Influence of Bark on Mechanics Strain Measures

Summary

Arboriculture researchers have begun utilizing the ARAMIS 3D image correlation systems, introduced to arboriculture by NASA engineers, to understand how trees respond to physical loading. The basic technique is to develop a series of reference points that are captured by the high resolution 3D imaging system and processed to allow for measurements of strain (displacement of wood related to the original length). One potential limitation of the ARAMIS system is that phloem and xylem are separate tissues that can potentially move independently. As such it is possible that the strain measured on the bark may not behave the same as stain in wood fibers beneath the cambial layer. While the bark can be removed to directly measure strain in the wood, it relegates the use of this promising tool to destructive sampling. The presentation will discuss the results of a research project that examines stain in samples with bark on and bark removed. The direct comparison will help determine if bark can be left in place, which would allow individual trees to be monitored over multiple growing seasons.