Summary
Highlights
Ecology emphasizes the relationships between all organisms and their environment. For instance, mice interact with other mice, plants (food), predators, and the surrounding environment by breathing and burrowing, which affects soil quality. Changes in one part of this system, like a decrease in mouse population, can have cascading effects on predators and soil.
Important terms in ecology include: 'Habitat' - the place an organism lives (e.g., a field for mice). 'Population' - all organisms of a particular species in a habitat (e.g., all mice in a field). 'Community' - all populations of different species living together in a habitat (e.g., mice, owls, and plants in a field). 'Biotic factors' are living environmental factors like food availability and predators, while 'abiotic factors' are non-living factors such as temperature and soil pH. An 'ecosystem' encompasses the interaction of a community with both biotic and abiotic elements.
Competition is a crucial process in ecosystems. Organisms require limited resources like space, food, water, and mates for animals, and light, space, water, and mineral ions for plants. This scarcity leads to competition, which can occur between different species (e.g., lions and hyenas for prey) or within the same species (e.g., male deer competing for females).
Interdependence signifies that all species rely on others. Food webs illustrate these feeding relationships; for example, mice, rabbits, and grasshoppers eat grass, while shrews and sparrows eat grasshoppers. A change in one species, like an increase in mice, dramatically impacts others: more mice mean less grass for rabbits and grasshoppers, potentially decreasing their populations. This could initially benefit hawks feeding on mice, but fewer rabbits might balance this.