Tundra: Tundra is the world coldest and driest biome. This type of biome is totally snow covered vegetation at mountain tops.
- Soils are rich in organic matter due to slow decomposition rate and it is also one among the earth’s three major carbon dioxide sink. There are three types or tundra-1. Arctic Tundra 2. Antarctic Tundra 3. The alpine Tundra
A grassland ecosystem is the collection of plants, animals and micro-organisms that live within an environment where grasses are the primary form of vegetation. Grasslands cover temperate and tropical regions, generally within the dry interior areas of land masses. Such grassland experience wide range of temperature from about -20 to 30°C in extreme winter and warm summer. The amount of rainfall in grassland ecosystems is too little to support many large plants, though some trees do occur.
- In tropical grassland ecosystems, the heavy precipitation of the rainy season follows months of dry heat
- Temperate grasslands alternate periods of abundance with periods of dormancy when the temperatures are too cold for growth.
- Some grassland ecosystems, such as the savanna or the prairie, produce tall grasses.
- Others, such as the windy steppes, grow very short grasses often less than an inch high.
Grassland ecosystems can support high densities of grazing animals. They are home to many familiar and fascinating species that live in herds, including zebras and antelopes, and the predators that prey on them, like lions and cheetahs.
- Temperate grassland: Such types of grassland have cold winters and warm summers. Summer temperature ranges to 38°C in summer and as low as -40°C in winter. Various species of grassland which include purple needle grass, blue grass, and buffalo grass are found here. Located between temperate forest at high latitude and desert at subtropical latitude and known by different names in different parts of the world as:
- The Prairies of the great plains of North America
- The Pampas of South America
- The Veldt of South Africa
- The Steppes of Central Eurasia
- The Savanna in Africa
Forest ecosystem is the scientific study of the interrelated patterns, processes, flora, fauna and ecosystems in forests. The management of forests is known as forestry, silviculture, and forest management. A forest ecosystem is a natural woodland unit consisting of all plants, animals and micro-organisms (Biotic components) in that area functioning together with all of the non-living physical (abiotic) factors of the environment. Forests accumulate large amounts of standing biomass, and many are capable of accumulating it at high rates, i.e. they are highly productive. Since trees can grow larger than other plant life-forms, there is the potential for a wide variety of forest structure (or physiognomies). The infinite number of possible spatial arrangements of trees of varying size and species makes for a highly intricate and diverse micro-environment in which environmental variables such as solar radiation, temperature, relative humidity, and wind speed can vary considerably over large and small distances.
Indian Forest Types
There are sixteen types of Indian forest. There are:
1. Tropical Wet evergreen forest
- Wet evergreen forests are found along the Western Ghats, the Nicobar and Andaman Islands and all along the northeastern region. It is characterized by tall, straight evergreen trees. The more common trees that are found here are the jackfruit. Betel nut palm, jamun, mango, and hol-lock. The trees in this forest form a tier pattern:
shrubs cover the layer closer to the layer closer to the ground, followed by the short structured trees and then the tall variety. Beautiful fern of various colors and different varieties of orchids grow on the trunks of the trees.
2. Tropical Semi-evergreen forests
- Semi-evergreen forests are found in the Western Ghats, Andaman and Nicobar Islands, and the Eastern Himalayas. Such forests have a mixture of the wet evergreen trees and the moist deciduous trees. The forest is dense and is filled with a large variety of trees of both types.
3. Tropical Moist deciduous forests
- Moist deciduous forests are found throughout India except in the western and the north-western regions, The trees are tall, have broad trunks, branching trunks and roots to hold them firmly to the ground. Some of the taller trees shed their leaves in the dry season. There is a layer of shorter trees and evergreen shrubs in the undergrowth. These forests are dominated by sal and teak, along with mango, bamboo, and rosewood.
4. Littoral and swamp
- Littoral and swamp forests are found along the Andaman and Nicobar Islands and the delta area of the Ganga and the Brahmaputra. They have roots that consist of soft tissue so that the plant can breathe in the water.
5. Tropical Dry deciduous forest
- Dry deciduous forests are found throughout the northern part of country except in the North-East. It is also found in Madhya Pradesh, Gujart, Andhra Pradesh, Karnataka, and Tamil Nadu. The canopy of the trees does not normally exceed 25 meters. The common trees are the sal, a variety of acacia, and bamboo.
6. Tropical Thorn forests
- this type is found in areas with black soil: North. West, Central, and south India. The trees do not grow beyond 10 meters. Spurge, caperand cactus are typical of this region.
7. Tropical Dry evergreen forest
- Dry evergreens are found along Tamil Nadu, Andhra Pradesh and Karnataka coast. It is mainly hard-leaved evergreen trees with fragrant flowers, along with a few deciduous trees.
8. Sub tropical Board-leaved forests
- Broad-leaved forests are found in the Eastern Himalayas and the Western Ghats, along the Silent Valley. There is a marked difference in the form of vegetation in the two areas. In the Silent Valley, the poonspar, cinnamon, rhododendron, and fragrant grass are predominant. In the Eastern Himalayas, the flora has been badly affected by the shifting cultivation and forest fires. These wet forests consist mainly of evergreen trees with a sprinkling of deciduous here are there . There are oak, alder, chestnut, birch, and cherry trees. There are a large variety of orchids, bamboo and creepers.
9. Sub tropical Pine forests
- Pine forests are found in the steep dry slopes of the Shive lik Hills, Western and Central Himalayas, Khasi, Naga, and Manipur Hills. The trees predominantly found in these areas are the chir, oak, rhododendron, and pine as well as sal, am la, and laburnum are found in the lower regions.
10. Sub tropical Dry evergreen forests
- Dry evergreen forests normally have a prolonged hot and dry season and a cold winter. It generally has evergreen trees with shining leaves that have a varnished look. There forests are found in the Shivalik Hills and foothills of the Himalayas up to a height of 1000 meters.
11. Montane Wet temperate forests
- In the North, Montane wet temperate forests are found in the region to the east of Nepal into Arunachal Pradesh, receiving a minimum rainfall of 2000 mm. In the North, there are three layers of forests: the higher layers has mainly coniferous, the middle layers has deciduous trees such as the oak and the lowest layes is covered by rhododendron and champa.
In the South, it is found in parts of the Nilgiri Hills, the higher reaches of Kerala. The forests in the northern region are denser than in the south. Rhododendrons and variety of ground flora can be found here.
12. Himalayan Moist temperate Forest
- This type spreads from the Western Himalayas to the Eastern Himalayas. the trees found in the western section are broad-leaved oak, brown oak, walnut, rhododendron, etc. In the vegetation is also more lush and dense. There are a large variety of broad-leaved trees, ferms, and bamboo. Coniferous trees are also found here, some of the varieties being different from the ones found the South.
13. Himalayan Dry temperate Forest
- This type is found in Lahul, Kinnaur, Sikkim, and other parts of the Himalayas.. There are predominantly coniferous trees, along with broad-leaved trees such as the oak, maple, and ash. At higher elevation, fir, juniper, deodar, and chilgoza are found.
14. Sub alpine forest
- Sub alpine forests extend from Kashmir to Arunachal Pradesh between 2900 to 3500 meters. In the Westerns Himalayas, the vegetation consists mainly of juniper, rhododendron, willow, and black currant. In the eastern parts, red fir, black juniper, birch, and larch are the common trees. Due to heavy rainfall and high humidity the timber line in this part higher than that in the Wests. Rhododendron of many species covers the hills in these parts.
15. Moist alpine scrub
- Moist alpines are found all along the Himalayas and on the higher hills near the Myanmar border. It has a low scrub, dense evergreen forest, consisting mainly of rhododendron and birch. Mosses and ferns cover the ground in patches. This region receives heavy snowfall.
16. Dry alpine scrub
- Dry alpines are found from about 3000 meters to about 4900 meters. Dwarf plants predominate, mainly the black juniper, the drooping juniper, honeysuckle, and willow.
Desert: Desert biomes is the driest of all the biome and is located at 30°North & South and cover about one fifth of the earth’s surface.
- Most of the desert receive about 250 mm of rain. Due to poor canopy and sparse distribution of plants. The leaf to poor canopy and sparse distribution of plants. The Leaf area index is less than one and productivity is also less.
- Most of the desert receive about 250 mm of rain per year as compared to rainforest which receive over 2000 mm. The largest desert of Earth is Antarctica. They are classified into:
- Arid desert: These types of deserts are found in North-America, South-America, Africa, and Southern Asia where there is low latitudes. Here generally the temperature is hot and dry with few occurrence of rainfall in winters. In daytime it is very hot as there are no clouds to cover the earth. The soil here is mostly sand or coarse and rocky. Here vegetation is mostly shrubs and small trees and leaves are adapted to retain water. the animals are generally active during night.
- Semi-arid deserts: These deserts are found in North-America, Europe, Russia and Northern Asia. Here also there is low rainfall during winters. Here animals can be found in daytime but under the trees or shades.
- Coastal deserts: These deserts are found in areas which are warmer to cooler such as in Nootropic and Nearctic area. Here, the summers are long and warmer while the winters are short and cold. The sand consists of alkaline and the soil is porous so that rain water can enter the ground. Mostly the vegetation here is thick foliage with good water retention quality. The roots of these plants re near to the surface so that they can get water before water drains to the soil. Animals of these desert comprise rough skinned amphibians, birds of prey, scavenger mammal’s reptiles and insects. Animals here are largely nocturnal during the warmer months.
- Cold deserts: They are the deserts which occur mainly in the cold regions. Here the temperature during the warmest mont is 10°C/ They are mostly covered with snow and ice and due to this they do not support life. Animals in the cold desert are burrowers, even the carnivores and reptiles, which even though cold-blooded, have made their homes in the cold desert. Antarctica is the largest cold desert.