Chapter 5 Flashcards
Predation
occurs when a member of one species
the predator) feeds directly on all or part of a member of another species (the prey
Parasitism
occurs when one organism (the para-
site) feeds on another organism (the host), usually by
living on or in the host.
Mutualism
is an interaction that benefits both spe-
cies by providing each with food, shelter, or some
other resource.
Commensalism
is an interaction that benefits one
species but has little or no effect on the other.
Resource partitioning
occurs when species
competing for similar scarce resources evolve specialized
traits that allow them to share resources by using parts
of them, using them at different times, or using them in
different ways.
Coevolution
When populations of two different species interact in such a way over a long period of time, changes in the gene pool of one species can lead to changes in the gene
pool of the other. Such changes can help both sides to become more competitive or to avoid or reduce competition.
Population
is a group of interbreeding individuals
of the same species
Age structure
its distribution of individuals among various age groups—can have a strong effect on how rapidly it increases or decreases in size.
Range of tolerance
Every species has a range of tolerance to different changes in its ecosystem before dying
Limiting factors
A number of physical or chemical factors can help to determine the number of organisms in a population. Sometimes one or more factors, known as
Limiting factor principle
Too much or too little of any physical or chemical factor can limit or prevent growth of a population, even if all other factors are at or near the optimal range of tolerance.
Environmental resistance
the combination of all factors that act to limit the growth of a population.
Population crash
When a species shoots over an environment’s carrying capacity and can no longer sustain itself
Population density
is the number of individuals in a
population found in a particular area or volume.
Ecological succession
The normally gradual change in species
composition in a given area is called
Interspecifc competition
occurs when members
of two or more species interact to gain access to the
same limited resources such as food, water, light,
and space.
Primary ecological succession
involves the gradual establishment of biotic communities in lifeless areas where there is no soil in a terrestrial ecosystem or no bottom sediment in an aquatic ecosystem. Examples include bare rock exposed by a retreating glacier (Figure 5-19), newly cooled lava, an abandoned highway or parking lot, and a newly created
shallow pond or reservoir. Primary succession usually takes hundreds to thousands of years because of the need to build up fertile soil or aquatic sediments to provide the nutrients needed to establish a plant community.
Secondary ecological succession
in which a series of communities or ecosystems with different species develop in places containing soil or bottom sediment. This type of succession begins in an area where an ecosystem has been disturbed, removed, or
destroyed, but some soil or bottom sediment remains.
Inertia or persistence
the ability of a living system such as a grassland or a forest to survive moderate disturbances
Resilience
the ability of a living system to be
restored through secondary succession after a more severe disturbance.
