- Standard deviation can be calculated by:
Therefore, the standard deviation for the site 1 is 1.261110622, for the site 2 is 0.9431860898 and for the site 3 is 1.341044369.
- From the graph below we can see the difference in the distribution of the number of species in these three areas very clearly:
● 1st site: most around 4 to 6 species
■ 2nd site: most around 3 to 5 species
▲ 3rd site: most around 2 to 4 species
This graph helps us to clarify the diversity of the three sites: 1st site the most, 2nd site the least & 3rd site the lowest.
Conclusion and Evaluation
From the results we can conclude that the number of species differs from one site to another and also from one area of the site to another area of the same site. The site 1 can be seen obviously being the most diverse and the site 3 the least diverse. This may be because of the different level of supply of resources required for growth in different areas/sites, for example the fertility of soil, the water availability, and the light intensity and also pollution. These are all very important factors and plants base on their need of these resources, they choose the environment that suite them the most, and thus adopting different niche. This is why there are fewer species in one site and more in another, and the type of species differs. Despite these, season also plays an important part. In different season there are different quantity of resources available and thus the number of species also differ.
Using the random sampling, with the quadrats, can give a rough idea of one area’s population and thus the species that live there, but however it is very difficult to use this method to represent the whole area, to give a very precise number of how many species are really living there. This is because to sample an area REALLY randomly is very hard. People often do look around and throw it into the direction they prefer or attract their sight the most/the least, this is because it is impossible to sample with shut eyes in a park, due to the fear of throwing it out of the park or onto something or someone, which may cause an accident. And also once the time comes to count the number of species within a quadrat, it’s pretty easy to miss one or add one, because they are either too similar or too small to be seen.
The experiment can be improved by repeating the whole experiment more than 3 times to get as many results as possible or using a specific equipment for counting the number of species in a certain region. And if using quadrats, there is a need to close eyes and to let the throwing person to turn around by himself and then throw it, to make it more random. A data of resources and the environment the plants live in should also be collected, to compare and understand why there are more species and more diverse in one area than another. The experiment should also be repeated in different seasons and years to see the difference in the number of species and also to compare the number in one year’s season with another year’s season, to find out how the number of species changes during the year and from one year to another.
Even though the results between each group differ, but the results do follow a certain pattern, so I suggest that this experiment can be carried on universally and the results can be used reliably.