 The biosphere or ecosphere, which includes the ground and the air, is characterized

as the region of the planet where organisms live. The biosphere is the world’s
ecological system as a whole.
 The biosphere is defined as the region on, above, and below the Earth’s surface
where life exists.
 The part of the world where life naturally exists, spreading from the deep crust to
the lower atmosphere. That means humans, plants, insects, bacteria, and living
things on land, air, and oceans make up the biosphere. Viruses are part of the
biosphere too. But they can be a bit tricky.
 Photosynthesis is the main source of energy for ecosystem processes. Processes in
the biosphere are intertwined with those in the atmosphere, hydrosphere, and
geosphere. Via the balance of photosynthesis and respiration, biological processes
play a significant role in controlling atmospheric CO2 concentrations. Living things
pull water from the soil and air. And oceans soak up carbon from the air. Finally,
specific bacteria from the biosphere are only capable of building certain types of
rocks.
 The biosphere is unique to Earth because it’s the only planet known to support life.
It’s believed that Earth’s biosphere started about 3.5 to 4.1 billion years ago. Since
the evolution of our very early ancestors, the biosphere has altered land, air, and
water for over a billion years.
 Living things depend on each other and their environment in many ways. Plants and
animals have special relationships that help them survive. For example, bees help
flowers by pollinating them, and in return, flowers provide bees with food. These
relationships keep nature in balance.
 During photosynthesis, plants use sunlight, air, and water to make food and oxygen.
This process helps feed other creatures and keeps the air clean. So, air and water
connect all living things by cycling energy and materials.
Organism/Individual: It is the lowest level of
organization in an ecosystem. An organism or
individual is a single organism, plant, animal,
or microorganism, such as bacteria and fungi,
capable of independent existence,
functioning independently, and can
reproduce. Thus, an individual is the smallest
component of the ecosystem and its building
block.
Population: a collection of organisms of a
particular species, sharing a particular
characteristic of interest, most often that of
living in a given area.
Community: A community includes populations
of different species living together and sharing
the same habitat in a given area. Various
factors determine the characteristics of a
community. They are its role in the ecosystem,
the range of its various populations, the
geographic area where it resides, the diversity
of the species, and the interactions between
various populations.
Habitat: a specific place or natural conditions
in which a plant or animal lives. Animals and
plants need the right places to live, find food,
and be safe. These places are called habitats.
Different creatures live in different habitats
that match their needs. Everything from tiny
insects to big trees rely on each other in some
way.
Ecosystem: a system formed by an ecological
community and its environment that
functions as a unit. An ecosystem is a
community of living organisms interacting
with each other and their environment.
Ecosystems occur in all sizes. A tidal pool, a
pond, a river, an alpine meadow and an oak
forest are all examples of ecosystems.
Organisms living in a particular ecosystem are
adapted to the prevailing abiotic and biotic
conditions. Abiotic conditions involve both
physical and chemical factors (e.g., sunlight,
water, temperature, soil, prevailing wind,
latitude and elevation).
Biome: any major regional biological
community such as that of forest or desert.
There are many biomes that make up the
biosphere. Various environments on Earth,
from the freezing polar regions to the
scorching depths of ocean vents, demonstrate
the incredible adaptability of life. For
example, polar regions, ocean vents, and the
deep biosphere are extreme environments in
their own unique way. But they can all harbor
life. These areas have unique climates,
vegetation, wildlife, and adaptations that
must be met in order to live.
In order to understand the flow of energy and matter within an ecosystem, it
is necessary to study the feeding relationships of the living organisms within
it. Living organisms in an ecosystem are usually grouped according to how
they obtain food.
 Autotrophs that make their own food are
known as producers. The producers include
land and aquatic plants, algae and
microscopic phytoplankton in the ocean.
 They all make their own food by using
chemicals and energy sources from their
environment. For example, plants use
photosynthesis to manufacture sugar
(glucose) from carbon dioxide and water.
Using this sugar and other nutrients (e.g.,
nitrogen, phosphorus) assimilated by their
roots, plants produce a variety of organic
materials.
 Heterotrophs that eat other organisms,
living or dead, are known as consumers. The
consumers are classed into different groups
depending on the source of their food:
 Herbivores (e.g. deer, squirrels) feed on
plants and are known as primary consumers.
 Carnivores (e.g. lions, hawks, killer whales)
feed on other consumers and can be classified
as secondary consumers. They feed on primary
consumers.
 Tertiary consumers feed on other carnivores.
 Some organisms known as omnivores (e.g.,
bears, rats and humans) feed on both plants
and animals.
 Organisms that feed on dead organisms are
called scavengers (e.g., vultures, ants and
flies).
 Detritivores (detritus feeders, e.g.
earthworms, termites, crabs) feed on
organic wastes or fragments of dead
organisms.
 Decomposers (e.g. bacteria, fungi) also feed
on organic waste and dead organisms, but
they digest the materials outside their
bodies. The decomposers play a crucial role
in recycling nutrients, as they reduce
complex organic matter into inorganic
nutrients that can be used by producers. If
an organic substance can be broken down by
decomposers, it is called biodegradable.
 Food Chain: In every ecosystem, each consumer level depends upon lower-level
organisms (e.g. a primary consumer depends upon a producer, a secondary consumer
depends upon a primary consumer and a tertiary consumer depends upon a
secondary consumer). All of these levels, from producer to tertiary consumer, form
what is known as a food chain.
 Organisms in the biosphere rely on each other as part of the food chain. The food
chain is the building block of the biosphere where energy is transferred from one
level to the next.

 Food Web: A community has many food chains that are interwoven into a complex
food web. The amount of organic material in a food web is referred to as its
biomass.
 When one organism eats another,
chemical energy stored in biomass
is transferred from one level of the
food chain to the next.
 Most of the consumed biomass is
not converted into biomass of the
consumer. Only a small portion of
the useable energy is actually
transferred to the next level,
typically 10 percent.
 Each higher level of the food chain
represents a cumulative loss of
useable energy. The result is a
pyramid of energy flow, with
producers forming the base level.
 Assuming 10 percent efficiency
at each level, the tertiary
consumer level would use only
0.1 percent of the energy
available at the initial
producer level.
 Because there is less energy
available high on the energy
pyramid, there are fewer top-
level consumers. A disruption
of the producer base of a food
chain, therefore, has its
greatest effect on the top-
level consumer.
 Ecosystem populations constantly fluctuate in response to changes in the
environment, such as rainfall, mean temperature, and available sunlight.
 Normally, such changes are not drastic enough to significantly alter ecosystems, but
catastrophic events such as floods, fires and volcanoes can devastate communities
and ecosystems.
 It may be long after such a catastrophic event before a new, mature ecosystem can
become established. After severe disturbance the make up of a community is
changed.
 The resulting community of species changes, as early, post disturbance, fast-
growing species are out-competed by other species. This natural process is called
ecological succession.
 It involves two types of succession: primary succession and secondary succession
 Primary succession is the development of the first biota in a given region where no life
is found.
 An example is of this is the surrounding areas where volcanic lava has completely
covered a region or has built up a new island in the ocean. Initially, only pioneer
species can survive there, typically lichens and mosses, which are able to withstand
poor conditions. They are able to survive in highly exposed areas with limited water and
nutrients. Lichen, which is made up of both a fungus and an alga, survives by
mutualism. The fungus produces an acid, which acts to further dissolve the barren
rock. The alga uses those exposed nutrients, along with photosynthesis, to produce food
for both.
 Grass seeds may land in the cracks, carried by wind or birds. The grass grows, further
cracking the rocks, and upon completing its own life cycle, contributes organic matter
to the crumbling rock to make soil.
 In time, larger plants, such as shrubs and trees may inhabit the area, offering habitats
and niches to immigrating animal life. When the maximum biota that the ecosystem can
support is reached, the climax community prevails.
 This occurs after hundreds if not thousands of years depending on the climate and
location.
 Secondary succession begins at a different point, when an existing ecosystem’s
community of species is removed by fire, deforestation, or a bulldozer's work in a
vacant lot, leaving only soil.
 The first few centimeters of this soil may have taken 1000 years to develop from
solid rock. It may be rich in humus, organic waste, and may be stocked with ready
seeds of future plants. Secondary succession is also a new beginning, but one with a
much quicker regrowth of organisms.
 Depending on the environment, succession to a climax community may only require
100 to 200 years with normal climate conditions, with communities progressing
through stages of early plant and animal species, mid-species and late successional
species. Some ecosystems, however, can never by regained.
 The biosphere provides the ecosystem that is needed for survival. Adaptation to the
biosphere’s climate is expected for living organisms. Biodiversity thrives within
ecosystems, and the biosphere is a reliable source of food on Earth. Biodiversity is just
what it sounds like biological variety.
 Safe areas for the protection of plants and animals are known as biosphere reserves. It
also helps to restore the tribals’ traditional way of life in the region. They protect the
region’s biodiversity. The biosphere is the ecological organization’s highest level. It
covers all types of life as well as any biome on the earth.
 The biosphere functions as the planet’s life support system, assisting in the control of
atmospheric composition, soil health, and the hydrological (water) cycle. A indicator of
a biome’s contribution to the earth. The biosphere is a narrow zone on the surface of
the earth where soil, water, and air combine to sustain life. Life can only occur in this
zone.
 Video: https://youtu.be/0xchPUSBSG0