Cascade Wetland - Micro-site

Preparation

The Cascade Wetland micro-site just "happened".

During 2012, John Hodges was looking for areas to clear, to assist with the planting season.

Andrew Jinks had noticed that there was an open stream-bank area where little Cascade Creek passes under the Maara Roa track through a culvert.  The area was covered with two common weeds often seen around the board walk:

Stone Parsley seedlings (Sison amomum)

Stone Parsley seedlings (Sison amomum)

  • Stone Parsley (Sion amomum)
  • Monkey Musk (Mimulus moschatus)

These plants smothered the area, covering the stream and the silt that had built up in the middle of the stream bed. 

Prime area for wetland plants, which would, as they got established, help retain this rich moist soil.

John worked hard clearing the area of these and other weeds.

The result: a great micro-site for wetland plants, and the flax (Phormium tenax) we had in abundance.

First planting

The Cascade Wetland was first planted by Dawn and Andrew, with help from three Victoria University International Exchange Students in September 2012.  One of the students was experienced with re-vegetation planting.

Everyone worked hard that day, to get 165 plants in the ground.

Since then, Andrew has been there with Paul Guiniven to plant the kiekie, and some other plants.

A large number of plants left over from the end of the 2012 planting season were also planted, as due to the moist environment and the available shelter, the planting season could be extended there.

Andrew has also been experimenting with naturalised planting, where suitable plants are grouped together in associations, i.e. cabbage trees and flax (Cordyline and Phormium), etc.

He has also been planting the seedlings closer together, as would happen in a natural environment, so that hopefully, these plants would vie with each other, and thereby more quickly displace the weeds.

No harenet sleeves were used on the plants, but on a subsequent tree care day, Dawn and others did some weeding, and collars were placed around certain species:

  • kahikatea (Dacrycarpus dacryioides)
  • mingimingi / swamp comprosma (Coprosma propinqua)
  • cabbage trees (Cordyline)
  • nikau (Rhopalostylis sapida)
  • wharangi (Melicope ternata)
  • tree fuchsia (Fuchsia excorticata)

Rabbits have unfortunately damaged some plants, swamp comprosma (Coprosma propinqua) taking the brunt.  All plants of these species have now received collars.

Andrew has been back to the area to weed the profuse natural re-seeding: he calls this "robbing the seed bank" (seed that lay viable in the soil).  Depending on the species this could go on for a while.

Early in 2013, Andrew is confident that the area is well on the way to looking after itself.

Progress by October 2013

Since planting over a year ago, many of the plants have done very well.

The lower area is now smothered with the plantings.  Fuchsia, Schefflera (seven finger), and the grasses, have out competed the weeds here.  Both these tree species have reached 2m, and considering they were 15cm when planted, they have exceeded expectations. (See the pink tag in the photo gallery image of the Schefflera.)

The Carex "Island" has sprouted to smother the area.  It is excluding the weeds, and still spreading.  The carex sp. have done well along the stream edge.

The Phormium (flax) have grown well, though the flax swamp has developed more slowly as this area has been under water in the floods we have had since planting.  Loses have been minimal.

The Cordyline (cabbage trees), and Coprosma planted there had been browsed by rabbits.  This stopped when first chili powder, then Treepel was applied. Treepel stops pests browsing when it's sprayed on plants.  More Coprosma propinqua were planted, but there is still a problem with weeds in the area where there is little in the way of competitive native species yet.

Inspite of the problems of browsing, flooding, and weeds, there are lots of native seedlings popping up: Tawa, Pennantia (kaikomako), Dysoxylum (kohekohe), lots of Coprosma, Melicytus (whiteywood / mahoe), and Macropiper (kawakawa).  There are also a lot of young ferns where the weeds have been controlled.

November 2012


January 2013


October 2013

Cascade Wetland - Fuchsia excorticata (tree fuchsia / kotukutuku) - has reached 2m - was only 15cm when planted - October 2013.

Fuchsia

Cascade Wetland - Schefflera digitata (seven finger / pate) - has reached 2m - was only 15cm when planted (see the pink tag on stake - that's knee-high) - October 2013.

Schefflera

Cascade Wetland - Carex lessoniana (cutty grass / rautahi) - has sprouted to smother the area, excluding the weeds and spreading - October 2013.

Carex "Island"

Cascade Wetland - Phormium (flax) - has developed more slowly as this area has been under water in the floods we've had since planting - October 2013.

Flax

Cascade Wetland - Photo shows seedling flax (Phormium tenax) at top, seedling fuchsia (Fuchsia excorticata) on left, and ferns - inspite of the problems of rabbit browsing, flooding, and weeds, there are lots of native seedlings and young ferns popping up - October 2013.

Seedlings


List of plants

The plants in the area are mostly tolerant of wet soil, though there were places where less wet-tolerant species could be planted.

Well over 500 plants have been put in, and many have done really well.

The Carex is a great soil stabilizer in this environment, and has already begun to cover up the stream edge.

Planted:

  • 100x flax (Phormium tenax)
  • 100x cabbage tree (Cordyline australis)
  • 60x swamp coprosma (Coprosma propinqua)
  • 57x nikau (Rhopalstylis sapida)
  • 40x cutty grass (Carex lessoniana)
  • 40x giant umbrella sedge / coastal cutty grass (Cyperus ustulatus) - more of a coastal species
  • 40x blueberry / inkberry (Dianella nigra) - on dry slopes
  • 35x NZ iris (Libertia grandifolia) - on dry slopes
  • 17x kahikatea (Darcrycarpus dacryioides)
  • 16x bush lily (Astelia fragrans)
  • 20x coprosma (Coprosma grandifolia) - in less wet area
  • 15x wharangi (Melicope ternata) - in less wet area
  • 10x pate / seven finger (Schefflera digitata)
  • 7x tree fuchsia (Fuchsia excorticata) - some of these have trebled in height!

Also planted were:

  • some kawakawa (Macropiper excelsum)
  • a kiekie (Freycinetia banksii)
  • a rough tree fern (Dicksonia squarrosa)

Also refer to our What we plant and protect page.