Air Quality Lab
Collaborators:
Environmental Science 1st Period Class
Abstract:
An experiment was done to determine the biodiversity of several samples of leaf litter as compared to the control group, a sample of soil. To calculate the biodiversity, a measurement tool known as Simpson's Index was used which uses both richness and evenness to determine a number between one and zero, zero being very diverse and one being not diverse at all. It was found that the leaf litter samples were .22 on Simpson's Index, meaning the leaf liter was very diverse. The soil was found to be 1, meaning it was not diverse at all.
Problem:
As described by Barcelona Field Studies Centre, Simpson's Diversity Index is "a measure of diversity which takes into account the number of species present, as well as the relative abundance of each species. As species richness and evenness increase, diversity increases." Using Simpson's Diversity Index, what is the biodiversity of leaf litter gathered in the forest behind Heritage High School?
Hypothesis:
If samples of soil and leaf litter are collected and the amount of organisms in each is measured, then it will be found that the biodiversity of the leaf litter samples is much higher than of the soil samples.
Parts of Experiment:
The independent variable is the location from which the sample is gathered. The dependent variable is the level of biodiversity of the sample. The control group is the soil sample. The experimental group is the leaf litter samples.
Materials:
Leaf litter, soil, compound microscope, alcohol, berless funnels, light sources, beakers
Methods:
1. Collect a sample of leaf litter and a sample of soil
2. Place the samples into seperate Berlese Funnels under light sources
3. Place a small beaker of alcohol under each funnel (pictured below)
4. After a few days, collect the beakers
5. Examine the organisms collected under a microscope
Collaborators:
Environmental Science 1st Period Class
Abstract:
An experiment was done to determine the biodiversity of several samples of leaf litter as compared to the control group, a sample of soil. To calculate the biodiversity, a measurement tool known as Simpson's Index was used which uses both richness and evenness to determine a number between one and zero, zero being very diverse and one being not diverse at all. It was found that the leaf litter samples were .22 on Simpson's Index, meaning the leaf liter was very diverse. The soil was found to be 1, meaning it was not diverse at all.
Problem:
As described by Barcelona Field Studies Centre, Simpson's Diversity Index is "a measure of diversity which takes into account the number of species present, as well as the relative abundance of each species. As species richness and evenness increase, diversity increases." Using Simpson's Diversity Index, what is the biodiversity of leaf litter gathered in the forest behind Heritage High School?
Hypothesis:
If samples of soil and leaf litter are collected and the amount of organisms in each is measured, then it will be found that the biodiversity of the leaf litter samples is much higher than of the soil samples.
Parts of Experiment:
The independent variable is the location from which the sample is gathered. The dependent variable is the level of biodiversity of the sample. The control group is the soil sample. The experimental group is the leaf litter samples.
Materials:
Leaf litter, soil, compound microscope, alcohol, berless funnels, light sources, beakers
Methods:
1. Collect a sample of leaf litter and a sample of soil
2. Place the samples into seperate Berlese Funnels under light sources
3. Place a small beaker of alcohol under each funnel (pictured below)
4. After a few days, collect the beakers
5. Examine the organisms collected under a microscope
Data:
The chart below shows the amount of each type of creature found in the leaf litter. As for the soil, only one aphid was found. Also of importance is that the samples were collected on September 18, 2013, which was sunny, 19 degrees Celsius, and had 28% Relative Humidity.
The chart below shows the amount of each type of creature found in the leaf litter. As for the soil, only one aphid was found. Also of importance is that the samples were collected on September 18, 2013, which was sunny, 19 degrees Celsius, and had 28% Relative Humidity.
Data Analysis:
The data shows that the leaf litter samples are very diverse as they turned out to be .22 on Simpson's Index. Although the samples aren't extremely even, they are very rich as 12 different species were found. Also, the samples are 4.55 on the Simpson Reciprocal Index and .78 on the Simpson index of Diversity. Because only one organism was found in the sample of soil, it was 1 on the Simpson's Index. This indicates that the soil sample was not diverse at all.
Conclusion:
Although it was found that the leaf litter was a lot more diverse than the soil as the hypothesis predicted, this information cannot be applied to the ecosystem as a whole. To elaborate, all of the leaf litter was gathered from the same general place. It would have been better if samples from locations all over the forest were collected and observed. Also, more soil samples should have been collected to make sure the control group was as reliable as possible. This is also true for the leaf litter samples (although not to the same extent).
Citation:
"Simpson's Diversity Index." Simpson's Diversity Index. Barcelona Field Studies Centre, n.d. Web. 03 Oct. 2013. <http://geographyfieldwork.com/Simpson'sDiversityIndex.htm>.
Questions:
1. What are two reasons the organisms move away from the light down the funnel? What does this indicate about the organisms?
Firstly, the organisms, move away from the light because it dehydrates them. Secondly, the organisms move away from the light because they are just not used to such a bright light source being so close to them; they want to live in the shade.
2. Summarize whether you think the biodiversity of this litter is high or low density. If low, try to give some reasons why this might be.
The biodiversity of the leaf litter is high density; all the organisms live close together. The reason I believe this to be the case is because multiple organisms were found close together in the alcohol, indicating they were close together in the leaf litter. This can be seen in the picture of the group of beetle mites.
3. Why would an environmental scientist need to make more than one measurement if he was calculating the biodiversity? How would you take samples of a large forest?
He or she would want to take more than one measurement because it is possible that the particular area tested was an outlier. These other measurements should be taken at different places throughout the forest and then averaged together.
The data shows that the leaf litter samples are very diverse as they turned out to be .22 on Simpson's Index. Although the samples aren't extremely even, they are very rich as 12 different species were found. Also, the samples are 4.55 on the Simpson Reciprocal Index and .78 on the Simpson index of Diversity. Because only one organism was found in the sample of soil, it was 1 on the Simpson's Index. This indicates that the soil sample was not diverse at all.
Conclusion:
Although it was found that the leaf litter was a lot more diverse than the soil as the hypothesis predicted, this information cannot be applied to the ecosystem as a whole. To elaborate, all of the leaf litter was gathered from the same general place. It would have been better if samples from locations all over the forest were collected and observed. Also, more soil samples should have been collected to make sure the control group was as reliable as possible. This is also true for the leaf litter samples (although not to the same extent).
Citation:
"Simpson's Diversity Index." Simpson's Diversity Index. Barcelona Field Studies Centre, n.d. Web. 03 Oct. 2013. <http://geographyfieldwork.com/Simpson'sDiversityIndex.htm>.
Questions:
1. What are two reasons the organisms move away from the light down the funnel? What does this indicate about the organisms?
Firstly, the organisms, move away from the light because it dehydrates them. Secondly, the organisms move away from the light because they are just not used to such a bright light source being so close to them; they want to live in the shade.
2. Summarize whether you think the biodiversity of this litter is high or low density. If low, try to give some reasons why this might be.
The biodiversity of the leaf litter is high density; all the organisms live close together. The reason I believe this to be the case is because multiple organisms were found close together in the alcohol, indicating they were close together in the leaf litter. This can be seen in the picture of the group of beetle mites.
3. Why would an environmental scientist need to make more than one measurement if he was calculating the biodiversity? How would you take samples of a large forest?
He or she would want to take more than one measurement because it is possible that the particular area tested was an outlier. These other measurements should be taken at different places throughout the forest and then averaged together.