Functions and Types of Ecosystem

Functions of Ecosystem

• Three major functions of an ecosystem are

1. Primary function : Ecosystem produces starch by interaction of biotic and abiotic components.

2. Secondary function : Ecosystem is related to processes and events that change form of energy and materials within biotic and abiotic components.

3. Tertiary function : Ecosystem allows flow of energy and cycling of materials so that system remains stable and there is continuity in life.

 

1. Ecosystem Conservation

• Ecosystem and its conservation are now vital environmental issues of international concern.

• There are several strategies which are adapted for conservation of ecosytem. Some of these are -

1. Legislation : Formal policies and programmes for conservation and sustainable utilisation of ecosytem resources.

2. In -situ Conservation : Conserving the animals and plants in their natural habitats is known as in situ conservation.

3. Ex-situ Conservation : Ex-situ conservation of plants and animals preserve/ or protect them away from their natural habitat.

4. Community Participation in Biodiversity Conservation.

 

Ecosystem Types

 

1. Forest Ecosystem

• A forest ecosystem is one in which considerably tall and dense trees grow that support many animal species within it.

a. Types of Forest Ecosystem

• A forest ecosystem can be classified depending upon climatic conditions. Several forest ecosystems are :

1. Tropical rain forests  2. Tropical deciduous forests

3. Temperature deciduous forests 4. Tropical scrub forests

5. Temperature rain forests.

 

b.  Structure and Function of Forest Ecosystem

• The forest ecosystem has two parts :

1. Abiotic (non-living) components.

2. Biotic (living) components.

1. Abiotic (non-living) components

• The abiotic components are inorganic and organic substances present in soil and atmosphere.

Examples : Climatic factors (temperature, rainfall light), minerals.

2. Biotic (living) components

• The biotic components includes both the large (macrophytes) and the microscopic plants and animals.

Examples

a. Producers - Trees, shrubs and ground vegetation.

b. Consumers - Ants, flies, insects, mice, deer, snakes, birds, tiger and lion.

c. Decomposers - Bacteria and fungi.

 

c. Characteristics of Forest Ecosystem

1. Forest have warm climate with adequate rainfall.

2. Forests have well defined seasons of about equal length.

3. Forest protects biodiversity.

4. Forests have tall and dense trees with many wild animals within ecosystem.

5. The soil of forest is rich in organic matter and nutrients.

6. Forests grow very slowly.

7. Forests provide various resources for human life.

 

2. Grassland Ecosystem

• A grassland has variety of grasses, herbs, insects depending on climatic conditions and temperature. The grass is major producers of biomass.

• The grassland may be either temperature or tropical. The grasslands are degraded because of overgrazing.

a.  Types of Grassland Ecosystem

• Grassland ecosystem can be classified depending upon climatic conditions. Different grassland ecosystems are

1. Tropical grassland 2. Temperature grassland 3. Polar grassland.

 

b.  Structure and Function of Grassland Ecosystem

• The grassland ecosystem has two parts :

1. Abiotic (Non-living) components

2. Biotic (Living) components.

1. Abiotic (Non-living) components '

• The abiotic components are sourced by CO₂, H₂O, nitrate, phosphates and sulphates.

Examples : Nutrients, C, H, O, N, P, S.

2. Biotic (Living) components

• Three biotic components are : producers, consumers and decomposers

I] Producers : Producers produce food.

Examples : Grasses, forbs and shrubs.

II] Primary consumers : They depend on grass for their food.

Examples : Cows, buffaloes, deer, sheep.

Secondary consumer : They feed on herbivores (primary consumers).

Examples : Snakes, lizards, birds etc.

Tertiary consumers : They feed on secondary consumers.

Examples : Hawks, eagles etc.

III] Decomposers - They decompose the dead organic matter.

Examples : Fungi and bacteria.

 

c. Characteristics of Grassland Ecosystem

1. Grassland ecosystem exists where rainfall is low and uneven.

2. The soil of grassland ecosystem is rich in nutrients and organic matters.

3. Grassland ecosystem provides largest biomass and is used for grazing animals.

4. The grassland ecosystem exists in moderate climates.

5. Grassland ecosystem is characterized by seasonal flowering plants and savannas (scattered trees).

 

3. Desert Ecosystem

• The ecological succession of grassland is deserts. Deserts are characterized by high temperature, less moisture, warm, dry, less vegetation, special habitats.

• Four major types of deserts are

1. Hot and dry desert.    2. Semiarid desert.

3. Coastal desert. 4. Cold desert.

a. Types of Desert Ecosystems

• Desert ecosystems can be categerized depending on climatic conditions:

1. Tropical desert

2. Temperature desert

3. Cold desert

b.  Characteristics of Desert Ecosystem

1. Desert are subjected to strong winds.

2. There is low annual rainfall. .

3. The desert air is dry and climate is hot.

4. Temperature variation is large (days are hot and nights are cold).

5. Without or rare vegetation.

6. No soil is present.

c. Structure and Function of Desert Ecosystems

• Desert ecosystem consists of two components

1. Abiotic components 2. Biotic components

1. Abiotic components

Examples : Temperature, rainfall, sunlight, water etc.

2. Biotic components

a) Producers : Mostly found plant in deserts are succulent (cacti). They have water content inside which keeps them alive. The waxy outer layer protects them from sun.

Examples : Shrubs, bushes etc.

b) Consumers : Animals dig holes in ground to live in. They come out at night to find food. They can extract water from the seeds they eat.

Examples : Mice, rabbits, reptiles, squirrles etc.

c) Decomposers : Desert has poor vegetation with a very low amount of dead organic matter.

Examples : Fungi and bacteria.

 

4. Aquatic Ecosystem

• The ecosystems exists in the medium of water is called as aquatic ecosystem. In aquatic ecosystems, plants and animals live in water.

• The organisms found in aquatic environment are determined by quality of water such as clarity, salinity, oxygen content and rate of flow.

a. Types of Aquatic Ecosystem

• The aquatic ecosystems may be classified as -

1. Fresh water ecosystems :

Examples : Rivers, pond, lake, streams, wetland.

2. Marine ecosystems :

Examples : Marine or ocean, estuary.

b. Pond Ecosystem

• A pond is a freshwater aquatic ecosystem, where water remain in the same area for a longer period.

• As the pond fills in the monsoon season, a large number of food chains are formed. It contains several types of algae, aquatic plants, insects, fishes and birds.

Characteristic features of pond ecosystem

1. Most pond are temporary that has water only in monsoon season.

2. It is a stagnant (standing) water body.

3. The medium contains less nutrients.

4. Most pond become dry after the rains are over and are covered by terrestrial plants for the rest of year.

5. Pond get polluted easily due to limited amount of water.

Structure and functions of pond ecosystem

• The two components of pond ecosystems are :

1. Abiotic components  2. Biotic components.

1. Abiotic components

Examples : Light, temperature, chemical environment such as dissolved and particulate matter, oxygen, pH, phosphorous.

2. Biotic components

a. Producers : These are green photosynthetic organisms. They are of two types :

I] Phytoplankton : These are microscopic aquatic plants, which freely float on surface of water.

Examples : Algae, volvox, pandorina, cosmarium.

II] Microphytes : These are large floating plants and submerged plants.

Examples : Hydrilla, jussiaea, wolfia, demma.

b. Consumers :

I] Primary consumers (Zooplanktons) : Microscopic animals which can freely float on the surface of water.

Examples : Protozoa, very small fish, ciliates, flagellates.

II] Secondary consumers (Carnivores): They feed on zooplanktons.

Examples : Insects like water beetles and small fish.

III] Tertiary consumers : They feed on smaller fish.

Examples : Large fish like game fish.

c. Decomposers : They decompose-the dead plant and animal matter and their nutrients are released and reused by green plants.

Examples : Fungi, bacteria and flagellates.

c. Lake Ecosystem

• A lake is a giant permanent pond. A large amount of its plant material is the algae, which derives energy from the sun.

Types of lake

• Important types of lakes are

1. Oligotrophic lakes: Low nutrient concentrations.

2. Eutrophic lakes : Ovemourished nutrients.

3. Dystrophic lakes : Low pH, brown water, acidic.

4. Volcanic lakes : Receive water from magma after volcanic eruptions.

5. Meromictic lakes : Salt rich.

Characteristic features of lake ecosystem

1. Lake is a shallow fresh water body.

2. Lake is a permanent water body.

3. Food chains are inter linked with terrestrial food chains.

Structure and function of lake ecosystem

1. Abiotic components

Examples : Temperature, proteins and lipids, light, CO₂, O₂.

2. Biotic components

a. Producers : They can be green plants submerged, free floating and amphibious plants.

Examples : Phytoplanktons, algae and flagellates

b. Consumers : I] Primary consumers (Zooplanktons): Ciliates.

II] Secondary consumers : Insects, small fishes.

III] Tertiary consumers : Large fish.

c. Decomposers : They decompose the dead plant and animals.

Examples : Bacteria, fungi and actinomy cetes.

d. River or Stream Ecosystem

• The river or stream has running water. The river water contains more oxygen. There exists less species in rivers.

• The nutrient content in the water is largely determined by the terrian and vegetation surrounding the river.

• Overhanging vegetation adds a substantial amount of organic material from fallen leaves. The erosion of the streambed adds inorganic nutrients to the running water.

Characteristics of river/stream ecosystem

1. Rivers are fresh water system.

2. Dissolved oxygen content is more in streams.

3. Moving down stream, numerous tributaries join to form a river.

4. It carries sediments (from the erosion of soil) and nutrients.

Structure and function of river ecosystem

1. Abiotic components

Examples : Temperature, light, pH, nutrients, organic and inorganic compounds.

2. Biotic components

a. Producers : Phytoplankton, algae, water grasses, aquatic masses and amphibious plants.

b. Consumers :

i) Primary consumers : Water insects, snails, fishes.

ii) Secondary consumers : Birds, mammals.

c. Decomposers : Bacteria and fungi.

e. Ocean (Marine) Ecosystem

• The ocean or marine is a saltwater aquatic ecosystem. The ocean environment is characterized by its high concentration of salts and minearls.

• The marine or ocean ecosystem is largest of all ecosystems. It supplies huge variety of sea products, minerals, natural gas etc. ocean contains the richest diversity of species.

Characteristics of ocean ecosystem

1. It covers large surface area with saline water.

2. Marine or oceans are rich in biodiversity.

3. The evaporation of sea water provides rain water for the land.

4. Algae are abundant in ocean and provide much of the world's oxygen supply by absorbing huge amounts of atmospheric carbon dioxide.

Structure and function of marine ecosystem

1. Abiotic components

Examples : Temperature, light, Nacl, K, Ca and Mg salts, alkalinity.

2. Biotic components

a. Producers : Phytoplanktons (diatoms, unicellular algae), marine plants (seaweeds, chlorophyceal, phaeophyceae).

b. Consumer : These are heterotrophic macroconsumers. They depend on producers for their nutrition.

i) Primary consumers / herbivores : They feed on producers.

Examples : Crustaceans, moiluscs, fish.

ii) Secondary consumers/carnivores : They feed on herbivores.

Examples : Herring sahd, mackerel etc.

iii) Tertiary consumers : They are top consumers. They feed on small fishes.

Examples: Cod, haddock.

c. Decomposers : They decompose the dead organic matter.

Examples : Bacteria and some fungi.

Review Question

1. Explain pond ecosystem.