I have been actively managing the only Alepis flavida plants known in the lower North Island; eight plants on three black beech trees in a remote part of Wairarapa called Ngahape.
Of these eight plants, six were in a large beech in serious decline and the remaining two plants on trees at possible risk from being undercut and toppled by the Kaiwhata River.
In 2009, these trees were protected by a Life of the Trees covenant plus an area of possible host trees also vulnerable to 100 year floods.
A further open space covenant over a small patch of remnant forest was also made with the intention of restoration planting and establishing a relatively flood-safer area with local black beech introduced on the edges.
Above: Yellow mistletoe Alepis flavida protected by a QEII covenant in the Wairarapa.
It was also important that new populations of A. flavida were established in other locations.
In 2007, I harvested 105 seeds and succeeded in getting one new plant established at the home site and two new plants on black beech at another site getting year-round quality pest control for possums and rats.
One of these subsequently suffered some invertebrate browse and, as so often happens, disease then took hold and the young plant died leaf by leaf.
I have observed this many times over the last 19 years that I have worked with Peraxilla tetrapetula and to a lesser extent Peraxilla colensoi in the Tararua Ranges.
We blame possums for mistletoe decline, and the lack of pollinators in forests ravaged by exotic predators, but some of our best specimen plants exist outside any Tb control area. There is much more to mistletoe decline than possums.
Above: Trevor checking the germination of mistletoe seeds. The bands on the beech indicate where seeds have been planted.
Rat and possum control using Pindone and protection from stock when new owners took over still saw some serious browse occur, mainly from deer, so more fencing was erected but the plants produced only a very small quantity of seed. No new plants are known from the 2008 fruiting year.
In 2009, partly due to a rest from browse and probably because of a bumper year of fruit being due cyclically, over 500 seed were harvested.
The trees at the Ngahape site were saturated with seed. The two sites identified as the only areas in the Wairarapa having year-round quality pest control were also given significant planting on suitable trees.
Results from this year’s planting are still coming in but marked seed at the Ngahape site show 30% are still attached to the host tree and have root contact with the host.
Many years of planting Peraxilla taught me that only when four or more true leaves are present can some long-term establishment hope for the new plant be assumed.
Above: Alepis flavida flowers in February 2009.
Above: Alepis flavida berries
The black beech with six of the eight plants was in serious decline. In big winds on 28 August 2009, this tree snapped off close to the ground.
On examining the trunk, there was very little sound wood holding the tree up.
The big effort to protect and artificially plant every seed produced in the three years I have managed this project means all is not yet lost.
One plant that produces a small amount of seed remains, with another high in the canopy that has not produced seed in the past.
It will take at least six years (and quite possibly 10 years) for any of the planted seed to produce seed if no setbacks occur.
Left: With Biodiversity Condition Funding, the mistletoe restoration project includes constructing new fencing and transplanting beech seedlings from local areas to increase the number of host trees.
As a point of interest, though Alepis flavida was known historically from this area, no one had ever approached local people to ask if they had seen anything unusual.
If they had, the landowner could have shown them the plants 10 years earlier and we would now be in a less difficult situation.
The same Ngahape property also has Tupaia antarctica growing on tree lucerne in the back garden and just down the road, there is totara with plenty of Illeostylis micranthus, so this is heaven for a mistletoe nut like me.
This article was originally published in Trilepidea, Newsletter of the New Zealand Plant Conservation Network, No 71. October 2009
Photos: Trevor Thompson and Kerri Lukis