Expanding the restoration site
Paul, an experienced restoration contractor/biosecurity management student with some experience of staged, site-based (rather than species-based) manual control has spent 4 hours on the site, assisting with the weed-control according to the methodology being trialled. He has been contracted for 20 more hours over the next 10 weeks, so we will be extending the weeding as far throughout the canopy as time allows, removing pampas, grasses, Watsonia, Elaeagnus, cotoneaster and ginger and other weeds as encountered.
Plant ID
With Paul's eyes on-site, some additional plant identification was done, including confirming a suspected, apparently isolated invasion of Polygala myrtifolia (2 specimens here, none observed elsewhere in the reserve so far). The seedlings were under canopy, spindly, and had not grown perceptibly since first observation 6 months ago. They were removed.
https://inaturalist.nz/observations/13730071
https://inaturalist.nz/observations/14035171
iNat had already helped , leading to a suspected ID but the plant could not be removed until this was confirmed, in case it was a native not kown to me. So it was a relief to have this confirmed and not have to let the plants mature to flowering for an iNat ID.
Gahnia Grove
The arena was cleared of its areas of mulch, which was composed of the mixed kikuyu and Japanese honeysuckle that had previously covered the area. The live honeysuckle and balckberry roots revealed were pulled out.
Removal of mulch also allowed the Calystegia to be broken off at ground level from these areas, as had already been done in the rst of the arena, and along the canopy margin. The soil in the unshaded arena is now too dry for significant amounts of underground runner to be uplifted with the leafy stems, so follow up on the Calystegia will be required regularly through the summer. It is an easy weed to remove (above ground), but kills small trees by occluding all light, and can also pull trees c.1.5m H to an almost horizontal position as it grows over the top of them then fastens itself to something on the other side.
Kikuyu was just long enough for a modest "pullback" the length of the arna-kikuyu margin, and a few places along the outer planting.
The big pampas in the Annexe planting, having been reduced by cutting and pulling down to about 1m H, received a good trampling to aid its decline.
Smaller pampas in the canopy were trampled or pulled out, along with a few honeysuckle runners recently emerged.
An assessment was made of Cape Honey Flower (CHF) Bank, strategies to control the honeysuckle, blackberry and CHF there, and the need to avoid baring a great area of clay to summer sun. Since there is no expectation of contractor assistance after December, and this steep unstable bank is physically challenging, the strategy used will have to avoid leaving plant material on top of live honeysuckle, making it more difficult to access for control. However, the blackberry would probably weaken with being mulched over.
The challenge will be to work with these three densely interwoven weeds to
- access and release the few native trees on the bank from honeysuckle (increasing canopy),
- reduce the density of CHF and limit their further spread, and
- eradicate, if possible, the blackberry
and in the process to
- create areas where native regeneration can occur, while
- minimising increased sun exposure.
The CHF trunks are light and make good movable mulch, but if dropped on top of honeysuckle would require removal later - to be avoided. It may be possible to use the CHF wood as a moisture-retaining mulch down the side of the bank, adjoining the Arena, where it will be possible to access it if needed to control the vines.
Update: Re whether CHF is a nectar supply for birds, and how it spreads:
http://www.terrain.net.nz/friends-of-te-henui-group/weeds-by-scientific-names/melianthus-major-cape-honey-flower.html
So we can remove all flowering parts at no cost to birds, (who might in fact be poisoned by it).
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