A finite-difference model of temperatures and heat flow within a tree stem

The authors present a finite-difference numerical model of heat flow within a horizontal section of a tree stem. Processes included in the model are solar radiative heating, infrared emission and absorption, convective heat exchange between tree surface and the atmosphere, and conduction inside the tree. Input variables include wood density, wood thermal conductivity, wood specific heat, wind speed, air temperature, and insolation. The model produces time series of temperature for grid points inside the tree stem. Based on comparison with observations from two case studies, the model appears capable of reproducing relative timing and amplitude of temperature patterns at the cardinal aspects. Sensitivity tests show that insolation and convection parameters, as well as the physical properties of the tree, can all have a strong influence on model results.