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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)