Relationships between Soil, Topography and Tree Growth in a Water Harvesting System in the Loess Plateau, China

The Loess Plateau in northwestern China is one of the most seriously affected regions by soil erosion in the world. We conducted investigations in a field afforestation site in the north of Loess Plateau to clarify the relationships between soil, topography and tree growth in a small scale water harvesting system, called "fish-scale-pit (FSP)". The site (200 × 50 m) was located on a northern slope (0 - 25˚) of a hill. There were 314 FSPs in the site. The survival rates of the planted trees at near hilltop and near gullies were lower than the other area. The tree height showed weak and positive correlations with slope angle (R = 0.43). Bottom of hills were better areas to make FSPs than hilltops, considering their water balances. Although the difference in the average tree heights between large-leaf and small-leaf trees was small, the bearing rate of the large-leaf trees was much higher than small-leaf trees.