Summary: | Mimusops caffra, Euclea netetensis, Olea woodiana and Peddiea
africana are tree species associated with different successional stages in a
coastal dune forest. Saplings of these tree species were established in four
different light intensities. These were full sun, 40% shade, 70% shade and
90% shade. The hypothesis proposed that the species from different
successional stages are preadapted for a particular light environment and are
disadvantaged in other light environments. Growth, morphological,
biochemical and physiological aspects of the four species in the four light
environments were determined.
Growth rates showed no consistent pattern with respect to light intensity.
However, most species, irrespective of their successional status, had the
best growth response in either 40% or 70% shade treatments. All the
species showed typical sun and shade responses for morphological,
anatomical and some biochemical characteristics. Photosynthetic responses
were complex and showed no relationship between the successional status
of the species and the light conditions in which they were grown.
There appears to be very little relationship between the growth responses,
the measured biochemical and morphological aspects, assimilation rates and
the successional status of the species.
Light intensity is therefore not the sole driving force of forest succession but
one of the many factors that contribute to the
overall process. === Thesis - (M.Sc.)-University of Natal, Durban, 1992.
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