her notes/college board 1.1

Ecology

Shift of the relationships among organisms and between organisms/their environment

Ecosystem

Any place on earth with biotic and abiotic components that interact

Communities and environments

Ecosystems are made up of

Community

All living organisms in the area-made up of populations

Environment

Physical parts of the area

Abiotic factor

Anything that is nonliving/never living ex:rain,sunlight

Biotic factor

Anything that is living/used to be living ex:trees, birds, bacteria

Trophic cascade

Changes in predator populations can have a ripple effect throughout the entire food chain ex: sea otters indirectly control the kelp population, despite not eating kelp -they eat sea urchins who eat kelp

Keystone species

Species that are essential to an ecosystem, which result in a significant shift in the ecosystem if removed

Predators

Not all keystone species are

Symbiosis

A close and long term interaction between two species in an ecosystem

Mutualism, commensalism, and parasitism

Types of symbiosis include..

Commensalism

One benefits and the other is not affected nor harmed (+/o)

Mutualism

Both benefit (+/+)

Parasitism

One benefits, one is harmed (±)

Repeated close contact between the parasite and host AND parasite does not necessarily KILL their host to get food

Parasitism is different from regular predator/prey relationships because of

Competition

Can occur within or between species in an ecosystem where there are limited resources

Resource partitioning

reduces the (-) impact of competition on survival by using the resources in different ways, places, or at different times