ECOLOGY AND ECOSYSTEM

Prepared byShantanu DattaM.Tech,HydroinformaticsNIT,Agartala

WHAT WE WILL LEARN?

•What do we mean by an ecology?•What do we meant by an ecosystem?•Types and Components of ecosystem.•Function of ecosystem . •Food chains, ecological pyramid.•Water ,nitrogen ,oxygen and carbon cycle.•Conclusion.

WHAT IS ECOLOGY?

Ecology is the branch of biology that deals with the study of interaction between organism and their environment

Source: www.cfkeep.org

ORIGIN OF THE WORD…”ECOLOGY

Greek origin OIKOS = household LOGOS = study of…

Study of the “house/environment” in which we live.

ECOLOGY IS STUDY OF INTERACTIONS BETWEEN

non-living components in the environment… light water wind nutrients in soil heat solar radiation atmosphere, etc.

LIVING ORGANISMS…

Plants Animals microorganisms in soil, etc.

TO STUDY ECOLOGY INVOLVES

For non-living (abiotic) living(biotic)

Climatology Animal Hydrology Taxonomy Oceanography Physiology Physics Mathematics Chemistry studies) Geology Soil analysis, etc.

ECOLOGY…

views each locate as an integrated whole of interdependent parts that function as a unit

ECOSYSTEM

.

WHAT IS ECOSYSTEM

An ecosystem may be defined as a dynamic system which includes biotic and abiotic environment influencing the properties

of each other and both necessary for the maintanance of life.

COMPONENTS OF ECOSYSTEM

Biotic components(living parts). Abiotic components(non-living parts).

BIOTIC COMPONENTS

The biotic components of an ecosystem can be classified according to their mode of energy acquisition.

In this type of classification, there are: Autotrophs and Heterotrophs Organisms that produce their own food

from an energy source, such as the sun, and inorganic compounds. e.g herbivores.

Organisms that consume other organisms as a food source. e.g carnivores,omnivores.

ABIOTIC COMPONENTS

ABIOTIC components: Solar energy provides practically all the

energy for ecosystems. Inorganic substances, e.g., sulfur,

boron, tend to cycle through ecosystems.

Organic compounds, such as proteins, carbohydrates, lipids, and other complex molecules, form a link between biotic and abiotic components of the system.

BIOTIC & ABIOTIC COMPONENTS

TYPES OF ECOSYSTEM

There are basically two types of ecosystems; 1)Terrestrial .

2)Aquatic.Terrestrial ecosystems: Terrestrial ecosystems are found

everywhere apart from water bodies. They are broadly classified into:

1)Forest Ecosystem. 2) Desert Ecosystem.

3) Grassland Ecosystem.

TYPES OF ECOSYSTEM

1)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.

2) Desert Ecosystem: Desert ecosystems are found in regions

receiving an annual rainfall of less than 25cm. Flora and fauna are very poorly developed and

scarce.

TYPES OF ECOSYSTEM

3) Grassland Ecosystem: Grasslands are found in both temperate

and tropical regions . This area mainly comprises of grasses

with very little amount of shrubs and trees.

Main vegetation is grasses, and plants are belonging to composite family.

TYPES OF ECOSYSTEM

Aquatic eco-system: 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, 1)Marine and 2) freshwater.

TYPES OF ECOSYSTEM

1)Marine ecosystem: Marine ecosystems are the largest

ecosystems. The water in Marine ecosystems has

salts and minerals . In marine ecosystems brown algae,Jelly

fish corals, cephalopods,, and sharks are found.

http://www.sciencelearn.org.nz/Contexts/Life-in-the-Sea/Sci-Media/Animations-and-Interactives/Marine-ecosystem

TYPES OF ECOSYSTEM

2)Freshwater Ecosystem: 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.

FUNCTION OF ECOSYSTEM

Reception of radiant energy of sun. Manufacture of organic materials from

inorganic ones by producers. Consumption of producers by

consumers and further elaboration of consumed materials

After the death of producers & consumers complex organic compounds are degraded by decomposer.

ENERGY FLOW IN ECOSYSTEM

•Begins with the SUN

•Photosynthesis

6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2

The chemical reaction by which green plants use water and carbon dioxide and light from the sun to make glucose. ENERGY is stored in glucose; glucose is stored as starch

CELLULAR RESPIRATION is the chemical reaction that releases the energy in glucose.6O2 + C6H12O6 -->  6H2O + 6CO2 + energy

The energy that is not used by producers & can be passed to consumers.

CONSUMERS. Organisms that cannot make their own energy are called consumers.

CLASSIFICATION OF CONSUMERS

Primary consumers. Secondary consumers. Tertiary consumers.Consumers that eat producers to get

energy are first order or primary consumers

E.g herbivores (plant-eaters such as cow)

A consumer that eats another consumer for energy:

Is called a secondary or second order consumerMay be a carnivore or a herbivore May be a predatorMay be a scavenger

A consumer that eats a consumer that already ate a consumer

Is called a third order or tertiary consumerMay be a carnivore or a herbivore May be a predatorMay be a scavenger

Consumers that eat producers & other consumers Are called omnivores, those eat plants and animals. Eg . Human,dogs etc

SOME DEFINATIONS

Consumers that eat other consumers that have already died are called scavengers

Consumers that hunt & kill other consumers are called predators.They animals that are hunted & killed are called prey

FOOD CHAIN

The transfer of energy from sun to producer to primary consumer to secondary consumer to tertiary consumer can be shown in a food chain.

ENERGY PYRAMID

The greatest amount of energy is found at the base of the pyramid.

The least amount of energy is found at top of the pyramid.

ENERGY PYRAMID

FOOD WEBS

Are interconnected food chains They show the feeding relationships in

an ecosystem

FOOD WEB OF A HOT SPRING

BIOMASS

Energy is sometimes considered in terms of biomass, the mass of all the organisms and organic material in an area.

There is more biomass at the trophic level of producers and fewer at the trophic level of tertiary consumers. (There are more plants on Earth than there are animals.)

Bio=life Mass=weight Bio + Mass = Weight of living things

within an ecosystem.

ECOSYSTEM NITROGEN CYCLE

Of all the elements that plants absorbe from the soil, nitrogen is most important for plant growth.theultimate source of nitrogen compounds is the atmosphere,which can not be directly metabolised by plants or animals.

Nitrogen cycle consist following steps : 1) Ammonification .2) Nitrification 3) Nitrogen

assimilation 4)Nitrogen fixation 5)Denitrification 6)Sedimentation

NITROGEN CYCLE

Source: http://en.wikipedia.org/wiki/Nitrogen_cycle

AMMONIFICATION

Nitrogen enters the soil through the decomposition of protein in dead organic matter

Amino acids + 11/2O2 CO2 + H2O + NH3 + 736kJ This process liberates a lot of energy

which can be used by the saprotrophic microbes

NITRIFICATION

This involves two oxidation processes The ammonia produced by ammonification is

an energy rich substrate for Nitrosomas bacteria

They oxidise it to nitrite:NH3 + 11/2O2 NO2

- + H2O + 276kJ

This in turn provides a substrate for Nitrobacter bacteria oxidise the nitrite to nitrate:

NO3- + 1/2O2 NO3

- + 73 kJ

This energy is the only source of energy for these prokaryotes

NITROGEN FROM THE ATMOSPHERE

Root uptake

Nitrate NO3-

Plant protein

Soil organic nitrogen

Out gass

Atmospheric Nitrogen

NITROGEN ASSIMILATION

Inorganic nitrogen in the form of nitrates,nitrites & ammonia is absorbed by green plants and converted to nitrogenous organic compound.

Nitrates converted to ammonia and form amino acids.

Amino acids are used in the synthesis of proteins.

NITROGEN FIXATION

Cyanobacteria are nitrogen fixers that also fix carbon (these are photosynthetic)

Rhizobium bacteria are mutualistic with certain plant species e.g. Legumes

They grow in root nodules Azotobacter are bacteria associated with the rooting zone(the rhizosphere) of plants in grasslands

University of Sydney

DENITRIFICATION

Ammonia and nitrates are converted into nitrogen by microbes.

2NO3- 2NO2

- 2NO N2

Increased nitrite levels

NO3- NO2

-

SEDIMENTATION

Nitrates of the soil are washed away to the sea and locked up in the rocks. This process is called sedimentation.

Nitrogen of rocks is released only when the rocks are exposed.

CARBON CYCLE

The Carbon Cycle is a complex series of processes through which all of the carbon atoms in existence rotate.

CARBONCYCLE

CARBON CYCLE

The carbon atoms in our body today have been used in countless other molecules since time began.

The wood burned just a few decades ago could have produced carbon dioxide which through photosynthesis became part of a plant.

When we eat that plant, the same carbon from the wood which was burnt can become part of us. The carbon cycle is the great natural recycler of carbon atoms

OXYGEN CYCLE

The Oxygen cycle is the biogeochemical cycle that describes the movement of oxygen. The main source of atmospheric oxygen is photosynthesis.

6CO2 + 6H2O + energy → C6H12O6 + 6O2

OXYGEN CYCLE

OXYGEN CYCLE

An additional source of atmospheric oxygen comes from photolysis, whereby high energy ultraviolet radiation breaks down atmospheric water and nitrous oxide into component atoms. The free H and N atoms escape into space leaving O2 in the atmosphere:

2H2O + energy → 4H + O22N2O + energy → 4N + O2

WATER CYCLE

WATER CYCLE

The water cycle, also known as the hydrologic cycle or H2O cycle, describes the continuous movement of water on, above and below the surface of the Earth.

Water can change states among liquid, vapor, and solid at various places in the water cycle. Although the balance of water on Earth remains fairly constant over time, individual water molecules can come and go, in and out of the atmosphere.

WATER CYCLE

The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, runoff, and subsurface flow. In so doing, the water goes through different phases: liquid, solid, and gas

CONCLUSION

Ecological studies suggest that there exists an ecological balance between biotic and abiotic components in biosphere.Deforestation and human activity disturbs this balance.So we have to control it for the contunity of ecosystem and hence biosphere.

ANY QUESTIONS ?