Ch 5: Species interactions, Ecological Succession, & Population Control
Ecological Succession (Secondary)
Secondary: in which a community or ecosystem develops on the site of an existing community or system, replacing or adding to the existing set of resident species Begins in an area where an ecosystem has been disturbed, removed, or destroyed
CONCEPT 5-2
The species composition of a community or ecosystem can change in response to changing environmental conditions through a process called ecological succession.
Interspecific competition
competition between different species
Environmental Resistance
All the limiting factors that act together to limit the growth of a population. the sum of all such factors in a habitat
Commensalism
An interaction that benefits one species but has little, if any, beneficial or harmful effect on the other - mussel shell with limpets
Coevolution
Back and forth adaptation A natural selection process in which changes in the gene pool of one species lead to changes in the gene pool of another species
Carrying Capacity
Limiting factors largely determine any area's carrying capacity; the maximum population of a given species that a particular habitat can sustain definitely
Predator-Prey relationship
Lion (the predator) and the zebra (the prey) are engaged in a predator-prey relationship This interaction has a strong effect on population sizes and other factors in many ecosystems
CONCEPT 5-3
No population can grow indefinitely because of limitations on resources and because of competition among species for those resources.
Ecological Succession (Primary)
Normal gradual change in species composition in a given area Primary: involves the gradual establishment of communities of different species in lifeless areas where there is no soil in a terrestrial ecosystem or not bottom sediment in an aquatic ecosystem Bare rock exposed by retreating glacier, newly cooled lava, abandoned highway or parking lot
Resource Partitioning
Occurs when different species competing for similar scarce resources evolve specialized traits that allow them to "share" the same resources
Parasitism
Occurs when one species (the parasite) lives in or on another organism (the host) The parasite benefits by extracting nutrients from the host The parasite weakens the host by rarely kills it, since doing so eliminates the source of its benefits
Population Crash
Population suffers a shard decline - dieback Unless. Part of the population can switch to new resources or move to an area that has more resources
Population
A group of interbreeding individuals of the same species
Predation
A member of one species is the predator that feeds directly on all or part of a member of another species, the prey - wolf and other animal
Range of Tolerance
A range of variations in its physical and chemical environmental conditions within which it is most likely to survive
Resilience
Ecological resilience: the ability of an ecosystem to be restored through secondary ecological succession after a severe disturbance
CONCEPT 5-1
Five types of interactions among species—interspecific competition, predation, parasitism, mutualism, and commensalism—affect the resource use and population sizes of the species.
R-selected Species
Species with a capacity for a high rate of population increase (r) Short life spans and produce many small offspring and give them no prenatal care or protection
K-selected species
Tend to reproduce later in life, have a few offspring, and have long life spans Deliver in mothers where they are safe, mature slowly after birth and protected by parents
Persistence (inertia)
The ability of an ecosystem to survive moderate disturbances Ecological resilience: the ability of an ecosystem to be restored through secondary ecological succession after a severe disturbance
Population Density
The number of individuals in a population found within a defined area or volume
Limiting factors
Those that are more important than others in regulating population growth
Mutualism
Two species behave in ways that benefit both by providing each with food, shelter or some other resource Pollination of flowering by plants by species such as honeybees - clownfish and sea anemone - bird and crocodile
Surviorship Curve
Which shows the percentages of the members of a population surviving at different ages Late loss, early loss, constant loss
Competition
most common interaction among species, it occurs when members of one or more species interact to use the same limited resources such as food, water, light and space