Quadrat Sampling at Spittal Pond
Hypothesis
If the quadrat method is used, then the population sizes of various species of organisms can be estimated.
Introduction
Quadrat sampling is a tool which ecologists use in order to estimate how the biotic factors of an environment influence population growth and biodiversity in an ecosystem. Biotic factors are living things that affect the progression of a population e.g. human activity, predators and competition. A group of organisms that live in the same area are said to be a population. A group of populations make up an ecosystem. Quadrat sampling allows us to take random samples of such population so that we can see what influences/inhibits the growth of the population thereof. Since it would be
impractical to count each individual organism in a large
area, ecologists randomly choose small portions of the whole area and classify and count the organisms in each small portion. They can then
estimate the size of each population in the larger community. This process is
called the quadrat method.
Small square areas,
called quadrats, are randomly selected. Once the population densities for all quadrats are determined, the population size within the larger
area can be estimated.
Materials & Methods
Transects ( Quadrats)
Tape Measure ( Optional)
Field Guides for Identification
Data Book
Measuring Species Richness
1. Select randomly two areas to conduct the transect study in approximately 100 square meter area. We selected two ponds in the Spittal Pond area.
2. Describe the location of your site as completely as possible. Draw a map of the quadrant. Observe the abiotic factors of the site.
3. Take inventory of the different kinds of plants and animals found in your site. Identify the species that are found in the transect.
4. Record in databook the number of organisms of each plant or animal species within the quadrant.
5. Repeat steps three and four twice more to obtain data for two other quadrants within the site.
6. For each species, add the number of organisms found in all four quadrants and divide by four to calculate the average population density per square meter. Record the average population densities in your databook.
7. For each species, multiply the population density by the total size or the area surveyed to estimate the total number of organisms in the larger site. Record the estimated population size in your databook.
Tape Measure ( Optional)
Field Guides for Identification
Data Book
Measuring Species Richness
1. Select randomly two areas to conduct the transect study in approximately 100 square meter area. We selected two ponds in the Spittal Pond area.
2. Describe the location of your site as completely as possible. Draw a map of the quadrant. Observe the abiotic factors of the site.
3. Take inventory of the different kinds of plants and animals found in your site. Identify the species that are found in the transect.
4. Record in databook the number of organisms of each plant or animal species within the quadrant.
5. Repeat steps three and four twice more to obtain data for two other quadrants within the site.
6. For each species, add the number of organisms found in all four quadrants and divide by four to calculate the average population density per square meter. Record the average population densities in your databook.
7. For each species, multiply the population density by the total size or the area surveyed to estimate the total number of organisms in the larger site. Record the estimated population size in your databook.