Download factors in the environment that are not alive

Chapter 3.1
Community Ecology
Notes
Vocabulary review
• ______________________- factors in the environment that are not alive an have never been alive
• _____________________- factors in the environment that are currently alive, or once were alive
• ________________- a group of the same species of organisms living in the same place at the same time
• _______________________________- a group of interacting populations that live in the same place at the same time
Communities
• Abiotic factors affect individual organisms and their populations
o How might a severe drought affect a population of ground hogs?
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Abiotic factors affect biological communities
o How might a pond that becomes too acidic affect biological communities?
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Populations of organisms ____________ to the conditions in which they live
o For example, wolves evolved heavy coats that enables them to survive harsh winter climates
o Cacti evolved the ability to retain water in order to tolerate the dry conditions of a desert.
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Limiting factors: any abiotic or biotic factor that restricts the numbers, reproduction, or distribution of organisms.
o Abiotic limiting factors include ________________, _____________, __________________,
_______________, ____________, ________, _________, ______________, and _______________
o Biotic limiting factors include ______________________________________________________
_____________________________________________________________________________
Range of tolerance: for any factor in the environment, there is an ______________________ and a
_________________________of the conditions that determine whether or not the organism can survive.
o _____________________________- the ability of any organism to survive when subjected to abiotic factors
or biotic factors.
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Range of tolerance continued
What is the lower limit of the steelhead trout?
What is the upper limit of the steelhead trout?
What is the optimum range of tolerance for the trout?
What is the limiting factor for the steelhead trout in this graph?
What is the zone called between 21 and 25 degrees?
Ecological Succession
• Ecological succession- the change in an ecosystem that happens when one biological community ______________
another as a result of ________________ abiotic and biotic factors. There are two kinds
o ________________________- the establishment of a biological community in an area of exposed rock that
does not have any topsoil. It usually occurs very slowly at first.
Areas covered by lava, newly formed mountain ranges are examples of areas of primary successionthere is no soil!
Most plants require soil for growth. In areas of primary succession, there is no soil, so it has to be
created before plants can move in.
_______________________- the first species to move into an uninhabited area
How is soil created? It starts with ________________, the pioneer species in areas of primary
succession. Lichens are a symbiotic relationship between fungus and algae. The lichens secrete
______________ that break down rock. As the lichens die, they mix with the bits of rock, which
begins the formation of soil.
As soil starts to develop, _________________________, ____________, _____________
____________________ move in. As these organisms die, the soil thickens.
As the soil thickens, seeds that are brought in by animals, wind and water can grow.
Eventually, enough soil is present so that shrubs and trees can grow
o __________________________- the orderly and predictable changes that take place after a community of
organism have been removed but the soil has remained intact
Disturbances such as fire, flood, and windstorm can disrupt and remove a community, but the topsoil
remains. After the disturbance, a new community of plants and animals might eventually occupy the
habitat
The _______________________ in areas of secondary succession are mainly plants
It generally occurs faster than primary succession because ________________________ and some
species will still be present, although in fewer numbers. Also, undisturbed areas nearby can be
sources of seeds and animals.
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In areas of both primary and secondary succession, mature communities eventually develop.
o ______________________________- the stable, mature community that results when there is little change in
the composition of species in the area.
It is important to note that scientists today realize that because disturbances, such as climate change,
are ongoing in communities, a true climax community is unlikely to occur.