Ecology :- is the study of organisms in their natural habitat.

It is concerned with the study of organisms in various habitats like land, oceans, fresh water and air.

Ecology• The word ecology comes from the Greek Oikos,

meaning house or place to live. • It refers to the study of organisms in their natural

habitat. • or the study of the structure and function of

nature. • It is a science which investigates organisms in

relation to their environment.• study of the relationships that

living organisms have with each other and with their natural environment

Ecologists seek to explain:

• Life processes and adaptations• Distribution and abundance of organisms• The movement of materials

and energy through living communities• The step by step development of ecosystems,

and• The abundance and distribution of biodiversity

in the context of the environment.

Ecology proceeds at three levels

1. The individual organism

At the individual level of organism ecology deals with how individuals are affected by and how they affect their environment

2. The population

consisting of individuals of the same species. At the level of population, ecology deals with the presence and absence of particular species and with trends and fluctuations in their numbers

3. The community

consisting of number of populations. Community ecology

deals with the composition or structure of communities and with the natural resources affected by

them

• An ecosystem is a complex set of relationships among living resources, habitat and residents of a region.

• And Ecology is the scientific study of the processes influencing the distribution and abundance of organisms, the interactions among organisms, and the interactions between organisms and the transformation and flux of energy and matter.

Ecosystem

“An ecosystem may be defined as - a system formed by the interaction of a group of

organisms and their environment

.

Ecosystem: The collection of all living organisms in a geographic area, together with all the living and non-living things with which they interact.

· Aquatic Ecosystems (water-based) ecosystems

· Terrestrial Ecosystems (land-based) ecosystems

concepts of ecology

1. Ecosystem

2. Cycles & its imbalance3. Community4. Food Chain5. Carrying Capacity6. Limiting factor7. Habitat8. Biological clock

Ecosystem: consists of population &

communities of organisms and their interdependence. It emphasis

relationship & interdependence.E.g. forest, sea

Ecosystem- dynamic system

Ecosystem is at a constant state of change.

Change can be in its structure and process of living beings over time. Or changes can be in its physical environment.

These changes leads to the formation of different or other ecosystem

Ecosystem is capable of self maintenance and self regulation.

Human intervention has being the main cause of imbalance in the ecosystem.

E.g. industrial revolution, green revolution (intense farming) etc.

Goal for higher rate of productivity has lead to conflict within the ecosystem.

Our country has a variety of ecosystems

2. Cycles & its imbalance

• Cycles Refers to circulation of elements like water or carbon in the atmosphere. This is from environment to organism & back. E.g. carbon cycle.

• Human activities can upset this cycle

• Recycling & its process is also a part of cycle. E.g. battery.

Community

• Community where organisms of different species live together.

• Imbalance is caused when the principle of interdependence is disrupted. E.g. Extinction of Dinosaurs or Breeding of Mosquito.

Food Chain

Transfer of food energy from plants through a series of organisms where eating & being eaten occurs.

Pollutants can also be transferred E.g. ban of DDT

Carrying Capacity

• Every ecosystem has limits in terms of various populations it can support

• The same concept is applicable to air and water .

• If the carrying capacity is exceeded by pollutants it will affect the quality

Limiting factor

• E.g. factors such as temperature, light and water in greater amount than required can inhibit organisms development

• Government and industry should focus on the impact of a project on these factors

Habitat

Habitat refers to place where an organism, population or community lives.LandWateraerial

Biological clock

• The internal clock operates through signals arising with in the organism or from the environment like temperature, light, or other seasonal changes.

• Changing environmental conditions can disturb the biological clock

ECOLOGICAL SERVICES• Resources like oxygen, water, food & other materials

• Cyclic mechanism like water, carbon & nutrient cycle

• Regulatory services like flood, disease & climate control, temperature regulation & pollination

Any disturbance in ecosystem would lead to breakdown of ecological services

For sustainability we have to redesign both our industrial and economic models

Industrial ecology• Means application of ecosystem concepts to

industry• It is based on minimization of raw material

usage, waste production and optimization of energy.

• The concept of closed loop manufacturing system must be adopted.

• It is a system that integrate profitability with social and environmental responsibilities

Eg:-many countries in Europe require manufacturers to follow life cycle thinking

• In Germany under law manufacturers has to use their products for ever

• E.g. :- INTERFACE worlds largest American company in manufacturing carpets and other flooring materials

• selenium

Extended Producer Responsibility (EPR),

• where producers have a responsibility for their entire product life cycle including the post consumer phase of their product, is one politically feasible way to promote closed loop systems.

• EPR holds product designers responsible for the environmental and public health impacts of their products.

The factors affecting ecosystem are

• Population growth• Human activities• Resources availability • Climatic factors

Population growth

• Population growth mainly affects ecosystem balance, if the number of population increases, than there exists a resource shortage.

• Population growth is the number of individuals present in each species of ecosystem.

Resources availability

• Two kinds of resources

• Renewable Resources: These types of resources can be renewed.

• Non- renewable: These types of resources cannot be renewed, once used it will not be produced back.

• These resources can be utilized by different species in the ecosystem, if the population size increases, there exists a resource shortage.

Climatic factors:

• Climatic factors such as temperature, rainfall, etc play the main role in ecological balance.

• Certain animals will exist only in moderate temperature; if there is high temperature these species can’t survive leads to extinction.

• Factors such as heavy rainfall, floods, cyclones and hurricanes lead death to many species

Human Activities:

• Human activities like deforestation and urbanization greatly destroys the habitats of animals and plants. So that they can’t get the sufficient resources to exist. They migrate to other places and some of the species will die .

STRUCTURE OF ECOSYSTEMS

Biotic and Abiotic components Every ecosystem is composed of two basic

units: a) Biotic components: the living organisms - all

plant & animals, human beings and microbesb) Abiotic: the non-living physical and chemical

component consisting of wind, temperature, water, soil, precipitation etc

Major biological (Biotic) components of eco system

1. PRODUCERS- Autotrophic components2. CONSUMERS – Heterotrophic components3. DECOMPOSERS- saprophytes

1. PRODUCERS: Autotrophic components includes Green plants, bacteria , algae, and other

organisms that carry on photosynthesis. Producers are self-nourished – they do not depend on other species to feed.

During photosynthesis, plants capture light energy with

their chlorophyll and use it to convert carbon dioxide and moisture (absorbed from air) into carbohydrates, protein etc. Oxygen is released as a by-product

Every major ecosystem has its particular green plants that

carry on photosynthesis and release chemical energy ,on which non-producers feed.

2. CONSUMERS: Heterotrophic components All other organisms which cannot convert solar

energy into food and depends on autotrophs to obtain their energy for survival

Consumers are subdivided into groups according to their food source.

Primary consumers: Species that feed directly on producers (plant-eating species). They are also called Herbivores. E.g. elephants, cattle, insects and grasshoppers

Secondary Consumers: Species that feed on the flesh of primary consumers. Secondary and higher order consumers are called Carnivores. E.g. fox, cat.

Tertiary and higher level Consumers: Species that

obtain their nourishment by eating other meat-eating

species. E.g. tiger, lion Multiple level Consumers: Species that obtain

their nourishment from eating both plants and animal species. Also called Omnivores

Plant

• Autotrophs (producer)

Insect

• Herbivors

Frog

• Primary consumer

Snale

• Secondary consumer

Eagle

• Topcarnivore

3. DECOMPOSERS: • They are the final link in the food chain.• Comprise of organisms that feed on dead

matter and break it down to release chemical energy back into the soil for plants to re-use them.

• E.g. fungi, bacteria, insects, worms and others.

• Also called scavengers.

Abiotic components of ecosystem

• All the non-living components of the environment such as light, temperature, humidity, moisture, solar radiation and salinity of soil as well as inorganic and organic compounds constitute the abiotic components of the ecosystem.

• The variation in physical factors that a

population can withstand and continue to thrive in an environment is termed Range of Tolerance.

• The quality of abiotic materials present in an ecosystem is known as the ‘standing stage’.

• All biotic organisms interact only with the abiotic components of the environment.

Major Abiotic factors are

Climatic factors- light ,temperature, rainfall, wind, humidity

Topographical factors-altitude, slope and direction of mountain

Edaphic factors-structure, formation and nature of soils

These factors are considered as resources and conditions.

• Resources are those factors that can be consumed or directly utilized by the organism like nitrogen, potassium etc.

• Environmental conditions are factors that are not directly utilized by the organism but affect the growth and survival of the organism

Types of ecosystem

1. Terrestrial ecosystem- includes forest ecosystem, desert ecosystem, grass land ecosystem, tree ecosystem, etc.

2. Marine ecosystem e.g.- seas, oceans.3. Fresh water ecosystem e.g.- ponds, streams,

rivers and lakes.4. Man-engineered ecosystem:- agriculture

and aquaculture

Terrestrial ecosystems are-

Forest ecosystem-

• Depending on annual rain fall and its distribution avrg monthly temperature, annual dry and wet periods, humidity etc Indian forests can be classified into 16 different types.

• Different components of the all forest ecosystems are the same – abiotic components (Inorganic and organic substances minerals present in the atmosphere ),biotic components (producers consumers and decomposers.

Grassland ecosystem

• Continental interiors with law rainfall are dominated by grasses

• Grassland comes under terrestrial ecosystem and occupy about 19% of the earths total surface.

• The abiotic components of grassland ecosystems are the nutrients of the environment- supplied by carbon dioxide, water, nitrates, phosphates and sulphates present in the air and soil of the area

• Biotic components includes producers, consumer sand decomposers in the grassland

Desert ecosystem

• Continental interiors with very law rainfall and with very law humidity are converted to deserts.

• The species composition is quite different because of the extreme climatic conditions.

Aquatic ecosystem

Fresh water ecosystem

• Fresh water ecosystem can be two types1. Lotic – having flowing water eg streams and

rivers2. Lentic- having stagnant or still water eg

ponds and lakes The components of a fresh water ecosystem

are self regulating and self sufficient.

The components of an aquatic system can also be classified into biotic and abiotic.

Abiotic components are carbon dioxide, oxygen, calcium, nitrogen, phosphorous, amino acids and water

Biotic components consists of producers consumers and decomposers.

Marine (ocean) eco system

• Marine ecosystem can be devided into 1. Littoral zone2. Neritic3. Pelagic4. Benthic zone

• Littoral zone- the shore line between the land and open sea is termed as littoral zone. waves and tides have the maximum effect in this zone.

• Just above the continental shelf lies the Neritic zone- this zone is rich in nutrients washed from land and hence rich in species too. Sunlight also penetrates the neritic zone. Hence the productivity of this zone is high. Pollutions affect this zone first

• Pelagic zone- the open sea constituting 90% of the total ocean surface forms the pelage zone .

• Photosynthesis is carried out by phytoplankton's are present in this zone.

• This zone is very large in area, it is low in nutrients and productivity.

• fin and blue whale are present here

• Benthic zone- the floor of the ocean constitutes the benthic zone. It streches from the edge of the continental shelf to the deepest ocean trenches. Organisms present here are heterotrophic