Oral Submission Presentation by Blake Foster - New Zealand ...

homestead trees (but they were also present further north on the lake shore – removed
some years ago – G. Seymour, pers comm).
It is very likely that most of the contorta wildings currently on Ferintosh and the
northern half of Pukaki Downs originated from the ‘mistake’ plantings established on
‘LINZ’ land by the lake shore in the mid 1970s . The contorta wildings on the southern
half of Pukaki Downs most probably established from seed blown from the older and
much denser lake-side stands of contorta pine growing closer to the homestead – along
the eastern lakeshore margins of block 32.
1980s. Apart from fringe spread alongside the wilding forests by the eastern
lakeshore margins of block 32 (in the south-eastern part of Pukaki Downs), wilding trees
in the 1980s would not have been very apparent to those not deliberately looking for them.
One has to look fairly hard at 1986 aerial photographs to see evidence of wildings.
Although the older lake-side forests close to the homestead are obvious, 10-year old
plantations on LINZ land north of the northern boundary can only just be seen. Just a
kilometre or so further north again, a closer inspection of the photo reveals scattered trees
(most likely contorta pine) along the lakeshore south of Big Rock Stream, plus a few
outlier trees with small downwind (S side) areas of fringe spread at the top of blocks 16
and 24. Even closer inspection can just detect the odd lone tree in the northern parts of
the middle terrace flats, the most obvious of the larger ones looking like larch – both on
the flats and the steep scarp slope running up onto the Little Rhoboro Hills.
1990s. During this decade, the major battles with wilding spread were waged in the
south eastern part of the property (block 32) along the western margins of the lakeshore
wilding forests – although higher sheep numbers meant that there was not much new
recruitment of wildings at that time. Plantings of less spread-prone ponderosa and
Douglas-fir were carried out along these forest margins, probably in order to restrict this
fringe spread. It appears that during the 1980s and 90s some seed from these contorta
stands blew over SH80 in a south-westerly direction to give rise to the denser wilding
stands in blocks 9 and 10, west of the airstrip, not far above the Rhoboro Downs
boundary.
Elsewhere on the station, wilding trees were still not obvious - an NL slide (from the
air) of the Big Rock Creek stream area (top of blocks 16 and 24) taken in 1990, shows
very few conifers – although two have discernable fringe spread. However, it was in this
decade that the foundations were laid for the later major advance of wildings elsewhere
on the property. Many of the older scattered trees which were seen (and found felled) all
over Pukaki Downs, particularly in the north and western parts (and out onto neighbouring
DOC land) can be aged back to an arrival date around 15-20 years ago – indicating that
they arrived in the early 1990s. Even though they would have been present as small
seedlings, there is no sign of these trees in an NL slide taken in the Twizel catchment in
1993, when the present owner was showing the area to forest company representatives
looking for afforestation opportunities. As stated above, all the evidence points to these
outlier wildings having established from seed disseminated from the MOWD lakeside
contorta ‘mistake’ plantings established in the early/mid 1970s. The fact that they are
widely scattered out to a distance of 10kms indicates that the seed was lifted high before
dropping in a widely scattered ‘salt and pepper-like’ distribution. The wind carrying the
seed must have had more of a north-easterly flow than usual, as some were carried right
‘around the corner’ of the Rhoboro Hills (over the Little Rhoboro Hills ridge) and up into
the junction area of the Duncan and Mackenzie Streams (the topmost tributaries of the
Twizel River). Such a wind-flow pattern is different from the normal prevailing nor-west
winds (see ‘2000s on’ below). It is these trees which have given arise to the very obvious
‘islands’ of fringe spread (often between 500 – 1000 m 2 in size), currently aged around 5-6
years old (and just starting to cone). The majority of the scattered outlier parent wilding
trees were removed between 2004-2008, but not before they had produced viable seed
and initiated the present islands of 5-6 year olds. In the upper Twizel river area there is
one major exception to the wilding origin being the Lake Pukaki shoreline plantings. This
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