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