关 键 字(英文)：south subtropics mixed coniferous and broad-leaf forest soil heat flux energy balance
摘 要(英文)：Soil heat fluxes and meteorology of a mixed conifer and broad leaf forest in Dinghushan, Southern China were monitored
by soil heat flux plates (SHFP) and a meteorological monitoring system, respectively. The results showed that measurement discrepancy
of soil heat flux by different SHFP might be more than 10%. If the soil heat storage above the SHFP was neglected, especially
in middle and short temporal scales(≤1 month), the surface soil heat flux data would be inaccurate, and the direction of heat transfer
might reverse sometimes. The diurnal changes of both soil heat fluxes at the surface and at the 5cm depth had an “S” shape. The
fluctuation of soil heat flux at the 5 cm depth lagged about 0.5 h to 1 h than that of the surface. In dry seasons, the soil was a heat
source, however, it was a heat sink in rainy seasons. The total surface soil heat flux was -0.44 MJ·m-2 per year, indicating that the soil
was a heat source at the annual temporal scale. The monthly changes of heat storage of the surface soil above the SHFP ranged from
-0.14 MJ·m-2 to 0.20 MJ·m-2, about -11.0% to 1.3% of that at the 5cm depth. The proportion of monthly surface soil heat flux to net
radiation above the canopy ranged from -12.0% to 3.3%. Since most studies on the energy balance were carried out in a short temporal
time scale, it is important to measure or calculate the short-term soil heat flux as well. Significant correlations between the surface
soil heat flux and net radiation above the canopy measured 2.5 h earlier were found, suggesting that response of the soil heat flux to
the net radiation above the canopy could lag 2.5 h.
南亚热带针阔混交林土壤热通量研究