Water dynamics of Pinus tabulaeformis stand during and after a severe drought.

摘要

The water dynamics of a Pinus tabulaeformis forest was studied during a drought period and after rainfall for 2 stands with different soil thickness in Shanxi Province, China. Although the water content of the topsoil reached the permanent wilting point before rainfall, Pinus tabulaeformis did not wilt, and avoided severe water stress by closure of the stomata. After the rainfall, the stand transpiration increased 3-fold. Soil water retention was high in both stands, but the stand with the thick soil layer maintained a high transpiration even during drought periods. The importance of soil thickness is considered in relation to available moisture and water balance during non-precipitation periods. The results obtained in this study suggests that the soil thickness is the most important factor for preserving the Pinus tabulaeformis stand during drought periods.