an investigation into the antibacterial activities of medicinal plants ...

2.2.1.3 Conservation of medicinal plants
The revival of medicinal plant usage as easily accessible therapeutic agents, has led
to an increase demand for medicinal plant resources. The medicinal plant trade has
become highly commercial with an estimated plant trade of R62 million per annum in
KwaZulu-Natal (http://www.kznwildlife.com/muthi_trade.htm). An estimated 20 000
tones of over 700 medicinal plant species are traded annually in the herb market
industry of South Africa (George et al., 2001).
The high demand of medicinal plants in South Africa has led to over 10% of more
than 20 000 plant species being threatened with a decreased availability and listed in
the South African Red Data books (Goldring, 1999; George & van Staden, 2000).
These plants may harbour active components that are needed to overcome or
reduce the problems experienced with some modern drugs. Despite the potential
medicinal plants have as sources for new antimicrobial agents, some plants without
proper scientific investigation and documentation are faced with extinction.
Some early conservation measures used by traditional herbalists include the
prevention of ring barking a tree, avoiding the complete removal of plant roots as well
as preventing repetitive plant harvesting from the same site. These early
conservatory methods were believed to maintain plant potency and the balance
between plant removal and plant re-growth in the wild (Matsiliza & Barker, 2001).
Despite some of the informal conservation measures employed by traditional
herbalists, destructive harvesting of some plants is still visible. Plant collectors that
are unappreciative and unfamiliar with the correct harvesting techniques carry out
destructive harvesting techniques such as ring barking and the complete removal of
roots that prevent plant re-growth for future use (Matsiliza & Barker, 2001). As a
result many plants are protected under law governing the harvesting of the medicinal
plants in KwaZulu-Natal (Diederichs et al., 2002).
The increasing popularity and high demand of some medicinal plants have made
them objects of extensive overexploitation. Ocotea bullata (black stinkwood) and
Warburgia salutaris are some of the many medicinal plant species that are under
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