Diario del proyecto Gahnia Grove - Site summary and discussion

In the Arena, at the top where it was previously mown kikuyu.

Giant Swan plant
https://inaturalist.nz/observations/20939024

Apparently there's another species of Swan plant, with ovoid fruit/follicles. This new invasion could be either, at this stage, but is probably Gomphocarpus physocarpus, the species commonly observed in the neighbourhood.

We will probably never know for sure, as I don't intend to become responsible for monitoring its seed spread here by allowing it to grow to fruiting stage.

A small piece of Nahui was collected from a wild occurrence in a neighbouring street berm. After thorough ID on iNaturalist, it was cultivated till it formed a small patch with enough root development to survive in the arid ex-kikuyu margin of Gahnia Grove. Usually observed in wetlands, it has survived despite dry conditions that have so far restricted the germination or development of other plants to a few stunted Yorkshire fog, oxtongue and broad-leaved docks.

https://inaturalist.nz/observations/20445416

Hours of input - February subtotals:

Liaison 6 YTD 79.75
Community Liaison - 0 YTD -1.5

Monitoring/research - 22.75 YTD -194.75
Sitework- 5.75 YTD- 256.25

February total: 34.5 YTD Total: 532.25

(Site work includes Weed control, fire prevention, mulching for moisture retention, "tiptoe" path creation for habitat protection, onsite assessment and planning, and maintenance of amenity through optimal disposition of weed materials and mulch bordering mown kikuyu)

Total hours of manual Kikuyu margin control since establishment of narrow wood mulch strip and rope cordon in mid-January:
4.75 hrs, covering c. 40m dense mown kikuyu parallel to Glenfield Rd

(This does not include the different manual management of the kikuyu ipresent among mixed grasses, primarily Axonopus fissifolius and Paspalum dilatatum, along Gahnia Grove's East-West margin, ie down the slope beside informal foot entry to the grassed recreational area, bordering the Annexe and continuing along the manuka canopy margin)

A new weed invasion, a single sturdy stem of Swan Plant (Gomphocarpus spp.) is being monitored during full identification on iNaturalist, but believed to be Gomphocarpus physocarpus, (known in some countries as "Giant Swan plant") as that is the species prevalent in the neighbourhood. (Another species, G. fruticosus, has longer ovoid fruit/follicles with a tapered tip).

Its iNat Observation is here:
https://inaturalist.nz/observations/20939024
with discussion welcome here:
https://inaturalist.nz/projects/gahnia-grove-site-summary-and-discussion/journal/22160-a-new-weed-invasion-in-gahnia-grove

The single specimen of Nahui introduced into the ex-kikuyu margin is doing well, and expected to spread aggressively with the first rainfall. Being monitored for its interaction with shade and other native plants:
https://inaturalist.nz/projects/gahnia-grove-site-summary-and-discussion/journal/22159-nahui-introduced.
Any experiences or comments re the introduction of Nahui would be very welcome there.

No weed control was required in February, the kikuyu margin control being only for aesthetic reasons and to ensure no long grass was present in the event of a FireWatch season.

We look forward to selecting further among the plants that have arisen, looking for native seedlings and assessing the ongoing need for micro-canopy, as soon as there has been significant rain.

The pink, yellow and purple wildflower bee-heaven of the Arena and, more lately, Cape Honey Flower Bank, is drying and fading now, thankfully having made it through to the recent rain before more than a few were dry enough to need cutting or trampling down to avoid creating fire hazard.

So the first cull was done yesterday, of any benign exotic now limiting the growth of native seedlings. There are not a lot, but at least a few ti kouka and karamu seedlings can be found within a metre or two of most places.

A long-awaited delight, the task was to penetrate the exotic herb thickets enough to spot any new seedlings, to relocate earlier seedlings lost to view since about Christmas, and to reduce the herb cover just enough, while trying to keep the cover dense enough to continue doing what its been doing so wonderfully ie suppressing the docks and creeping buttercup, and keeping all the others in what must be balance, because most of the species that arose wild on the bare clay banks are still present.

The native seedlings discovered or rediscovered were released to partial light, along with some young carrot seedlings which will create only the lightest of canopies over a sjngle slender stem. Any areas of soil bared by this were mulched with branched herbaceous material that partially shades and retains moisture while leaving space beneath for germination.

4 or 5 Senecio seedlings to c. 2cmH were found in the moist shade of dense leafy benign exotics under the rescued ti kouka and karamu. They look like Esler's weed, and some wild seed was scattered in that area osometime during the summer, so hopefully they will prove to be this often overlooked native:
https://inaturalist.nz/observations/21108227

A couple of ladybird, or ladybird-like, species were seen for the first time. Perhaps the breaking of the drought encouraged their emergence as adults.

https://inaturalist.nz/observations?place_id=any&project_id=gahnia-grove-umbrella-project&subview=grid&taxon_id=48486&user_id=kaipatiki_naturewatch&verifiable=any

Bees are still abundant and , as throughout summer, especially thick in the midday warmth. The tiptoe-path down the middle of the Arena was finally cleared to create a gap about 50cm wide between walls of wildflowers, so it can be now be traversed even at midday when pollinator flight paths cross before one at every step.

https://inaturalist.nz/observations/21106188

[NB this report was on March 18th. Hundreds more seedlings were removed in the last 2 weeks of March, and continue in April]

Probably 100-200 brush wattle seedlings, only 5-20cmH so could have waited, as they are a little hard to pull while the ground is so dry, but most observed have been quickly grabbed while cutting or uprooting dried oxtongue and wild carrot. The wattle seedlings are mostly in groups of 5-10, probably reflecting fallen pods.

We presume there are no birds that spread the seed, which is without fruit or other obvious attraction? And they are too heavy to spread on the wind, except perhaps in high winds while hanging on the tree. Do the pods open explosively, with enough force to move them far?

Moth plant seedlings are fewer in number this month, but some of those found, mostly among dense exotic herbs, have been up to 20cmH. One was c.1mH, on the margin of the Flame Tree Zone and under the karamu and ti kouka where a mature vine was found last year. This one, among a pile of cut Cape Honey Flower wood, may have broken and will need further removal when it regrows, the wood has been moved, and the ground is wetter. Most of the others seemed to be entirely uprooted.

Two Swan plant seedlings, and one on the kikuyu margin under the Flame Tree, were being observed as a novelty, and to perhaps determine which species they are, but after a recent news item about the toxic sap having caused 6 months' blindness in a Whangarei man, we decided to remove them now while they are small.

Having always been careful to avoid contact with moth plant sap, we recently experienced our first plant sap incident, with half-an-hour's partial blindness at home after accidentally snapping a Harakeke stem, causing a splash into one eye, and a smaller splash - with smaller effect - in the other eye.

Eye-wash with sterile saline helped soothed the discomfort, but it was an hour before both eyes could tolerate light.

Mentioning this incident in conversation, another volunteer reported having had a 3cm blister on his leg after walking through a Bayview reserve, off-track, in shorts.

Another volunteer was reportedly hospitalized after accidentally disturbing a wasps' nest in a Bayview Reserve.

And I learned that I am not alone in having had an eye injury from a stick. The mesh safety goggles are proving comfortable and effective, though they would not prevent dust or sap.