1 / 12

Understanding Population Dynamics: Growth Patterns and Influencing Factors

This overview explores population dynamics, detailing key concepts such as population size, density, growth rates, and age structure. Factors impacting populations, including births, deaths, immigration, and emigration, are examined, highlighting exponential and logistic growth patterns. Exponential growth occurs under ideal conditions, resulting in a rapid increase, while logistic growth sees a stabilization as it approaches carrying capacity. The document also distinguishes between density-dependent and density-independent limiting factors, providing insights into how these factors affect population health and sustainability.

tamera
Download Presentation

Understanding Population Dynamics: Growth Patterns and Influencing Factors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Populations • Population= a group of the same species in a particular area

  2. Factors that impact a population: • Geographic distribution/range= the size of the area inhabited by a population • Population Density= the # on individuals per unit area (ex: 1458 rabbits per square km) • Growth rate= change in growth over time • Age structure= how many individuals of different age groups are in a particular population (Is the population mostly young or mostly old?)

  3. 3 Factors Affect Population Size: 1. # births 2. # deaths 3. # of individuals that enter or leave the area Immigration= movement of individuals into an area. Emmigration= movement of individuals out of an area. A population will grow if its birthrate is greater than its death rate.

  4. Exponential Growth • Occurs when individuals reproduce at a constant rate. # of individuals increases slowly at first, then becomes very large • Graph is “J” shaped

  5. When will exponential growth occur? • Occurs in populations with ideal conditions and unlimited resources • Example: bacteria that double in number every 20 minutes

  6. Logistic growth • Occurs when the rate of population growth slows down or stops after a period of exponential growth • Graph looks like an “S” shape

  7. Carrying Capacity • Point on logistic graph where growth rate (the change in growth) = 0 This is the largest # of individuals the environment can really support. Graph “flattens out”.

  8. Limiting Factors • Anything that causes population growth to decrease--may or may not be affected by population density. • 2 Types: • Density Dependent • Density Independent

  9. 1. Density-Dependent= depends on population size, has stronger impact on very densepopulations .Examples: • Competition- compete for food, space, sun, H2O… • Predation- more predators result in more prey being eaten, but population numbers cycle • Parasites & disease

  10. 2. Density-Independent= Affects all populations equally • Weather, natural disasters, seasons, human habitat destruction

  11. Logistic or Exponential?

  12. Logistic or Exponential?

More Related