1 STRUCTURE AND FUNCTIONS OF FOREST ECOSYSTEM
Different organisms exist within the forest layers. These organism interact with
each other and their surrounds .It consist of two parts :
1 Abiotic and
2 Biotic component
The non living or Abiotic aspects of the forest
All inorganic, organic substance present in the environment and minerals in
the forest consist the abiotic component. The type of forest depends upon the
abiotic conditions at the site
The living or the biotic aspects of the forest
The biotic component consist of all living things of the environment which
constitute producers, consumers and decomposers. The biotic component
includes both the large (angiosperms), and the microscopic plants and animals.
As the plant and animal species are closely dependent on each other, together
they from different types of forest communities.
Producer:
Plants produce their own food in the form of carbohydrate ,plants are there for
called the primary producers ,since they produce the basic food stuff for other
organism within food chains and food webs. photosynthesis is the chemical
reaction that allows plants to produce their own food
Consumers
Animals cannot produce their own food. They must consume food source for
the energy they need to survive.
Primary consumers : these are herbivores which feed directly on producers .
eg: elephants ,deers
Secondary consumers : these are carnivores and feed on primary consumers
eg: birds,frogs
Tertiary consumers : these are secondary carnivores and feed on secondary
consumers . these include top carnivores like lion,tiger
Decomposer:
They include variety of saprotrophic micro-organisms like bacteria fungi . they
attract the dead or decayed bodies of organisms and thus decomposition takes
place there for nutrients are released for reuse
2 STRUCTURE AND FUNCTIONS OF GRASSLAND ECOSYSTEM
Biotic component:
1producer organisms
In grass land producers are mainly grasses though a few herbs and shrubs also
contribute to primary production of biomass. Some of the most common
species of grasses are brachiaria sp,cynodon sp,desmodium sp,digitaria sp
2consumers
In a grassland consumers are of three main types
Primary consumers are herbivores feeding directly on grasses these are grazing
animal such as cows sheeps goats etc.besides them numerous species of
insects are also present
Secondary consumers :these are carnivores that feed on primary consumers
.these include frogs snakes
Tertiary consumers :these include hawks which feed on secondary consumers
3decomposer
These include wide variety of saprotrophic micro-organism like bacteria fungi
actinomycetes. They attract dead or decayed bodies of organism and thus
decomposers take place. There for nutrients are released for reuse by
producers
Abiotic component:
These include basic inorganic and organic component present in the soil and
aerial environment. The essential elements like c,h,n,o,ps etc. Are supplied by
water nitrogen, nitrates, sulphates, phosphates present in the soil and
atmosphere
3 STRUCTURE AND FUNCTION OF DESERT ECOSYSTEM
Biotic components
1producer organism
In desert producers are mainly shrubs; some grasses and a few trees.
Dominant plant species include succulents(water retaining plants adapted to
aided climate ).beside somme lower plantd such as lichens and xerophytic
mosses are also present
2consumer organisms
These include animal such as insects, reptiles which are capable of xeric
conditions. Beside some nocturnal rodents, birds and some mammalians like
camel are also found.
3decomposers
Due to poor vegetation with very low amount of dead organic matter,
decomposers poor in desert ecosystem.the common decomposers are some
bacteria and fungi, modt of which are thermophillic
Abiotic components
Due to very high temperature and very low rain fall, the organic substances are
poorly present in the soil
4STRUCTURE AND FUNCTIONS OF POND ECOSYSTEMS
Abiotic components
The chief non living components are heat, light, ph value of water, and the
basic inorganic and organic compound such as water, carbon dioxide, oxygen
calcium, nitrogen, phosphates, amino acids, humic acids etc.
Biotic components
1producers
These are photoautotrophic green plants and photosynthetic bacteria. The
producers fix radiant energy of sun and with help of minerals derived from
water and mud
producers of pond are following types
phytoplankton: it is literally “wandering plants” are microscopic algae that float
in the open water and give it a green appearance. that carry out
photosynthesis using carbon dioxide that is dissolved in the water and release
oxygen that is use by bacteria and animals in the pond.
Periphytic algae:they are that attach themselves to substrates and give the
rocks and sticks a greenish brown slim appearance. They carry out
photosynthesis and produce oxygen, offer near the bottom of the pond where
it can be used by decomposers
Macrophytes :
These include mainly the rooted large sized plants which comprise three typses
of hydrophytes : partly or completely submerged, floating and emergent
aquatic plants, floating emergent aquatic plants. The common plants are
species of trapa, typha, chara, hydrilla, etc.
Consumers
These all are zooplankton are microscopic animals that eat phytoplankton or
smaller zooplankton. Some are single –celled animals,tiny crustaceans,or tiny
immature stages of larger animals.
Decomposers
Animal waste and dead and decaying plants and animals form detritus on the
bottom of the pond.Decomposers ,also known as detritovores,are bacteria and
other organism that break down detritus into material that can be used by
primary producers.Thus returning the detritus to ecosystem.
5 STRUCTURE AND FUNCTIONS OF LAKES
Important abiotic factors are:-The abiotic factors do include acidity
,tubidity(clarity),nitrogen nutrient concentrations plus dissolved oxygen
concentration.These are affected by the catchment or volume of the pond or
lake.size pf the input flow,the type of bedrock impact the ph,that in turn alters
the nutrient composition.Nitrogen may enter by runoff ,precipitation or be a
result of a biotic process by fixation from the atmosphere by cyano bacteria.
Temperature ,light and turbulence are other abiotic factors but they
are independent of the size of the drainage system since they can affect a
larger region.
Important biotic factors are:-Bacteria ,Algae,Invertebrates:,Fishes and other
vertebrates.Distinct stratification and zonig are characterstics features of
lakes.Typically a littoral zone containing rooted vegetation,a limnetic zone of
open water dominated by plankton,and a deep water profundal zone
containing heterotrophs .also the lakes become thermally stratified in winters
and summers.
6 Structure and functions of River ecosystem
large stream flowing from mountain high lights are rivers
abiotic component: They not only differ widely in volume of water but they
also differ much in their speed of flow, dissolved oxygen content, temperature,
and many other physical and chemical parameters the nature as well as
composition of flora and fauna largely depends on the source or origin of the
river
biotic component: the plankton, both phytoplankton and zoosplankton are
quite common in this region. Various species of reptiles, mammals and birds
obtain their food from the river water
• Biotic: phytoplankton,fishes, snails, insects, birds etc
•
Producers - primary producers are phytoplankton, periphyton
•
Consumers -these include vertebrates and macro invertebrates
Decomposers-these include bacteria
Biofilm on the surface of rock sand vegein between particles that compose
and suspended in the water column
7 STRUCTURE AND FUNCTIONS OF STREAM ECOSYSTEM
Fresh water ecosystem where water current plays a major role. oxygen and
nutrient content are uniform. large surface area of water provide more oxygen
supply.stream organism have to face extreme difference in climate conditions
Abiotic components: These include volume of water, speed of flow,
dissolved oxygen content, temperature, physical and chemical
parameters
Biotic component: River bottom are covered by algae and bacteria The lower
reaches of rivers sustain phytoplankton, zoozplankton,crustaceans, small
fishes, big fishes etc.In stagnant pockets detritus feeders are prominent
8 STRUCTURE AND FUNCTIONS OF OCEAN ECOSYSTEM
biotic factors
Producers: primary producers are autotrophs which trapthe radient energy
of sun with the help of their pigments. They are mainly the phytoplankton
like the diatoms, diano flagellates and macroscopic algae
Consumers :all the consumers are heterotrophic macro consumers
which feed on the primary producers
primary consumers: include crustaceans, molluscs, fishes etc.
secondary consumers: these are carnivores that feed on the herbivores.
These arev chiefly various species of fish such as herring, mackerel
tertiary consumers : these are carnivores fishes like cod, haddock, shark
Decomposers: these include mainly bacteria and fungi
abiotic component:
The dominant ions are sodium and chloride followed by sulphur,
magnesium and calcium. the salinity varies with depth and latitudes
more stable chemical composition due to salinity Gigantic reservoirs of
water covering >70 of earth surface. Provide huge variety of sea products,
drugs etc. Provide Fe, Mg, oils, natural gases, sand etc. Major sinks of
carbon dioxide Regulate biochemical cycle
9STRUCTURE AND FUNCTIONS OF ESTUARY ECOSYSTEM
An estuary is the area at the mouth of the river where river joins the ocean
Abiotic components:
In estuaries the physical conditions are different as the fresh water from the
river mixes with the sea water. These include ph, nutrients, temperature,
climatic conditions. Silt laden water meets the saline, sea water coagulation
take place and slit settles down and forms shoals and mudflats Rocky
shorelines support organisms that grow attached to any solid surface
biotic component:
These include phytoplankton, fish, snail, insects and birds. They are nurseries
for crustacean (crabs and shrimps) and mollusks (clams, cockles and oysters).
Burrowing species like clams and worms are found in sandy beaches. the
estuaries are rich in nutrients and usually support an abundance of fish. Due to
this they are important breeding sites for commercially significant fish and as
fishing areas