Abstract

The present study was conducted in two forests in Abha (Capital of Asir Region) and two forests in Al Namas (130 km north of Abha), south western Saudi Arabia (Asir region) with the objective of investigation of the effect of terraces on rainwater harvesting and growth of Juniperusus procera Hochst. ex Endlicher. Study plots were established in four forests, two of which contained maintained terraces and the other two have abandoned and damaged terraces. The results showed that maintained terraces served as important means for rainwater harvesting, whereas abandoning of terraces resulted in increased soil loss, surface runoff, bulk density and reduced infiltration rates. Significant correlations and regression between soil loss, total runoff, soil bulk density and infiltration rate were provided. DBH, total height, basal area, volume, number of trees, crown coverage and regeneration/ha of J. procera were significantly (p < 0.0001) higher in forests with maintained terraces compared with abandoned terraces. In conclusion, maintained terraces improved rainwater harvesting and growth performance of J. procera, whereas abandoning and damage of terraces produced more soil loss, increased surface runoff and bulk density, reduced infiltration and less growth of Juniperus which was characterized by extremely poor regeneration.

Key words: Juniperusus procera, terracing, rainwater harvesting, soil erosion, surface runoff.