The CO2 concentration in soils of montane cloud forests of southern Mexico

We studied the CO₂ concentration in the soil air of Folic Albic Podzols at heights of 2500 and 2400 m a.s.l. within the area of montane cloud forests of southern Mexico. Soil air samples were collected from the depths of 5, 10, 20, 30, 40, and 50 cm every three hours from 9 a.m. to 18 p.m. during one day. The mean CO₂ concentrations in the soil air at the heights of 2500 and 2400 m a.s.l. reached 2170 and 6930 ppm, respectively. The spatial and temporal variability of the CO₂ concentration in the soil air of the Podzols of the montane cloud forest were revealed. The spatial variability was controlled by the differences in the species composition of the surface vegetation and the depth of the soil organic horizon, whereas the temporal variability was related to the generally low level of aeration of the topsoil layer and, presumably, to the cyclic pattern of the root respiration.