc.
Montane subtropical forests: These forests are not typical evergreen forests as Montane subtropical forests: These forests are not typical evergreen forests as trees tend to be dwarf and without any tiers or canopy. Important species are Actinodaphne angustifolia, Cinnamomum verum, Elaeocarpus serratus and Garcenia indica etc.
8. SOUTHERN WESTERN GHATS, WEST COAST AND LAKSHADWEEP
The coastal region between Goa and
Kanyakumari is termed as ‘south western ghats.
Also known as ‘Shayadri’ in Maharashtra.
Also known as ‘Shayadri’ in Maharashtra.
Mean annual temperature is around 24OC while in southern parts the mean annual temperature is 20OC. Mean annual rainfall is 2350 mm in north and 7450 mm in south.
LAKSHADWEEP
An archipelago Consists of 12 atolls, 3 reefs and 5 submerged banks.
Total area 36 sq km.
Only ten (Agatti, Amini, Andrott, Bitra, Chetlat, Kadmat, Kalpeni, Kavaratti, Kiltan and
and Minicoy) are inhabited.
Rivers, streams and ground water absent. Highest point not
more than 5m above msl.
CLIMATE
Humid tropical type. Temperature ranges between 17OC to 38OC.
Annual rainfall varies between 1500 mm in the northern islands to 1640 mm in southern islands.
VEGETATION Forest cover nil.
Forest cover nil.
Natural flora consists only of psammophytic herbs and shrubs There is no endemic species on these islands.
Important species are Alstonia scholaris, Azadirachta indica, Bombax ceiba, Callophyllum inophyllum, Terminalia catappa, Casuarina littorea.
Other species are Cordia subcordata, Pemphis acedula, Guettarda speciosa, and Thalassia hemprichii.
9. DECCAN
Bounded on the eastern side by Eastern Ghats, on the west by Western Ghats, forms a broad based inverted triangle comprising a part of Madhya Pradesh, and the plains and tablelands of
Maharashtra, Karnataka, Andhra Pradesh, and Dharmapuri district of Tamilnadu.
PHYSIOGRAPHY: Deccan consists of three distinctive physiographic subdivisions
(a) North Deccan Plateau/Maharashtra Plateau (b) South Deccan Plateau
(i) Telangana plateau (i) Telangana plateau (ii) Rayalaseema uplands (iii) Karnataka plateau (iv) Tamilnadu uplands (c) East Deccan plateau
VEGETATION: Main forest types are as follows 1. Moist Tropical Forests: Maharashtra plateau,
Trees: Tectona grandid, Haldina cordifolia, Terminalia bellerica, T. chebula, Anogeissu latfolia 2. Dry Tropical forests: Drier parts of the plateau.
Anogeissus latfolia, Boswellia serrata, Tectona grandis, Cochlospermum religiosum Hardwickia binata.
Tropical Dry Deciduous forests: Telangana Plateau, Karantaka plateau, East Deccan plateau.
Vegetation: Aegle marmelos, Boswellia serrata,Diospyros melanoxylon, Gardenia gummifera, Gmelina arborea, Tamilnadia uliginosa, Capparis sepiaria, Clerodendrum philomidis.
Tropical moist deciduous forests: Telangana plateau, Karnataka plateau.
Vegetation: Anogeissus acuminata, Barringtonia acutangula, Lagerstroemia parviflora, Miliusa tomentosa, Strychnos nux-vomica, Woodfordia fruticosa.
Tropical dry evergreen forests: Occur in gorges, ravines, and valleys in Rayalaseema uplands.
uplands.
Vegetation:Abizia amara, Cassine glauca, Manilkara hexandra, Santalum album and Syzygium cumini.
Tropical Thorn Forests: Rayalaseema uplands, Karnataka plateau, Tamilnadu uplands.
Vegetation: Acacia ferruginea, Capparis sepiaria, C. zeylanica, Carissa spinarum, Lantana camara, Mimosa rubicaulis and Ziziphus oenoplia.
10. EASTERN GHATS AND COROMANDEL COAST
Extend in a north-east south-west direction.
These hill ranges extend from Mahanadi in Orissa in the north to the Nilgiris in south through the states of Andhra, Tamilnadu, and small part of Karnataka.
Total area 75000 sq km and length 1750 km. The altitude varies from 666 m (Kollimalai, Bodamalai) to 1803 m (Shevaroy hills).
Vegetation:
Northern Tropical moist deciduous forests: Includes sal forests and rest.
Northern Tropical moist deciduous forests: Includes sal forests and rest.
Sal forests in which sal forms 60-90% of canopy occur only in Orissa.
Southern Tropical moist deciduous forests: Also called non-sal forests.
Occur in Gudem-Rampa agency, parts of west-Godavari district, Gundlabrhmeswaram in Nallamalais, some portions of Tamilnadu, and Bedguli hills.
Vegetation: Albizia odoratissima, Ardisia solanacea, Careya arborea, Dalbergia latifolia, Pterocarpus marsupium, Tectona grandis etc.
Southern Tropical Wet Evergreen Forests: In valleys of Shevaroy hills and Bedguli hills. Rich in epiphytic aroids, ferns and orchids.
Orissa tropical semi evergreen forests: Number of top storey trees deciduous and those of second storey evergreen. Mostly found in orissa.
Vegetation: Top layer--- Artocarpus lakoocha, Dillenia petagyna, Mangifera indica, etc.
Lower strey: Aphamixis polystachya, Murraya koenigii, Polyalthea cerasioides.
Red Sanders bearing forests: Occur along the middle and southern sections of eastern ghats.
Most characteristic species ‘Red Sanders’ (Pterocarpus santalinus) known as pride of eastern ghats.
11. ANDAMAN AND NICOBAR ISLANDS
A group of 500 plus islands in bay of Bengal.
The islands extend from 6° to 14° North latitudes and from 92° to 94° East longitudes.
Two separate groups, Andaman (northern) and Nicobar (southern) separated by the ‘ten degree channel’.
The Andaman group: 325 islands, total area 6,170 km2.
The Nicobar group: 247 islands, total area 1,765 km2.
The Nicobar group: 247 islands, total area 1,765 km2.
The Andaman Islands are home to the only known Paleolithic people, the Sentinelese people.
CLIMATE
Climate in general is tropical type.
Average temperature around 26 – 27OC.
Average temperature around 26 – 27 C.
Average precipitation 2200-3100 mm.
March is the driest month.
VEGETATION
The climatic climax is typically the ‘Tropical Lowland Rain Forest’.
Forests occupy 94.6% of the geographical area (FSI, 2015).
Balakrishnan (1977, 1980) classified the vegetation into 2 major groups and 8 types.
Group 1: Littoral (Tide affected near shore) Type i: Submerged vegetation
Type ii: Mangrove vegetation
Type iii: Strand vegetation (a relief beyond the high tide limit)
Type iv: Tidal and swampy forests
Group 2: Inland (Away from the effect of tide water) Type i: Evergreen forests
Type ii: Deciduous forests Type iii: Grasslands
Type iv: Hydrophytic vegetation
Group 1: Littoral (Tide affected near shore) Type i: Submerged vegetation
Includes marine algae and angiosperms.
Enteromorpha, Ulva, Acetabularia, Padina, Sargassam, and Ceramium common algae.
Cymodocea rotundata (Cymodoceaceae), Enhalus Cymodocea rotundata (Cymodoceaceae), Enhalus acoroides, and Halophila, and Thalassia
(Hydrocharitaceae) are angiosperms.
Group 1: Littoral (Tide affected near shore) Type ii: Mangrove Vegetation
Mangrove forests of Andaman and Nicobar one of the best in the world having high floristic
richness, complexity index and biomass production.
Cover about 15% of the total area. Better Cover about 15% of the total area. Better formed in Andaman Islands.
Common tree species are Rhizophora mucronata, R.
apiculata, R. conjugata, and Carallia brachiata.
Nypa fruticans is a common mangrove palm.
Group 1: Littoral (Tide affected near shore) Type iii: Strand vegetation
Herbaceous vegetation on sand dunes and beach forests behind the dunes.
Common herbaceous species are Ipomoea pes-carpae, Vigna marina, Phyla nodiflora, Ischaemum muticum, and Spinifex littoreus.
Ischaemum muticum, and Spinifex littoreus.
Common beach forest species are Hernandia peltata, Thespesia populnea, Sophora
tomentosa, and Cycas rumphii etc.
Group 1: Littoral (Tide affected near shore)
Type iv: Tidal and swamp forests
Occur in areas where soil is slightly saline and wet or marshy but not permanently flooded by sea water.
The trees show certain adaptations like buttress roots, stilt roots and conically thickened stem bases roots, stilt roots and conically thickened stem bases
Common trees are Barringtonia racemosa, Heritiera littoralis, Ficus religiosa, Xylocarpus granatum, Dolichandron rheedii and Sonneratia acida.
In Great Nicobar Island large wild populations of Areca catechu associated with Syzygium samarangense, Ficus rumphii, and
Mangifera camptosperma may be seen.
Mangifera camptosperma may be seen.
Group 2: Inland (Away from the effect of tide water) Type i: Evergreen forests
Represent the climax vegetation in islands. Canopy is closed with little light reaching the floor, three or more strata of storeys, and soil very poor in humus.
Evergreen forests of Andaman and Nicobars are Evergreen forests of Andaman and Nicobars are ecologically similar but floristically different.
Andaman forests are mainly composed of various species of Dipterocarpus which is absent in Nicobars.
Group 2: Inland (Away from the effect of tide water) Type ii: Deciduous forests
Grow on hill slopes where soil has low water holding capacity.
The trees remain treeless for major part of dry season.
Mainly found in North, Middle and some Mainly found in North, Middle and some
part of South Andamans. Pterocarpus dalbergioides is the main timber tree of these forests.
Deciduous forests replaced by mixed evergreen forests in Nicobars.
A characteristic gymnospermous tree Gnetum gnemon occurs in these forests.
Gnetum gnemon
Group 2: Inland (Away from the effect of tide water) Type iii: Grasslands
Disturbed and degraded hillocks in Andaman Islands show rich grasslands dominated by Imperata
cylindrica, associated with Themeda triandra and
Saccharum spontaneum. Other less dominant species are Heteropogon contortus, Chloris barbata and
are Heteropogon contortus, Chloris barbata and species of Eragrostis.
Group 2: Inland (Away from the effect of tide water) Type iv: Hydrophytic vegetation
Fresh water flora is poor due to scarcity of natural stagnant water bodies. Few man made and natural ponds and paddy fields provide abode to plants like Ipomoea aquatica, Nymphaea nouchali, Hydrilla
verticillata, and Najas indica etc.
verticillata, and Najas indica etc.
Ludwigia perennis, Blyxa roxburghii, Monochoria
vaginallis and Polygonum barbatum occur in marshy areas.
