关键词: 林芝云杉, 原始林, 水化学特征, 养分含量, 西藏

Abstract:

Chemical concentrations in rainfall, throughfall, stemflow, soil infiltration and surface runoff were measured in a primeval Picea likiangensis var. linzhiensis forest in Nanyigou of Tibet from October 2006 to July 2007. There were a lower silt concentration of 5.56 mg·L^-1 and pH value of 7.61 in the rainfall outside the forest. SO^2-₄ concentration was highest (7.201 mg·L^-1) of all ions or elements in the rainfall. N concentration was lower (0.505 mg·L^-1). Other elements had relative low concentrations in the rainfall. SO^2-₄ and Zn concentrations were reduced in throughfall, but other elements were increased. All elements had higher concentrations in stemflow than in throughfall. Except for SO^2-₄, other elements displayed a positive canopy leaching. The concentrations of SO^2-₄, Zn and Fe were lower in surface runoff and soil infiltration than in rainfall, while other elements were concentrated in surface runoff and soil infiltration. The stream had more HCO^-₃, K, Ca, Na, Mg, and Cu than rainfall, suggesting loss of those elements in the forest. The stream contained less P, Fe, N, Zn, Cl- and SO^2-₄ than rainfall, due to adsorption in the soil and litter and absorption by plants. Our results provided a basic knowledge for further study on the nutrient cycling and evaluation on role of the forest in the water purification.

Key words: Picea likiangensis var. linzhiensis, primeval forest, hydrochemicalcharacteristic, chemical concentration, Tibet