Simpson’s Diversity Index Essay

To determine diversity with Simpson’s Diversity Index, index ranges between 0 and 1. Thus, the more the value approaches to 0, the more diversity results. Diversity indexes corresponding to each group are resumed in the following table. In this case, if all the results were added, site B has a value closer to 0, which means that there is a higher species diversity on the un-grazed land than in the grazed land.

Just to remind, the hypothesis stated were that there will be greater species diversity on the grazed Moorland because the sheep will add nutrients to the soil due to their waste or there will be less species diversity on grazed Mooreland because the sheep will eat certain plant species such as Calluna Vulgaris and leave others. As seen in the results, it appears that there is a smaller average percentage and species diversity on the Grazed Mooreland since it counts with 6 different species and in the Mooreland that is not used for grazing appeared 9 different species. This might mean that the grazing does not affects the species diversity on each land, however other variables such as other animals or the different nutrients on the soil of each site were not considered. Therefore, the species diversity results might seem affected from a beginning.


Many important variables were not taken into consideration from the beginning. Different plant properties that may affect the whole species diversity, the nutrients each soil contained, the amount of water and its pH, among others, should have been considered in order to obtain a more accurate result. Thus a method to control variables is also required to be designed. Perhaps, the fact that the groups were randomly selected may also affect the results since there was no research of any variable that could affect a group instead of the whole site. Besides the recollection of data was not very accurate which might have probably affected the results, hence the whole experiment too. Each pair must have a different perception of the percent coverage and it may have not been realized completely correct. Also, these percentages were rounded, which gives information that is not exact. And as previously mentioned group 4 did not look underneath the heather coverage therefore Sphagnum coverage may have been left unnoticed.

For this, different instruments could be used for the experiment in order to control the different variables that may have affected the results of the experiment. Analyzing sheep’ faeces may also provide important information about the nutrients whereas the species that the sheep might had consumed more. Also, the habitat should be monitored within other organisms to identify whenever there is a fluctuation on the species diversity, it may have been caused by other organisms or natural disasters. As during the experiment, data collection should be standardized and the same perception of each group in order to realize the percentage will allow more accurate results.


In conclusion, Hypothesis B seems to be more proper since there is less species diversity on the grazed land, which automatically discards Hypothesis A. Yet this results are not completely certain since other factors were not considered such as a other wildlife that may have caused fluctuations on the species diversity, human activity that may have eliminated part of some species or even the sheep that might had step on the species, harming and ending with them.

However, this experiment can further be realized again, yet more factors should be considered such as sunlight accessibility, human actions, and external factor like water from other sources. Data collection must be standardized and exact values must be used instead of rounding. In addition that a small research of the historical background of the moorlands may help for a better distribution of groups.

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