Ecosystems and Communities

Role of Climate Weather: day-to-day condition of Earth’s atmosphere at a particular time and place. Climate: the average year-after-year conditions of temperature and precipitation in a particular region.

Earth’s Temperature Co2, methane, water vapor, and other gases trap heat energy and maintain Earth’s temperature. Greenhouse effect: the natural situation in which heat is retained by the layer of greenhouse gases.

Climate Zones Different because of latitude and angle of heating. Polar zones: cold areas; sun’s rays strike at very low angle. Temperate zones: sit between the polar zones and tropics. Tropical zone: near the equator; climate almost always warm

Biotic Factors The living influences on organisms within an ecosystem. Ex: birds, trees, bacteria

Abiotic Factors Physical, or nonliving factors that shape ecosystems. Ex: soil, water, temperature Together biotic and abiotic factors determine the survival and growth of an organism and how productive that ecosystem is.

Habitat The area where an organism lives. Niche: role in the ecosystem. Ex: place in the food chain, temps for survival, how reproduces, types of food eaten. No two species share the exact same niche

Community Interactions Competition Predation Symbiosis

Competition Occurs when organisms attempt to use ecological resources in the same place at the same time. Resource: any necessity of life, such as water, nutrients, food, or space. Usually a winner and a loser, with the loser failing to survive.

Predation An interaction in which one organism captures and feeds on another organism. Predator: the organism that does the killing. Prey: the organism being hunted.

Any relationship in which two species live closely together. Mutualism Commensalism Parasitism

Mutualism Both species benefit from the relationship. +/+ Ex: flowers and insects

Commensalism One member of the association benefits and the other is neither harmed nor helped. +/0 Ex: shark and fish, barnacles and whales.

Parasitism One organism lives on or inside another organism and harms it. The host organism is harmed. +/- Ex: fleas and ticks

Succession As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing changes in the community. Primary succession: succession that occurs on surfaces where no soil exists. Pioneer species: first species to populate the area. Secondary succession: occurs when land cleared and plowed for farming is abandoned; or after fires.