Japanese honeysuckle control in Gahnia Grove June 2019-20

There is still the occasional regrowth of small roots in the clay bank near the top of CHF Bank, with more and thicker vines on FTZ Bank. This is expected, as weed control did not reach these areas till Oct-Dec 2018, and was not done as extensively on FTZ Bank as it had only been accessed once, by the contractor assigened to assist us for a few hours in this heavy work on a steep bank, and because arborism was expected for the Flame Trees.

The dense deep Tradescantia has made ongoing extension of control relatively easy, with semi-rotted roots being uplifted successively as the Trad mulch piles are moved around.

This process is likely to be successful in eradicating the remainder of the honeysuckle from FTZ Bank, but thereafter there is a vast honeysuckle invasion covering many mature and juvenile native trees, from the kikuyu margin to an unknown point down the steep bank of what appears in satellite view to be a gully head, with two separate run off channels meeting near the top forest Path ("Kauri Path") below.

Mature trees affected include puriri, titoko, karo, ti kouka, tarata, Pseudopanax and manuka, with juveniles of the same species, as well as kanono and kauri, either already dead or hidden, or facing total light exclusion by the end of this summer (based on the progress of this invasion observed over the last year).

Moth plant and Madeira are also present in the honeysuckle, and a large area of Palmgrass is hidden behind it.

Aiming to save as much as possible of this valuable habitat and the birds and other life they support, we have been releasing the nearest trees progressively, so far having released three ti kouka (possibly trunks of the same tree), a horizontal tarata and almost horizontal puahou, two puriri, a mature manuka and karamu which may not survive, several manuka, ti kouka and karamu which are unlikely to survive, and a number of dead trunks and branches of unidentified species.

Since the honeysuckle and moth plant are now reaching older trees on the bank below through the canopy alone, there is no way to control the vine from the ground beneath these trees, so the invasion will proceed through the canopy until cut off at all points where it is rooted.

We have spent a few hours cutting as much as possible to help disclose the remaining live vines, but have only scratched the surface. It remains to be seen whether we will find time to extend this release of trees.

Here are some observations, as seen from the top of the bank, of the honeysuckle zone.

Publicado el 21 de agosto de 2019 a las 08:39 AM por kaipatiki_naturewatch