Ecosystem
Ecosystem is a geographic area where plants, animals and other organisms, as well as weather and landscape, work together to form a bubble of life
- An ecosystem is a dynamic system formed by a community of living organisms (biotic components) interacting with their physical environment (abiotic components) in a specific area.
- Ecosystems function as open systems, meaning that both energy and matter can enter and exit continuously.
- The balance of these flows maintains ecosystem productivity and stability.
Open system
An open system is one in which energy and matter can enter and exit freely, allowing interaction with the surrounding environment.
Components of an Ecosystem
- Biotic Components: Producers (plants, algae), consumers (herbivores, carnivores, omnivores), and decomposers (bacteria, fungi).
- Abiotic Components: Sunlight, temperature, soil composition, water, oxygen, minerals, and atmospheric gases.
- These two sets of components are linked through energy flow and nutrient cycling.
A forest ecosystem includes trees, shrubs, birds, mammals, and decomposers interacting with abiotic factors like sunlight, rainfall, soil nutrients, and temperature to sustain life.
Ecosystem as an Open System
Energy Flow in an Ecosystem
- Energy enters ecosystems primarily from the Sun.
- Producers (autotrophs), such as plants and algae, convert solar energy into chemical energy through photosynthesis.
- This energy is then passed through trophic levels via feeding relationships: Producers → Primary Consumers → Secondary Consumers → Tertiary Consumers → Decomposers.
- With each transfer, energy is lost as heat, following the Second Law of Thermodynamics.
- In a grassland ecosystem, sunlight is captured by grasses, consumed by zebras (herbivores), then transferred to lions (carnivores).
- Energy is eventually released as heat through respiration.
Always mention that energy flows in one direction, while matter cycles within an ecosystem.
Matter Cycling in an Ecosystem
- Unlike energy, matter cycles through ecosystems.
- Essential elements like carbon, nitrogen, phosphorus, and water move through biotic and abiotic components in interconnected cycles.
- Decomposers are vital, breaking down dead material and recycling nutrients into soil and atmosphere.
Energy moves through the ecosystem like a one-way street, while matter cycles like a loop, continuously reused and recycled.
Examples of Ecosystems and Their Interactions
1. Tropical Rainforest
- Energy Flow: High levels of sunlight support dense plant growth, which in turn sustains a diverse array of herbivores and predators.
- Matter Cycling: Rapid decomposition due to warm, moist conditions ensures nutrients are quickly recycled, supporting continuous plant growth.
2. Coral Reef
- Energy Flow: Algae living within coral polyps photosynthesize, providing energy to the coral and forming the base of the food web.
- Matter Cycling: Nutrients like nitrogen and phosphorus are recycled through the interactions between coral, algae, and fish.
Coral reefs are highly efficient at recycling nutrients, allowing them to thrive in nutrient-poor waters.
3. Arctic Tundra
- Energy Flow: Limited sunlight and a short growing season restrict energy input, resulting in fewer trophic levels.
- Matter Cycling: Decomposition is slow due to cold temperatures, causing nutrients to remain locked in the soil for long periods.
- Ecosystems vary widely in their efficiency of energy flow and matter cycling.
- Tropical rainforests, for example, have rapid nutrient cycling, while the Arctic tundra has much slower processes.
Mangrove Ecosystem (Coastal India):
- Inputs: Solar energy, tidal water, river sediment, nutrients.
- Outputs: Organic matter, heat loss, dissolved gases.
- Processes: Photosynthesis, decomposition, respiration, nutrient cycling.
- Interactions: Fish, crabs, and trees create a balanced open system dependent on tidal flow and sunlight.
Sustainability in Ecosystems
Sustainability
Sustainability is the natural capacity of ecosystems to maintain equilibrium between resource inputs and waste outputs while continuing to support life.
- A sustainable ecosystem maintains a balance between inputs and outputs, allowing it to persist over long periods.
- In a steady-state ecosystem, energy and matter cycle efficiently, preventing depletion of resources.
