Large variations in important pulping properties have been demonstrated for
wood from trees, not only of different genera, but also between species wi
thin a genus, and between their provenances, families and even the individu
al clones within families. Tree breeders, who in general have been among th
e leaders in measuring this variation have shown that much of it is under g
enetic control but site and growth factors affect expression.
Some of these properties such as pulp yield, rate of delignification, alkal
i consumption and residual unbleached pulp brightness have strong financial
implications on the profitability of processing. The industry has been slo
w in becoming sufficiently flexible and adapting processes to take advantag
e of this variation to optimize financial return from the furnish.
A way needs to be found to compensate the wood grower for successfully grow
n, bred or genetically modified superior pulping material. The processor th
en needs to find a way to adjust the process to match the properties of the
se materials to best advantage. Both interests call for the development of
a rapid evaluation technique at the mill gate or in loading the digester, a
nd near infrared spectroscopy (NIRA) is suggested as a possible way forward
. Harvest scheduling, woodyard management and ways of directing batches of
timber with predictable properties to the digester in an ordered manner to
minimize within-batch variability are lesser challenges that will surely fo
llow.