Study on Water Conservation Capability of Cunninghamia lanceolata Plantation Mixed with Schima superba

The water conservation capacity of pure stands and mixed plantation composed of Schima superba and Cunninghamia lanceolata was studied by field investigation and plot experiment. The results showed that the aboveground water holding capacity, the soil water holding capacity, and the total water holding capacity of the mixed stands was respectively larger than that of the pure stands of the two tree species, and the three types of waterholding capacity was ordered as the mixed stand of Schima superba × Cunninghamia lanceolata（the proportion of the two species as 6∶4）＞ the mixed stand（4∶6）＞ the pure stand of Schima superba ＞ the pure stand of Cunninghamia lanceolata. The water holding capacity of different layers of the stands was in the following order as soil layer ＞ canopy layer ＞ litter layer ＞ groundcover layer. The total water holding capacity of the stands was mainly contained in the soil layer, and the water holding capacity in the 0-100cm soil layer accounted for 99% of the total stand water holding capacity. There was significant difference in 0-40cm soil waterholding capacity among the different stand types, there was less difference in water holding capacity at 60-100cm soil depth among different stand types. The study indicated that the water conservation function of the mixed stands was larger than that of the pure stands.