kaipatiki_naturewatch's Journal

Restoration and conservation are the most delightful undertakings imaginable. It gives the utmost joy to pass the hours in a place of great beauty or great potential, using one's wits and body to work towards an increase in the good things one sees or has seen, and to reduce the bad things.

The outcome, however, is not always what we envisaged. It takes several years, sometimes twenty, to assess the full impact of people coming into a natural area, and the flow-on effects of increased numan activity, however well-intentioned or appreciative of the surroundings.

My experience and observation suggest weed control will result in loss of native species and habitat unless it is slow, careful and based on:

a) thorough plant identification and assessment of actual and future impact of weeds both positive and negative

b) careful staging of weed reduction

c) knowledge of manual techniques necessary to avoid chemical contamination of soil, plants, fauna incl. freshwater life and land invertebrates

(Google the effects of the breakdown products of poisons, not just the poisons themselves, some of which reportedly break down quickly in soil. water etc. The breakdown products of some popular herbicides are mobile in soil and water, and have been reported to be taken up by other plants and organisms over far greater area; in fact the extent of uptake appears to be unknown).

Any proposals to make or "upgrade" public access, paths etc, or to address weed invasion, must be met with vigorous scrutiny and undertakings to

a) provide a non-destructive surface (ie no loose metal or plastic)

b) clearly and actively prohibit channelling of water off the land into waterways or reticulation, (eg by rutting of trodden clay without organic swale above it, or by piping of runoff into the stream or reticulation to elsewhere)

c) avoid increased runoff due to removal of weeds without replacement ground cover, rearranging forest floor debris or other vegetation; instead, ensure retention of even small amounts of debris, by placing sticks, fallen fern fronds etc transversely across slopes, directing the path of droplets across the slope instead of downhill, allowing time for more water to be absorbed before running off.

Fortunately, it appears that the recent Indian Dipole effect that contributed to Australian and NZ drought in the last few years is ending, or ended:
https://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=12299203
These Dipole events have not apparently been recognised and recorded over a long history, but are reported to have occurred with increased frequency in the last decade or two, and are predicted to occur more frequently with global warming.

Though the recent Diplole event may have concluded, the Auckland drought persists and "The New Zealand Drought Index (NZDI) shows that meteorological drought and severe meteorological drought remain in place across parts of the Coromandel Peninsula and a small part of northern Auckland."

https://niwa.co.nz/news/hotspot-watch-1-may-2020

Confirmation of our observations in Gahnia Grove, where the impact of the drought is visible and tangible, particularly because of itstreeless, roadside ridge-top situation. Temperatures recorded by our camera on the ridge and specifically at the treeless bank top of Gahnia Grove's Arena and CHF banks, have confirmed our formerly untested pperception that this ridge is several degrees than streets a few hundred metres away, and the kikuyu at the top of Gahnia Grove is several degrees hotter hotter than Rimu Ridge, ie 50-100m down the road on the same Northern aspect of this East/West facing ridge.

The light intensity and angle change throughout the day, so that leaf litter under trees in a cool shady spot at 10am can be hot to the touch at 2 or 3pm.

None of this is surprising, but land managers need to be aware of the conditions being experienced in this location, to take into account the extreme stress currently experienced by vegetation, and likely unprecedented impacts of works impacting soil and plant hydration, eg the planned removal of the large stand of Flame Trees, the source of a growing invasion down the adjoining forest, but also the most significant source of shade along this ridge in summer, at a gullyhead with a streamside plant community.