CHARACTERISTICS OF SOME TROPICAL TREE SPECIES
M B D P Gunawardana*,
E R N Gunawardana*, and I R Calder**
of Peradeniya; **Institute of Hydrology, Wallingford, UK
Interception is a physical process, which represents a definite loss of
rain water since most plants can absorb water only through roots. This
loss depends on how the canopy is wetted by the falling rains and the
amount of water stored on the vegetation after the rain ceases. This information
is needed for modelling studies to estimate the interception loss under
varying climatic conditions.
This study was conducted to compare the wetting characteristics of Syzygium
rundifolium, Rhododendrons zeylanicum, Eucalyptus microcorys, Hedyotis
confertiflora, Artocarpus heterophyllus, Pinus caribeae, Tectona grandis
and Acacia decurrens. A rainfall simulator consisting of drip irrigation
nozzles and spray heads was used to generate three drop sizes. A branch
representing a projected area of about one square meter was used to measure
the maximum interception and the interception loss.
The results showed that the interception loss depends on the species and
not on the rain drop size. Species with smaller leaves, such as Syzygium,
Acacia and Pinus tends to have more interception loss compared to larger
leaves. Therefore, planting of these species in low rainfall areas may
have serious consequences with regard to water yield. Species with larger
leaves such as Jack and Teak which gives the lowest interception loss
are far more suitable for drier areas.
Department of Forestry and Environmental Science,
of Sri Jayewardenepura,Sri Lanka. 1999. All rights reserved.