Ecosystems

Understanding Ecosystems

• An ecosystem is a biological community of interacting organisms and their physical environment.
• Abiotic factors, such as air, water, and soil, are non-living conditions that influence the ecosystem.
• Biotic factors, such as plants, animals, and microbes, are living or once-living components that interact in an ecosystem.

Components of an Ecosystem

• Producers, primarily plants, convert sunlight into energy through photosynthesis, starting the energy flow in an ecosystem.
• Consumers are organisms that consume other organisms to get energy. They are further classified into primary, secondary, and tertiary consumers.
• Decomposers break down dead organisms and organic wastes, returning nutrients back to the ecosystem.
• Detritivores, like earthworms and beetles, eat decomposing plant and animal parts as well as faeces.

The Energy Cycle

• Energy in an ecosystem flows from producers to consumers through the food chain in the form of calories.
• Energy transfer between trophic levels is rarely efficient; usually, only about 10% of energy is transferred to the next level.
• The rest of the energy is lost as heat due to metabolic processes, a concept known as the Second Law of Thermodynamics.

Biotic and Abiotic Interactions

• Abiotic factors such as temperature, light, and soil composition can determine which species exist in a given ecosystem.
• The interactions between organisms, including mutualism, competition, and predation, shape the community structure within an ecosystem.
• The complexity of these interactions promotes biodiversity and ecosystem robustness.

Ecological Succession

• Ecological succession is the changing sequence of the varieties of species that make up a community over time.
• Succession can be primary, occurring on land where no soil exists or secondary, where disturbance has destroyed an existing community but soil remains.

Human Impact and Sustainability

• Human activities can have a significant impact on ecosystems, causing habitat destruction, over-exploitation of resources, and pollution.
• Ecological balance and sustainability can be positively influenced through conservation measures and sustainable practices such as recycling and renewable energy use.

Biodiversity

• Biodiversity refers to the variety of life in an ecosystem.
• High biodiversity generally means a healthier, more resilient ecosystem.
• Threats to biodiversity include climate change, habitat loss, and overexploitation of species.
• Conservation measures aim to protect and enhance biodiversity.