Resin duct characteristics in the wood of fire-scarred North American conifers

Traumatic resin ducts form in xylem and phloem tissue of conifers in response to abiotic wounding, fungal invasion, and insect attack. Little is known about resin duct characteristics in the wood of fire-scarred trees. The aim of this study is to quantify changes in traits of both axial and radial resin ducts, along with those of associated epithelial cells and fusiform rays, in 2 individuals each of Larix occidentalis and Pseudotsuga menziesii. Transverse and tangential microsections were cut from samples for light microscopy. Using image analysis, anatomical measurements of cells are being performed three-dimensionally: at 4 heights along the tree axis, within 4 cm from the wound margin and in different rings, including 2 rings from the wound xylem. The forthcoming results will provide new insights into one of the most important defense mechanisms of trees.