In the 19th cen­tu­ry, large parts of the Grünewald were bare as a con­se­quence of an exces­sive exploita­tion, main­ly due to the met­al­lur­gi­cal site of Dom­mel­dan­ge and oth­er met­al­lur­gi­cal plants (around 1850) in the south of the coun­try, need­ing huge quan­ti­ties of fire­wood for the fur­naces. Soon a seri­ous lack of wood with threat­en­ing con­se­quences came up and new reg­u­la­tions con­cern­ing the exploita­tion of tim­ber had to be set up.

Timber forest

Tim­ber for­est struc­tured by age

In order to stop the wild rav­age, the Grünewald usage was reg­u­lat­ed by the sys­tem of for­est regen­er­a­tion up from the sec­ond half of the 19^th cen­tu­ry. In the tim­ber for­est, trees of dif­fer­ent ages did not grow togeth­er on the same site, but were sep­a­rat­ed accord­ing to their ages. Often trees were cut down by com­plete clear­ing and these sur­faces were refor­est­ed lat­er on by plant­i­ng new ones. With the time snow, ice, insect and storm dam­ages became more and more fre­quent and the com­plete clear­ing sys­tem weak­ened the vital strength of the for­est con­sid­er­ably. There was absolute­ly no nat­ur­al devel­op­ment and the dam­age of the storm Wiebke and Vivien in 1990 were fatal for those zones that had not been nat­u­ral­ly constructed.

Permanent forest

Beech grove in mul­ti lay­er struc­ture with herb and bush layer

As a con­se­quence it was decid­ed that the tim­ber for­est sys­tem had to get replaced by the process of nat­ur­al for­est regen­er­a­tion, lead­ing to a per­ma­nent and nat­ur­al com­posed for­est. In such a for­est human inter­ven­tions are lim­it­ed to a min­i­mum in order to sup­port to max­i­mum the nat­ur­al evo­lu­tion of the for­est for a prop­er usage. This sys­tem of for­est exploita­tion allows hav­ing on one same sur­face trees of dif­fer­ent ages, from the young sprouts to the coarse wood debris, offer­ing a rich habi­tat for many ani­mal and botan­i­cal species.

A strong and mul­ti­lay­er struc­tured for­est is much more resis­tant to bad weath­er con­di­tions and offers many habi­tats for fau­na and flo­ra. The typ­i­cal trees of this kind of for­est in the region are: beech, oak, ash, maple, cher­ry tree, alder and birch.

In the Grünewald no chem­i­cal fer­til­iz­er are used either and the trees that have to get cut down are cho­sen indi­vid­u­al­ly. A new tree gen­er­a­tion is born out of the young seedlings, grow­ing on the ground lev­el, per­fect­ly pro­tect­ed by the crowns of the high stemmed upper lay­er trees (prin­ci­ple of the nat­ur­al for­est regeneration).

The per­ma­nent for­est aims to deliv­er an excel­lent high qual­i­ty tim­ber, gen­er­at­ed by a long last­ing, nat­u­ral­ly grow­ing and pro­tec­tive forest.

In the tim­ber for­est, trees of dif­fer­ent ages do not grow togeth­er on the same site, but are sep­a­rat­ed accord­ing to their ages. Trees are cut down by com­plete clear­ing and these large sur­faces are refor­est­ed lat­er on by plant­i­ng new ones with only one or a few dif­fer­ent species, gen­er­at­ing monot­o­nous sur­faces of one same age.	In the per­ma­nent for­est all age cat­e­gories are rep­re­sent­ed on a min­i­mum sur­face. When sin­gle trees are cut down clear­ings that allow the light to pen­e­trate to the ground lev­el (light shaft) are formed and gen­er­ate new plants and trees find­ing per­fect vital conditions.
Oak seedling	Beech seedling