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Although the main use made of eucalyptus in Spain is the production of cellulose, it is not the only use that eucalyptus generate. The exploitation of every forest species depend on the technological characteristics of the wood, that in the case of southern blue gum (Eucalyptus globulus) are the following:
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Synonymy:
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Eucalyptus globulus Labill Eucalyptus cordata Mig. Eucalyptus diversifolia Mig Eucalyptus delegatensis Dehn. Eucalyptus glauca DC Eucalyptus perfoliata Desf |
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Common
Name (in Spain):
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White eucalyptus or Blue eucalyptus | ||
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Description
of the wood:
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White-greyish or pale-cream coloured outer wood; inner varies from cinnamon to brown-reddish or pale-yellow colours. It's mid-grained and the fibre is twisted. | ||
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Physical
properties:
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Density
Coef. contraction Total contraction Volumetric contraction Tangential Radial Hardness |
740 - 830 kg/m3 0,67 - 0,73 |
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Mechanical
Properties:
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Static flexion Modulus of elasticity Axial compression Perpendicular comp. Dinamic flexion |
142 - 153
N/mm2 16.500 N/mm2 59 - 76 N/mm2 12,7 N/mm2 5,5 J/cm2 |
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| The ME-2 quality of UNE 53,544 rules, in structure wood in the Spanish origin, is equivalent to the hardy class D35. | |||
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Drying:
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Difficult. Risks of warping, cracks and collapses of the wood. | ||
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Natural
Durability and Saturation:
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No durable if attacked by fungi or termites. | ||
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Technological
Propierties:
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sawing is difficult due to the growing tensions. It requires the use of powerful equipments. It's suitable for the rotary cutting but the quality of the veneer is not very good. No problems to mechanize. Problems when nailing and screwing. | ||
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Eucalyptus globulus
is the most suitable spanish species for cellulose production, because of the
size and quality of its fibre, as well as its light colour. The average output
of the species ranges between 6m3/Ha./year in the Peninsular South to 15 m3/Ha./year
in the north. It's the most profitable species in Europe for this kind of exploitation,
exceeding birch trees and other leafy trees.
As for the Eucalyptus camaldulensis, its wood is of shorter fibre, compared
to that of the former species, with a more reddish colour, and inferior output
in the exploitation, so it is less used in the production of cellulose.
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The kino can be obtained through distillation, as a dun coloured, opaque, astringent and bitter product. The species richest in kino are those of the group "ironbark".
The foliage of
many species is distilled to obtain oils (specially the eucalyptus of
“peppermint” group ), that are applied in medicine (extraction of the
routine, substance of great therapeutic importance), perfumery and several
industries.
There are some species proper for honey-making (especially of the groups "ironbark" and "boxes").
As for the tree itself, without considering the products obtained from it, there are many species that are planted with a decorative purpose, isolated, in groups, aligned or in mass. Some species are used with protector purpose: securing dunes, stabilizing eroded zones, draining marshy zones, forming windbreaks, etc. They are also used as suppliers of shadows and shelters to cattle in pastoral zones in arid or semi-arid countries. In Australian deserts, some eucalyptus with lignotubers are an important source of water for aborigines. Some eucalyptus have edible seeds or sugary excrescences produced by certain woodlouse. The Koala bear (Phascolarctos cinereus) feeds exclusively on the leaves of certain species of eucalyptus.
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| Nowadays, the investigation about the eucalyptus is focused on the following aspects: |
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Its duty consists of the production of trials to prepare soils, fertilization, and realization of silvicultural works. The CIT of ENCE, in this line of investigation, has developed several own methods of mass management, as well as a program of biological attack against Phoracantha semipunctata, the main pest of the eucalyptus, through the breeding of its specific parasitoid Avetianella longoi.
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The paper-pulp factory at Huelva is carrying out some studies and analysis on the possibility of producing TCF pulphaving into account different factors that influence the process, that is: water, wood, etc... with the aim of producing high whitenessed pulp with high technical characteristics. A tal fin se ha diseñado un prototipo de digestor piloto que pretende reproducir cualquier tipo de modificación en la cocción.
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The main purpose of eucalyptus plantation is the production, so all the actions are driven to its achievement. As a forest exploitation, its ecological and environmental profits are, in certain cases, inferior to those achieved in natural populations. However, the possibility of using its products to satisfy the social necessity of them has indirect positive effects in the natural protection by contributing to the decreasing of pressure on natural populations in other countries.
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The establishment of an
eucalyptus mass requires, firstly, the removal of the pre-existent vegetation.
The methods will depend on the ecological and physiographical conditions of
the zone.
It
is also advisable the previus preparation of the soil by working it, what in
hard soils mainly favours the growth of the plantation, while in soft soils
influences in the reduction of the number of deaths.
It's
generally used a one sap plant (one year old), at least, which does not exceed
45 cm. above the ground.
The advisable season for plantation is autumn, so that the plant can have a
good tolerance of winter cold and be perfectly rooted when summer rigours arrive.
The plantation should be done in wet soil. So, in the South of Spain, eucalyptus
are planted after the first strong rains, from autumn, to Spring. In the North,
they are planted in Spring and even in Summer.
If the
searched product does not requires especial size or quality values,dense plantations
with short rotations in which the output is higher, are preferred. If the aim
is to obtain wood of certain dimensions, it will be used a space of plantation
varying from 4 x 4 metres in the South to 3 x 3, and even 2 x 2 metres in the
North.
In the early years of growth of the plantation (one or two years),
it's necessary to provide certain cares driven to reduce the competition of
other species, so slight ploughings are carried out; sometimes they are combined
with harrows when the plantation has not reached the second year, when this
practice can damage the root. In the North, harvests are carried out to remove
brackens. When the eucalyptus are around three years old, they can control the
surrounding vegetation although the necessity of going on carrying out cleaning
tasks is common in wet zones.
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The age for cutting the eucalyptus depends on factors such as the species, the quality of the season and the space of plantation. The price of different dimensions of the wood also influences. After cutting it, appears a coppice from the stump, which is characterized by:
-a quick initial growth,
-a high number of shoots,
-a higher extraction of nutrients through the plant,
From these shoots, a number similar to the initial density of the plantation will be selected, depending on its vigour. These shoots are usually cut at an earlier age that the first time, starting the process again, until three or four times in the South and five or six in the North. After the last shoots, when the stump has lost its vigour, it is extracted from the ground.
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Made by: Javier Muñiz Glez |
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Modify by:
Angel Muñoz
Sotomayor
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