With the
ecogram, Technodiversity indicates under which forest conditions a harvestingmethod can be used. It has the same basic structure like the technogram of
the stand. When both graphs, technogram and ecogram, match well, then the
method is suitable under these conditions.
Every
method has its limitations. Concerning the structure of the ecogram, the following
rules will help to find them:
The upper limit is defined by technical restrictions. A harvester, e.g.,
has its limits because of the length of its crane. Other methods are limited by
the maximum length of the pre-skidding devices. And all methods, where machines
must drive on the soil, cannot work at P5.
To the
right side (towards wet soils), the damage on the ground limits any acceptance.
Heavy machines are perfect for dry soils, good on fresh soils, and come to
their limits with moist soils. If there are aids like bogie tracks or traction
chains on the wheels, compatibility moves one column to the right.
The left
and lower limits are given by competing methods, that are better for those
conditions. No one who can take these alternatives would decide to take the option
in dispute, because it is too expensive, too cumbersome or just not necessary
for those conditions.
In the
figure, the functiogram of an almost fully mechanizedmethod with bogie-tracks
for 40 m distance of the trails is shown together with its corresponding
ecogram. By the chainsaw, this method is specialized for P3 (= 40 m trail distance),
not less and not more. For a fresh soil (T2), the suitability is assessed as very
good (star symbol), for moist soils it is good (plus symbol), and for wet
conditions it is only limited (minus symbol). Also for dry conditions we
decided to give a minus symbol, because there a method without bogie-tracks is
better.
Matching the technogram of the stand and the ecogram
of harvesting methods, those methods can be found that are best under the given
conditions.
The
problem is, that the ecogram of a working method must be composed by the
ecograms of the sub-processes. Here, some rules must be regarded.
