Jozani biodiversity inventory report 2002 - Coastal Forests of Kenya ...

5.0 EVALUATION OF BIOLOGICAL RESOURCES AND THEIR CONSERVATION
VALUE
Although in terms of biodiversity Jozani and Zanzibar as a whole may not be as rich as the
coastal forests (Frontier, 1995) and Eastern arc mountains on the mainland most of the species
on Zanzibar are isolated from the mainland populations. Some are endemic or near endemic
and others are races of their congeners on the mainland. Others are threatened or endangered.
All these species need to be protected and some of them may need special attention and
conservation programmes.
Apart from maintaining biological diveristy, plant resources at species and community level
are important in many respects ranging from life support systems, climate control, ecological
processes and as wildlife habitats.
Some species found in Jozani are of potential value as a genetic resource. Species like Coffea
psudozanguebariae (Rubiaceae) is of potential importance in crossbreeding to produce coffee
hybrids.
A tree species Pandanus rabiensis has been singled out as the most inactive indigenous
species in the groundwater forest. Accounts of its regeneration capacity are not available. This
could form part of a research project to study its biology including breeding systems,
dispersal mechanisms and seed viability. The species may not be economically importyant but
its conservation is essential in terms of biodiversity conservation.
It is known that over 75% of the closed forests originally present on Zanzibar were destroyed
by 1966 (Hedberg and Hedberg, 1966), more of the forest has been cleared since then. Human
population increase was a major factor in the decline of forests. Understanding human
demography of populations living on the edge of proposed park is essential in the biodiversity
conservation of the area since this will allow designing appropriate conservation programmes
taking which take into account the growing human populations.
There is also the issue of alien species like Areca catechu (mipopoo) (Palmae). No studies
have bee conducted on this species which is known to suppress indigenous vegetation and
little effort appeart to have been unable to control their spread.
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