Ecological Relationships and Energy Flow
Ecological Relationships and Energy Flow
Energy Flow in Ecosystems
- Producers are organisms, generally plants, that convert solar energy into chemical energy (food) through photosynthesis.
- Each step in a food chain or web is known as a trophic level.
- Consumers, also known as heterotrophs, cannot produce their own food and depend on producers or other consumers for nourishment.
- Consumers are divided into three categories: herbivores (primary consumers), carnivores (secondary and tertiary consumers), and omnivores (consume both plants and animals).
- Decomposers, including bacteria and fungi, are vital for breaking down dead organisms and animal wastes, returning nutrients to the soil.
- The flow of energy in an ecosystem is unidirectional. This is the principle that energy moves from the sun to producers to consumers to decomposers.
- Energy is gradually lost at each trophic level primarily as heat due to respiration.
- Typically, only 10% of the energy at each trophic level is passed on to the next trophic level.
- This energy loss through the trophic levels results in the shape of an ecological pyramid, where the primary producers make up the base and the top consumers make up the peak.
Relationships Among Organisms
- Symbiosis refers to the close and prolonged interaction between two different species. Types of symbiotic relationships involve mutualism, parasitism, and commensalism.
- In mutualism, both organisms benefit from the relationship, such as the relationship between bees and flowers.
- In parasitism, one organism (parasite) benefits at the expense of the other (host), such as lice on a human.
- In commensalism, one organism benefits and the other is unaffected, like barnacles growing on a whale’s skin.
- Predation happens when one organism (the predator) kills and consumes another (the prey).
- Competition occurs when organisms vie for the same limited resources, including food, water, space, light, and mate.
- In an ecosystem, the community of organisms interact with each other and with the non-living environment. This interaction is referred to as the biotic and abiotic interactions.