Ecosystems

An ecosystem is a community of living organisms (biotic components) interacting with their non-living (abiotic) environment. These interactions form a system where energy and nutrients are transferred. The term "ecosystem" was first used by English botanist A.G. Tansley in 1935.

Understanding Ecosystems

• Definition: A biological community of interacting organisms and their physical environment.
• Interaction between Biotic and Abiotic Factors: The living and non-living components of an ecosystem interact with each other to create a stable system. Energy flows from one trophic level to the next, starting with the sun's energy captured by producers. Ecosystems also cycle essential nutrients between biotic and abiotic components.

Biotic Components

Biotic components are the living parts of an ecosystem, such as plants, animals, and microorganisms. They are categorized by how they get nutrition:

• Producers (or autotrophs): Organisms that produce their own food, usually through photosynthesis. Plants are a prime example.
• Consumers (or heterotrophs): Organisms that obtain their food by eating other organisms. They can be primary consumers (herbivores), secondary consumers (carnivores or omnivores), or tertiary consumers.
• Decomposers (or saprotrophs): Organisms that break down dead organic matter, such as bacteria and fungi.

Food Chain, Food Web, and Pyramid of Numbers

• Food Chain: A series of organisms in which each organism is the food of the next. Energy flows from one trophic level to the next.
• Food Web: A system of interconnected food chains, showing the complex feeding relationships in an ecosystem.
• Pyramid of Numbers: A graphical representation of the number of organisms at each trophic level in a food chain. It shows that the number of organisms decreases as you go up the food chain.

Interdependence between Organisms

• Symbiosis: A close and long-term interaction between two different biological species.
• Parasitism: A relationship between two organisms in which one organism, the parasite, benefits at the expense of the other, the host.
• Predation: A biological interaction where one organism, the predator, kills and eats another organism, its prey.

Abiotic Components

Abiotic components are the non-living chemical and physical parts of an ecosystem.

• Air: The mixture of gases that surrounds the Earth.
• Soil: The upper layer of earth in which plants grow, providing nutrients and support.
• Water: A colorless, transparent, odorless, tasteless liquid that forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms.
• Climatic Factors:
  • Sunlight: The primary source of energy for most ecosystems.
  • Temperature: The degree or intensity of heat present in a substance or object, which affects the rate of metabolic reactions.
  • Humidity: The amount of water vapor in the air.
  • Wind: The perceptible natural movement of the air, which can affect temperature and humidity.

Types of Ecosystems

Ecosystems are broadly categorized into two types:

• Terrestrial Ecosystems: These are land-based ecosystems.
  • Forest Ecosystems: Dominated by trees, these are vital for biodiversity.
  • Grassland Ecosystems: Characterized by vast open spaces of grass.
  • Desert Ecosystems: Very dry and often hot environments.
  • Tundra Ecosystems: Cold, windy, and with little rainfall.
• Aquatic Ecosystems: These are water-based ecosystems.
  • Freshwater Ecosystems: Include rivers, lakes, and wetlands.
  • Marine Ecosystems: Include oceans and coral reefs.

Forest Ecosystem

• Flora: The plants of a particular region, habitat, or geological period.
• Fauna: The animals of a particular region, habitat, or geological period.