Background/Question/Methods:
Wind disturbances may become more frequent and common in the face of global change. As one of the most common natural disturbances, understanding patterns of wind disturbance in forests is important to understand future forest composition. This study will examine the relative resistance of two common tree species in the eastern United States to simulated wind disturbance. Quercus alba, also known as white oak, and Liquidambar styraciflua, known as sweetgum, are our two study species. We hypothesize that Q. alba will be more resistant to wind disturbance. To measure their resistance to simulated wind disturbance, we used winches with a series of straps and pulleys to measure tension (lbs). We will compare tree diameter at breast height (DBH) versus tension for the two species as part of a first look at this relationship. Using linear regressions, we will determine whether the relationships between tension and DBH differs by species.
Results/Conclusions:
Predictably, tension increased as DBH values increased for both tree species. Neither linear regression was significant for either Q. abla (p=0.1328; r2=0.597) or L. styraciflua (p=0.0715; r2=0.335). However, the linear regressions showcased the following pattern: as DBH increased, tension needed to pull down L. styraciflua trees increased at a lower rate (slope=108.23) than tension needed to pull down Q. alba trees (slope=331.53). A steeper slope such as Q. alba’s slope is an indication that it generally takes more force to winch down trees with greater DBH values. Greater DBH values most likely indicate greater tree resistance to wind disturbance. This is an ongoing study that aims to calculate the critical turning point of these trees, a more detailed measurement of wind resistance. This study reveals that tornados may impact the species composition in forests, as species have different levels of resistance to wind disturbance. Determining which trees species are more resistant to wind damage has management and human safety implications.