Macrocarpas (Was: Re: Kakariki - St Patrick Day Planting, Wilding Pines)

Brian Sandle bsandle at
Thu Mar 18 09:20:19 EST 1999

I hope that the bionet.agroforestry people might be able to offer some 
advice on some aspects, here:

In nz.reg.christchurch.general "Moz (Chris Moseley)" <moz1 at> wrote:

: Brian Sandle wrote
:>What do big trees do for climate?
:>Obviously they provide shade - not only for cars to park under but for
:>improving chances of other plants in hot sun.
:>How much moisture can they put into the atmosphere?

: A lot. The Amazon desert-to-be has already suffered noticably from the
: small % that has been burnt to date. Large groups of trees provide
: a thermal pump for gliders, and the wet rising air can have big effects
: on a microclimatic level. Can in the sense that, say, the West Coast
: would be wet even if we burned it to bare earth, but the Canterbury
: plains could be a lot wetter than they are now if we had more trees
: there.

This stand of macrocarpas is about 1/3 mile long at one every few yards.

They are about 3 times as high as the lighting poles in places. They have 
been in some 50 or 60 years.

A City Council tree specialst says that macrocarpas are dangerous because 
they are shallow rooted and will fall over easily. He says it is more the 
case with close trees especially as some are taken out.

But I look at these trees and their roots are not showing, though those 
of some pines are. The macrocarpas protect the pines from the sea air so 
that they have been able to grow tall. Over half the stand the pines have 
been removed so the macros have no live vegetation showing except at the 
tops on that side. They are tending to lose branches in heavy winds, 
though not many have gone.

Here near the beach the water table must only be several yards from the 
surface. Is it possible with macrocarpas that the roots will not stay on 
the surface if there is a water table below?

What are they like for plants around about them then? The tree specialist
says that they stop other plants growing, but new plants, some New Zealand
natives, ngaio and broadleaf plants seem to be doing quite well in place
of the pines that were there, nearby.

Further along, where a children's playground is, a pine snapped off some 
yards above the ground. It happened a couple of months after a big wind 
that broke some macrocarpa branches. I am thinking that the macrocarpas 
are safer because the damage is evident earlier. Children will not be out 
in the strong winds.

The plan is to replace with more ngaios &c. Ngaios are poisonous to the 
liver, all parts of them. They also have attractive berries. What is the 
danger of branches falling compared to other dangers in the area, poisoning 
and cars on the road between the park and beach?

It is intended to prune the ngaios to 6 feet or so so that the park can 
be observed from the road. But at the first heavy snow ngaois will break. 
The tree specialist says then we must hope for no more snow. Perhaps he 
means I should have been more vocal beofre a vote was taken, though we 
were urged not to speak too often, to let others.

Can Christchurch people tell me if they knew that a meeting was being held
on Wednesday evening last? I reported the result to some touch rugby
players last evening. The meeting had decided 13 for chopping and 7
against and the reply from a touch rugby player was, `20 people decided that 
fate of these trees? That sucks.'

There is a stand of trees on the other side of the park, one football 
field away and it has been a majestic experience for me walking along 
there. Also further down, in the children's play area, where there are 
more large trees, it is really some sort of power experience walking 
between them.

As a writer to the Christchurch Star said on Wednesday, I wonder if it is 
being done for short term economic reasons. I believe macrocapra can be 
quite valuable. But the tree specailst is cagey on whether this 
particular wood would be valuable. But it seem significant that the 
felling part of the job would happen before June (NZ winter) in this 
financial year. Redevelopment would wait.

I have had two other articles on the macrocarpas on 
nz.reg.christchurch.general under subject headings:

Security Cameras for Thomson Park?
Y2K Celebrations Missing Macro Trees?

 :>How many trees of what size does it take to help 
attract rain?

: One, any size if you need a fine weekend to plant it <g>

: Moz

Though I believe trees do attract rain. Does it make so much difference 
if they are near the sea?

Are they bringing deep water to other plants or robbing them of it
considering shade?

Brian Sandle

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