BIOSPHERE- LIFE ON THE EARTH
Meaning
• That part of earth which supports life
• Known as the organic realm
• Lies at the interface between the three inorganic
realms
• It’s the inter-action between the three realms
• Most important realm- contains all forms of life
– 9000 metres under oceans
– 300 metres under land
– 5000 metres in the atmosphere
Type of life existing in Biosphere
• Vary from minute bacteria to large whales and
huge trees
• Plant Kingdom
• Animal Kingdom
• Human Beings- Homo Sapiens
• 1,000,000 animal species, 3,00,000 plant
species
Ecology and Ecosystems
• All organisms interact with each other and others
in their physical environment
• The study of these interactions between life
forms and environment is called Ecology
• The complex system of interaction between
organisms and their physical environment in any
unit of area is called an ecosystem
• An ecosystem can be anything- from a small pond
to the Amazon river basin or the entire world
Components of Ecosystem
• Energy Component• essence of life, enables organisms to work.
Without energy transfers no life and no
systems
• All energy is obtained from the sun
• Radiant energy travels from the sun to the
earth through space in the form of waves.
• This energy is used by plants and animals to
sustain life
Components of Ecosystem
• Biotic Components
• All living organisms
– Autotrophic- producers- plants & certain bacteria
– Hetrotrophic- consumers- herbivores, carnivores,
omnivores, decomposers
– Decomposers- bacteria, fungi etc.
• Abiotic Components
– Land, atmosphere, hydrosphere and radiant solar
energy
FLOW OF ENERGY THROUGH THE
ECOSYSTEM
• Ecosystems function due to energy
transmission through its various components
• Energy transformation occur by means of a
series of steps or levels called food chains
FOOD WEB
ECOLOGICAL BALANCE
• Native of an ecosystem are numbered to
ensure that all get enough basic necessities to
survive
• Requirement of small animals is less, their rate
or production is more
• Bigger animals require large amounts of food,
water and space. They are less in number and
their rate of reproduction is low
• Perfect harmony exists
• When relative number of different species
change, imbalance occurs
HUMAN IMPACT ON THE
ECOSYSTEM
• Man-more adept and omniscient, has rare
wisdom, so he interferes and alters the
ecosystems
• Influences other plants and animals with help
of science and technology
• Drastic change in the environment, animals
and plants transferred to other environments
• Serious threat to the environment
ENVIRONMENTAL POLLUTION
• New irrigation projects in dry areas, increased
agricultural production, led to salinization of
soil and spread of water borne diseases
• Purification of water naturally takes its own
time. Humans have polluted it very fast. If this
trend continues, very soon all the fresh water
will be unsuitable for consumption
• Rapid industrialization and urbanization, large
scale pollution.
• Adverse effects on biosphere and damaged
quality of life
Resource deterioration and
depletion
• Reduction in quality and quantity of resources
• Wasteful usage of water
• Deforestation
• Exhausting mineral oil, good quality coal
Measures that can be taken
• Substitution
• Recycling