Abstract:
Calamus ovoideus Thw. and Coscinium fenestratum Colebr. are economically
important, naturally growing liana species in the disturbed habitats of lowland
rain forests in Sri Lanka. Harvesting their mature stems has jeopardised their
survival and led to dwindling populations. Growth performance, population sizes
and the eco-physiology of these species were examined under three different canopy
removal treatments and a closed canopy control of a Pinus caribaea buffer zone
plantation of the Sinharaja forest. Population studies of Calamus spp. and C.
fenestratum revealed that they survive and regenerate naturally in disturbed
habitats compared to undisturbed forest.
After nine years, both liana species grew poorly in the Pinus understorey
(control) compared to the canopy removal treatments. During the study period,
height increment of C. ovoideus was best in the three-row canopy removal treatment.
In contrast to C. ovoideus, the eco-physiological features of C. fenestratum
varied little among the canopy removal treatments, suggesting that they tolerate
a wider range of light levels.
The study revealed that both species could be successfully introduced to the
Pinus caribaea buffer zones, degraded areas of lowland rain forests in Sri Lanka,
in order to conserve them in the wild and manage them sustainably.
