The unexpected effect that our height growth curves do not
exhibit a clear point of inflection may be a result of the lacking
observations at the ages where the culmination of current
annual height growth is to be expected. Nevertheless, there are
examples of site index systems of Eucalyptus grandis and
Eucalyptus saligna in Southern Brasil (Finger, 1991) and of
Pinus cembra in the Austrian Alps (Lick, 1991) which also
exhibited an r in Eq. (2), not differing significantly from one. In
both these investigations the dominant heights were well
available at those ages where the culmination of dominant
height growth should have been expected. Nevertheless, it must
be admitted that the height growth curves found by Teshome
and Petty (2000) for C. lusitanica in the same region, but
developed from stem analyses data, have distinct points of
inflection at an age around 3.5 years. They used the
Schumacher equation (Schumacher, 1939), which by definition
has to exhibit a point of inflection, whatever the parameter estimates are. The extremely small predicted heights in ages of
1 year (15–20 cm) may indicate that this condition of the
Schumacher’s equation is fulfilled at the costs of underestimated
early height growth
The unexpected effect that our height growth curves do notexhibit a clear point of inflection may be a result of the lackingobservations at the ages where the culmination of currentannual height growth is to be expected. Nevertheless, there areexamples of site index systems of Eucalyptus grandis andEucalyptus saligna in Southern Brasil (Finger, 1991) and ofPinus cembra in the Austrian Alps (Lick, 1991) which alsoexhibited an r in Eq. (2), not differing significantly from one. Inboth these investigations the dominant heights were wellavailable at those ages where the culmination of dominantheight growth should have been expected. Nevertheless, it mustbe admitted that the height growth curves found by Teshomeand Petty (2000) for C. lusitanica in the same region, butdeveloped from stem analyses data, have distinct points ofinflection at an age around 3.5 years. They used theSchumacher equation (Schumacher, 1939), which by definitionhas to exhibit a point of inflection, whatever the parameter estimates are. The extremely small predicted heights in ages of1 year (15–20 cm) may indicate that this condition of theSchumacher’s equation is fulfilled at the costs of underestimatedearly height growth
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