An ecosystem is a community of organisms together with the non-living (abiotic) components of their environment, interacting as a system.The components of an ecosystem can be divided into two groups:
• biotic components are the living organisms: producers, consumers and decomposers;
• abiotic components are the non-living conditions and resources, such as light, temperature, water, soil, pH, oxygen and mineral ions.Ecosystems can be any size. A rock pool, a pond, a hedgerow and a whole tropical rainforest are all ecosystems. Their boundaries are often chosen for convenience, because organisms and materials move between them.Two processes run through every ecosystem:
• energy flows through it. Light energy is captured by producers in photosynthesis and passed to consumers and decomposers, with energy lost at each stage, mainly as heat from respiration;
• nutrients are recycled within it. Elements such as carbon, nitrogen and phosphorus pass from the abiotic environment into organisms and are returned by decomposition.Ecosystems are dynamic. They change over time as populations rise and fall and as conditions change, but the interactions between organisms and their environment tend to keep many populations within limits.For example, in a pond the water temperature and oxygen level (abiotic) affect which fish survive, while the fish (biotic) affect the numbers of insects and algae, and the algae in turn change the oxygen level.
• biotic components are the living organisms: producers, consumers and decomposers;
• abiotic components are the non-living conditions and resources, such as light, temperature, water, soil, pH, oxygen and mineral ions.Ecosystems can be any size. A rock pool, a pond, a hedgerow and a whole tropical rainforest are all ecosystems. Their boundaries are often chosen for convenience, because organisms and materials move between them.Two processes run through every ecosystem:
• energy flows through it. Light energy is captured by producers in photosynthesis and passed to consumers and decomposers, with energy lost at each stage, mainly as heat from respiration;
• nutrients are recycled within it. Elements such as carbon, nitrogen and phosphorus pass from the abiotic environment into organisms and are returned by decomposition.Ecosystems are dynamic. They change over time as populations rise and fall and as conditions change, but the interactions between organisms and their environment tend to keep many populations within limits.For example, in a pond the water temperature and oxygen level (abiotic) affect which fish survive, while the fish (biotic) affect the numbers of insects and algae, and the algae in turn change the oxygen level.