Page Chapter 18 Section 2 & 3

  Identify the characteristics that describe populations.  Examine the different types of relationships that occur among populations in a community.  Determine the habitat and niches of a species in a community. Objectives for Section 2

  Population Size  Number of individuals in the population  Difficult to measure  Small populations that are made up of organisms that do not move are determined by counting the individuals.  Usually individuals are too widespread or move around too much to be counted. Characteristics of Populations

 What does this graph tell us?

  Change in population size due to-  Older mice die  Mice are born  Mice eaten by predators  Some mice move away Is this a fast changing population size or slow? What happens if you observe Field Mice in a pasture for several months?

  What have you noticed about the Pine Trees here in Kentucky over the last several years? Has this effect been fast or slow?  How can Pine Tree population be effected more quickly?  Forest Fire?  Disease?  Logging? Pine Trees in a Mature Forest

  The number of individuals in a population that occupy a definite area  Example:  100 mice live in an area of 1 square kilometer, the population density is 100 mice per square kilometer. Population Density

 Population Density Map

  How the organisms are arranged in a given area  Can be:  Evenly spaced  Consistent distance between them  Randomly spaced  Wind or birds dispersing seeds  Clumped together  Resources such as food or living space are clumped  Results when animals gather in groups or plants grow near each other in groups Population Spacing

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  What are the five limiting factors from the video below? Limiting Factors

  Any abiotic or biotic factor that limits the number of individuals in a population  A limiting factor can affect other populations in the community indirectly:  Example:  A drought might reduce the number of seed- producing plants in a forest clearing. Fewer plants means that food can become limiting factor for deer that eat the plants and for a bird population that feeds on the seeds of these plants. Food also could become a limiting factor for animals that feed on the birds. Limiting Factors

  Lets go outside!!!! Limiting Factor Example

  Get out worksheet:  Key Terms  Interactions of Living Things Bell Ringer

 Open Book to Pages Each group is responsible for the section they are assigned.  Include Key Term  Definition  Explanation of the section must be presented to class, so they can put in their notes! Group Presentations