Humans and Changing Ecosystems

biodiversity

the variety of organisms on Earth or in a particular habitat or ecosystem

extinction

when all of the members of a species die and the species no longer exists

keystone species

a species that affects the diversity of an entire ecosystem

niche

the ecological role that a species plays in an ecosystem

proportion

the relationship between a part and a whole

invasive species

a species that has been introduced to a place where it is not naturally found and causes ecological or economic harm

natural resource

a material or source of energy found in nature that benefits humans

scavenger

an organism that eats other organisms that are already dead

habitat degredation

changing or destroying natural ecosystems in ways that disrupt their healthy functioning

over-exploitation

harvesting species from the wild faster than those populations can recover, resulting in population decline