ECOSYSTEMECOSYSTEM -Palash ratner-Palash ratner

➔ECOLOGICAL SUCCESSION

➔ECOSYSTEM DEGRADATION

➔FOOD CHAIN

➔FOOD WEB

➔ECOLOGICALPYRAMIDS

ECOSYSTEM DEGRADATION

● WHAT IT IS ?● Ecosystem degradation it is an environmental problem that

diminishes the capacity of species to survive like, Tiger

CAUSES● Deforestation● Mining and the extraction

of construction materials● Habitat change● Over exploitation● Pollution ● Climate change

● Deforestation- more lands deforested for commercial agriculture and due to more use of resources such as forest for wood and energy.

● Habitat change- the conversion of natural forest into farmlands and plantations.

● Pollution- industrialization and urbanization create soil,water and air polluted.

● Climatic change- depletion of ozone layer because of rise in greenhouse gases.

Causes

ECOLOGICAL SUCCESSION

● WHAT IT IS?● Ecological succession refers to

more or less predictable and orderly changes in the composition or structure of ecological community.

● For example, the growth of hardwood trees (such as ash and oak) within the red pine planting area. hardwood trees are much taller than red pine trees. So the hardwood trees growth is increased in shading but red pine trees need sunlight. Thus, the consequence of the growth of the hardwood is the decline of the pine forest.

Reasons for ecological succession-

● Every species has a set of environmental conditions under which it will grow and reproduce most optimally.

● Constant temperature.● Changed condition.● Suddenly and drastically

change.

Reasons

Types of succession

● Primary succession- succession that begins in areas where no soil is initially present is called primary succession (such as lava flow).

Types of succession

● Secondary succession- succession that begins in area where soil is already present is called as Secondary succession (such as fire, wind-throw).

FOOD CHAIN

● A food chain shows how each living things gets its food. Some animals eat plants and some animals eat other animals.

● Food chain means flow or transfer of energy.

● Food chain is also called as nutrition cycle, food networks and tropic social networks.

TABLE: FOOD CHAIN TROPIC CLASSIFICATION

LEVEL NAME ENERGY SOURCE

FIRST PRODUCER AUTOTROPHS (EX GRASS)

SECOND PRIMARY CONSUMER HERBIVORES (EX GRASSHOPPER)

THIRD SECONDARY, TERTIARY, ETC CONSUMERS

CARNIVOROUS (EX TOAD,SNAKE, HAWK)

FORTH DECOMPOSERS DECOMPOSERS(EX BACTERIA)

Table:food chain

Functions of food chain

● Represents the life community

● Helps in the transfer of energy from one level to another

● It shows energy flow mechanisms

● The food chain helps in feeding relationship and interaction between organization.

TYPES OF FOOD CHAINGrazing food chain

● Grazing food chain : The producer/green plants depends upon sunlight and producer are consumed by herbivorous animals i.e eat plants and they are consumed by carnivorous .

PLANTS(PRODUCER)

GOAT (HERBIVORE)

TIGER(CARNIVORE)

Dead Bodies of animals Files Frog Snake Hawk

● Importance :

Interdependency within a food-chain helps to maintain the balance of plant and animal population.

● Detritus Food Chain :Type of food chain Initiated by microorganism like bacteria and fungi

TYPES OF FOOD CHAINDetritus food chain

FOOD WEB

● Graphical description of the feeding relationship among species

● Represent the multiple food chain in the form of web .

● Very Complex Due to its interdependency with all their Food Webs .

● Shows How many animals are interconnected by different food chains .

Food web in a grassland ecosystem

Grass rabbit hawk

mouse snake

grasshopper lizard

ECOLOGICAL PYRAMINDS

● The different tropic levels in any ecosystem can be represented graphically and these graphic representations are called ecological pyramids.

Types of ecological pyramids

1.Pyramids of

number.

2.Pyramids of

biomass

3.Pyramids of

energy.

Pyramids of number

● Showing the number of individual organisms at each level.

Pyramids of biomass

● Showing the weight of individual organisms at each level.

Pyramid of energy

● Showing the rate of energy flow of individual organisms at each level.