Technodiversity Glossary

In several countries, there are systems to prevent forest soil from destruction by forest operations. One example is the Saxonian technological map where the soil conditions are divided into 5 trafficability classes.

In Technodiversity, the technogram of a stand as well as the ecogram of harvesting methods have as their x-axis the T-classes. They are seen as crucial criterion how much the soil will react to any technical impact. This is the scientific context of traffic on bare grounds.

As the guiding criterion we take the soil moisture and divide it into 5 trafficability-classes. Dry (T1), fresh (T2), moist (T3), wet (T4) and very wet (T5). These classes correspond with the assessments of soil sciences.

(See more at TDiv PR1-D04)

The term "tactic" originally has been used by military and means the art of best positioning. Today the term is adapted by civil life. Tactical decisions try to make the best using a given, limited pool of instruments.  

In the context of forest operations, persons like local foresters use the available resources in order to solve their practical problems finding an optimal solution. In detail they decide which tools, machines and workforce should be used in concrete situations.

(see more in TDiv PR1-A05)

Technodiversity is a made-up word that 2021 has been selected as the name of a European ERASMUS+ project (project No. 2021-1-DE01-KA220-HED-000032038). The objective of this project is to point out the diversity of technological solutions in forestry to fulfill the operations under diverse conditions and objectives. Following the principle of biodiversity, the word technodiversity assigns a high value to the variety of solutions and opposes the unified application of standard solutions. The aim of the project is an E-learning course for forest students on master’s level and for decision makers in forestry. This course aims to explain how to select the most suitable harvesting technique for each given case with its specific ecological, economic and societal conditions. It gives to the decision-making process based a transparent path based on clear and objective elements. (See more in lecture TDiv PR1-A01)

In Technodiversity, the technogram of the stand is a central element for decision making, which forest harvesting method will fit to the local stand conditions. It has the same structure as the ecogram of the harvesting methods. When both graphs match the methods is well suited for the given stand.

The structure of the technogram is a 5x5 matrix with the T-classes as X-axis and the P-classes as Y-axis. The T-class is given by the natural conditions of the stand.Concerning the P-class, the owner can decide for himself about the value of the stand. The higher the value, the higher the costs for technical actions that he accepts. This represents the idea of “sacrifice”.

As a principle, all 25 fields can be selected.But if the owner decides that for him the value of a forest stand is correlated with its biological productivity, then some combinations of P-classes and T-classes are quite unlikely (i.e., dry and very productive, wet and very productive, moist and not productive). Under this condition, only 16 “fields” are filled up.

Let us take an example:A decision maker sees that the soil in his forest is moist. So, the T-class is fixed at T3. In addition, the stand has a high productivity. He may personally decide that this productivity is so important for him, that he doesn’t want to sacrifice more than 10% of the soil. So, the distance between the trails must not be less than 40 m.In the graph, he localizes this stand at the field T3P3 (see the red ring).

Unfortunately, this is an assessment only for normal weather conditions. In case of a dry weather spell, the moist soil may dry a bit and behave like fresh soil. So, he should move one column left (sun symbol) to T2 “fresh”. And when it has rained for several days (rain symbol), then he moves one column right to T4 “wet”, because the soil, which normally is moist, now behaves like a wet soil. 0During this “movement” the system of opening-up, that is fixed by the P-class, does not change.

Given this technogram, harvesting methods are searched that match it; this is decided by the ecograms of the harvesting methods.

(See more at TDiv PR1-D04)

Technological maps have the task to make decisions more operational. For every point they specify the technological conditions and the best method for harvesting, e.g.

In 2006, the state forest of Saxony (North-Eastern Germany) introduced a guideline that aimed to forecast the stress on the soil in order to avoid soil damage in advance by suitable harvesting methods.

This guideline is based on three main information streams:

•       soil moisture

•       inclination of the terrain

•       sensitivity of the soil.

A technological map was developed to make thesethree dimensions transparent for every single stand.

With this map, the user can select a working method that fits best to the local environmental conditions. It is binding for all forest officers in the state forest of Saxony.

This approach has sparked a heated debate, because it demands to enlarge the distance of the trails from 20 to 40 m as far as the soil has a higher sensitivity.

The opponents argue that this will push the harvesting costs without any compensation. So, it prevents earning a decent income in forestry.

This Saxonian approach is very normative and can only work inside a state forest or by law. It seems not to be an adequate solution for the European diversity.

Nevertheless, we like the basic idea to steer the selection of working methods to those ones that minimize the risk of any damage on the trail.

Thus instead, we look for an approach that leaves a maximum of freedom to the decision maker to decide for himself according to the conditions of his region.

Therefore, as a proposal, in Technodiversity we suggest a decision-making tool that combines a technogram of the stand with the ecogram of the working methods.

(See more at TDiv PR1-D04)

The three-step-model of decision-making in forest operations divides the decision-making process into three logical sub-steps:

·      The first step looks for those technical methods that can be able to do the job that is demanded under the given conditions. These methods are mostly defined by the machines, but the decision-maker should be sure that the operators are available, too, and that the necessary infrastructure for support, repairs etc. is there. It can be recommended to look for 3 to 5 options that are as different as possible concerning different machines, different degrees of mechanization… In addition, one more option should be regarded at every decision-making process: the zero-option, say to do nothing and not to fulfil the demanded job at all. This first step is called the functionalization.

·      The second step makes the assessment of all options at the background of the given environment and conditions. We call it localization. The criteria are the economic suitability for the company (effectiveness and efficiency), the ecological suitability for the local environment (ecological compatibility and eco-efficiency), and the social suitability for the local population (societal compatibility and ergonomics). If any option fails under one criterion due to official rules or laws, it must be separated from the further decision-making process.

·      The third step asks for the best option. Since all remaining options follow the rules and laws, the decision-maker is free to select that option that fulfils his individual priorities or preferences in the best way. This selection can be done emotionally without a transparent procedure, so we call this third step individualizing. But there are some decision-making rules that make the way to find the final decision more transparent and reliable.

(See more under TDiv PR1-A04)

Total system costs are a part of the cost calculation. Since most processes are composed by two or more sub-processes, their costs must simply be added, too.

But there are some exceptions. In a case, where one sub-process must wait for another one, the productivity of the total system is defined by the productivity of the slowest sub-process.    

(See more at TDiv PR1-C05)

A tractor winch is used for pre-skidding full trees, tree length and logs from the stand (buffer 11, 12 or 13) to the trail (buffer 21, 22 or 23). Alternatives are the horse in flat terrain or the mule in steep terrain or the portable winch.

Like the portable winch, the tractor winch reels in or pays out cable. In contrast to the portable winch, the tractor winch is located on a tractor and therefore does not have to be tight to a standing tree to perform its dragging function. Also different from the portable winch, the tractor winch manages to drag more than just one tree length/ full tree/ log out of the stand.

The work with the tractor winch is declared as simple mechanized work.

See T-classes for trafficability

The tree length method is one of four different functional groups of harvesting methods. The others are fulltree, cut-to-length and chip method.

With the tree length method, two beginnings are possible: (a) Either the tree is delimbed at the felling site and moved as a tree length all the way to the forest road. Or (b) it is felled, pre-skidded to the strip road as a full tree and delimbed there, prior to extraction to the forest road. In both cases, the tree reaches the forest road as a tree length.

Once at the forest road, the tree length can be transported to the factory as such (c), or cross-cut into logs before transport (d) or even chipped at the roadside and transported as chips (e).

(See more at TDiv PR1-B07)