Exploring Biology Topics can reveal the incredible complexity and interconnectedness of living systems.
Concept and Dynamics of Ecosystem – Energy Flow in Ecosystem
In different environmental situations, different types of ecosystems are as follows:
|Type of Ecosystem||Producers||Herbivores||Primary Consumers||Secondary Consumers||Tertiary Consumers|
|A. Grassland Ecosystem||1. Grasses||Insects, Grasshopper||Frogs||Snakes||Predatory birds|
|2. Grasses||Mice||Snakes||Predatory birds|
|B. Pond Ecosystem||Phytoplankton||Zooplankton||Small fishes||Large Fishes||Predatory birds|
|C. Forest Ecosystem||Trees||Insects, Herbivore, Mammals||Lizards, Birds, Foxes||Lions, Tigers, etc.|
Different Types and Components of Ecosystem
Different types of Ecosystem are as follows:
A. Grassland Ecosystem
Grasslands are areas where the vegetation is dominated by grasses, however, sedge (Cyperaceae) and rush (Juncaceae) families can also be found. Grasslands occur naturally on all continents except Antarctica. Grasslands are found in most ecoregions of the earth. Its abiotic and biotic components are described below.
1. Abiotic Components:
The abiotic components of a grassland ecosystem are the non-living features of the ecosystem that the living organisms depend on. Each abiotic component influences the number and variety of the plants that grow in an ecosystem, which in turn has an influence on the variety of animals that live there. The major abiotic components are climate, parent material, and soil, and topography.
- Climate: It includes the rainfall, temperature, and wind patterns that occur in an area, and is the most important abiotic component of a grassland ecosystem. Temperature in tandem with precipitation, determines whether grasslands, forests, or some combination of these two will form. The amount and distribution of the rainfall an area receives in a year influences the types and productivity of grassland plants.
- Parent material and Soil: It is the geological material that lies on the top of the bedrock and is the foundation on which soil has developed.
- Topography: It is the variety of shapes found on the landscape determined by the slopes, elevation, and aspects. The topography of grassland ecosystems is a varied landscape of gently rolling hills and prairies, rock outcrops, cliffs, gullies, and low-lying areas.
2. Biotic Components:
The biotic components of a grassland ecosystem are the living organisms that exist in the system. These organisms can be classified as producers, consumers or decomposers.
They are able to capture the sun’s energy through photosynthesis and absorb nutrients from the soil, storing them for future use by themselves and by other organisms. Grasses, shrubs, trees, mosses, lichens, and cyanobacteria are some of the many producers found in a grassland ecosystem. When these plants die they provide energy for a host of insects, fungi, and bacteria that live in and on the soil and feed on plant debris. Grasses are an important source of food for large grazing animals such as California bighorn sheep, mule deer, and elk, and for much smaller animals such as marmots, pocket gophers, and mice.
They are organisms that do not have the ability to capture the energy produced by the sun but consume plant and animal material to gain their energy for growth and activity. Consumers are further divided into three types based on their ability to digest plant and animal material.
They eat only plants, such as the elk that graze the grasslands of the Columbia Valley, or an insect nibbling on the leaf of a sticky geranium.
They eat both plants and animals, such as the black bear.
They eat only animals, such as the red-tailed hawk or western rattlesnake.
It includes the insects, fungi, algae, and bacteria both on the ground and in the soil that help to break down the organic layer to provide nutrients for growing plants. There are many millions of these organisms in each square meter of grassland.
It has many biotic functions in a grassland ecosystem. It provides the material in which plants grow, holds moisture for plants to absorb, is the “recycling bin” for plant and animal matter, and provides an important habitat for soil organisms. Soil is a vital link between the biotic and abiotic parts of a grassland ecosystem.
B. Pond (Aquatic) Ecosystem
A pond is a typical aquatic ecosystem. Like other typical ecosystems, it also comprises abiotic components, producers, consumers, and decomposers. It shows three distinct zonations:
- Littoral zone, which is a shallow water region.
- A limnetic zone is an open water zone to the depth where effective light can penetrate.
- Profound zone, the bottom and deep water area beyond the depth of effective light penetration.
1. Abiotic Components:
The abiotic components of a pond include various inorganic and organic compounds, such as water, oxygen, carbon dioxide, nitrogen, calcium, phosphorus, carbohydrates, proteins, fats, light, temperature, etc.
The producers in a pond are of two types-
- Larger macrophytic plants that grow in shallow water like Vallisneria, Hydrilla, Utricularia, Nymphaea, etc., with larger rooted and floating vegetation, e.g., Pistia.
- Smaller microphytes or phytoplanktons like algae Ulothrix, Oedogonium, Spirogyra, Anabaena, Microcystis, Volvox, etc., are distributed throughout the pond as deep as light penetrates. The phytoplanktons are much more important than the rooted plants in food production for the ecosystem.
The producers are Phytoplanktons: Nostoc, Anabaena, Volvox, etc. Filamentous algae: Spirogyra, Oedogonium, Chara etc. Marginal and Emergent plants: Typha, Phragmitis, etc. Submerged plants: Ceratophyllum, Utricularia etc. Surface floating plants: Wolffia, Pistia, Lemna etc.
Consumers are heterotrophs which depend for their nutrition on other organisms. The consumers are primary, secondary, and tertiary. The primary consumers are zooplankton like Cyclops, Stenocypris, Daphnia, Brachionus, etc., who feed on phytoplankton. Some other benthic (bottom forms) animals like insects, larvae, small fishes snails, etc., act as primary consumers. The secondary consumers are carnivores which feed on the plant eaters, e.g., prawns, fish, etc. The tertiary consumers eat primary carnivores, e.g., snakes and big fishes like bhetki, boal fish, soal fish, etc.
Different types of aquatic bacteria and fungi act as decomposers. Bacteria, and fungi (Aspergillus, Rhizopus, Fusarium, Cladosporium, etc.) are more abundant in the soil layer underneath the water or in the mud rich in dead, decaying plants and animals. They act on the dead and decayed organic matter and help rapidly decompose the dead body into simpler substances which are used as raw materials by the producers.
C. Ecosystem of Forest
A forest is a typical terrestrial ecosystem. Its abiotic, biotic components are described below:
1. Abiotic Components:
The abiotic components of a forest include various inorganic and organic components, such as sun, temperature, soil, humus, air, soil water, minerals, proteins, fats, carbohydrates etc.
2. Biotic Components:
- Producers: Different types of green plants (herbs, shrubs including grasses and trees).
- Consumers: They are of 3 types
- Primary Consumers: They are also called herbivorous animals, i.e., plant eaters, e.g., all types of insects, larvae, rats, small birds, pigeons, rabbits, goats, cows, pigs, etc.
- Secondary Consumers: Carnivorous animals feeding on the primary consumers, are called secondary consumers, e.g., toads, lizards, spiders, dogs, foxes, cats, etc.
- Tertiary Consumers: Such carnivorous animals feeding on both primary and secondary consumers, are tertiary consumers, e.g., tigers, lions, eagles, vultures etc.
Microscopic organisms break down and decompose the complex substances of dead organisms, e.g., different kinds of fungi, protozoa, and bacteria.
Dynamics in Ecosystem
Sun is the chief source of energy in all ecosystems. Biological activities require the consumption of energy which ultimately comes from the sun as radiant energy. By the process of photosynthesis, this solar energy is transformed into chemical energy and stored on plant tissue and then transformed into mechanical and heat forms of energy during metabolic activities. In the biological world, the energy flows from the sun to plants and then to all heterotrophic organisms. Mechanical energy has two forms: Kinetic energy or Free energy and Potential energy.
Kinetic energy means the energy which a body possesses by virtue of its motion. It is measured by the amount of work done in bringing the body to rest, whereas potential energy is stored energy (the energy at rest) and becomes useful after conversion into kinetic energy. All organisms require a source of potential energy which is found in the chemical energy of food. The oxidation of food releases energy which is used to do work. Thus, chemical energy is converted into mechanical energy. Plants synthesize food with the help of solar energy and inorganic substances (viz. chlorophyll, CO2, H2O, nutrients) in a biochemical process, called photosynthesis. An ecosystem is a community of living organisms and non-living components of the environment, interacting as a system.