Spatial Variability of Net Radiation and Soil Heat Flux Density on Two Logged Sites at Montmorency, Quebec

Abstract

Net radiation data from 32 sample points and soil heat flux density values from six sample points on two logged sites at Montmorency in 1979 are presented. The two sites were of different ages; one had been clearcut in 1975 and the other in 1978. The newer site had a thick cover of logging debris, whereas the revegetation process was well under way on the older clearcutting. On both sites the spatial variability of net radiation is of comparable magnitude for clear and overcast sky conditions. During cloudy/bright conditions, no significant difference is found between the spatial average value and the single-point average value on either site. The hourly soil heat flux density is most strongly differentiated spatially for the newer clearcutting. The daily totals of soil heat flux differ between the sites; the older clearcutting exchanges more energy in soil heating and cooling than does the newer clearcutting.