By Fr. Fredrick Rodrigues
Meaning
 An ecosystem is a natural system consisting of all
plants, animals and microorganisms, which function
with all the physical factors of the environment.
 The term ecosystem was coined in 1930 by Roy
Clapham, to denote the physical and biological
components of an environment considered in relation
to each other as a unit. British ecologist Arthur Tansley
later refined the term, describing it as the interactive
system established between all the living and nonliving factors of the environment.
Kinds of Ecosystem
 There are basically two types of ecosystems; Terrestrial
and Aquatic.
 Terrestrial ecosystems
 Terrestrial ecosystems are found everywhere apart
from water bodies. They are broadly classified into:
 The Forest Ecosystem
These are the ecosystems where abundance of flora
(plants) is seen and they have a large number of
organisms living in relatively small areas. Therefore,
the density of life in forest ecosystems is very high. Any
small change in the ecosystem can affect the whole
balance and collapse the ecosystem. You can see
wonderful diversity in the fauna of these ecosystems
too. They are again divided into few types.
 Tropical evergreen forest: Tropical forests which
receive an average rainfall of 80 to 400 inches in a year.
These forests are marked by dense vegetation
comprising of tall trees with different levels. Each level
gives shelter to different kinds of animals.
 Tropical deciduous forest: Dense bushes and
shrubs rule here along with broad levels of trees. This
type of forests is found in many parts of the world and
large variety of flora and fauna are found here.
 Temperate evergreen forest: These have very few
number of trees but ferns and mosses make up for
them. Trees have spiked leaves to minimize
transpiration.
 Temperate deciduous forest: This forest is found in
the moist temperate regions with sufficient rainfall.
Winters and summers are well defined and with trees
shedding their leaves during winter
 Taiga: Situated just south of the arctic regions, Taiga is
distinguished by evergreen conifers. While the
temperature is subzero for almost six months, the rest
of the year it is buzzing with insects and migratory
birds.
 The Desert Ecosystem
 Desert ecosystems are found in regions receiving an annual
rainfall of less than 25cm. They occupy around 17 percent
of all land on the planet. Due to very high temperature,
intense sunlight and low water availability, flora and fauna
are very poorly developed and scarce. Vegetation is mainly
bushes, shrubs, few grasses and rarely trees. Leaves and
stems of these plants are modified to conserve water. The
best known desert plants are the succulents like spiny
leaved cacti. Animal life includes insects, reptiles, birds,
camels all of whom are adapted to the xeric (desert)
conditions.
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 The Grassland Ecosystem
Grasslands are found in both temperate and tropical
regions of the world but the ecosystems are slightly
varying. This area mainly comprises of grasses with
very little amount of shrubs and trees. Many grazing
animals, herbivores and insectivores are found in
grasslands
 Two main types of grasslands ecosystems are:
 1. Savanna: These tropical grasslands are seasonally
dry with few individual trees. They support large
number of grazers and predators like giraffes, zebras,
buffaloes, kangaroos, snakes, worms etc
 2. Prairies: This is temperate grassland. It is
completely devoid of trees and large shrubs. Prairies
can be categorized as tall grass, mixed grass and short
grass prairie.
 Aquatic Ecosystems
An aquatic ecosystem is an ecosystem located in a
body of water. It comprises aquatic fauna, flora and the
properties of water too.
 There are two types of aquatic ecosystems, Marine and
freshwater.
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 The Marine Ecosystem
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Marine ecosystems are the largest ecosystems with
coverage of nearly 71% of the Earth's surface and
containing 97% of the planet's water. The water in Marine
ecosystems has salts and minerals dissolved in them in
high amounts. Different divisions of marine ecosystems
are:
Oceanic
Profundal: Bottom or deep water.
Estuaries
Salt marshes
Coral reefs
 The Freshwater Ecosystem
 In contrast to the Marine ecosystem, freshwater ecosystems
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only cover 0.8% of the Earth's surface and contain 0.009%
of its total water. There are three basic types of freshwater
ecosystems:
Lentic: Still or slow-moving water like pools, ponds, and
lakes.
Lotic: Fast-moving water like streams and rivers.
Wetlands: Places where the soil is saturated or inundated
for at least some time.
These ecosystems are home to amphibians, reptiles and
almost 41% of world’s fish species