The litter layer is an important component of forest ecosystems, although little is known about the differences in litter characteristics and hydrological properties of unmanaged, overgrown broadleaved and coniferous mixed forests in the subtropical and temperate zones. This study was carried out in a naturally generated broadleaved and coniferous mixed forest at the Qinling National Forest Ecosystem Research Station, Shaanxi Province, China. We quantified the litter thickness, mass, and its hydrological properties in evergreen pine (Pinus tabulaeformis) stands and deciduous oak (Quercus aliena var. acuteserrata) stands through in situ surveys and laboratory immersion experiments. The thickness of the litter layer for P. tabulaeformis averaged 9.3 ± 2.8 cm, and it was not significantly different from that detected in the Q. aliena stand (8.3 ± 3.6 cm). The total mass of the litter layer for P. tabulaeformis, 27.94 ± 9.81 Mg ha^-1, was significantly higher than the total mass of 16.04 ± 3.60 Mg ha^-1 found for Q. aliena. The mass of the semi-decomposed, fermented litter (OF) layer was significantly higher than that of the non-decomposed litter (OL) layer, irrespective of species. The rate of water absorption by dry litter was the highest at the onset of the immersion experiment and decreased exponentially with time. The water-holding capacity (W_m) and water-interception capacity (W_i) of the OF layer were higher than the OL layer for both forest stands. The W_m and W_i for the P. tabulaeformis stand were higher than those for the Q. aliena stand at our study sites. The higher W_m and W_i for P. tabulaeformis may be more effective in ameliorating the splash impact from high-intensity storms to improve water quality, while relatively lower W_m and W_i for Q. aliena may be considered favorable for augmenting water yield. Forest resource managers should consider those differences along with the other components of the water budget when making management decisions.

Keywords

Water Conservation Forest, Hydrological Properties, Forest Succession