Simulated Seasonal Spatio-temporal Patterns of Soil Moisture, Temperature, and Net Radiation in a Deciduous Forest

The temperature and moisture regimes in a forest are key components in the forest ecosystem dynamics. Observations and studies indicate that the internal temperature distribution and moisture content of the tree influence not only growth and development, but onset and cessation of cambial activity[1], resistance to insect predation[2], and even affect the population dynamics of the insects[3]. Moreover, temperature directly affects the uptake and metabolism of pollutants from the soil into the tree tissue[4]. Additional studies show that soil and atmospheric temperatures are significant parameters that limit the growth of trees and impose treeline elevation limitation[5]. Directional thermal infrared radiance effects have long been observed in natural backgrounds[6]. In earlier work, we illustrated the use of physically-based models to simulate directional effects in thermal imaging[7-8]. In this paper we describe the simulated spatial and temporal patterns of soil moisture, temperature, and net radiation in a deciduous forest using our recently developed three-dimensional, macro-scale computational tool that simulates the heat and mass transfer interaction in a soil-root-stem system (SRSS). The SRSS model includes the coupling of existing heat and mass transport tools to simulate the diurnal internal and external temperatures, internal fluid flow and moisture distribution, and heat flow in the system.