APES Period 2
January 23rd, 2013
Chapter 8 - Community Ecology
1. The species of equilibrium model/theory of island biogeography states that there is a balance between two factor which determine the number of different species found on the land: the rate at which new species immigrate and the rate at which existing species become extinct.
Native species are those that live and thrive in a particular community.
Nonnative species, invasive species, and alien species are those that have evolved somewhere else and then migrate or are accidentally introduced into a community.
Indicator species are those who serve as early warnings of damage or danger to a community.
Keystone species help determine the types and numbers of …show more content…
Parasitism occurs when one species feeds on another organism by living on or in the host.
Mutualism occurs when two species interact in a way that benefits both.
Commensalism is a species interaction that benefits one species but has little, if any, effect on the other.
Ecological succession is the gradual change in species composition in an area.
Early successional plant species grow close to the ground, establish large populations, and have short lives.
Late succesional plant species are mainly trees that can tolerate shade.
A disturbance is a change in environmental conditions that disrupts a community.
Inertia/persistance is the ability of a living system to resist being disturbed or altered.
Consistency is the ability of a living system such as a population to keep it's numbers within limits imposed by available resources.
Resilience is the ability of a living system fo repair damage after an external disturbance.
Complexity refers to the number of species in a community at each trophic …show more content…
Three characteristics of the structure of a community/ecosystem are physical appearance, species diversity, and niche structure. Species diversity consists of the combination of a number of different species, called species richness, and the abundance of members in each species, called species evenness.
4. Latitude, the distance from the equator, affects species diversity because plants and animals are more densely located in the tropics rather than in the poles.
5. Factors determining the species diversity on an island are: the rate at which the species arrive and old species become extinct, island size, and how far the island is from the mainland; this is also known as the theory of biogeography. The size of island and distance from mainland either increases or decreases immigration and extinction rates.
6. Native species are those that live and thrive in a particular community. Nonnative species, invasive species, and alien species are those that have evolved somewhere else and then migrate or are accidentally introduced into a community. Indicator species are those who serve as early warnings of damage or danger to a community. Keystone species help determine the types and numbers of various other species in a