Extinction of the St. Helena Olive
Contributed by Rebecca Cairnswicks
The St Helena Olive, Nesiota elliptica, once
grew on the highest parts of the eastern central
ridge. It became very rare in the 19th century.
At the beginning of the 19 only 12 to 15 trees
were recorded as growing on the northern side
of Diana's Peak, although in 1883 it was
recorded from both the central ridge and
Diana's Peak areas. It was subsequently thought
to have gone extinct until a single tree (not far
from Cuckhold's Point) was discovered by
George Benjamin in August 1977. This tree was
found dead on 11th October 1994 and the
species became extinct in the wild. The dead
tree was found to suffer from numerous
systemic fungal infections, which may have been
exacerbated by damage sustained during
attempts at conservation.
The olive survived on in cultivation but only
precariously. Cuttings have proved very difficult
to root: of hundreds attempted, success was only
achieved with one. This was planted at Scotland
in November 1988. However, despite being kept
well mulched and carefully protected it
developed a die back of fungal origin. This tree
died in 1996 after a period of very wet weather
(the ground in which the olive as planted was a
heavy clay soil) and despite considerable
attempts to revive it.
The olive very rarely sets good seed as it is 99%
self-incompatible. Two seedlings were raised
and planted out at High Peak in 1984, although
they died while George Benjamin was away
from the island at Kew Gardens. Two further
seedlings were raised and planted out in George
Benjamin's garden at Pounceys. A third
seedling was planted out near to the main plant
at Scotland. This seedling was transplanted into
Taylors when the main tree died and its growth
was also severely impeded. A fourth seedling
was raised from the main tree and this was planted beside the third seedlings at Taylors.
The health of the smaller olive at Pounceys and
the two at Taylors declined and they were all
dead by 1999.
Only the larger seedling survived at Pounceys
and like the others showed signs of ill health due
to fungal infections. In 2003 this individual
deteriorated extremely quickly following a dry
winter. So much so that it is highly probable that
this beautiful endemic species will become
extinct. The only hope is that cuttings taken
from the last individual and sent to the Royal
Botanic Gardens, Kew in the UK will provide a
viable bud from which to grow on in
micropropagation.
The extinction of the St Helena Olive will be a
tragic loss to St Helena and the world. It is
taxonomically unique, it not only was a species
only found on St Helena and nowhere else but it
was the only species in a genus, a higher order
than species, that was totally unique to St
Helena. A beautiful tree who's majesty will
never again have an opportunity to grace the
ridges and inspire Islander's and visitors alike.
As we reflect on the Olive and the many other
species of critically endangered endemics we are
reminded of historic environmental
mis-management but also our ability to save
these acutely rare species is affected by our
continuing inability to provide continuity in
conservation. This in turn is a reflection of our
shrinking economy and the drain of human
resources who are leaving the Island in search of
prosperity elsewhere and ultimately on our
understanding of how economic development
and the environment are linked.
www.ascensionconservation.org.ac/Newsletters/Newsletter%202003%20Dec.pdf
