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Elena Mosyagina,
Project expert
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A uniform system of requirements to the quality of standing
timber under international and Russian standards was developed
on the basis of a comparative analysis of data on Russian requirements
to the quality of timber depending on its sort and size and
similar requirements agreed upon among Finnish forest companies.
Analyzing the national requirements to the quality of timber
project specialists compiled a list of defects which determine
sorting of timber into different assortments. The list was complemented
by the data obtained from the analysis of requirements of foreign
companies. In addition to compiling a list of timber defects
which are taken into account in product specifications, project
specialists described methods of measuring these defects. In
this way they produced a comprehensive list of defects used
in the national and foreign standards and various methods of
measuring these defects.
Comparison of Russian and international requirements to the
quality of timber revealed certain differences, which may
result in different yields of assortments. For example, for
round wood the Russian GOST (“government standard”)
specifies the same requirements to sound and dry knots, but
different to decayed knots. In most foreign standards, however,
the rate of tolerance to the diameter of dry knots is almost
twice as low as to the diameter of sound knots. This difference
is especially evident in product specifications of timber
from forests that have low site index (SI V or Va). Trees
in such stands have low crowns with thick branches in the
bottom part of the crown (6 cm in diameter or more). According
to the Russian GOST, such forest stands have a certain amount
of low-quality sawlogs produced from the biggest trees. According
to foreign standards, all timber harvested in such stands
is classified as pulpwood.
The uniform list of assortment-related timber defects and
methods of their measuring will help to use similar approaches
to developing models of the assortment structure of growing
timber. |
