A phyto-geographical region is described as an area with consistent climatic conditions and a specific plant type. India may be classified into nine phyto-geographical areas, according to D. Chattarjee (1962).
A phyto-geographical region is described as an area with consistent climatic conditions and a specific plant type. India may be classified into nine phyto-geographical areas, according to D. Chattarjee (1962).
Western Himalayas
North and south Kashmir, as well as parts of Punjab and Uttaranchal’s Kumaon area, make up this region. The area receives 100-200 cm of rain each year on average. The outside southern mountains are damp, whereas the interior parts are fairly dry. Snowfall occurs at high heights throughout the winter. There are three zones in the area.
a) Submontane (lower, tropical and subtropical) zone: This zone encompasses the outside Himalayas, including the Siwalik Hills and surrounding territories, which range in altitude from 300 to 1500 meters. The zone’s average annual rainfall is roughly 100 cm. Subtropical dry evergreen, subtropical pine, and tropical wet deciduous woods make up the vegetation.
b) Temperate (montane) zone: Between 1500 and 3500 metres above sea level, this zone may be found in the western Himalayas. The climate is rainy between 1500 and 1800 metres, and dryer at higher elevations. Wet woods, Himalayan moist, and Himalayan dry temperate forests make up the vegetation.
c) Alpine zone: This zone is located between 3500 and 5000 metres above sea level. Rainfall is scarce, and the temperature is chilly and dry. Alpine forests make up the vegetation.
Eastern Himalayas
This area stretches from Nepal’s east coast to Arunachal in the Himalayas. In comparison to the western Himalayas, the climate is warmer and wetter. The tree line and snow line are roughly 300 meters higher in the eastern Himalayas than in the western Himalayas. Because of the tropical climate and rainfall, the region’s flora has a greater diversity of general species, a larger variety of oaks, but a smaller variety of conifers than the western Himalayas. There are three zones in this region as well.
a) Submontane (lower, tropical and subtropical) zone: This zone stretches from the foothills to an elevation of 1850 meters. The climate is tropical and subtropical in nature. Subtropical broad-leaved woods, pine forests, and moist temperate forests make up the vegetation.
b) Temperate (montane) zone: The zone extends from 1850 m to 4000 m altitude, about 500 m higher than in the western Himalayas. The vegetation consists of typical temperate forests with oaks and Rhododendron at lower and conifers at higher altitudes.
c) Alpine zone: This zone extends from 4000-5000 m altitude. The climate is very cool and dry. The vegetation consists of alpine forests.
Indus plain
A portion of Punjab, Delhi, Rajasthan, and a portion of Gujrat and Cutch make up this area. Summers are extremely dry and hot, with dry and frigid winters in between. Annual rainfall is often less than 70 cm, with some places receiving as little as 10-15 cm. The majority of the land is now desert, while it once had lush woods that were devastated by biotic causes, mainly significant livestock grazing, some 2000 years ago. In certain locations, the vegetation currently consists of tropical thorn woods and grasslands.
Gangetic plain
Parts of Delhi, Uttar Pradesh, Bihar, West Bengal, and Orissa are included in this area. From east to west, yearly rainfall averages 50 cm to 150 cm. Tropical moist deciduous woods, dry deciduous forests, thorn forests, and mangrove forests make up the vegetation.
Assam
The area encompasses the majority of Assam. Extremely high temperatures and rains define the climate. In the lower lowlands, tropical evergreen and moist temperate forests predominate, while subtropical pine forests may be found up to 1700 meters above sea level.
Central India
Parts of Orissa, Madhya Pradesh, the Vindhyan area, and Gujrat make up this region. The terrain is primarily hilly, with some parts reaching 500-700 meters in altitude. The yearly rainfall averages 100-170 cm. In this region, biotic disturbances are prevalent, resulting in the degradation of forests into thorny forests in the open. Tropical wet deciduous forests, mostly Sal forests in places with annual rainfall over 150 cm and mixed deciduous forest in areas with annual rainfall between 125 and 150 cm, make up the vegetation. Tropical thorn forests grow in locations with annual rainfall of less than 125 cm.
Western coast of Malabar
This is a short area that stretches along the Western Ghats from Gujrat to Kanyakumari. The climate is hot and humid, with an annual rainfall of more over 400 cm. On the beaches, the climate is tropical, whereas in the highlands, it is moderate. Tropical wet evergreen, moist evergreen, and moist deciduous forests make up the vegetation. In Nilgiri, wet temperate woods (Sholas) can be found, whereas mangrove forests can be found in coastal saline marshes.
Deccan
The region encompasses southern Peninsular India, excluding the Western Ghats, from southern Madhya Pradesh to Kanyakumari. The area receives roughly 100 cm of rain each year on average. Tropical dry evergreen, dry deciduous, and swamp forests make up the vegetation.
Andaman and Nicobar
Andaman and Nicobar Islands are part of this area. The region’s climate is hot and humid, with high temperatures and yearly rainfall. Littoral mangroves, evergreen, semi-evergreen, and deciduous woods make up the vegetation.
