7 5. Ecosystem

E C O S Y S T E M

Created by Alfi_MSK, a Biology teacher of GIS JH


What is ecosystem?

• Ecosystem is interaction between organism or indivuals and the abiotic environment.


According to the process of its establishment, there are 2 types of ecosystem ;1. Natural ecosystem

made by natureex. Forest, oceans, lakes, swamps, etc

2. Artificial ecosystemmade by humanex. Rice fields, aquarium, etc


2 kinds of ecosystem components

1. The biotic componentsconsist of all organism such as plants, animals, and microorganismsgrouped into 3 kinds ; producers, consumers, decomposers

2. The abiotic componentsconsist of physical or non-living factorsex. Sunlight, air, water, temperature, etc


Producers • Producers are organisms that produce food

for both themselves and other organisms• Producers are all plants and photosynthetic

organisms, because they can photosynthesize

• During the photosynthesis, H O₂ and CO₂ are converted into C H O₆ ₁₂ ₆ and O₂

• Due to their ability to manufacture their own food, plants are called autotroph organism


Consumers • Consumers are organisms that eat other organisms, because

they can’t manufacture their own food

• Consumers are categorized into primary consumer, secondary consumer, tertiary consumer, etc

• The primary consumers directly eat the producers

• The organisms that indirectly depend on producers and eat other consumers are called secondary and tertiary consumers

• Base on their foods, animals in ecosystem are categorized into 3 groups namely herbivore, carnivore, and omnivore

Decomposers • Decomposers are organisms that decompose organic

materials of dead organism into inorganic ones

• The inorganic materials resulted from this process fertilize the land since they are rich of nutrients necessary for the soil

• The decomposers include bacteria and fungi

• If there were no decomposers, the earth would be full of stocks of garbage and remnants of organisms



Sunlight

• Sunlight is the main source of energy for all organisms on earth

• H₂O and CO₂ are transformed into C₆H₁₂O₆ and O₂ during photosynthesis by using sunlight


Air • Air is composed of different types of gases such

as oxygen, hydrogen, carbon dioxide, and nitrogen

• All organisms need air for their activities, for ex. Oxygen is required during the respiration that oxides (burn) carbohydrate to generate energy

• Plants use carbon dioxide as the raw material to produce carbohydrate and nitrogen to produce protein

Water

• All organisms on earth need water to survive

• Plants will dehydrate and die if they lack of water

• In human body, water functions as dissolver dissolving all the materials eaten by organisms

• Water is also a habitat for fish and frogsCreated by Alfi_MSK, a Biology teacher of GIS

JH


Temperature

• Temperature is one of important components for the organisms to survive on earth

• Each organism needs a certain range of temperature to survive

• Therefore, plants living in hot area as cactus will die or grow poorly if they are planted in cold area and vice-versa

Interaction between abiotic and biotic components

• All organisms on earth need water for their survivals

• The water on earth will form a water cycle

• On a clear day, seawater evaporates and forms a mass of condensed water in the atmosphere

• The condensed water form clouds which also condense and result in rain

• The rain-water is absorbed by the soil

• Then, the water accumulates into water springs and flows to the rivers and ends up in seas

• This process is called water cycleCreated by Alfi_MSK, a Biology teacher of GIS JH


Water Cycle


Carbon Cycle

Interactions within biotic components• The interaction within biotic components in the ecosystem can be

seen in the rank of food consumption in the organism, which is called food chain

• For ex. the plants are eaten by the herbivores, then the herbivores are eaten by the 1st carnivores which are finally eaten by other carnivores

• In the end, all producers and consumers will die and they will be decomposed by the decomposers

• The plants will use the decomposed materials as nutrients for their growth

• If an ecosystem has several related food chains, those food chains will form food web Created by Alfi_MSK, a Biology teacher of GIS JH

in food web, one consumer can have more than one role, for example the role as a first level consumer and also as a second level consumer.

in food chain, energy in food can be tranferred from one organism to another, but the energy tranferred is only a small amount.

in food chain, some of the energy is utilized for growth, some is excreted as residue, and some is released as heat.

Only 10% of energy is stored inside the body of an organism. Created by Alfi_MSK, a Biology teacher of GIS JH

This one tenth energy is available for the organism which becomes a predator.

The 90% reduction of energy at every trophic level is the answer to the question “why are there more plants compared to herbivores, and more herbivores compared to carnivores?”

in other words, in order for a food chain to last, the number of producers have to be higher than the number of 1st level consumers, the number of 1st consumers have to be higher than the 2nd consumers, and so on.Created by Alfi_MSK, a Biology teacher of GIS JH


Food Chain


Food Web


Food Pyramid


The interaction within biotic components can occur in several form

A. Symbiosissymbiosis is a close relation between 2 different types of organisms.

symbiosis classified into;1. Mutualism is an association that benefits all the participants.

ex. An association between the wasp and flower2. Commensalism is an association of organisms of different types

where one organisms gains benefit without causing loss to the other.ex. An association between sharks and remora fish

3. Parasitism is an association between 2 organisms of different species where one organism gains benefit and the other suffers losses.ex. An association between bacteria and the human body


Mutualism Symbiosis Commensalism Symbiosis


Parasitism Symbiosis


B. Competitionorganisms in an ecosystem compete with each other to gain things they need to survive.ex. The competition between zebra, horse, buffalo, and deer to obtain grass in savannah ecosystem

C. Predation predation is an association between the eater and the eaten.ex. The association between deer and lion

D. Antibiotic antibiotic is an association of 2 organisms where one organism resists the growth of the other one.ex. The association between penicillium notatum and pathogenic bacteria


Competition Predation


Anti biosis Netral


Material Cycle and Energy Flow

• Material Cycle it is a continual cycle of material from abiotic component

to biotic one and then back to the biotic one.

Material cycle starts from abiotic component, for ex. the water and mineral cycles

On land ecosystem, matrials such as water and mineral from the ground go through plant body, then the plants transform the water and the minerals into different substances such as glucose, protein, and fat, which is consumed by herbivores

to biotic component and then going back to abiotic components


Then the herbivores are eaten by the carnivores. Finally , the plants, herbivores, and carnivores are decomposed by the decomposers.

The materials in those bodies are transformed into water and nutrients which then return to the soils.

The materials will keep cycling from abiotic component


• Energy Flow In nature the energy flows from the outside of the ecosystem

into the ecosystem and then exits from the ecosystem.

Energy flow starts from outside, for example from the sun energy

The source of energy on the Earth is the Sun. It enters the ecosystem through the plants.

The plants capture sunlight energy and convert it into chemical energy.

Chemical energy from the plant flows into the body of herbivores in the forms of food such as leaves, fruits, and seeds.

where do living organisms obtain their energy to live from?

Through photosynthesis, green plants use energy from sunlight to produce energy stored in the form of food or nutrients.

if plants are eaten by 1st consumers, the energy stored within the plants is transferred into the 1st level consumers.

furthermore, if 1st level consumers have been eaten by 2nd level consumers, energy from 1st consumer is transferred into the bodies of 2nd level consumers, and so on.

this phenomenon is called a transfer of energy.



Chemical energy in herbivores flows to the body of carnivores in the form of food such as meat.

The chemical energy in the plants, herbivores, and carnivores then flow into the microorganisms.

Beside flowing from one organism to other organisms, some energy is transformed into heat that in the end exits from the ecosystem.

Each level of the energy flow in an ecosystem is called trophic level.

The producers are in the 1st trophic level, the herbivores are in the 2nd trophic level, the carnivores eating herbivores are in the 3rd trophic level, and the carnivores eating other carnivores are in the 4th trophic level.


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7 5. Ecosystem