Backyard Species Diversity

Tyron Arnett

Brock Smith

4/10/20

In this week’s lab, we analyzed the biodiversity of Brock Smith’s and Tyron Arnett’s backyards. Biodiversity is very important element of ecosystem stability. Simply put biodiversity is the variety of life that is present within a particular ecosystem. For this lab, we focused on the biodiversity of the plants in our backyards. The species that were present in Brock’s yard were cypress, Valerianella radiata, Houstonia caerulea, Houstonia micrantha, Platanus ocidentalis, and Sambucus canadensis. The species that were present in Tyron’s yard were Quercus shumardii, Acrostichum danaeifolium, Saccharum ravennae, and St. Augustine grass. We then calculated the Shannon Diversity index for each yard. The H’ value for Brock’s yard was 0.16. The H’ value for Tyron’s yard was 0.16. We also calculated the species richness and evenness values for each yard. Species richness is the number of species found in the community. The richness value for Brock’s yard was 6. The richness value for Tyron’s yard was 4. Species evenness is a measure of how similar the abundance of each species is. The evenness value for Brock’s yard was 0.54. The evenness value for Tyron’s yard was 0.11. Brock’s yard had a high degree of dominance and Tyron’s yard had a low degree of dominance. 

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REFLECTION QUESTIONS

1.) Identify the backyard that was most diverse.

-Brock’s backyard was more diverse among the two backyards.

2.) Did any single species exhibit dominance in either community? Write a plausible explanation why you think this occurred.

-In Tyron’s backyard, the St. Augustine grassexhibited dominance in its community. While in Brock’s backyard the Valerianella Radiata exhibited dominance in its community. The dominance displayed from the species of the St. Augustine grassand Valerianella Radiata could be a result of either low stability or reduced productivity in their community. It is common that the diverse community displays greater productivity than either single specie communities. 

3.) What global locations and physical characteristics of an ecosystem could cause it to have a high value for the Shannon-Wiener Index? Explain.

-A location that would have a high value for the Shannon-Wiener Index would be a Tropical Rainforest. A tropical rainforest such as The Amazon Rainforest has an extreme amount of diversity across a large distance. The higher the Shannon-Wiener Index number the higher the diversity. The Amazon Rainforest has a lot of diversity because of many reasons. The Amazon Rainforest has warm weather and water access almost year-round which promotes plant growth. All of this plant diversity creates habitats for many animal species which increases animal diversity. Another reason that The Amazon Rainforest has a high level of diversity is because there are large patches of relatively undisturbed land.  

4.) The importance of biodiversity has been positively correlated to ecosystem resilience and stability. According to your results, which backyard demonstrates the higher degree of ecological stability? Explain why this relationship exists.

-According to the result’s Brock’s backyard demonstrated the higher degree of ecological stability. Which is proven by the numbers being ranged a lot closer than they were in Tyron’s backyard. Also because of the Shannon-Wiener that was produced from the data collect from the two communities. Biodiversity positively correlates to ecosystem resilience and stability because it can help an ecosystem maintain stasis and continuity while dealing with disturbance. If disturbance occurs and severely alters the populations it could crash an ecosystem, however if the biodiversity is high and their other organisms to fill the same niche or survive the disturbance then the ecosystem can continue with a healthy existence. Great biodiversity also helps an ecosystem respond to natural sways in environmental fluctuations and can drastically reduce the strength of competition between species (Loreau, 2013.)

Tyron Arnett was responsible for the images and data tables. Brock Smith was responsible for the introduction paragraph. Tyron and Brock both worked on the reflection questions.