Functional Biodiversity Analysis

The functional biodiversity of each sample was tested by plating an Ecoplate, that held 31 carbon sources commonly found in soil, and examining the absorbance values at 595 nm a week later to determine their presence. We then put that data in a pre-made Excel file to calculate the H (Shannon), S (Richness), E (Evenness) of the soil. 

Figure 3 Evidence: From the data presented in figures 3A – 3C, we can conclude that there is no significant statistical difference between the native and non-native soil samples, through the unpaired t-test assuming unequal variance, as the values for richness, 0.09, Shannon diversity, 0.13, and evenness, 0.72, are all above the threshold of 0.05. The similarities between samples are also seen through the averages, with the average richness of native soil being 27.38, and non-native soil being 29.38, showing only a slight increase of 0.068%. The Shannon diversity average for the native soil samples was 3.26, and 3.33 for the non-native samples, showing a mere increase of 0.021%, and evenness average values being equal to 0.99 for both native and non-native soil samples, showing a 0% difference. Similarly, the standard deviation values are relatively low suggesting consistency and accuracy of our testing, with the richness values being 2.62 for the native soil, 1.51 for the non-native, Shannon diversity values being 0.11 for the native soil, and 0.07 for the non-native, and evenness values once again being equal holding a value of 0.01 for both native and non-native soil samples. Figure 3D, however, must be examined more closely through visual and statistical comparisons to determine the similarity in carbon utilization level between native and non-native soil samples. In fact, all categories except carboxylic acids and carbohydrates are the same. This includes amino acids which are at 20.689 for both, polymers which were at 13.793, and amines which were at 6.896 respectively. Carboxylic acids were at 27.586 for the native condition and 24.138 for the non-native condition with only about a 3.0 difference. This then evens out with our carbohydrates which are at 31.0345 for the native condition and 34.483 for the non-native condition to get another approximately 3.0 difference. This ensures that the levels still equal 100%, but there is only a 6.7965% difference between the values that make up 100%. Thus, leading to the conclusion that the functional biodiversity between native and non-native plants, particularly pertaining to richness, Shannon diversity, evenness, and carbon utilization are comparable between species, showing no significant statistical differences. 

Figure 3 Conclusion: From the graphs and data, the conclusion can be made that there’s no significant statistical differences between the soil richness. The p-values from the unpaired t-test assuming unequal variance were all above the critical value of 0.05 for figures 3A-3C richness being 0.09, Shannon diversity being 0.13, and evenness being 0.72. For figure 3A, averageness, have very similar values with native being 27.38 and non-native being 29.38, a two-point difference. For figure 3B, Shannon diversity, the averages have only a small amount of margin between the two being 3.26 for the native condition and 3.33 for the non-native condition, resulting in only about a 0.07-point difference. With such an insignificant difference we can conclude that the Shannon Diversity in our soil has not affected the biodiversity of the soil. Our evenness data (figure 3C) is not statistically significant either because our averages of both conditions were 0.99 when rounded, and because our standard deviation also had equal values for figure 3C at 0.01 for both conditions. This makes sense with our conclusion because our values are either super close together or exactly the same making them incomparable, and not statistically significant. This trend in our data continues to our carbon utilization data in figure 3D. Our data shows that amino acids were at 20.689% for both the native and non-native conditions, polymers were at 13.793% for the native and non-native conditions, and the amines were at 6.896% for the native and non-native conditions. These similarities along with only a total of 6.965% change between carboxylic acid and carbohydrates has led us to conclude that we do not have a major change in carbon utilization between our two conditions. Therefore, we can confidently conclude that richness, Shannon diversity, evenness, and carbon utilization have no statistically significant data due to the high p-values and the similarity of the data we collected.  

Figure 3 Explanation: There are several different reasons that we have similar values across the board. When it comes to soil richness using the journal Plant Community richness and Microbial interaction's structure bacterial communities in soil, we learn that richness is a large contributing factor to the health of the bacteria in the soil and the overall composition of the soil and its biodiversity. (Schlatter, 2015) But when it comes to the soil richness itself, the sites in which the plants are growing could be a factor, because the tomatoes are in the middle straw covered part of the garden. While on the other hand, the flowers are on the frame, no straw section of the garden. When we think back to when we initially took our soil samples, we noticed some differences between the two soil samples, native being dry and dusty while non-native being moist and soft, but we thought there would be more of a major difference in our resulting data than we have found. The reason that our data makes sense depends on our understanding of the Shannon Diversity Index. In the article Diversity Indices, it describes the important information that the Shannon diversity index can tell us as the presence of different species and species diversity levels in a specific area. (M. Beals et al., 2000) This helps us conclude the biodiversity of the soil which helps the plants, therefore helping the gardeners. By comparing our two samples with the Shannon Diversity Index, it gives us direct feedback that we are able to communicate to the gardeners to help them continue to make their garden thrive. All of this makes sense because we know what evenness means. According to Brian J Wilsey and Catherine Potvin’s journal article called Biodiversity and ecosystem functioning: importance of Species Evenness in an old field, evenness is the measure of how well distributed the abundance is among species within a community. (2000, Pg 1) This could be an abundance of whatever you are studying, so for us it is an abundance of bacteria in the soil. Because our evenness is extremely similar to each other this means that both plant species have similar levels of biodiversity in their soil. We can see this trend continuing when we look at figure 3D, carbon utilization. In the article The Carbon Balance of Plants by H.A Mooney, it describes carbon as an energy transferring and storing vehicle for plants which enables many other processes to happen. (1972, Pg 1) Because we know that plants use carbon a lot we can measure it to see how well the plant is doing. From our data we can tell that both of our conditions, native and non-native, have similar carbon utilization levels which can lead us to conclude that they have similar biodiversity. With all of what we know about plants, what we have researched, and what we have observed, we can conclude that our data proves there will be no change in the functionality of the biodiversity between the native condition and the non-native condition.