Abstract: Transformation of low-quality forest stand is an important measure to improve forest stand quality and its ecological functions. In this paper, two transformed stands and one control stand of Eucalyptus urophylla plantations in the Dongguan Forest Research Park, Guangdong Province of South China were taken as the objects to study the waterholding capacities of soil and litter. The two transformation modes were 1) evenly removing 70% of E. urophylla trees followed by planting native broadleaved trees in canopy gaps (Mode Ⅰ) and 2) evenly removing 40% of E. urophylla trees followed by planting native broadleaved trees in the gaps (Mode Ⅱ), and the un-treated E. urophylla plantation was served as the control (CK). After 3year transformation, as compared with CK, the surface (0-20 cm) soil capillary porosity, natural water content, field waterholding capacity, and effective water retaining capacity in Mode Ⅰ and Mode Ⅱ had a significant increase, while the noncapillary porosity in 0-40 cm soil layer was in adverse. The waterabsorption rate and the maximum waterholding rate of the litters under Modes Ⅰ and Ⅱ were significantly higher, but the litter biomass and its maximum waterholding capacity were significantly lower than those under CK. The water-absorption rate of the litters in the three plantations had a power function relationship with the litter’s immersion time, while the water-holding rate and water-holding capacity of the litters were exponentially correlated with the immersion time. Overall, stand transformation increased the water-holding capacity of 0-60 cm soil layer significantly, and no significant difference was observed between Modes Ⅰ and Ⅱ. For all the plantations, the water-holding capacity of soil was far higher than that of litter, and the maximum water-holding capacity of litter was only 0.59%-2.06% of the effective waterholding capacity of surface soil layer.

Key words: wind-water erosion crisscross region, re-vegetation pattern, re-vegetation age, organic carbon, total nitrogen.