Totara – Northland’s farm forests of the future
New Zealand Tree
Grower November 2007
Helen Moodie, Paul Quinlan, David Bergin and Chris Kennedy
Introducing the vision, activities, objectives and profile of the
Northland Totara Working Group
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| Birds spread seed out from existing trees
and totara progressively colonise grazed environments. |
It may be hard for people outside Northland to imagine, but totara are
so vigorous and abundant in this region that farmers often consider
them firewood at best – or more commonly, weeds. Seedlings can be seen
colonising grazed paddocks and growing through fences. Dense thickets,
young pole stands, and trees of various shapes and sizes are all common
in the scrub or even out in the open pasture. In many parts of
Northland totara have now become an ingrained part of the local
landscape identity.
To the farm forester these weed-like characteristics are also among the
attributes that allow this native tree to occupy a unique place and
play a useful and potentially productive role within the farm.
Vision for the land
The Northland Totara Working Group is exploring the potential to change
this ‘weed problem’ into an asset for the landowner. While sustainable
timber production is a primary focus, the other benefits that come
along with the trees are also an important part of the background
motivation. These include increasing indigenous biodiversity, erosion
control, enhanced soil and water quality, riparian management,
landscape and amenity values and of particular interest to the farm
forester stock shade and shelter. Management for the productive use of
the timber is seen an effective way to achieve those other benefits.
Points of difference with totara compared to many other native trees
are −
Totara is a pioneer
Totara is a light demanding species. It produces seed from a young age,
germinates successfully in grazed pasture, and compared to other New
Zealand podocarps, is relatively fast growing. The extensive conversion
of forest to pastoral farming has probably assisted in its current
proliferation particularly on hill country landscapes and along
riparian areas
Regenerating totara are stock proof
Totara is relatively unpalatable to most farm stock. It is likely that
grazing may be assisting the establishment of totara on farms. This
attribute allows an opportunity to integrate a native tree species
within a livestock grazing system.
Abundant natural regeneration
Rather than relying on planting, totara can successfully colonise
grazed environments, especially poorer quality pasture areas and
steeper slopes. On many farms in Northland, totara now dominates the
character of scrub cover and farm landscapes.
Finding ways to work with this abundant natural regeneration has many
attractions. It is a constant natural process occurring without human
effort. There are no planting, spraying or fencing costs. There is
likely to be no immediate loss of significant grazing as totara often
grows on less productive grass sites such as steep hillsides.
Another attraction relates to its scale. Many farms have small and not
so small patches of totara and collectively they may add up to a
significant regional resource. Opportunities to buy time are few and
far between – but use of the existing totara resource is just that.
How much totara is there on farms?
A pilot study survey is presently underway to evaluate the totara
resource on Northland farmland. This project, funded by ASB Community
Grants, is being undertaken by Chris Kennedy of Geoinfo Ltd. The main
aim is to develop a practical way of estimating the resource of totara
on private land.
The pilot survey area focuses on private land in the Whangaroa − some
47,000 hectares. It uses a combination of GIS technology, high
resolution aerial photography and ‘ground-truthing’ with sample plots
in the field. Data on stocking rates, diameter at breast height, form
and volume is all being captured to help build a picture of the
existing resource. As a secondary objective, a less reliable estimate
of the total regional resource in terms of quantity and quality will be
extrapolated from this work, which can be updated and refined as more
survey data becomes available from outside the initial study area.
While a full technical report will set out the results when the project
is complete, early indications are confirming what many of us believed
– that the resource out there on private land is significant. Some
trees are already of a harvestable size and form.
Some sustainable regional production could be started now, with
significantly more coming on in the future.
Management potential
Potential lies in developing the size and quality of the future
resource of regenerating totara. Farm grown totara has notoriously poor
form especially when grown in open conditions. In contrast, tree form
can be very good in natural stands with high stocking rates, although
growth rates can be significantly slowed due to competition.
Contrary to a common perception, totara are capable of surprising
growth rates on good sites. In managed stands in Kaeo, Paul Quinlan has
recorded vigorous individual stems around the 20 to 30cm diameter
classes putting on up to 1.76 cm mean annual increment over an eight
year period, and around one centimetre mean annual increment for a
thinned stand stocked at 575 stems per
hectare.
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| A thinned and pruned plot within a small
grove of young totara poles on a farm owned by Doug and Sally Lane in
Kaeo. |
Silviculture to improve growth form
Research trials into the growth response to thinning and pruning and
potential to improve tree form is another project currently under way,
thanks to funding from MAF’s Sustainable Farming Fund project.
Previous studies indicate that mean annual increment for naturally
regenerating totara on these farm sites is about three millimetres
where stand densities can be 5,000 stems or more per hectare. Improved
growth rates of natural stands are therefore expected to be achieved by
thinning.
Stem form of residual trees can also be enhanced by pruning. Research
scientist David Bergin has set up silvicultural trials to compare
responses to a range of different levels of intervention. Groups of
well stocked natural pole stands in three districts in Northland have
been thinned to residual stocking rates of 700 to over 2000 stems per
hectare. Sometimes this has removed as much as 75% of the stems. In an
attempt to cover the wide variation in stocking and composition of
regenerating stands, over 40 plots have been established on nine
different farms. Control plots, where no pruning or thinning is carried
out, are also included for comparisons with treated plots.
Planted stands included
Comparisons with planted totara are also planned. Two of the best
performing totara plantations occur in the Northland and Auckland
regions. Both stands were planted at densities in excess of 2,000 stems
per hectare and have a decreasing mean annual growth rate due to
intense competition. Thinning of these plantations will provide an
opportunity to compare growth responses to thinned naturally
regenerating stands of totara.
Timber quality of young trees
Testing of the timber quality from these relatively young regenerating
trees is also intended. Anecdotal evidence suggests that sapwood or
transition wood from the young trees still has some fine qualities and
is suitable for many uses. Laboratory assessment of wood quality from
the thinnings is planned. Sapwood will also be evaluated by carvers
from local iwi to determine any differences in qualities compared to
traditionally used heartwood totara.
Research results
These are clearly long term projects with the re-measurement and
analysis of the trial plots planned over the coming years. At the end
of the current three year funding from the Sustainable Farming Fund,
preliminary results of this work will be reported and widely
distributed. Tane’s Tree Trust, the Far North District Council and the
Northland Regional Council are also assisting with the funding of these
research trials as are the landowners themselves.
Legal issues around harvesting
There is widespread fear amongst landowners that harvesting of any
natives is or will be prohibited by law. Fortunately this is not
necessarily the case. The legal rights to harvest can be obtained and
members of the working group have successfully done so. However the
Forests Act applies to the naturally regenerating totara and this
requires commercial harvests to be done on a sustainable basis −
planted native trees are exempt from the Act. The Ministry of
Agriculture and Forestry’s Indigenous Forestry Unit administer the
Forests Act and should be the first port of call if anyone is
considering milling any trees.
District Plan rules also apply. The Far North and Whangarei District
Plans permit harvests under an approved permit or plan.
So again, a key point is that harvests are possible. Nevertheless the
Northland Totara Working Group does make submissions to local
authorities and is in dialogue with the Indigenous Forestry Unit
concerning the relationship between the unique regenerating totara
resource and the various legal issues and processes.
Future projects
We are now looking to address the final objective – to investigate the
feasibility of developing a supply chain for sustainably harvested
totara regenerating on farms.
There is a lack of market demand or misconceptions of the value of farm
grown totara, and on the other, an absence of information on the scale
and utility of the resource. A smoothly operating supply chain of
material to markets is required.
Totara is not alone in confronting these difficulties, which are
complicated by numerous indirect influences such as imported timber
prices, and consumer perceptions regarding uses of native timbers.
Nevertheless, harnessing the power of the market is a key nut to crack
if this resource is to have a significant role in the future
sustainable land use of regions such as Northland.
This article is based on the work of
the Northland Totara Working Group
and prepared by Helen Moodie NZ Landcare Trust, Paul Quinlan Landscape
Architect, David Bergin Ensis and Chris Kennedy Geoinfo Ltd.
The who, what and whys
The Northland Totara Working Group is a landowner driven project
looking to promote the productive use of farm grown totara. Its
scientific foundation is the doctoral thesis of David Bergin which
indicated the potential in totara for productive sustainable
management. However its strongest base is the significant community
support and enthusiasm shown by landowners throughout Northland. Field
days and workshops held by the group have been consistently well
attended.
Established in September 2005 and convened by Helen Moodie from the NZ
Landcare Trust, the group includes local farmers and representatives of
the NZFFA branches, Far North District Council, Northland Regional
Council, wood millers and processors, Tane’s Tree Trust, NZ Forest
Owners Association, and Ensis.
Interest in the project from the Northland community is very high,
providing the crucial basis for the initiatives of the working group.
The group maintains a database of people interested in hearing about
progress of the projects underway. Anyone keen on inclusion in this
database should contact Helen Moodie on 09 435 3863 or Helen.moodie@landcare.org.nz.
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