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Management of Forests and Wood Industries − 2000
BASED ON A PRESENTATION AT THE SECOND WORKSHOP OF IUFRO
WORKING PARTY S5.01-04 ON:CONNECTION BETWEEN SILVICULTURE AND
WOOD QUALITY THROUGH MODELLING APPROACHES AND SIMULATION
SOFTWARE”. KRUGER NATIONAL PARK, SOUTHAFRICA, AUGUST 1996
AN INTEGRATED APPROACH TO IMPROVED
WOOD UTILISATION
Dr. Lars Björklund, Swedish University of Agriculture
M. Sc. Klas Bengtsson, Orgut Consulting AB
Professor Göran Lönner, Swedish University of Agriculture
Department of Forest-Industry-Market Studies
Swedish University of Agricultural Sciences
Uppsala, Sweden, August 6, 2000
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THE INTEGRATED APPROACH
1 The situation today
More than 10 years of research in the field of integration and improved wood
utilisation has clearly shown that one main obstacle for improved profitability
in forestry and in the sawmilling sector is the very poor communication
between forestry, saw milling and the further processing wood-working
industry.
Figure 1. Improved communication - the key to success! Today the information is
often blocked
The number one target for our research team is to present possible strategies
and relevant tools to overcome this situation. We approach the problem in
two interlinked but very different ways; 1) Developing tree-models for raw
material descriptions and optimisation programmes for improved utilisation
of stems or logs and 2) Action oriented research where raw material is
selected in the forest, test sawn and delivered to specific customers.
The basic structure of the problem is very simple. On one side we have
different stands, different trees and different parts of these trees. All
representing raw material with different properties. On the other side we
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have customers with different requirements (product specifications). The task
is to find the best raw material for the different products.
Figure 2. The task is to find the best combinations of raw material and wooden
products
The first, and maybe the most serious, obstacle for an improved
communication forest-industry-market is the lack of direct communication
between the sawmill and the further processing wood-working industry. In
the traditional, and still very dominating, system for selling sawn wood from
Scandinavia, information from the customers (the industrial end-user) has to
pass several "middlemen" before it reaches the sawmill. Included in this
system is also the standardised methods for sorting and grading developed
already in the early days of this century. The general experience from this
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system is that very little information of importance for optimising the wood
utilisation ever reaches the sawmill and, consequently, not the forest.
Figure 3. Direct communication - an important part of our approach.
The next critical obstacle for an improved communication forest-industry-
market is
that the logs normally are delivered to the sawmills without any information
about their origin. At the sawmill, logs from different logging areas are mixed
and then sorted only by top diameter. With no information at all about origin,
and no attempts to sort the logs after quality at the mill, the optimisation of
the sawing is restricted to volume optimisation. From quality- and value-
optimisation point of view, the sawmiller is today more or less blind.
Figure 4. Most information about the origin of the logs is lost when they are at the
sawmill
This is what we call the "Information Catastrophe" also described in figure 5.
However, at the moment of harvesting we have access to a lot of important
information, such as site index, silvicultural history, "social class", age, part of
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tree etc. This information could give us knowledge about the properties of the
logs but it is now lost "on the road" between harvesting and sawing.
Figure 5. The "Information Catastrophe"
This is of course a situation that cannot be accepted in an efficient system for
wood utilisation. Different methods are also discussed to make this
information available also at the moment of sawing. Marking the logs with
different colours is one possibility and using "high tech", for example some
kind of transponders, is another.
2 Tree models - a tool for improved communication
In figure 5 we have indicated that tree models can considerably increase the
amount of information about the properties of stems and logs. Tree models
can be developed into strong tools for improved communication forest-
industry market. Figure 6 gives one example of how tree models can be used
as such a tool.
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Figure 6. Tree models as a tool for improved communication forest-industry-market
Based on the product specification derived from the market (here exemplified
by an industrial end-user) the forester can "find" wood with the requested
properties. Problems and possibilities in the supply of raw material can be
discussed and specifications can be changed when needed. Relevant stands,
trees and cross-cutting patterns can be proposed.
The primary industry (here exemplified by a sawmiller) must understand
why a certain raw material is chosen and what kind of products will be made.
They can then, based on technical limitations and possibilities, and
production costs, give suggestions that can contribute to an overall
optimisation of the production chain.
Assuming comprehensive knowledge about the needs of the customers, and
an understanding of how to combine the raw material resource with the
product specifications on the market, the next task is production planning.
Once again tree models can be a strong instrument. The goal is here to
optimise the entire flow of wood over a certain time period.
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Figure 7. Tree models as a tool for production planning forest-industry-market
2 Basic requirements for tree models as tools for improved integration
Tree models are here seen as a tool needed to improve the communication
between foresters and forest product manufacturers. It means that the models
should be informative and easy to understand. Good graphical presentations
can in this sense be more useful than mathematical functions. Tree models
should also be product oriented in order to function as a catalyst for the flow
of information. The models will therefore not contain measures like relative
heights in the stem. The modelling must encompass a range of properties to
make it possible to analyse and compare different products. However,
simplicity must not overshadow the fact that graphics or models must show
correct relationships between the interior properties of the stems and tree and
stand characteristics. For this they must be based on sufficient empirical data
that minimises the need for extrapolations. They must also generate
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information that is so detailed that the potential extra value can actually be
recovered. Furthermore, it is v
very important that the modelling is based upon an understanding of how
trees grow. Different trees grow differently, also within a specific stand. An
individual tree, a type tree, in a specific stand is therefore the basis for the
modelling.
An example of Tree models based on CT−scanned stems from Swedish mixed
conifer forest (Pinus sylvestris).
Figure 8 Example of tree model (Pinus sylvestris)