Temporal changes in feeding-marks on sugi and hinoki cypress trunks gnawed by sika deer

Abstract

From March 2007 to November 2009, morphological changes in bark-feeding traces on the trunks carved by sika deer (Cervus nippon) were investigated in 11 young and middle-aged sugi (Cryptomeria japonica) and hinoki cypress (Chamaecyparis obtusa) plantations in Mie Prefecture, central Japan. In the tree growing season (March–September), cambium was peeled off together with bark, and morphological changes accompanied with histogenesis were not observed on the exposed surface of the xylem after debarking. In trees debarked during the non-growing season (December–February), the outer bark was stripped off leaving the inner bark adhering to the xylem, and many tooth-marks were observed on the inner bark. However, in trees with a relatively small number of tooth-marks, occlusions caused by enlargement of the xylem around tooth-marks were sometimes observed. The trees damaged in the growing and non-growing seasons were still distinguishable from each other even after two growing seasons.