Arboretum Freiburg-Günterstal: Preface
The Freiburg-Günterstal Arboretum has been set up in the Municipal
Forest District of Freiburg - Günterstal Forest Range - in cooperation with the Forest
Faculty of the Albert-Ludwig-University of Freiburg and its Botanical Garden.
Arboretum Freiburg-Günterstal: Assignment
An Arboretum should be an enrichment of native forests both for the
experts and the non-specialists. Providing a description of native tree and shrub species
as well as of those from forests in other continents is of first priority for an
Arboretum.
For experts:
the Arboretum is a spot of supplementary education: proving and enhancing knowledge of
family order, generic term or species of trees and shrubs; determining them and becoming
acquainted with them; gathering illustrative material; verifying economical usability and
suitability for landscape architecture. It is supposed to help maintain and develop tree
species endangered at their natural stands.
For non-experts:
the Arboretum is - as for a globetrotter - an opportunity to learn about trees and shrubs
of other continents and countries. People interested in dendrology, forestry or
horticulture meet new and versatile forest aspects that contribute to the diversity of
forests and to the enrichment of landscapes. For native but so far unnoticed or mostly
ignored tree and shrub species, e.g. Yew or Service Tree the Arboretum should be
conducive.
Tree species diversity of comparable geographical latitudes is strikingly higher in
America or Eastern Asia than in Europe. The reason for this was the evasive movement of
tree species during the Ice Age and their later remigration. On the European Continent
remigration was - because of the East-West-extension of the Alps - either infeasible or
possible only on a small scale. Many tree species that are going to be reintroduced today
had been native before the Ice Age Period, e.g. Big Tree (Sequoiadendron giganteum), Red
Cedar (Thuja plicata), Yellow Poplar (Liriodendron tulipifera) and others. From this point
of view, reintroducing does not mean cultivating "foreign tree species" but the
return of former native species. This is what the Arboretum wants to contribute
to.
Arboretum Freiburg-Günterstal: Natural Geographic Region
The arboretum is situated in the Atlantic Climatic Zone from 290m to
430m m.s.l., precipitation comes to 1.000 mm/year, from which 600 mm go to the vegetation
period (IV-IX), annual mean temperature is ca. 9° C, average temperature during
vegetation period reaches about 17° C. Bedrock is Gneiss. Soils usually are deep, humous
and clayey brown soils. The whole Arboretum area belongs to more or less inclined,
sometimes steep slopes covering all aspects.
Arboretum Freiburg-Günterstal: History
Around the turn of the century large-scale cultivations of various tree
species - especially Japanese and American - occurred in the Municipal Forests. Plantings
of Douglas Fir were started provably in 1896. Today, Douglas Fir Stands of the Municipal
Forest District are - beyond regional borders - widely known and are object of national
and international excursions. From 1901 to 1911 several hundred thousands of foreign tree
specimen were cultivated in the Municipal Forests. An example from 1902 may elucidate
this. During that year the forests of Günterstal were planted - among others -
with:
- 1.940 Mountain Pines (Pinus montana)
- 3.800 Douglas Firs (Pseudotsuga menziesii)
- 2.600 Caucasian Fir (Abies nordmanniana)
- 100 Siberian Larches (Larix sibirica)
- 370 Hybrid black poplar (Populus x canadensis)
Beside the above mentioned species further conifers and deciduous trees
were planted: Japanese Larch, Eastern White Pine, Sitka Spruce, Red Cedar, Japanese Cedar,
Atlas Cedar, Ginkgo (Maiden Hair Tree), Black Walnut, Black cherry, Locust, Red Oak,
Japanese Big-Leafed Magnolia, Sugar Maple and others.
Reasons for success or failure in cultivation were quite miscellaneous. At first
everything - anyhow obtainable - was planted. Geographical, geological and climatic
conditions were disregarded. So it was mere accident, whether or not one of those tree
species was successful in making its mark against growth energy of domestic species. Many
a forester quickly found the cause of the failure: The "new tree species" is
good for nothing... Vitality of some tree species however was that obvious a few years
after their cultivation, that they were preferably grown, while others weren't taken into
account anymore. The cultivation of Douglas Fir and Red Oak could count for a positive
example, while - from today's view - predictable negative examples were efforts on Atlas
Cedar and Kentucky Coffee Tree.
Prior Forest Management Planning Reports prove the continuously ongoing use of foreign
tree species, admittedly confined by the period of World War I and II. From those many
years of experience in cultivation some up to 80 years old specimen, groups or even stands
remained until now. Within the Günterstal forest area, besides the extensively dominating
Douglas Fir (Pseudotsuga menziesii) conifers like Pinus strobus, Pinus banksiana, Picea
orientalis, Pinus ponderosa, Abies nordmanniana, Larix leptolepis, Cryptomeria japonica,
Pinus austriaca, Chamaecyparis lawsoniana are found as well as deciduous trees like
Quercus rubra, Juglans nigra, Robinia pseudoacacia and Populus x canadensis. All
cultivations of various tree species since the beginning of this century were - not only
in the Municipal Forest - were aiming at finding tree species with a better growth
performance and therefor being suitable for forestry in general.
Today we know, that only few 'foreign' tree species meet the requirements of forest
management as for example Douglas Fir or Red Oak do. And even in the future only few,
beside those yet mentioned, will be used in forests; on Pleistocene soils in Northern
Germany, for example Pinus contorta latifolia will gain in importance, while
Sequoiadendron giganteum in climatically favored areas of Western Germany and some
Abies-Species in mountain areas are cultivated and tested. On the whole however, these
tree species will reach only little shares of the total forest area. Away from economical
interests, foreign tree or shrub species become more and more important in medical and
aesthetic sectors.
Arboretum Freiburg-Günterstal: Location
The Municipal Forest District of Freiburg, 5.000 ha in size, has 40 % of
its area situated in the meadow lands of the Rhine affluents, 60 % belong to mountain
forests of the Western Black Forest Slopes. The Arboretum is part of the mountain forest
and surrounds Günterstal, a suburb of Freiburg City.
Arboretum Freiburg-Günterstal: Area
The whole area of the Arboretum is about 100 ha. It is and will stay
integrated into the existing forest stands. They are part of 6500 ha forests (= 43 %
forested area) belonging to the urban district (200m - 1300m m.s.l.).
Arboretum Freiburg-Günterstal: Technical Manager
Dipl.-Ing. Forst Hubertus Nimsch
Haus Nr. 31
79283 St. Ulrich/Bollschweil
Tel: ++49 ( 0 )7602 - 920309
Fax: ++49 ( 0 )7602 - 920319
e-mail: hubertus.nimsch@t-online.de
top |
