Monday, December 2, 2013

Beach Trees

Silver beech on the Wilmot Pass road

It’s hard to think about Fiordland without Beech forest coming to mind.  Southland has several main forest types – plantation forests which are pine and eucalypt, lowland podocarp forest dominated by kamahi, rata, rimu and miro, and beech forest.  Beech forest can be almost a monoculture and there are great swathes of forest which are just Mountain beech and little else. Beech comes away readily after disturbance such as fire or bulldozing and the growing seedlings form a dense crop which allows nothing to grow beneath.  Although 99% of the seedlings die, the solid canopy allows little light to enter.

 The entrance to the Borland Lodge Nature Walk is an example of this.     The land was cleared for farming perhaps 60 years ago and reverted first to scrub then beech as the numerous seedlings overtopped the bracken.  The trees are a uniform age, form a dense canopy and deer have effectively stopped palatable species growing beneath.  At first glance there is little there apart from beech seedlings and moss.  In reality beech forests host some of our best fungi, three species of mistletoe, numerous insects, spiders and orchids and a range of native and introduced birds. 

New Zealand has five native beeches.  Hard beech is a North Island species extending through the Marlborough area and down the West Coast.  Red beech is our tallest native flowering plant, seen at its best on the Milord Road.  Silver beech is a higher altitude species and Mountain beech is probably the commonest.  Red beech reaches its southern limit somewhere north of Lake Monowai.  The fifth species is Black beech from the top of the South Island.  It is similar to Mountain beech but has oblong leaves with more obvious venation although some trees seem to have the foliage of both species.  Red beech and Silver beech have toothed leaves, Mountain beech and Black beech have small untoothed leaves and Hard beech has bluntly toothed leaves.

a Mountain beech in flower

For those who have managed to remember the Latin names – Nothofagus menziesii, N. fusca and N. cliffortioides for Silver, Red and Mountain beech respectively – guess what?  Some scoundrel of a taxonomist has done away with Nothofagus and replaced it with Fuscospora fusca for Red Beech, Fuscospora cliffortioides for Mountain beech and Lophozonia menziesii for Silver beech.

Red beech reaches about 40m.  There are some very impressive ones on the Cascade Creek nature walk at Lake Gunn.  I saw what could be the record for a Silver beech last weekend when the Fieldclub had a hike in to Deep Cove from Lake Manapouri.  There is a very gnarled and impressive example on the roadside not far from Mica Burn.  I measured it at about thirteen metres girth, making it rather larger than the Motu Totara in the Dean Forest.  It was dripping with epiphytes.

Beech trees have been extensively milled for boards, furniture, brush handles and joinery where it is known in the timber trade as Maple beech.  The Beechmark website says, “Beech creates a modern, lovely warm look.  It is a sustainably harvested New Zealand native and can be used as an alternative to Rimu, Matai and Kauri.”

Beech trees grow readily from seedlings in the garden but be aware that it never stops growing so what might be an attractive sapling at five years may be a monster in 30 years, dominating your section.  For some truly impressive beeches, check out the European beeches in Hagley Park in Christchurch.  These northern hemisphere ones are deciduous in contract to the natives which lose only about a third of their leaves annually.  There is a collection of foreign ones in the Alex McKenzie arboretum at Otautau.

Sunday, August 11, 2013


Red Admiral

The sight of a Red Admiral the other day reminded me that I was going to ask for unusual butterfly sightings over the spring and summer.  Red and Yellow admirals are around for much of the year, there is the odd one over winter.  They fly fast and settle on flowers, especially Buddleia, and their food plants which are several species of nettles.  I think they are in decline owing to the loss of nettles and the effects of the tiny wasp parasites introduced to take care of the White butterfly menace.

  The White butterfly has been around for 70 years, the parasites help but they attack other butterflies as well.  There is a new butterfly getting established in the north of the South Island "The Large White".  Lets hope the climate is too cool for it to get a foothold in the south.

 The Tussock Butterfly

  The common butterfly of rough country and tussock grassland is the Tussock butterfly.  It is brown with a slow wingbeat and it breeds from sealevel to the subalpine meadows.  It has a relative "The Black mountain butterfly" which only lives above about 1200m.  You see them on scree slopes and although not uncommon, you rarely get a chance to get a close look at one.

Copper Butterfly

  We have three or more sorts of Copper butterfly depending on how you classify them.  A recent study suggests there are dozens of species, each representing an isolated population, but superficially most of the proposed new species are hard to distinguish.  The caterpillars feed on three pohuehue (Muehlenbeckia) species.

Boulder Copper butterfly

  One is our tiniest butterfly, the Boulder butterfly, found in riverbeds and coastal gravel bars.  The others are brighter orange with varying black marks.  They frequent bush margins and visit urban gardens.  If you see a monarch, it is almost certain to have been bred in captivity and released,  They reach their southern limit about Christchurch where they are common along the herbaceous borders in the Botanic Gardens in Hagley Park.

  Another butterfly was added to the Southland list recently. The small Blue butterfly is found throughout New Zealand except for coastal Otago and Southland.  In February I found a small population at Piano Flat, the first Southland record, but only by a few kilometres.  It could be more widespread so look for a small pale butterfly attracted to clover.  The other butterflies that might turn up are vagrants and something we can watch for.  We can expect them after prolonged westerlies.  It's only about four days flying time from Australia and the western parts of New Zealand seem to get the vagrants.  The hot spot is probably Haast but Southland will have its share if you know what to watch out for.

Painted Lady

The Painted lady is the world's most travelled insect.  It is related to the admirals and about the same size but with paler wings.

  The Blue moon is unmistakeable, you know when you have a Blue moon!  It's as big as a monarch and blue with black and white markings.  It is one of the tropical species bred in the butterfly house at Otago Museum.  The Meadow Argus and the Lesser Wanderer are known from a few specimens, mostly from the west coast.  Some turn up in New Zealand each year, possibly more than we imagine because of the unlikelihood of one being spotted by someone interested enough to catch it, photograph it or report it.

There is a single New Zealand record of the Black jezebel, an Australian butterfly which turned up in Waikaia a couple of years ago.  That's as far from the sea as you can get so it must have covered a bit of land first.  Perhaps it was bred there! In Australia the caterpillars feed on mistletoes so maybe we have a breeding population.  The prevalence of mistletoes in Western Southland might suggest that somewhere like the Tuatapere Domain the summer might be the right spot to look for a smallish black and white butterfly with red zig-zags on the wings.

For lepidopterists, that's butterfly and moth enthusiasts, there is a new book by Brian and Hamish Patrick "Butterflies of the South Pacific".  Before buying a moth book it might pay to check the contents.  I heard of a boy who found a book for his moth-collecting brother in a second hand shop.  It was a birthday present and the thought was appreciated but the contents left the recipient rather puzzled.  It was called  "Advice for Young Mothers".

Thursday, May 9, 2013

Coastal Sites

  midden at Stanley town site 26

  Have you seen shells and blackened stones eroding out of a bank? There is a new project in Southland – SCHIPS Southland Coastal Heritage Inventory Project – which records Maori coastal sites. 

The pre-European Maori population spent almost all of its time on the coast.  The coast provided food and other resources such as whalebone, the best travelling routes and the vantage points from which to observe the weather and sea conditions and to look for approaching friends or foes.
 Inland it was swampy, thickly forested or dissected with deep rivers. There was food but it was harder to find. Food was collected on the coast and cooked in pits called umus. Heated rocks were placed in the pit and layers of leaves, food, more leaves, mats or bark were added, then buried and allowed to steam. After several hours the food was ready. The discarded shells, bird bones and fish bones were heaped in a midden and it is these rubbish heaps that provide our knowledge of the early diet.

 midden at Tiwai Point

 Much of our coastline is unstable, with erosion and accretion on an irregular cycle. Big storms, extreme tides and tsunamis bite deeply into the shore and windblown sand, suitable currents and tides, and flood debris carried down rivers can build the coast again. The erosion cycle takes away the midden sites; it also exposes new ones. This can be quite exciting, particularly if the site is very old or contains well preserved bones. Sometimes a burial is exposed – a skull perhaps, or a few toe bones. Human remains are a police matter, no matter what their age but the police will refer obvious old burials to iwi for excavation and re-interment.

 A new urupa has been established on Mason Road near Invercargill and some of the bones to be buried there have come from exposed coastal sites. Sometimes there are artefacts exposed as well, or more likely the flakes left behind when stone tools have been shaped.
 I guess each tool means about 100 chips. These can be very numerous and the stone-working site excavated on Tiwai Point before the smelter was built yielded tons of flake.

SCHIPS aims to locate and photograph coastal sites and monitor their deterioration. Observers have been trained and we aim to do perhaps twenty sites each in a year. I recently photographed two in Western Southland.
There is a well-known site near the settlement at the mouth of the Waikoau River on Te Waewae Bay close to the cribs. It has shells and a few rocks and fish bones. It is being eroded by high seas, and vehicle and foot traffic.
I found a new one as well, about a mile west of Gemstone beach. The eroding bank has cut an umu in half and you can see the cooking stones and shells. Let someone know if you find a Maori site on the coast.

Thursday, March 7, 2013

Exploring Gemstone Beach

Scouts from the Riverton Scout Venture at Gemstone Beach

The Riverton scout Venture was held in early January.  There was a good turnout and despite one or two scares with the weather it turned out OK with the high winds and torrential rain by-passing Riverton.  I helped sort out the gear and took fieldtrips to Gemstone Beach.  We weren’t lucky with the tides but still had a great couple of hours each time fossicking.  The seas were high and surging up the gravel slopes and we all got wet feet.  It’s a bit risky I guess but the Venturer motto is ‘Look Wide’ so if they are swept away it’s their own fault.  They must have grown up with the scout motto ‘Be Prepared’ as well.  They were reasonably prepared for the Venture but most of the Venturers are from Australia and they can’t conceive of how cold and wet it can be in Southland in the middle of summer.  There were some quick trips to buy winter clothes when the temperature dropped.  This is a problem with overseas tour groups as well.  They are told they are coming from a northern hemisphere winter into a tropical land, only to find that there can be snow and cold winds.

Anyway the only casualty of the beach foray was a small dog – a ‘rat-on-a-string’ sort of critter which was swept off its feet and tumbled out into the surf.  Fortunately it was tethered and it was easily wound back in again.  It shook the foam off and carried on sniffing.  We were reasonably successful with the stones and everyone ended up with at least one garnet.  These are translucent green, amber or white and are noticeably glossier and heavier than the other stones.  One girl picked up a fist-sized pale green garnet.  Once, I would have been jealous, but advancing age changes your perspective on things, and I found myself being as excited for her with her treasure as she was.  The prize mineral from the beach is sapphire.  I’ve seen them in collections but we didn’t have any luck finding one.  Gemstone Beach ‘works’ because of the geography of the coast.  The heavier stones coming down the Waiau River plus the heavy sand – iron sand – with its speckles of gold and platinum, are concentrated by wave action along a relatively short distance.

 A selection of gemstones

 The beach also has lumps of shale which I flaked with a pocketknife and burned with a match.  “Smells like burning oil,” they said.  No wonder – it is burning oil.  When you bang two quartz pebbles together they spark although you can’t see that in daylight.  The bang also produces a smell like gunpowder.  I tell kids they can carry on reading their good book after lights-out by the illumination of quartz sparks.  ‘Once upon a time’ – spark – ‘there were three bears’ – spark – etc…   My best find was a rhodonite pebble.  It’s a striking pink tone with black squiggles.  It’s not particularly rare but it’s the first time I have picked up rhodonite.  The last mineral worth mentioning is coal.  There are lumps of it there, probably from a seam just offshore but possibly from a shipwreck.  I find myself compulsively collecting coal from the beach.  I think it is a primitive instinct that hasn’t been purged out completely.