Ecology Overview

Ecology

study of how organisms interact with each other and with their environment.

Organization of Life

Organism - One individual living thing

Population - A group of the same species living in the same area

Community - All the different populations living and interacting in one area

Ecosystem - A community plus the abiotic environment, such as water, soil, sunlight, and air

Biome - A large geographic region with a specific climate and characteristic plants and animals

Biosphere - All ecosystems on Earth. The parts of Earth where life exists.

Biotic factors

Living parts of an ecosystem

Abiotic factors

Nonliving parts of an ecosystem. For example, sunlight, temperature, water, soil, air, rocks, pH, and nutrients.

Producer

 organism that makes its own food, usually through photosynthesis.

Consumer

organism that gets energy by eating other organisms

Food chain

single pathway showing how energy moves from one organism to another

Food web

network of many interconnected food chains

Competition + what organisms compete for

struggle between organisms for limited resources. Organisms compete for food, water, territory, sunlight, shelter, nutrients, and mates.

Symbiosis

close and long-term relationship between two different species.

Mutualism

Both organisms benefit. 

• Ex: Bees and flowering plants. The bee gets nectar for food. The flower gets pollinated, helping it reproduce.

Commensalism

One organism benefits while the other isn’t helped or harmed.

• Ex: Barnacles on whales. Barnacles get transportation and access to food. The whale is unaffected.

Parasitism

One organism benefits while the other is harmed.

• Ex: Tick on a deer. The tick gets food (blood). The deer loses blood and may get diseases.

Weather

Day-to-day conditions of the atmosphere.

Climate

average weather conditions in an area over many years.

Causes of ecosystems changes…

Ecosystems can change because of climate change, natural disasters, drought, disease, invasive species, pollution, deforestation, and urbanization.

Biodiversity

Biodiversity is the variety of life in an ecosystem, including different species, genes, and ecosystems. Biodiversity is good because it makes ecosystems more stable, helps ecosystems recover from disturbances, provides food, medicine, and natural resources, supports healthy food webs, and increases resistance to diseases and environmental changes.

Keystone species

A keystone species is an organism that shapes its whole environment. Its impact is much bigger than its population size. An example is a sea otter. Sea otters eat sea urchins, and they eat kelp. Without sea otters, sea urchin populations grow rapidly and destroy kelp forests, affecting many other species.