Saturday, 7 March 2009

Acacia melanoxylon

This is our local invasive species par excellence. I that this species had just about been eliminated in the Monserrate Woods - but there is always one that escapes ....

originally planted as an ornamental, but what really got it established were forestry scale plantings in 1930'-50's. Big cyclone in 1941 gave it some room to expand followed by series of forest fires - now we have hundreds of hectares of the (beautiful) menace.

Nº 2 in the line up is Pittosporum undulatum. This is even more insidious because of the way that it infiltrates native woodlands (mostly Cork Oak), grows up through the shade, then tops out the oaks.


Anonymous said...

I've seen some beautiful colonial cabinetry of Tasmanian Blackwood, and it is popular with luthiers..but,yes,it is now a globe-trotting weed . Is it still being used in plantations in Portugal,despite problems?

Pittosporum undulatum has achieved weed status in its own country, benefiting greatly from fire suppression and excessive urban water use and runoff, particularly around Melbourne. However,as troublesome as it is, it pales in significance with Cinnamomum camphora,Celtis sinensis, Ligustrum lucidum and L.sinense, which are transforming landscapes and waterways on the south-eastern coast of Australia.

What of your local forests? Are they hanging on? Has Monserrate,or Sintra, any remnants of a Lusitanian element?

Gerald Luckhurst said...

I knew about the cabinet work, though I've never seen any. Luthiers I had to look up! Most of Sintra's acacias end up as firewood, I try to get them chipped and spread over cleared land to retain organic matter. We are getting quite good at controlling/eliminating now, but it is expensive and, outside of historic gardens, difficult to justify since land has "apparently" no other viable use. More to do with politics than forestry. It is now illegal to plant this species.

Pittosporum undulatum is another lovely weed. A few years ago we had a fairly big drought and I thought we were going to get rid of them - the the rains came just in time to save them. But I'm sure if the Pittosporum goes something else will take its place - Madeiran Laurisilva like Ocotea or Persea for instance. Of the rogues you mention only the Ligustrum is in any way a nuisance here - and that in a very mild way.

Our local forests are very very depleted. There are some good relicts in some of the historic gardens though. Monserrate has quite a bit - but I have not been down into these inacessible parts for some time. Another thing to do. Best local woods are perhaps at the "Cork Convent" a disused monastery that was once part of the Monserrate estate. Nowdays it is run by the same organisation (Monte da Lua -

We have a number of oaks, both deciduous and evergreen - much hybridised amongst themselves. Myrica faya is almost unique on European continent (common on Azores) Chesnuts, Hazel, Holly (this is almost Southern European limit) Prunus lusitanica, Viburnum tinus, Phillyrea latifolia, Arbutus unedo, Laurus nobilis.

This is I think an important role for Monserrate in the future. Management of native woodlands and recuperation of areas occupied by pine and/or invasives.

Much of the unique character of Monserrate is derived from the admixture of native woodland and exotics. A fact not lost upon the Victorians.