Ecology

Target Language or Knowledge:

Ecology is the study of the relationships amongst organisms (living things) and the connections between organisms and their physical environment. Organisms do not exist in isolation – they are interdependent. Individuals depend on other organisms for food, protection or mates. Each organism exists in a network of relationships with organisms belonging to the same species (group of similar organisms that can breed together) and to different species. The physical environment is the context in which organisms live and may include the land they live on, the air that surrounds them, as well as bodies of water. Organisms depend on the physical environment for nutrients, light, water, warmth, shelter and spaces to live in. The word ‘ecology’ comes from a Greek word meaning home, so ecology can be said to be the study of organisms in their home environment. The ecology of organisms can be studied at different levels: Niche – the study of members of a species in their environment; the main focus is on how they are adapted to survive. Populations – the study of a group of organisms belonging to the same species and living in the same place; the focus is on population features Communities – the study of relationships between the different species that live in a defined area; the main focus is on feeding relationships. Ecosystems – the study of the interactions between the community and the physical environment; the focus is on energy flow and the recycling of chemicals. The niche of a species describes how members make a living and reproduce in the environment in which they exist. A description of the niche of the gannets shown above would include where the gannets are found (habitat); the environmental conditions they encounter; the feeding role they occupy in the community; and the features (adaptations) that enable them to survive and reproduce in their environment. Adaptations for Survival Adaptations are features of a species that enable it to survive. To survive, members must carry out all of the life processes (feeding, movement, reproduction, etc.). A structural adaptation involves some part of an organism’s body, e.g. the horns of the male mountain goat to compete with other males for mates. A physiological adaptation refers to a process occurring inside the organism, e.g. gum tree leaves produce toxins (poisons) that discourage grazing by animals such as possums. A behavioural adaptation can be an individual or group activity, e.g. a flock of sheep moves into the shade to prevent overheating in the sun. A life history adaptation involves a particular stage in the life cycle of an organism that benefits the species. For example, organisms may have different feeding roles or habitats during the stages of their life cycle. This reduces competition for resources, e.g. juvenile frogs exist as tadpoles feeding in ponds while adults feed on insects on land.

organisms interdependent physical nutrients home Niche Populations Communities Ecosystems survive reproduce structural physiological behavioural