Saturday, May 27, 2017

Lacebarks do the trick

Silk cover over the Puriri Moth Caterpillar hole
Mangaiti Gully Restoration Trust is an innovative, progressive Trust that is pushing conventional boundaries in urban restoration.  This means enhancing the environment within the gully system to take the negative pressure off the native fauna (birds, invertebrates, reptiles and fish) which urbanisation invariable brings.

Selective and targeted planting is one way to achieve this. An example is the Puriri Moth. An impressive native moth that is the largest native in NZ with a wing span of 150mm. Their caterpillar bore into the trunks of Grey Willow and Privet when native species are absent. If these are removed during weed clearing our native moth is also removed. To manage this, extensive planting of a native substitutes like Lace Bark is being done. This winter 62 Lace barks that we grew from seed have been planted in the latest cleared area. These grow relatively fast giving good early canopy cover which helps to shade out sun loving weeds.

Adult Puriri Moth

Red and Yellow Admiral Butterflies

Red Admiral
Progress is being made to reintroduce Red Admiral butter flies to the gully. We have propagated a number the nettle plants that they require for breeding. We are fencing off an out-of-the way area for the nettle and there will be signage on the fence to warning people that touching the plants will cause an unpleasant irritation.

Yellow Admiral
We have identified a river bank on the Hauraki plans that has nettle and Red Admirable butterflies. This will be the source of stock once our nettle plants are established. Yellow admirals are already present in the gully so we are looking forward for their population to increase.

New track being constructed

One of the things Paul Duffy from Hamilton City Council (now works for Auckland Council) said when we first started this project was, "don’t have the tracks going in a straight line. It is much more interesting to meander through the bush". We have started to push through another track into a new planting area and with Paul advice put curves in it. It does look impressive.

Working with continual threats

Rainbow Skink
There always seems to be some threat to our restoration programme in an urban location. There is the perennial rat and possum invasion to control. Now we have Rainbow skinks, an invasive species from Australia that is common in some areas of Hamilton and is being easily spread. One of our team members purchased to load of firewood and found one among the wood. The Rainbows are prolific breeders out breeding our native Copper Skinks.   

Giant Willow Apids
Then there is the Giant Willow aphid which arrived a couple of years ago, which in its self does not attack our native trees but in our gully produce so much honey dew that the understory of natives got covered in black mould  cutting off, or heavily restricting, the understory plants ability to photosynthesise. We are poisoning the willows but that is a big job that we cannot do all at once. 

 Myrtle Rust

Now it looks as though we will have to contend with Myrtle Rust in the near future.

Book review

The Song of the Dodo Island Biogeography in an Age of Extinction
By David Quammen
A Scribner 1996 publication
This brilliant, easy to read book is about the unravelling ecosystems, ecosystem decay and about evolution and extinction. David Quammen travels the earth visiting islands and reserves where science is being done on the environmental pressures, predominantly from humans, that is driving many species into extinction. While the ecosystem decay does dominate this book, running parallel is his investigation and documentation of how species evolved in the first place, with the main focus on the animal evolution on isolated islands – island biogeography. There is interesting discussion on the Wallace line that divides Indonesia into two separate evolutionary segments with Asian fauna on one side and the Australian fauna on the other.  He follows Alfred Wallace’s adventures that led to this discovery in 1859 and the lead up to Darwin’s publication of the Origin of Species. 
While the subject could be pretty heavy going to read, Quammen has scripted it is such a way that it flows well into a “hard to put down” book. All 625 pages of it. This book is brilliant. It’s so good it is the only book I have ever started to read a second time and still enormously enjoy reading. 
David Quammen is a two-time National Magazine Award winner for his science essays and other work in Outside magazine. The author of three novels and several other books, he is the recipient of an Academy award in literature from the American Academy of Arts and Letters. 

Plant barrow

The advantage of being part of a team is that you get a variety of talents. The standard wheel barrow is not really that suitable for carting plants around so one of team members built a platform on a wheel barrow base specially designed to carry pants. It works a treat and carries three time more than a standard barrow.