Ecosystem
Ecosystem is the basic structural and functional unit of the environment.
- Ecosystem is the study of physical and biological processes and their interaction with the environment.
- The term "ecosystem" was coined by A.G.Tansley in 1935 to explain the interaction between biological and physical components of the environment.
- Tansley believed that ecosystems include not only the organism complex but also the entire complex of physical factors that make up the environment.
Ecology
- The word ecology comes from the Greek word ‘Oikos’ meaning home or place to live in. In simple term the meaning of ecology is to study of organisms in their natural habitat.
General characteristics of an eco-system
- The function of the ecosystem is related to energy flow in material cycling through and within the system.
- The ecosystem is a major structural and functional unit of ecology.
- The structure of an eco-system is related to its species diversity; as such the more complex ecosystem has high species diversity.
- The relative amount of energy required to maintain an ecosystem depends on its structure.
- The more complex the structure, the lesser the energy it requires to maintain itself.
- Ecosystems mature by passing from less complex to more complex states.
- Early stages of such succession have an excess of potential energy. Later (mature) stages have less energy accumulation.
- Both the environment and the energy fixation in any given ecosystem are limited.
- They cannot be exceeded in any way without causing serious undesirable effect.
Level of organization in ecology
1. Organism ‐
- An individual living organism can be either a macro or microorganism.
2. Species ‐
- Species means group of individuals that are closely related & can mate to produce fertile offspring.
3. Population ‐
- It is the group of all the members of the same species that Live in the same place at the same time.
Example-
- Asiatic lions at Gir National Park
4. Community ‐
- It is a group of various species that live in the same place and interact with each other.
5. Ecosystem -
- It a collection of all the organisms that live in a particular place
together with their non-living, or physical environment.
6. Biome -
- It is a group of terrestrial communities that covers a large area and is characterized by certain soil and climate conditions and particular assemblages of plants and animals.
7. Biosphere -
- Biosphere is a part of the earth where life can exist.
- Bio-sphere represents a highly integrated and interacting zone comprising of atmosphere (air), hydrosphere (water) and lithosphere (land).
Structural and Functional components of ecosystem
- Each ecosystem has definite organization comprising structural and functional components.
Structural component -
- It includes abiotic and biotic component.
Functional component-
- It is the volume and rate at which material circulates and energy flows in the ecosystem.
Structure / Structural component of ecosystem
Biotic component
- The biological (biotic) factors of ecosystem include all the living organisms-plants, animals, bacteria and viruses.
It is further divided as follows-
A. Producers.
B. Consumers (primary, secondary and Tertiary).
C. Decomposers.
A. Producers
- Producers are the autotrophs (auto means self, troph means to nourish) of the ecosystem.
- They are the green plants and green microorganisms who can make their own food material by using carbon dioxide and water in presence of sunlight with the help of chlorophyll present in them.
- Example-All green plants, Algae, Cyanobacteria.
B. Consumers (primary, secondary and Tertiary)
Primary Consumers –
- They are the herbivores who eat directly the autotrophs / plants. They cannot eat any animals.
- Example- Grasshoppers, Rabbits, Goats.
Secondary Consumers –
- They cannot directly eat the producers of the ecosystem, that is the plants. They can eat only herbivores.
- Example- Frogs, Jackal, Snakes.
Tertiary Consumers –
- They are carnivores in nature means they are the meat eaters. Thus, they depend on the secondary consumer for their food. They are the top-level carnivores.
- Example – Tigers, Lions, Vulture, Kite.
C. Decomposers
- These are microorganisms like fungi and some bacteria which are incapable of preparing their food and live on dead and decaying plants or animal parts.
- They decompose complex organic substances of the dead parts into simple forms to make them available to the producers
- They are saprotrophs (=osmotrophs) they include mainly bacteria, actinomycetes and fungi.
Process of Decomposition
The process of decomposition involves three interrelated components as follows-
1. Leaching-
- Leaching is a physical phenomenon operating soon-after litter fall. Soluble matter is removed from detritus by the action of water. Sometime over 20% of the total nitrogen content of litter maybe leached off.
2. Catabolism
- The process in a plant or animal by which living tissue is changed into waste products.
3. Comminution
- Comminution to make small to reduce to power or minute particles.
- Comminution means the reduction in particle size of detritus. During the course of feeding, the decomposer animals community detritus physically. And utilize the energy and nutrients for their own growth (secondary production).
The two major functions of decomposition within ecosystems are as under-
1. The mineralization of essential elements.
2. The formation of soil organic matter to inorganic form. The formation of soil organic matter in nature is a slow process.
Types of decomposers
1. Nectroph-
- They cause rapid death of the food source because they have a short-term exploitation of living organism.
- Nectrophs include may plant parasitic microbes as well as some herbivores, predators, and microtrophs (organisms which feed on living bacteria and fungi.)
2. Biotrophs-
- Biotopes resort to a long-term exploitation of their living food resource. For example, root-feeding nematodes and aphids, obligate plant parasites, e.g., and mycorhizae and root nodules, etc.
3. Saprotophs-
- The apostrophes utilize food already dead, and most of the decomposers belong to this category.
Examples of Different Ecosystem
1. Marine Ecosystem
Producers-
- Phytoplankton and algae
Primary Consumer-
- Zooplanktons, Crustaceans, Small fishes.
Secondary Consumer-
- Carnivorous fish, seals, sea stars, whales, squid, some crabs, lobsters etc.
Tertiary Consumer-
- Giant Carnivorous Fish, Sharks, Whales, Snakes, Hawks etc.
Decomposers-
- Bacteria, fungi, marine worms, echinoderms, crustaceans and mollusks.
2. Grassland Ecosystem
Producers-
- Grass and tree.
Primary Consumer-
- Grasshoppers, Rabbits, Deer, Sheep, Goats etc.
Secondary Consumer-
- Frogs, Lizards, Birds, Snakes.
Tertiary Consumer-
- Hawks, Eagle, Tiger Etc.
Decomposers-
- Insects, fungi, algae and bacteria.
3. Pond or Lake Ecosystem
Producers-
- Microscopic phytoplankton (plant plankton), algae, aquatic plants
Primary Consumer-
- Insects, Frogs, Larvae, Beetles, Zooplanktons, Crustaceans etc
Secondary Consumer-
- Insects, Larger fishes, Cranes, Other Birds
Tertiary Consumer-
- Largest Fishes, Water Snakes, Hawks etc
Decomposers-
- Insects, fungi, algae and bacteria
Abiotic component
These are the non-living factors in form of solid, liquid or gas found in the nature (ice, water, moisture). They can be categorised into 2 types-
A. Inorganic Components-
- The inorganic components of an ecosystem are as under carbon dioxide, water, nitrogen, calcium, and phosphate.
- All of these are involved in matter cycles (biogeochemical cycles).
B. Organic Components-
- The organic components of an ecosystem are proteins , carbohydrates ; lipids and amino acids, all of these are synthesized by the biota (flora and fauna) of an ecosystem and are reached to ecosystem as their wastes, dead remains, etc.
Important One Liner on Ecosystem.
What is an ecosystem?
An ecosystem is the basic structural and functional unit of the environment.
Who coined the term "ecosystem"?
A.G. Tansley coined the term "ecosystem" in 1935.
What is the study of ecosystem?
The study of ecosystem involves physical and biological processes and their interaction with the environment.
What is the meaning of ecology?
Ecology is the study of organisms in their natural habitat.
What are the general characteristics of an ecosystem?
The function of the ecosystem is related to energy flow in material cycling through and within the system. The ecosystem is a major structural and functional unit of ecology. The structure of an ecosystem is related to its species diversity.
What is the biotic component of an ecosystem?
The biotic component of an ecosystem includes all the living organisms such as plants, animals, bacteria, and viruses.
What are producers in an ecosystem?
Producers are the autotrophs of the ecosystem that make their own food using carbon dioxide and water in the presence of sunlight with the help of chlorophyll present in them.
What are primary consumers in an ecosystem?
Primary consumers are herbivores that eat directly the autotrophs or plants.
What are secondary consumers in an ecosystem?
Secondary consumers cannot directly eat the producers of the ecosystem, that is the plants. They can eat only herbivores.
What are tertiary consumers in an ecosystem?
Tertiary consumers are carnivores that depend on the secondary consumers for their food.
What are decomposers in an ecosystem?
Decomposers are microorganisms like fungi and some bacteria which are incapable of preparing their food and live on dead and decaying plants or animal parts.
What is leaching in the process of decomposition?
Leaching is a physical phenomenon operating soon-after litter fall. Soluble matter is removed from detritus by the action of water.
What is catabolism in the process of decomposition?
Catabolism is the process in a plant or animal by which living tissue is changed into waste products.
What is comminution in the process of decomposition?
Comminution means the reduction in particle size of detritus.
What are the major functions of decomposition within ecosystems?
The major functions of decomposition within ecosystems are the mineralization of essential elements and the formation of soil organic matter to inorganic form.