1 / 17

Population Ecology

Population Ecology. Population Demographics. Demographics are the various characteristics of a population including, Population Size, Age Structure, Density, and Distribution Demographics allow one to determine the ecological and evolutionary relationships between various species populations.

clinton-cox
Télécharger la présentation

Population Ecology

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. Population Ecology

  2. Population Demographics • Demographics are the various characteristics of a population including, Population Size, Age Structure, Density, and Distribution • Demographics allow one to determine the ecological and evolutionary relationships between various species populations

  3. Population Size • Population size is represented by the variable N • Peterson Population Estimating is a common method for determining Population Size (N) • Population Growth can be represented as either ‘exponential’ or ‘logistic’

  4. Peterson Population Estimate • The Peterson Estimate is a mark and recapture method divided into two sample periods (Precensus and Census)

  5. Peterson Estimate Calculation • During the Precensus, individuals are captured and marked (M) • During the Census, individuals are captured, some of which have marks (R) and some which do not. The total captured on the Census equals (n). • Peterson Estimate = (n x M) / R

  6. Peterson Estimate Assumptions • Assumes that no births, death, immigration, or emigration occur during the census period • Assumes that mark are permanent and do not adversely effect the organism

  7. Population Growth • Factors that increase population size include ‘births’ an ‘immigration’ • Factors that decrease population size include ‘deaths’ and ‘emigration’ • The Net Reproductive Rate (r) r = [(births + immigration) – (deaths + emigration)]

  8. Exponential Growth • Population Growth (G) G = r x N • New Population Value (Nx) N1 = (r x N) + N N2 = (r x N1) + N1

  9. Logistic Growth • Population Growth (G) G = r x N [(K-N) / K)] • New Population Value (Nx) N1 = (r x N [(K-N) / K)]) + N N2 = (r x N1 [(K-N1) / K)]) + N1

  10. Age Structure • Age structure is the number of individuals in each of several to many age categories

  11. Population Density • Population Density is the number of individuals in a specified area of a habitat

  12. Population Distribution • Population Distribution is the general pattern in which individuals or a population are dispersed through a specified area • Clumped, Uniform, or Random

  13. Survivorship Curves • Type I • High Survivorship until fairly late in life, then a large increase in death

  14. Type II • Fairly constant death rate at all ages

  15. Type III • Low survivorship early in life due to high death rate but if they reach adulthood they survive long

More Related