TEMPERATURE AND ITS VARIABILITY IN OAK FORESTS IN THE SOUTHEASTERN MISSOURI OZARKS

This paper examines air and soil temperature, their variabilities, and their relationships with decomposition and ground flora diversity wit hin an oak Quercus forest in the southeastern Missouri Ozarks (USA). W e conducted 3 experiments with 9 mobile weather stations at Missouri O zark Forest Ecosystem Project (MOFEP) study sites from September 1994 to August 1995. We used the cotton strip assay technique to quantify d ecomposition rate and Simpson's diversity index to evaluate the divers ity of the ground flora. We found that air temperature at each site di ffered significantly from every other site (p < 0.001) based on a temp oral scale of 20 min; this was also the case for soil temperature (p < 0.001). The spatial variation of soil temperature was consistently gr eater than that of air temperature. The spatial Variation of air tempe rature increased with increasing spatial scale. Spatial variation of s oil temperature increased rapidly from the 0 to ca 40 m scale, then de creased slowly before it began to increase again at a spatial scale of ca 700 m. Temperature was not highly correlated to decomposition rate in the study area (correlation coefficients were 0.51 and 0.64 for ai r and soil temperature, respectively). The spatial variation of temper ature was inversely related to the species diversity of the ground flo ra (R-2 was 0.87, 0.93, and 0.76 for air, soil surface, and soil tempe rature, respectively, at the 400 m scale). These results suggest that temperature Variation can be quite significant, even at the stand leve l, and can impact some ecological patterns and processes at the same s cale.