P4.6
Spatial Variation in the Duration of Exposure to Low Temperature in Hinoki Cypress (Chamaecyparis obtusa Endl.) Forest Damaged by Resinous Canker Disease
Koji Tamai, Forestry & Forest Products Research Institute, Tsukuba, Ibaraki, Japan
Temperatures at various stem height of hinoki (Chamaecyparis obtusa Endl.) which had been damaged by resinous canker disease were measured during winter and spring seasons. The sum of time when a stem temperature was lower than a given criterion was difined as a exposure duration to low temperature condition. The spatial variation of the exposure duration was analyzed statistically with Quantification 1. When a cold wave came, the stem temperature dropped lower than -2.9 - -2.3 degrees Celsius through the day. On the contrary, a radiation cooling have the stem temperature dropped lower than -1.6 - -0.9 degrees Celsius but never dropped lower than -2.9 - -2.3 degrees Celsius. The statistical analysis showed that the lower part of a slope and the stem heights between 1.0 and 3.0m had a longer exposure duration to the lower temperature than -2.9 - -2.3 degrees Celsius in comparison with other part of slope and other height of stems. This spatial variation of the exposure duration to the lower temperature than -2.9 - -2.3 degrees Celsius corresopnded to the distribution of the resinous canker diseased parts on hinoki stem. In conclusion, sever low temperature due to the cold wave approach might be influential on resinous canker.
Poster Session 4, Poster Session: Plants, Phenology, and Drought
Thursday, 31 October 2002, 12:30 PM-1:30 PM
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