Soil respiration from four aggrading forested watersheds measured over a quarter century
Soil respiration was measured in four aggrading, forested second-growth watersheds in the southern Appalachians using an identical method (alkali absorption) at intervals 23 and 24 years apart. Seasonal trends were similar, with mid-summer maxima and winter minima. Amounts of carbon dioxide evolved were higher in the recent measurements (1995) compared to the earlier ones (1971-1972), despite similar soil water and temperature regimes. The overall trend across all four watersheds may reflect changes in organic matter levels and subsequent root growth.