Soil, Water, Natural Vegetation and Wildlife Resources
Q51. What are the reasons for the degradation of the soil?
Ans. Soil erosion and depletion are the major threats
to soil as a resource. Both human and natural factors can lead to degradation
of soils. Factors which lead to soil degradation are deforestation,
overgrazing, overuse of chemical feritilisers or pesticides, rain wash,
landslides and floods.
Q52. Differentiate between tropical evergreen forests and
forests do not shed their leaves simultaneously in any season of the year.
forests shed their leaves in a particular season to conserve loss of moisture
Q53. Name any two steps that government has taken to conserve
plants and animals.
Two steps that government has taken to conserve plants and animals are:
It has set up national parks, wildlife
sanctuaries and biosphere reserves to protect our natural vegetation and
It has banned the killing of lions, tigers,
deers, great Indian bustards and peacocks.
Q54. Suggest three ways to conserve water.
Ways to conserve water
Rain water harvesting.
The canals should be properly lined to
minimise losses by water seepage.
In dry regions with high rates of
evaporation, drip or trickle irrigation is very useful.
Q55. In what forms is freshwater found on the earth?
Ans. Fresh water accounts for only about 2.7 per cent.
Nearly 70 per cent of this occurs as ice sheets and glaciers in Antarctica,
Greenland and mountain regions. Due to their location they are inaccessible.
Only 1 per cent of freshwater is available and fit for human use. It is found as
ground water, as surface water in rivers and lakes and as water vapour in the
Q56. What do you know about CITES?
Ans. CITES (the Convention on International Trade in
Endangered Species of Wild Fauna and Flora) is an international agreement between
governments. It aims to ensure that international trade in specimens of wild
animals and plants does not threaten their survival. Roughly 5,000 species of
animals and 28,000 species of plants are protected. Bears, dolphins, cacti,
corals, orchids and aloes are some examples.
Q57. Why there is uneven distribution of population in different
parts of the world?
The uneven distribution of population in different parts of the world is mainly
due to varied characteristics of land and climate. The rugged topography, steep
slopes of the mountains, low-lying areas susceptible to water logging,
desert areas, and thick forested areas are normally sparsely populated or
uninhabited. Plains and river valleys offer suitable land for agriculture.
Hence, these are the densely populated areas of the world.
Q58. How does rainfall affect vegetation?
Ans. In areas of heavy rainfall, huge trees may
thrive. The forests are thus associated with areas having abundant water
supply. As the amount of moisture decreases the size of trees and their density
reduces. In the regions of moderate rainfall short stunted trees and grasses
grow forming the grasslands of the world. In dry areas of low rainfall, thorny
shrubs and scrubs grow. In such areas plants have deep roots and leaves
have thorny and waxy surface to reduce loss of moisture by transpiration.
Q59. Why is wildlife important to us?
Ans. Wildlife is important to us because
They provide us milk, meat, hides and wool.
Insects like bees provide us honey, help in
pollination of flowers and have an important role to play as decomposers in the
The birds feed on insects and act as
decomposers as well.
Vulture due to its ability to feed on dead
livestock is a scavenger and considered a vital cleanser of the environment.
Q60. What are the factors affecting soil formation?
Factors affecting soil formation are:
- Determines colour, texture, chemical properties mineral, content, permeability
Temperature and rainfall influence rate of weathering and humus.
Altitude and slope, determine accumulation of soil.
Fauna and Micro-organism - Affect the rate of humus formation.
Determines thickness of soil profile.