Variation in air and soil temperatures in forest communities on the H.J. Andrews Experimental Forest, 1970-1972

Air temperatures at 1 m and soil temperatures at 20 cm are reported fortwenty-one forest stands in the central Western Cascades of Oregon. Recordsbegan in 1970 for some stands, in 1971 or 1972 for most. Temperature GrowthIndex for a stand, based on temperature effects on Douglas-fir seedling growth,varies from 32 to 101, and ordinates the stands similarly for 1971 and 1972.However, the index is not closely related to stand position in a vegetationordination. A strong nocturnal temperature inversion causes summer minima toincrease with elevation up to 1100 m. All lapse rates are low up to 1100 m.Comparisons with studies of montane forests in Arizona and Colorado show thatthe sites studied here lack the temperature variation, particularly the lowminima, characteristic of the other areas.