Baobab Monograph.pdf - Crops for the Future

2.2.3 Seed dispersal and tree regeneration
When fruits fall in the field, the woody outside fractures and termites enter
to eat the sweet pulp, thus freeing the seeds. A range of animals carry seeds
away from the trees: Wickens (1982) records monkeys, squirrels and rats;
and fruits are widely eaten by humans and a number of large animals such as
elephants and elands as well as birds.
Fruits can also be dispersed by water systems and this is important when
considering the disjunct distribution of the genus and the distribution
patterns of A. digitata (see Chapter 3).
African baobab is characteristic of thorn woodlands of the savannahs and
fears have been expressed that severe droughts of recent years have affected
regeneration. Equally significant was a tendency to eliminate baobab when
near cotton and cocoa production areas in West Africa because baobab is
known to be an alternative host for pests affecting these crops and there was
also a fear of certain cocoa viruses in the 1950s. In Eastern Africa, reduction
in populations of baobab have been considered a result of increased elephant
browsing in national parks.
Surprisingly little is known about natural regeneration rates, but to a large
degree this could be because seedlings are not readily recognised since they
lack the obvious palmately digitate leaves and swollen trunks. Additionally
the association of baobab with the farmed parklands or savannah (plate 30)
is a deliberate association with the agricultural environment because of the
tree uses, and regeneration may well depend on trees being deliberately
planted near settlements. A study in Burkina Faso clearly points in this
direction (Gijsbers et al., 1994). This probably marks a change from the past,
when rural settlements could well have been made in areas where baobabs
were naturally frequent, as postulated by Wickens. Artificial planting is also
noted by Giffard (1974) in Senegal and by Sidibé et al. (1996) in Mali (plate
32).
For the above reasons, many populations are near to villages or exist as
relicts from old human habitation patterns. Young trees respond well to
transplanting. In the past some ethnic groups in Mali such as the Dogon,
Kagolo and Bambara used to take cuttings from the wild and transplant them
around their villages. The Dogon people used to transplant them next to their
toilets where they could use wastewater to enable better growth of baobab.
This practice originated from the shortage of water at certain times of the
year and also a scarcity of wild seedlings: the germination rate of the hard
seeds is usually less than 20% (Danthu et al., 1995). In addition, the
regenerated plants must be protected from wandering animals during the dry
season. Using rigid stakes or fences ensures this protection. Efforts are
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