Effect of terracing on rainwater harvesting and growth of Juniperus

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) to investigate the effect of terraces on rainwater harvesting and growth of Juniperus procera Hochst. ex Endlicher. Farmers grow their crops within Juniper forests and woodlots by constructing terraces from soil and stones to harvest rainwater. Juniper forests and woodlots present important watersheds and sources for water. Study plots were established in four forests, two of which contained maintained terraces and the other two have been covered by 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. Diameter at breast height, 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. Finally, maintained terraces improved rainwater harvesting and growth performance of J. procera