Cape Biology Notes

An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving or abiotic, physical components of the environment with which the organisms interact, such as air, soil, water and sunlight. In a typical ecosystem, plants and other photosynthetic organisms are the producers that provide the food. (Leibold) Ecosystems can be permanent or temporary and they usually form a number of food webs. Examples of ecosystem include:
Marine Ecosystems: oceans, coral reefs, intertidal zones, estuaries (harbour, lagoons)
Terrestrial Ecosystems: deserts, forest, grasslands, tropical rain forests, tundra, taiga
Freshwater Ecosystems: streams, rivers, pond, lake, swamps and marshes A habitat is a place or area in which organisms or a community of organisms live, including all the living and non-living conditions or factors of the surrounding the environment. The habitat must supply the needs of the organism including water, sunlight and oxygen, therefore a habitat is specific to a population (a group of similar organisms living and interacting in the same place at the same time).
Examples of habitats include:
Under a stone, the forest floor,
A rotten log- insects and fungi
The intestine- E.coli bacteria
Forest- deer, rabbit. Fox
Tropical grasslands: zebra, giraffe, Lion, Ostrich
Tundra: Snow birds, Polar bear An ecological niche refers to the role of a population in its ecosystem, or in its living and non-living environment. This usually means its feeding role in the food chain, so a particular population niche could be a producer, a predator, a parasite or a herbivore. ( Mader) A niche includes many different aspects such as its food, its habitat, its reproduction methods etc. The different niches help us to identify the interaction between populations. Members of the same population always have the same niche, and will be adapted to that niche. For example nectar feeding birds have long thin beaks.