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.