The pulp and paper industry has shown, mainly in the last two decades, a strong North-South displacement. This is to a large extent due to the favourable climate, which promote the development of the trees. Similarly, the paper fibres have gone from being almost exclusively softwoods from natural forests of the Northern-Hemisphere cold regions, such as spruce and fir, to fast growing species of short fibres, such as eucalyptus, and willow and poplar hybrids from plantations.
These new species, that begin to dominate the paper panorama, not only differ from classic ones in fibre length, but they present particular characteristics, like large amounts of juvenile wood, different fibrillar angle and so on, because trees are used increasingly at younger age.
This leads us to question whether the old paradigms concerning the relationships between fibres characteristics and pulp properties are still valid or should be reviewed and updated, in which case, the basic fibre parameters, their influence in pulping and refining, and their impact on paper quality should be redefined.
This book surveys publications from the last decade, to verify which morphological characteristics of the fibres authors currently consider relevant, in order to establish the state of the art for this topic. Relatively recent data were surveyed because of the continuous changes that occur in the species due to genetic improvement.