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Population : 

Population - A group of species occupying a particular space at a particular time Characteristics: Size or Density Age distribution Genetic composition Pattern distribution


NATALITY& MORTALITY Life Tables - is termed demography which tells how the populations grow Time-Specific Life Tables Age- Specific Life Tables Reproductive Rate-Fecundity Deterministic model: Geometric Growth Stochastic Growth

Population Parameters that affect the size /density : 

Population Parameters that affect the size /density DENSITY EMIGRATION - IMMIGRATION MORTALITY NATALITY + - +

Density : 

Density numbers of species/unit area or per unit volume FORMULA: Density = No. of species Total area

Slide 5: 

TYPES OF DENSITY 1. Absolute Density Total Counts – human population, large plants on small areas and territorial birds

Sampling Methods - counting a small proportions and use the sample to estimate the total.. : 

Sampling Methods - counting a small proportions and use the sample to estimate the total.. Use of Quadrats – count all the species on several quadrants of known size and get the average of the whole area used extensively in sampling plants TYPE OF DENSITY

Sampling Methods : 

Sampling Methods Capture-Recapture Method – capture, marking, release and recapture is extensively used in animal ecology, can also be use to estimate" birth-rate “ and “death rate”

B. Measurements of Relative Density - is expressed as a percentage of the total density : 

B. Measurements of Relative Density - is expressed as a percentage of the total density FORMULA: Relative Density of a Species = Density of species Total densities of all species X 100

Measurements of Relative Density : 

Traps – number of species are determined and their activities Number of Fecal pellets – the average rate of defacation can get the index of population size Measurements of Relative Density

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Measurements of Relative Density Vocalization frequency- humming of birds,pheasant calls are used as index of population size Pelt Records – number of animals caught that extend back a century Catch per unit fishing effort –index of fish abundance per 100 hours of trawling

Measurements of Relative Density : 

Measurements of Relative Density Number of artifacts- counts for organism that leave evidence of their activities Questionnaire – this can be sent to different scientists/trappers to get a subjective estimate of population Frequency – calculating the sum of quadrats in which a particular species occurs Formula: F = number of species/number of the total quadrats Feeding Capacity –the amount of bait taken by the species in a given time


SAMPLING PLANT POPULATIONS Quadrats/Sample Plots List Quadrat-organisms found are listed by name only Count Quadrat – numbers and names are recorded Chart Quadrat – mapped to show the location of different species Cover Quadrat - to know what percentage of the land surface in the study area is “covered’ by a certain species.

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Belt Transect- cross section of an area used as sample for mapping, recording or studying vegetation Line Intercept-one dimensional, used for shrubs stands, woody plants in the forests SAMPLING PLANT POPULATIONS

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Point Quarter Method- using the radius method of forest sampling Dendrochronolgy- aging of trees by using growth rings SAMPLING PLANT POPULATIONS

Slide 15: 

Phytoplankton - can be obtained drawing water sample from several depths -Sedgewich-Rafter counting chamber or Whipple ocular or by filtration Periphyton - by using the transmission of light to pass through a thin or transparent leaves ALGAE

Sampling Animal Populations : 

Sampling Animal Populations Flying Insects Diurnal insects- using aerial nets - Nocturnal insects – by using traps containing UV light or mercury vapor light or if the insects are to be killed we can use plaster of Paris

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Aquatic Organisms - dip nets -bottom nets - wire basket scraper nets - plankton towing nets - aquatic throw nets Birds and Mammals - live traps with baits - marking with cellulose paint for arthropods - ship-fouling paint for mollusks and insects - strap tags for fishes - toe clipping for frogs toads and salamander Sampling Animal Populations


SOIL ORGANISMS can be extracted from the soil by using Tullgren funnel Flotation Funnels for spiders and beetles Sticky boards for millipeedes,slugs,and centipedes Meat bait in small wire - Combination of formalin and shovel for sampling earthworm