First Progress Report - 5. to cordon a Tradescantia trial site

We have partially cordoned off a Tradescantia trial site to safeguard it from accidental trampling by public, volunteers or reserve users, and to make contractors aware of the Trial.

A pigtail cordon has been erected along 2 sides of the site so far:

-beside Kaipatiki Rd opposite Glenfield College Tennis Courts, under the canopy margin parallel to the mown-grass footpath , and

-beside the public footpath from the entry to the path to ValeCrest Place and to the "Native Plant Trail".
https://inaturalist.nz/observations/22911594
https://inaturalist.nz/observations/22911786

The 3rd side of the Trial site is cordoned only part of the way down a steeply sloping bank through dense forest understorey not likely to be accessed by the public. We have indicated this boundary in onsite meetings with Wildlands and Ventia path maintenance operations managers, and no difficulties are foreseen in keeping the Trial site free of conflicting interventions.

UPDATE: The area is to be marked with pigtail cordon when funds permit, and in the meantime is partially indicated by piles of Tradescantia removed from the streambanks to decompose in site, creating habitat and restoring soil health.

Spot-spraying of weeds by Ventia has been suspended in this area for the duration of this Trial.

The boundary between the revegetation area and the Native Plant Trail has been identified in principle, ie 1.2m wide and following the curving line of its original construction, with the onsite advice of the Auckland Council Parks Service Delivery Coordinator (SDC) and Ventia operations manager.

Our Trial site borders this path for about 65m, following the twists and turns of the path as it winds through dense lush streamside forest, including some areas where earlier revegetation has been lost through off-track walking, but can be restored with careful handweeding and improved path defjnition.

Weed-removal often facilitates and encourages pedestrian access to areas of existing or future revegetation, so that seedlings and small plants are destroyed and soil becomes compacted.

In the case of this Native Plant Trail, which no longer has a layer of permeable material and is also too uneven to walk on easily in some places due to erosion by constant runoff from the steep banks above combined with compaction by heavy footfalls in winter, there has also recently been a great deal of unauthorised cutting of vegetation by Reserve users, widening the bare area from a single c.1m wide planned and constructed path, to a bare and compacted area up to 2-3 m. Native plants arising in the borders are likely to be mistakenly perceived by Reserve users as weeds, and trampled or removed. Conversations with Reserve users over the years and currently indicate that perceived "weeds" include the intended native revegetation essential to the survival of the forest and stream, eg tree seedlings and juveniles, grasses (Oplismenus hirtellus supsp. imbecilis or "Basket grass", Microlaena spp) sedges, reeds and rushes, (Carex, Gahnia, Dianella, Schoenus), mosses, fungi, diverse native ferns and tree ferns and their sporelings, and Centella uniflora, a soft and compact groundcover currently abundant on the streambank where there is no path, but absent alongside of the Native Plant Trail.

To help define the borders of the path and restore compacted soil, we plan to place piles of decomposing tradescantia brought out of infested areas and moved uphill away from runoff, to restore soil health, habitat and the integrity of wild revegetation. The borders of the path in the two years after its construction naturally hosted diverse native trees, shrubs, vines, groundcovers, mosses, lichens and fungi, some of them locally uncommon or rare such as Fuchsia excorticata.

Under the large pine tree near the entry, the pine litter inhibits many species but hosts an interesting combination including some not seen elsewhere on the site. Under this 80-100 year old pine, tanekaha, pigeonwood, parsonsia, kanono, karamu, aruhe, hangehange, tree ferns, and mahoe, with kiekie, ti kouka, carex and ferns at the streamside, are accompanied by toropapa (Alseuosmia macrophylla), native orchids, and single specimens of petako and huruhuruwhenua in the root buttresses of the pine. There are few weeds due to the pine litter.

Several of the young toropapa observed over twenty years had grown to about a metre high at the base of the cutting beside the c.2.5m wide metalled path of the entry. In mid- March they were cut down, along with several aruhe, hangehange, and kanono, and Parsonsia, the clay bank left starkly bare and the freshly cut stems found tossed down a bank.

We hope to restore soil quality and re-establish the integrity of the pathside habitat throughout the approx. 60m width of our Trial site.

The cordon already holds small home-made signs explaining its purpose and providing contact numbers for the writer, Auckland Council, and Watercare (to encourage reporting of sewage overflows).

It could also be used to hang small interpretive signs identifying plants and features along the Trail, and the techniques used to protect them.

Posted on April 26, 2019 04:50 AM by kaipatiki_naturewatch