Chapter 8 Flashcards
Species richness
a combination of its number of different species.
species evenness
the abundance of individuals within each of its species
niche structure
the number of ecological niches, how they resemble or differ from each other, and how species interact with one another.
species equilibrium model/theory of island biogeography
a balance between two factors determines the number of different species found on an island: the rate at which new species immigrate to the island and the rate at which existing species become extinct on the island.
habitat islands
national parks surrounded by a sea of developed and fragmented land.
native species
are those that normally live and thrive in a particular community.
nonnative species/invasive species/alien species
others that evolved somewhere else and then migrate into or are deliberately or accidentally introduced into a community.
indicator species
species that serve as early warnings of damage or danger to a community.
fragmentation
the draining and filling of inland wetlands, deforestation, and development.
keystone species
they have a much larger effect on the types and abundances of many other species in a community than their numbers would suggest.
interspecific competition
Attempts by two or more organisms of a singe species to use the same limited resources in an ecosystem.
resource partitioning
process of dividing up resources in an ecosystem so that species with similar needs (overlapping ecological niches) use the same scarce resources at different times, in different ways, or in different places.
predation
situation in which an organism of one species captures and feeds on parts or all of an organism of another species.
chemical warfare
some prey species discourage predators with chemicals that are poisonous, irritating, foul smelling, or bad tasting.
parasitism
Interaction between species in which one organism preys on another organism, by living on or in the host.
mutualism
type of species interaction in which both participating species generally benefit.
commensalism
an interaction between organisms of different species in which one type of organism benefits and the other type is neither helped nor harmed to any great degree.
ecological succession
process in which communities of plant and animal species in a particular area are replaced over time by a series of different and often more complex communities.
primary succession
ecological succession in a bare area that has never been occupied by a community of organisms.
secondary succession
ecological succession in an area in which natural vegetation had been removed or destroyed but the soil is not destroyed.
pioneer species
first hardy species, often microbes, mosses, and lichens, that begin colonizing a site as the first stage of ecological succession.
early successional plant species
plant species found in the early stages of succession that grow close to the ground, can establish large populations quickly under harsh conditions, and have short lives.
mid successional plant species
grasses and low shrubs that are less hardy that early successional plant species.
late succession
mostly trees that can tolerate shade and form a fairly stable complex forest community.
disturbance
a discrete event that disrupts an ecosystem or community.
