Water holding capacity of ground covers and soils in different land uses and land covers in subalpine region of Western Sichuan, China
川西亚高山林区不同土地利用与土地覆盖的地被物及土壤持水特征

Subalpine forests in Western Sichuan are an important part of water conservation forests in Southwestern China. Since the middle of the 20th century, old-growth coniferous forests have been transferred or degraded into croplands, grasslands, shrublands, natural secondary broad-leaved forests and plantations depending on disturbance intensity, frequency and duration for the increase of agriculture and timber supply. In 1998, Natural Forest Protection Program (NFPP) and Slope Land Conversion Program (SLCP) were initiated to restore forest ecosystems. In order to assess the effectiveness of those restoration programs, the eco-hydrological effects of those land uses must be compared. Through field investigation and laboratory experiments, water holding capacity of ground covers and soils were compared among croplands (CL), grasslands (GL), afforestation lands (AL), shrublands (SL), natural secondary forests (SN), plantations (PL) and old growth forests (OG) in subalpine region of Western Sichuan. The results showed that there were significant difference in water holding capacity of ground covers and soils among different land uses and land cover types. With the increase of disturbance intensity, the cumulative mass and the maximum water holding capacity (MWHC) of moss and litters decreased, soil bulk density increased, and soil water holding capacity decreased. The MWHC of moss in descending order was OG, PL, NS, and SL. The MWHC of litters in descending order was OG, NS, PL, SL, GL, and AL. There was no difference in MWHC of moss and litters between PL and NS, and between GL and AL. MWHC at the soil layer of 0-40 cm in descending order were NS, OG, PL, SL, FL, GL, and AL. Although MWHC at the soil layer of 0-40 cm was significantly higher in NS than that in PL, there were no difference between GL and AL. Various forest ecosystem services should be considered when selecting tree species for implementation of SLCP.