Teak growth rates

• To: Multiple recipients of list FOREST <FOREST@LISTSERV.FUNET.FI>
• Subject: Teak growth rates
• From: Paul Romeijn <treemail@VR.NL>
• Date: Sun, 1 Sep 1996 10:28:46 +0200
• content-length: 2883
• Content-Transfer-Encoding: 7BIT
• Content-Type: text/plain; charset=us-ascii
• Reply-To: FOREST Mailing list on forest research and studies <FOREST@LISTSERV.FUNET.FI>
• Sender: OWNER-FOREST@LISTSERV.FUNET.FI

Dear Colleagues,

With kind permission Treemail circulates the following "Rule of tumb" on
growth rates for teak, by Dr. Raymond Keogh.

There exists no legitimate resason for any confusion on growth rates for
teak. Treemail fully agrees with Dr. Keogh when he writes:

"I feel that the debate on growth rates of teak has gone on too long; growth
rates for this species are well known and it is time to make this abundantly
clear!"

Follows the text by Dr. Raymond Keogh:



                    TEAK GROWTH RATES


                     A RULE-OF-THUMB


The question of growth rates in teak plantations has become a contentious issue
in recent times. It is of crucial importance to teak growers and investors
because timber production forecasts and financial returns depend on accurate
predictions. Fortunately, we know more about teak growth rates in plantations
than any other tropical hardwood. Growth and yield studies began in earnest
last century and continue today. Growth is normally expressed in terms of cubic
metres per hectare per year and highest growth rates are normally expressed in
terms of maximum mean annual increments (note: maximum current annual
increments, which are higher than mean annual increments are not normally used
in timber forecasting as they would produce erroneous predictions over the life
of the crop).

A very tolerable rule-of-thumb can be applied across the tropics regarding
highest growth rates in teak plantations. This rule-of-thumb does not change
for wide definitions of stem volumes. GROWTH RATES WHICH EXCEED AN AVERAGE OF
TWENTY CUBIC METRES PER HECTARE PER YEAR IN TWENTY YEARS ARE UNLIKELY TO BE
ENCOUNTERED. In other words, only in exceptional circumstances will the total
production of stem woody material exceed four hundred cubic metres in twenty
years.

Growers and investors must base their predictions on averages and not
exceptional growth rates. Most practicing foresters in the tropics would be
content to encounter an average annual growth rate of ten to fifteen cubic
metres per hectare per year over twenty years on all their plantation sites.
Through good site selection and the planting of genetically improved seed,
growers can boost averages and avoid poor producing sites.

Genetic improvement may boost growth but is an expensive long-term activity.
Growth may also be boosted in some cases by fertilizer application, but the
identification of the necessary chemicals and their optimum rates of
application are not fully understood. At the present state of development in
teak, it would be unwise to expect that average growth rates can be boosted to
reach or surpass the maximum rule-of-thumb growth rate for teak throughout the
tropics. Even if it were possible to do so, it would be wise to have a clear
understanding of the effects of this increase on wood quality.

Raymond M. Keogh

Teak 2000

1 May 1996

• Next: Eucalyptus seeds, leaves, roots: growth inhibitors?
• Index: Forest mailing list September 1996
• Thread: Forest list subjects in September 1996