Hydrological Characteristics of a Makino Bamboo Woodland in Central Taiwan
摘要
Hydrological characteristics of litterfall, interception, infiltration, evapotranspiration, and subsurface runoff of a makino bamboo (Phyllostachys makinoi Hayata) woodland, a special forest type found mainly on mid-elevation slopelands from the central to the northern part of Taiwan, in the Lienhuachih Research Center of Taiwan Forestry Research Institute were investigated during the period 1999 to 2004 and compared with those of natural hardwood forests and other major vegetation cover types in Taiwan. Results of the investigation indicated that the peak of litterfall for the makino bamboo woodland was from April to May. The average yearly litterfall was 4.66 ton ha^(-1) yr^(-1), which is relatively low in comparison to that of a natural hardwood forest (7.98 ton ha^(-1) yr^(-1)). The estimated average annual interception loss was 13.6% of gross rainfall, and the average stemflow ratio was 4.6%. Both of the ratios are slightly higher than those of a natural hardwood forest owing to the special structure of the canopy and the smoother bark of culms in the makino bamboo woodland. Estimated daily average evapotranspiration was about 4.56 mm day^(-1) as detemined with a simplified lysimeter. The final and initial infiltration rates were respectively as 0.20 and 2.15 cm min^(-1). The infiltration capacity is higher than those of betelnut and China fir plantations. More than 95% of the subsurface runoff, the main component of quickflow, came from the top 30-cm layer of the soil profile due to abundant quick pathways associated with roots in that layer and the steep slope. The quickflow often appeared during the same day as precipitation with a1.5~4.0h time lag between peaks of rainfall and quickflow.