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.