Pukaha
Mount Bruce is involved in recovery work for a regionally
threatened shrub, Teucridium parvifolium, a nationally
endangered tree, Pittosporum obcordatum and a critically
endangered tree, Olearia gardneri. These plants are growing
in the park and can be pointed out by staff. Seeds and
/ or cuttings are collected from wild populations of these
species and are grown to establish breeding populations.
This acts as an insurance policy if the wild plants are
lost. When seed is produced on the plants at Mt Bruce,
it can be collected and propagated. The seedlings will
be planted back in the wild to bolster the original populations.
This is essentially the same approach that we use in many
of our bird breeding programmes. Our ultimate goal is
to ensure the survival of natural wild populations.
Teucridium
parvifolium
|
| The
endangered Teucridium parviflorium when walking through
the national Wildlife Centre. |
Visitors
can see the rare Teucridium parviflorium when walking through
the National Wildlife Centre. Teucridium parvifolium This
shrub is found only in New Zealand, living in forest margins
on fertile river terraces and alluvial lowlands such as
those found in the Wairarapa. Although widespread in the
South Island, it is now known from only a few sites in the
North Island. Careful searching in the Wairarapa over the
past years has found a number of new plants. Teucridium
parvifolium has declined because of the destruction of forest
in fertile lowland areas of New Zealand. As a result, fragmented
populations survive in the few suitable areas of forest
that remain. These areas are highly vulnerable to impact
from browsing by introduced animals (eg goats, cattle, deer
and possums) smothering by weeds (eg wandering jew) and
habitat modification by humans.This shrub is found only
in New Zealand, living in forest margins on fertile river
terraces and alluvial lowlands such as those found in the
Wairarapa. Although widespread in the South Island, it is
now known from only a few sites in the North Island.
More
about this plant...
 |
O
gardneri leaves |
Pittosporum obcordatum
Regionally,
this species is extremely threatened, and is ranked as a
Nationally Endangered species with only a small number of
populations known . The fact that the male and female flowers
are on different trees means that the opportunity for seed
production only exists when plants are growing close together.
Once
our plants are mature and suitable locations found in
the wild seed will be gathered as part of a programme
to return this plant to the wild.
More
about this plant...
Olearia
gardneri
|
O
gardneri seedling |
With less than 160 trees left, this species is one of the
rarest in the country. Its favourite habitat was among the
first to be cleared, and this plant, whose distribution
was probably always patchy, has been reduced to a few scattered
locations.The NWC hold plants which were grown from one
of these sites, as an insurance against the death of the
parent plants and to provide seed for the eventual return
of the species to the wild.
Olearia
gardneri is endemic to the southern half of New Zealand's
North Island. It has a conservation status of Nationally
Critical. This reflects its small and fragmented populations,
poor regeneration, the patchy and mostly grazed nature
of the habitat, weed infestations and the fact that most
known plants are growing on unprotected land.
The
total number of plants known to be growing naturally in
the wild is 159. This makes O. gardneri the third-rarest
native tree in New Zealand. Olearia gardneri is associated
with podocarp-broadleaved forest Olearia gardneri is more
likely to be found on valley floors or lower side slopes
(as opposed to ridges); on the edges of forest rather
than the interior (but is occasionally found in canopy
gaps); close to small streams, especially where there
is a 1.3 m bank; on seasonally dripping mudstone slopes;
and in places where other threatened or disjunct tree
or shrub species have been found. It was found most frequently
on sites with past natural disturbance and probably high
fertility. Most were on forest margins or in light gaps
in forest. Sometimes near O. gardneri were land-slips
that probably occurred within the last 5 years.
In
the Wairarapa, the Kaumingi Stream catchment had shrubs
on stream banks within the flood zone. Although river
banks seem to offer some suitable habitat for seedlings
to establish, and some other native shrub and tree species
grow within the flood zones of the rivers and large streams,
the rarity of O. gardneri in such sites suggests that
it does not cope well with flood events. Mudstone hillslopes
with O. gardneri are seasonally wet with running water,
but the species was not found in places where standing
water occurs for any length of time. Though the range
of O. gardneri overlaps with that of Pittosporum obcordatum
and Coprosma pedicellata, the Olearia does not grow in
the seasonally waterlogged sites occupied by these other
species.
Most
adult O. gardneri are to be found on forest margins or in
gaps, growing on the forest margin, or a metre or so beyond
the margin in pasture, or just inside the forest edge with
part, or all, of its crown in a light gap. The present-day
forest margin is almost always the result of forest clearing
for farming and it is hard to envisage where O. gardneri
fitted into the pre-farming landscape. Ages of specimens
from the Hautapu Valley showed them all to be under 100
years of age indicating that they established after the
forest had been reduced to patches.
More
about this plant....
Brachyglottis
kirkii (kohuhurangi, kohukohurangi)
 |
Brachyglottis
kirki |
This plant has recently been seen for the first time in
the Pukaha Mount Bruce forest. It is a highly palatable
shrub, much reduced by possums and goats. Control of these
pests now gives this species a chance to flourish. Within
New Zealand the plant it is ranked as a species in serious
decline, while in the Wellington region it is regarded as
critically endangered.
Brachyglottis
kirkii grows to 1.5 metres tall, but is usually found
high in the crowns of the tall trees, among the epiphyte
gardens. Without a powerful pair of binoculars it is often
difficult to see, even in the spring when its large bunches
of white daisy flowers are open. These are followed by
the typical windborne dairy seeds.
Sometimes,
as with this plant, Brachyglottis kirkii descends to the
ground and grows as a member of the shrub community.
More
about this plant....
The
Plant Conservation Network website...
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