5 the state of science in south africa
B I O L O G I C A L S C I E N C E S
search with management questions at both ing, water relations, nutrient relations and
national and local scales. Invasion research photosynthetic characteristics, using both
received an additional boost when, in June gas exchange and chlorophyll fluorescence
2004, the C•I•B was established. With its hub techniques.
at SU, this interdisciplinary, interinstitution-
al DST-NRF Centre of Excellence has rapidly There is some excellent work on evolution
become established as a world leader of and ecology of C4 grasses which is challen-
research into biological invasions, building ging some of the accepted dogma on this
upon an already substantial and well-rec-
topic. Similarly, some of the work assessing
ognised science base.
interactions between transpiration and nu-
trient uptake is strongly influencing current
5.2.7 Plant physiology
thinking. There have also been some good
studies on plant hydraulics, linking hydrau-
lic characteristics to plant survival, growth
P
lant physiology can be divided into
and distribution. Studies have been under-
cellular/biochemical and whole plant
taken on tree-grass interactions in terms of
or ecophysiological studies, although
water relations and, especially, the impor-
there are studies that span the range, and
tance of atmospheric CO
2
concentrations
stress response can be seen as a common
on these relationships.
theme. Much of the cellular physiology has
biotechnological leanings and some of the
Cellular physiology
physiological studies are covered elsewhere
Cellular physiology studies in South Africa
in other sections of this chapter.
cover a wide range. There is considerable
work on plant growth regulators (including
Ecophysiology
the action of smoke as a germination stimu-
There is a small group of active ecophysi-
lant), and their importance in developmen-
ologists in the country; some of whom spe-
tal physiology, including seed development
cialise in a particular biome, whereas oth-
and dormancy. Studies have been under-
ers have an interest in a particular aspect
taken on the control of sucrose production
of physiology and investigate this over a
in sugarcane, linking this to source-sink re-
wide range of biomes. There has been some
lationships. There is also work on plant-pest
good work on the fynbos biome, savannas,
interactions, particularly some fungal pests
the arid Karoo, coastal sand dunes and sub-
and aphids. In common with worldwide
Antarctic islands. In addition, studies have trends, a major thrust in cellular physiology
been undertaken on managed ecosystems, is the study of gene regulation associated
and there is substantial physiological input with various biotic and abiotic stresses, with
into the sugarcane industry and commer- the ultimate possibility of genetic modifica-
cial forestry plantations. tion to improve stress resistance.
Plants in these systems have been stud-
ied in terms of growth, biomass partition-
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