Effect of sunlight on biodiversity of soil invertebrates

1. Effect of sunlight on biodiversity of soil invertebrates Loretta McNamee Undergraduate Student (Environmental Biology Concentration), Department of Biology, Tennessee Tech University , Cookeville, TN 38505

2. Introduction • What is biodiversity? • Very important starting point to explaining patterns of community dynamics and structure • Soil Invertebrates are detritivores. • Influence many soil properties, which influence above-ground plant abundance (Dr Brown’s Ecology website. http://iweb.tntech.edu/cabrown/Ecology.htm.2006)

3. Introduction continued… • Studies suggest presence of plants affect soil communities. They provide nutrients that organisms need to survive (Dunfield 2003) • Soil invertebrate prefer to occupy areas that are artificially or naturally covered, due to more moisture in the soil. (Ferguson 2004) • One study showed that many chemical and physical properties of the soil differ based on its location (Pankhurst 1992). • The forest or canopy environment of the biodiversity experiment should have more invertebrates present. This would coincide with hypothesis that stated the canopy habitat would have a greater soil biodiversity. (Chamberlain 2006)

4. Objective • To examine biodiversity in soil invertebrates in two distinct communities. • canopy communities- those in forest locations in which sun does not shine directly on the soil. • open ground communities- in a field, where the sun shines directly on the soil, potentially drying it out

5. Hypothesis • Hypothesis: I predict that the canopy community will have a more diverse selection of soil invertebrate; therefore it will show more soil biodiversity. • Null Hypothesis: there is no difference in biodiversity of soil invertebrate in the two communities.

6. Methods and Materials • Location was on the TTU campus in back of the varisty baseball field • 8 samples from each community, 1 collection (16 total) • Samples were collected by using shovel and placing each different sample into a plastic bag.

7. Methods and Materials • Placed samples into its own Berlese Funnel • Funnel with mesh filter placed in a mason jar and put under a lamp. • After a week obtained samples in the bottom of funnel, identified and counted each species Reference: Dr. Brown's Lab Handouts

9. Statistical Tests performed 1. T-test: tests the hypothesis that two population means are different 2. Kolmogorov-Smirnov test: compares the distribution of the two habitats 3. Species diversity Measurements: Simpson and Shannon Indexes (H&D, E&J) • Sources: t-test and Kolmogorov-Smirnov Test

10. Results • More species were found in the open ground data, but more species were identified in Forest data • Shows Pi, which is needed to perform species measurements

11. Results • It takes more individual organisms to reach a new species for the open ground data • Accounts for the higher abundance of species, but lower number of species found in open ground

12. Results • Difference in slopes suggests a difference between communities • Forest data has a steeper slope, so less even • However, so small doesn’t impact data as much

13. Statistical test Results • t Stat < t Critical two-tail, accept null hypothesis • Dcrit > Dmax in the Kolmogrov-Smirnov test

14. Discussion • It was concluded that there was no difference in the two distinct habitats; forest habitat and open ground habitat. This does contradict the original hypothesis that stated that there would be a distinct difference in the two habitats. • Although the results show that the two distinct communities showed no difference in species diversity, most previous long term studies show a great difference. • One study showed that many chemical and physical properties of the soil differ based on its location (Pankhurst 1992). These chemical and physical properties influence what type of organisms can survive in that type of soil. • The amount of moisture or the amount of carbon would affect such property. Other studies suggest that the presence of plants (alder) affects the communities in the soil (Dunfield 2003, Chamberlain 2006).

15. Discussion • Agrees with Dunfield’s study suggests that the plants provide nutrients that the soil organisms can use for survival. While the Chamberlain study suggests that a large presence of alder is the reason for a high abundance of Collembola. • Disagrees with the studies that stated the forest or canopy environment of the biodiversity experiment should have had more invertebrates present. • Interspecific and intraspecific competition has a lot to do with species abundance (Heemsbergen 2004) • A bigger sample size and more distinct habitats would have helped the experiment be more accurate.

16. Conclusions • No difference in invertebrate biodiversity between the two distinct habitats • Accepted the null hypothesis, rejected my hypothesis • Forest Data was found to be less even than open ground, but had more species found • Both Kolmogorov-Smirnov and t-tests statistically showed no difference

17. Works Cited • Briones, M.J.,Ostle N.J., Garnett M.H. 2006. Invertebrates increase the sensitivity of non- labile soil carbon to Climate Change. Soil Biology & Biochemistry39(3): 816-818 • Chamberlain, P.M., and McNamara, N.P.2006 Translocation of Surface litter Carbon into Soil by Collembola. Soil Biology & Biochemistry. 9:2655-2664. • Dunfield, K.E., and Germida, J.J. 2003. Impact of Genetically Modified Crops on Soil and Plant Associated Microbial Communities. Journal of Environmental Quality. 33:799-804. • Ferguson, S.H., and Berube, D.K. Invertebrate Diversity under Artificial cover in Relation to Boreal Forest Habitat Characteristics. Canadian Field-Naturalist.3: 386-394. • Heemsbergen, D.A., Berg, M.P., Loreau, M., van Hal,J.R..2004.Biodiversity effects on soil processes explained by Interspecific functional dissimilarity.(Reports). Science306: 1019-1021. 

18. Effect of sunlight on biodiversity of soil invertebratesLoretta McNameeBiology Department of Tennessee Technological University, Cookeville, TN 38501 • Results • As shown in Figure 1, This graph shows that the forest data is less even then open ground data due to the steep slope on the graph. • Table 1 shows the statistical measurements of species diversity that was needed to produce the species abundance curve • Introduction • Soil biodiversity is the number and abundance of species inhabiting a community • Research has also been conducted on the chemical properties of soil and how it affects the invertebrate • Carbon is a huge factor, which is somewhat dependant on if and how much the sun hits the soil • Research shows that plant abundance directly affects invertebrate abundance, because plants provide so many nutrients for the soil invertebrates to survive • Conclusion • It was found that there was no difference in the two distinct habitats • Therefore, the null hypothesis was accepted • These findings disagreed with many other studies before, in which they found differences in soil biodiversity. • Forest data showed more species evenness than that of the Open Ground data • Objective & Hypothesis • The objective of this study is to examine biodiversity in soil invertebrates in two distinct communities; canopy and open ground. • Based on the objective, this experiment tested the null hypothesis that sunlight has no affect on the biodiversity of soil invertebrates • Acknowledgements • Dr. Morgan for his help in this semester long process • Dr. Brown for using his set-up • TTU Biology Department for the use of the media • Emily Shrum for help along the way • Methods & Materials • This experiment somewhat followed the basic methods outlined by Dr. Brown in his Ecology Lab handout. • Took 8 samples from each habitat, which was a total of 16 different soil samples. • Each sample was placed into a Burlese funnel in order to get the specimen out of their natural habitat of the soil • Species were collected and counted to form the basic data set • T-test and Kolmogrov-Smirnov test were both used to perform statistical analysis on the data collected.