The respiration of the soil beneath some Eucalyptus forest stands as related to the productivity of the stands

Abstract

The respiration of the soil in situ was studied during a period of 15 months in four Eucabpbus stands of diverse physiognomy and productivity. Respiration rates were low in winter, and during periods of drought in summer; they were high in spring, and were stimulated by precipitation during the summer. Although soil respiration rates were not directly related to the organic matter content of the soil, to the amount of litter fall, or, in general, to the productivity of the stands as measured in terms of tree growth, the magnitude of the spring flush of respiration and the levels of respiration that were maintained during periods of summer drought were found to be related to stand productivity. The pattern of variation of the carbon dioxide content of the soil air differed markedly between stands, and there was a positive relationship between the productivity of the stands and the depth in the soil to which biological activity occurred.