Dear Simon Orr,
You asked for information about ProSilva and the "Plenterwald".
These are two different, although related, things.
* ProSilva
ProSilva is an European association of foresters with the aim to promote a
"silviculture close to nature" (One of these silvicultural systems being
the "selection forest").
The president is, now and for the next four years,
Mister Jaap H. Kuper
Koninklijk Park 1
7315 JA Apeldoorn
The NETHERLANDS
* Plenterwald - Foret jardinee - Selection forest
There is a lot to say about selection forests. the best would bee to read
some publications about it, but I'll try to give you a brief overview.
The definition and the practice of selection forest differ from country to
country, so take the following as specific for Switzerland.
The main characteristic of selection forests is to have all the development
stages (from regeneration to mature trees) on the smallest possible spot.
The aim is to harvest no more than the growth and to preserve the specific
structure of the forest (control through the diameter distribution).
In Switzerland, the main species in the selection forest are Picea abies,
Abies alba and Fagus silvatica (the latter represent max. 10%). Research
is going on about selection forest with broadleaves, but in practice the
selection forest is dominated by conifers.
Closely related to the selection forest is the "control method". It was first
presented by GURNAUD in 1878, than implemented and developed by BIOLLEY.
This method consist in a 100% inventory for each compartment (about 1 ha) and
in a control of the standing volume of the harvested trees. It is a quite
intensive method (Bachmann 1991). The aim is to reach an equilibrated state
("etale" in French) which is not known in advance. This state depends on the
site conditions and the tree species.
The harvest operations are determined on the base of visual appreciation of
the forest and on the inventory data (especially: growing rate, distribution
of diameters and volume).
The choice of the trees to be cut in the same intervention rely on the
following 5 criteria (Schuetz 1989):
1. criteria of regeneration
2. criteria of selection and education
3. criteria of regulation of the structure
4. criteria of harvesting
5. sanitary reasons (dead or sick trees)
As you mentioned, it is difficult to find literature about this subject in
English. Everything is in German or French (if you wish, I could send you
these references).
Christina Giesch
Chair of forest management and inventory
ETH-Zentrum, HG G21.2
Raemistr.101
8092 Zurich
Switzerland
giesch@waho.ethz.ch
************
References: Bachmann, P. (1991): Skript Forsteinrichtung III/IV. Prof. fuer
Forsteinrichtung, ETH-Zurich.
Schuetz, J.-Ph. (1989): Le regime du jardinage. Chaire de
sylviculture, ETH-Zurich, 55p. (sorry, no english
translation available)
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