1. Species Richness and Clear Cut Age
Brooke Gauthier
Charlie Karoff
Tyler Quinn Smith
Peter Tansey
All

2. Introduction
Clear cutting has noticeable effects on species composition and succession of forests.
Physiological characteristics (Elliott et al. 1996)
Richness per 100 individuals increased with successional stage (Bruelheide et al. 2011)
Species diversity over successional time in abandoned fields (Howard and Lee 2003):
Increase? Decrease? Peak sometime? No trend?
Charlie
Clear cutting impacts forest succession: the sequential changes in abundances of dominant species in a community. 
-Often due to physiological characteristics of trees such as stress tolerance, rapid growth, or high nutrient acquisition (Elliott et al.)
Bruelheide.....
Howard and Lee tested four hypotheses of how species diversity would change over successional time: increase, decrease, peak at mid-succession, or show no trend?

3. Objective
Understand the relationship between clear cut age and species richness.
Hypothesis: tree species richness will increase with the age of clear cut.
Peter or Tyler

4. Methods Field Lab Analyzed data in Microsoft Excel
UNH Woodman Horticultural Farm in Durham, NH
9 plots total in 3 different clear cuts (1985, 1989, and 2011)
Plots 30 meters apart
Identified 20 trees closest to midpoint 
Analyzed data in Microsoft Excel
Split trees into groups (intolerant, lower mid-tolerant, high mid-tolerant and tolerant)
Used JMP Pro 13 to run Kruskal-Wallis test
Brooke

5. Brooke

6. Results
Tyler

7. Tyler

8. Tyler

9. Tyler

10. Peter

11. Results Continued
Peter

12. Statistical Analysis
Species richness increased significantly with clear cut age.
 Kruskal-Wallis Test
 X^2 > 5.954
d.f. = 2
 P < 0.05
Brooke

13. Discussion Tree species richness did increase with age of clear cut.
Richness was lowest year after clear cut and increased thereafter (Grove et al. 1992)
Intermediate Succession Hypothesis? (Howard and Lee 2003)
Tyler

14. Discussion
Data shows patterns of species composition relating to shade tolerance.
Elliott et al. (1996) found clear cutting to favor shade-intolerant species initially and shade-tolerant species years after.   
Peter
Lienard et al. 2015

15. Limitations Time restrictions
Inexperience in tree species identification
Physiography varied among clear cuts
Brooke

16. Conclusion
Maximum species diversity in immediate years following the clear cut.
Self-thinning and interspecific competition lead to decreased richness.
Shade tolerance of species within the stand that have a lower R* will prevail better than tree species with a higher R*.
When will these stands experience a plateau or decrease in richness?
Charlie

17. Literature Cited 
Bruelheide, H., Bööhnke, M., Both, S., Fang, T., Assmann, T., Baruffol, M. et al. (2011). Community assembly during secondary forest succession in a Chinese subtropical forest. Ecological Monographs, 81, Elliott, K., Boring, L., Swank, W., and B. Haines Successional changes in plant species diversity and composition after clearcutting a Southern Appalacian watershed. Forest Ecology and Management. 92(1997): Grove, J., Wayne Martin, C., Paul, G., Solomon, D., and J. Hornbeck Plant species diversity on even-aged harvests at the Hubbard Brook. Experimental Forest: 10-year results. Canadian Journal of Forest Research. 22(11): Howard, L. and T. D. Lee Temporal patterns of vascular plant diversity in southeastern New Hampshire forests. Forest Ecology and Management. 185(1-2): Lienard, J., Florescu, I. & N. Strigul An appraisal of the classic forest succession paradigm with the shade tolerance index. PloS one, 10, e