Ivy Invading the Trees of Kaipatiki's Journal

We saw an Observation this morning noting an ivy invasion at Horseshoe Lake, Burwood, Christchurch.

We have been wondering if our own neighbourhood is particularly badly affected and our own forest unusually at risk due to its proxikmity to so many and such large ivy invasions around housing.

It would be very interesting to hear of other neighbourhoods and habitats affected by ivy.

And is there any "good side" to an ivy invasion? Are there any vulnerable habitats protected by ivy from trampling by people or animals, fauna loss from predators, perhaps plant loss through erosion ?

https://inaturalist.nz/observations/13169836
Mature trees have been observed to die AFTER a large amount of ivy cover was removed. Ivy stems have tiny roots throughout, grasping and appearing to penetrate the bark throughout the surface of the tree trunk, at least on some species like ti kouka.
How will this nikau fare, even if the ivy is ever killed?

And here is the oak tree on which the invasion was partially controlled in June 2018 with chemical herbicide:
https://inaturalist.nz/observations/13780972

I read a US forum thread about common ivy once. I've never forgotten this salient cobservation: A homeowner controls it for 20 years, then gets too old to do so, the ivy gets out of control, the house is sold, eventually the new tenant realises its a problem and does a massive cutback....and so on and on.

...but perhaps we have an even greater problem here with the spread of seedlings and their occult development, both in "gardens", many of which nowadays are rarely tended or even observed by either tenant owner, and in forests and other native habitats.

As with other invasive plants, in landscaped parks ivy is often "maintained" (for better or worse), ie intermittently pruned to stop it actually damaging buildings or obstructing access.

Natural urban "reserves", however, having been inherited by various successive "management" bodies as a liability, and not being seen as of economic value, have no surveying or maintenance budget.

But perhaps roadsides and uncultivated farmland and bush pockets are just as much at risk. Not getting out in the countryside myself, I don't know.

Recent observations of the number and size of both new and old ivy invasions locally are most alarming. It appears that, without comprehensive and urgent intervention, in 20-30 years many of this area's present trees, a breeding-site for kereru and part of or near to the largest native forest in the Auckland area, will have fallen from ivy invasion.

There is no regular monitoring or control of Ivy in Kaipatiki Reserves, and there was no reported intervention regarding the ivy said to have killed a Heritage Rimu in Hiwihau Place.

We are attempting to either alleviate or communicate our concerns through encouraging and reporting the observation of occurrences of Ivy, of any species, in the Kaipatiki area.

The leaves of Common Ivy can take several different forms, and are often unrecognised, especially the fruiting branches which throughout Autumn 2018 provided copious food to birds - and thus copious new invasions of the seedlings which generally develop unnoticed in mulch, leaf litter, or soil, under trees and shrubs, along fences and walls, in street berms, borders, gardens and reserves, before eventually climbing the nearest tree, fence or wall. Once they reach a wall or tree they can progress slowly but inevitably to a height of at least 12m.

At this stage the damage to tree health and/or property is likely to be extensive and costly. An invaded tree, though recently apparently healthy, is likely to die even with immediate removal of the ivy.