Natural Vegetation Flashcards
Define natural vegetation
Natural vegetation refers to the plant community which has grown naturally without any human assistance and has not been disturbed over a long time, so as to allow its individual species to adjust themselves fully to the climate and soil conditions
What constitutes the natural vegetation of an area?
Grasses, shrubs and trees
What does flora refer to?
Flora refers to plants of a particular region or period, listed as species and considered as a group
How many species of plants do the Eastern Himalayas have?
4000 species, which vary with increasing altitude from tropical to temperate and alpine
What does vegetation refer to?
Vegetation refers to the assemblage of plant species living in association with each other in a given environmental setup.
What are the major vegetation types in the world grouped as?
Forests, grasslands, scrubs and tundra
What does forest refer to?
Forest refers to a large tract of land covered with trees and accompanying undergrowth of shrubs, herbs and sustaining thousands of life forms, which include both plants and animals.
What is a forest in legal terminology?
It is ant land with a vegetative cover, that has been so declared under a legal provision
What are the productive functions of a forest?
- Various trees provide us with various products. Wood is used for making furniture in houses as well as as industrial units.
- Wood and bamboo pulp are used for manufacturing paper and paper boards.
- Wood is used as a source of energy for cooking and for providing warmth.
- Forest products like timber, firewood, fibres, essential oils, oil seeds and edible plants.
- Bamboo provides a means of livelihood for the tribals who make mats, baskets, ropes , etc., using bamboo.
- It is used in the manufacture of rayon. (yarns and artificial silk fibres)
What are the protective functions of forests?
- Forests control the water flow. The thick layer of humus in the forests prevents evaporation of water. The humus acts as a natural sponge and helps to soak the rain water in the soil. The thick humus over the years is formed by the decay of forest litter, which increases the fertility of the soil
- The forest with its complex root system binds the soil thereby preventing soil erosion and loss of nutrients.
What are the regulatory functions of forests?
- The trees utilise carbon dioxide and release oxygen during photosynthesis. The oxygen released by trees is used in the animal world. Thus, the trees perpetuate the cycles of oxygen and carbon dioxide in the biosphere.
- They also regulate the water cycle. The trees absorb water from the ground, release water (during transpiration) into the atmosphere which helps to form clouds and precipitation, which brings water again into the soil, thus completing the water cycle.
Give the accessory functions of forests
- Forests provide habitat for the wildlife.
- Forests also provide aesthetics and recreation to human beings through National Parks, Wildlife Sanctuaries and Biosphere Reserves
Why does India have a variety of forest and natural vegetation?
Due to variations in climatic conditions, soil types and relief features
Name the five major vegetation regions of the country
- Tropical Evergreen or Rain Forests
- Tropical Deciduous
- Tropical Desert
- Littoral or Tidal
- Mountain
What are the climatic conditions for tropical evergreen forests?
These forests are found in areas where the annual rainfall is more than 200 cm with a short dry season, average annual temperature is between 25 C and 27C and average humidity exceeds 77 per cent
Give the distribution of Tropical Evergreen Forests
These forests are chiefly distributed in the heavy rainfall areas of the western slopes of the Western Ghats, hills of north-eastern region and the island groups of Lakshadweep, the Andaman and Nicobar Islands and the Tamil Nadu coast
Give the characteristic features of Rain Forests
- Since this region remains warm and wet throughout the year, it has a luxuriant vegetation of all kinds - trees, shrubs and creepers which give it a multi-layered structure
- Trees reach great heights of more than 60 m
- The carpet layers of herbs and grasses cannot grow because of the dense canopy of trees which do not allow enough sunlight to reach the ground
- The trees in these forests do not have a fixed time to shed their leaves, to flower of for fruition. That is why these forests appear green year round.
Which trees are found in Rain Forests?
Rosewood, ebony, mahogany, toon, chaplas, sissoo, gurjan, telsur, etc
Give the economic value of Rain Forests
Tropical Evergreen Forests produce various plant species of high economic value. The timber produced is hard, durable and fine grained. Due to tangled mass of canes, palms, bamboos, ferns and climbers, along with the lack of means of transport, these forests have not been fully exploited
What are tropical deciduous forests known as?
Monsoon forests
Which forests are the most widespread in India?
Tropical Deciduous Forests
Name the two types into which monsoon forests have been categorised on the availability of water
- Moist DF
2. Dry DF
Give the climatic conditions of Moist DF
Such forests are found in areas with moderate or low annual rainfall of 100 cm to 200 cm and the mean annual temperature of 24 C and 27 C and humidity percentage of 50 to 80
Give the distribution of Moist DF
These forests occur in the north-eastern part of the Peninsula, along the foothills of the Himalayas and eastern slopes of the Western Ghats. They occupy a sizeable area in UP, Maharashtra, Karnataka, Tamil Nadu and have an area bigger than Evergreen Forests
Give the characteristic features of Moist DF
- The trees in these forests shed their leaves from six to eight weeks during spring and early summer when the storage of water is acute. Further, the sub-soil water is not enough for the trees to keep their leaves all the year round.
- A particular species can be found over a large area.
- They are commercially most exploited forests of India
Which are the common trees found in Moist DF?
Sal, teak, shisham, sandalwood, palas, semul, mulberry, arjun, mahua
Give the economic value of moist DF
Tropical DF are commercially the most exploited. Besides providing valuable timber, they provide various other products. Sandalwood found in these forests is in great demand in India and abroad
What are the climatic conditions in Dry DF?
These forests are found in areas having a mean annual temperature of 23 C to 27 C, annual rainfall between 70 cm and 100 cm and humidity between 51 to 58 percent
Give the distribution of Dry DF
These forests are found in the rainier parts of the Peninsular Plateau and the plains of Bihar and UP
Give the characteristic features of Dry DF
- These forests thrive between moist deciduous forests (in the east) and tropical thorn forests (in the west). On wetter margins, these forests have a transition into moist deciduous, while on the drier margins they degrade into thorn forests
- In the northern Indian Plains and in the areas of higher rainfall in the Peninsular Plateau, these forests have open stretches in which teak and other trees and interspersed with patches of grass.
- During the dry season, the trees in these forests shed their leaves completely and give the forests a look of vast grassland with naked trees.
Give the common trees of dry DF
Bel, khair, axlewood, teak, tendu, sal, rosewood, amaltas