Sampleing Under Pressure Assignment Example | Topics and Well Written Essays - 500 words

Sampleing Under Pressure - Assignment Example A simple randomized sampling strategy was used to provide an estimate of the total number of species inhabiting the ecosystem. Table 1 below shows the summary of the number of species discovered from the forest and their exact population in the sample areas. According to this data, the total number of species identified is 42 % lower than the expected number, which is 42, according to the lab manual. The data also shows that more than a half of the total number of species discovered has a population of greater than three in the whole sampling area. This low frequency number may be accounted by the nature of sampling strategy used, which aimed at getting a diverse and species rich data. To provide an estimated number of the species present in the habitat a cumulative number of new species discovered in each sample was recorded. This cumulative number was plotted against the number of samples as shown in figure 1 below. The slope of the graph shows an increasing number of new species discovered with an increase in the number of the samples collected. This association is not observed after the tenth sample where further increase in the number of samples has insignificant effect on the number of new species found. This is perhaps at this point the number of new species is nearly exhausted. A general rule to determine the total number of species can be formulated from the shape of the plot. For instance, the total number of species can be determined by taking ten samples, doubling the cumulative number of new species and subtracting 10 (the number of samples taken). This rule however, has an error margin of 4.7 percent and still needs further validation. When applied in this lab, the rule gives an estimated number of 40 species, which is relatively closer to the exact number of species in the habitat. There are several sampling schemes that can be used to collect data in different case studies of this nature. For