Alex Cavacas, Brandon Chatfield, Kevin Chen, and Steven Meigs

1. http://dnr.wi.gov/topic/Invasives/fact/images/JapaneseBarberryA.jpghttp://dnr.wi.gov/topic/Invasives/fact/images/JapaneseBarberryA.jpg The Effect of Berberisthunbergii on Species Diversity Alex Cavacas, Brandon Chatfield, Kevin Chen, and Steven Meigs

2. Our Inspiration • Bio 130 –Ecology • Learned about how invasive species affect the environment • Learned about invasive species at Church Farm • Removed Japanese Barberry, Winged Wahoo, etc. • Bio 442 – Plant Ecology • Studying effects of invasive plant species

3. http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Berberis_thunbergii_files/image002.jpghttp://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Berberis_thunbergii_files/image002.jpg Introduction Study Species Berberis thunbergii ‘Japanese barberry’ • Dense, woody shrub with spine-bearing branches • 3-6 feet tall • Bright red berries • Seed dispersal facilitated through defecation of birds and other small animals • Originally brought from Asia as an ornamental plant • Grew out of control, became invasive species in Northeast U.S. http://www.nps.gov/plants/alien/map/img/beth1.gif

4. Our Hypotheses Abiotic Biotic In the presence of B. thunbergii, the number of individuals of each resident species will be lower The number of individuals of each resident species will decrease as the cover of B. thunbergiiincreases In the presence of B. thunbergii, the number of resident species will be lower. The number of resident species will decrease as the cover of B. thunbergii increases. • Light intensity will be lower in areas with B. thunbergii and higher in areas without B. thunbergii • Light availability will decrease when the cover of B. thunbergiiincreases • Soil will be wetter in areas with B. thunbergii • Soil moisture holding capacity will decrease when the cover of B. thunbergii increases.

5. Field Study at Church Farm 1 7 2 5 8 3 4 6 Eastern deciduous temperate forest in Ashford, CT

6. Our Research Plan • 8 plots with percent cover of B. thunbergii • 8 adjacent plots with no percent cover of B. thunbergii • Each plot will be 10 square meters • Randomly placed 1 square meter quadrat per plot

7. Data Collection • Measure percent cover and number of B. thunbergii and other plant species in each 10 square meter plot within the understory • Measure percent cover and number of individuals of resident plant species in each 1 square meter quadrat within the understory • Measure abiotic factors in each plot (soil moisture, light intensity) http://www.biconet.com/testing/GIFs/ep2.jpg http://www.testersandtools.com/images/QVTIMG20080917091740650.jpg

8. Light intensity will be lower in areas with B. THUNGBERII and higher in areas without B. thunbergii • Significant difference between average % light reduction and invasion status Figure 3 – A comparison of average percent light reductions between invaded and non-invaded plots. Percent light reduction was calculated with light intensity measurements at knee and shoulder height for each plot with and without B. thunbergii. Standard error was used to determine the possible range of light reduction of the plots.

9. Soil moisture holding capacity will be greater in areas with B. thunbergii • No significant difference between average SMHC and invasion status Figure 5 – A comparison of average percent soil moisture holding capacity between invaded and non-invaded plots. Percent SMHC was calculated using the difference between saturated and dried soil for each plot with and without B. thunbergii. Standard error was used to determine the possible range of light reduction of the plots.

10. In the presence of B. thunbergii, the number of individuals of each resident species will be lower • No significant difference between resident species evenness and invasion status Non-invaded Invaded Figure 7 – A comparison of species diversity between invaded and non-invaded plots. Species diversity was calculated using the Shannon-Wiener Index for resident species evenness measurements. Standard error was used to determine the possible range of light reduction of the plots.

11. In the presence of B. thunbergii, the number of resident species will be lower • No significant difference between the resident species richness and invasion status Non-invaded Invaded Figure 9 – A comparison of resident species richness between invaded and non-invaded plots. Resident species richness is the number of species that are not B. thunbergii in the 10m2 plots. Standard error was used to determine the possible range of light reduction of the plots.

12. Light availability will decrease when the cover of B. thunbergii increases • Weak, positive correlation between percent cover and average percent light reduction Figure 4 - A relationship between percent light reduction and percent cover of B. thunbergii in invaded plots. Percent light reduction was calculated with light intensity measurements at knee and shoulder height for each invaded plot. A linear regression was performed to detect a correlation with its corresponding r2.

13. Soil moisture holding capacity will decrease when the cover of B. thunbergiiincreases • Negative correlation between SMHC and percent cover of Japanese Barberry • Strong relationship when percent cover of barberry >40% • Weak relationship when percent cover of barberry >25% Figure 6 – A relationship between percent SMHC and percent cover of B. thunbergii. Percent SMHC was calculated using the difference between saturated and dried soil for each invaded plot. Percent cover is an estimation of invasive plant cover (A) in all invaded plots and (B) in invaded plots with invasive plant cover greater than 40%. A linear regression was performed to detect a correlation with its corresponding r2.

14. The number of individuals of each resident species will decrease as the cover of B. thunbergiiincreases • Weak, negative correlation between percent cover barberry and Species Diversity Index • Species Diversity Index is a Shannon-Wiener calculation using species evenness of invaded quadrats Figure 8 – A relationship between species diversity and percent cover of B. thunbergii. Species diversity was calculated using the Shannon-Wiener Index for resident species evenness measurements. Percent cover is an estimation of invasive plant cover in invaded plots. A linear regression was performed to detect a correlation with its corresponding r2.

15. The number of resident species will decrease as the cover of B. thunbergiiincreases • Weak, negative correlation between percent cover barberry and resident species richness (10 sq. meter plots) Figure 10 – A relationship between resident species richness and percent cover of B. thunbergii. Resident species richness is the number of species that are not B. thunbergii in the 10m2 plots. Percent cover is an estimation of invasive plant cover in invaded plots. A linear regression was performed to detect a correlation with its corresponding r2.

16. Discussion Rejected or supported? Justification Light intensity decreased in invaded plots because barberry forms dense shrubs As barberry cover increased, light intensity decreased because barberry forms dense shrubs • Light intensity will be lower in areas with B. thunbergii and higher in areas without B. thunbergii • Light availability will decrease when the cover of B. thunbergiiincreases

17. Discussion Rejected or supported? Justification Perhaps barberry actually does better in dryer soils because there is a weak, negative correlation • Soil will be wetter in areas with B. thunbergii • Soil moisture will increase when the cover of B. thunbergii increases.

18. Discussion Rejected or supported? Justification Perhaps there was another factor that we didn’t account for such as nutrient availability, soil pH, or the resident plant species could be good competitors An increase in percent cover of Barberry did not significantly decrease the resident plant species population • In the presence of B. thunbergii, the species diversity will be lower. • The species diversity will decrease as the cover of B. thunbergiiincreases.

19. Discussion Rejected or supported? Justification Perhaps there was another factor that we didn’t account for such as nutrient availability, soil pH, or the resident plant species could be good competitors An increase in percent cover of Barberry did not significantly decrease the number of resident plant species • In the presence of B. thunbergii, the species richness will be lower. • The species richness will decrease as the cover of B. thunbergii increases.

20. Strong Relationships Light intensity will be lower in areas with B. thunbergii and higher in areas without B. thunbergii *Soil moisture holding capacity will decrease when the cover of B. thunbergii increases Significant difference between average % light reduction and invasion status Strong relationship when percent cover of barberry >40% *Need more replicates to support definitively

21. In Conclusion Supported Hypothesis Future Research We were limited in time and study area (Roughly 2 months and only Church Farm) More replicates Could have supported some of our other hypotheses Experimental Design Manipulate the barberry to find results Variety in Replicates Spread out across a larger area Light intensity will be lower in areas with B. thunbergii and higher in areas without B. thunbergii • Light intensity decreased in invaded plots because barberry forms dense shrubs