Environmental Engineering Reference
In-Depth Information
about 2300 - 2500 m ( Ö AG 2000 ; Krautzer et al .
2004a). Thus, restoration efforts above this altitudinal
belt can generally not be accomplished with plant
material found in the horticultural trade. Conse-
quently, a good understanding of target species' repro-
ductive behaviour and vegetative growth patterns and
the dynamics of initial phases of succession, are essen-
tial for development of appropriate restoration methods
(Urbanska 1997 ; Peratoner 2006 ).
Prevailing environmental conditions within high
Arctic and high alpine zones are usually so harsh for
plant growth that restoration even with site-specifi c
plant material is nearby impossible. As is the case for
Arctic bogs and alpine Carex curvula meadows, few veg-
etation types in these regions can be restored within
the period of one human life span and their distur-
bance should therefore - whenever possible - be
avoided. Restoration with site-specifi c seed and plant
material results not necessarily immediately in the tar-
geted vegetation type. Therefore, it should at least
promote an ecosystem state from which the planned
vegetation type can develop through natural succes-
sion within 10-20 years.
Taking account of the targets and limitations of res-
toration in Arctic-alpine environments and incor-
porating the knowledge developed during the last
decades, we can make some recommendations on how
to achieve sustained success.
Figure 15.3 Essential key factors for plant establishment
and growth within Arctic-alpine environments.
to the use of feasible plant material, improvement of
(1) substrate stability, (2) physical and chemical soil
conditions for plant establishment and growth and
(3) site - specifi c climatic conditions are essential resto-
ration measures.
15.4.1
Abiotic key conditions
15.4
RESTORATION APPROACHES
It is essential in restoration planning to meet the
required abiotic conditions of a habitat (e.g. nutrient-
poor, dry or damp). Particular requirements for the
restoration in Arctic-alpine environments are given
below.
Globally there is a wide range of different vegetation
types in the varying vegetation zones, and one has to
be careful when attempting to transfer or adapt materi-
als and methods from, for example, middle Arctic areas
from Alaska to Norway, or from European alpine areas
to South American alpine areas. Restoration with
plant material can be successful only within the eco-
logical amplitude of the selected species. The restora-
tion techniques applied have to balance the site-specifi c
plant growth limiting key factors with respect to the
selected plant material. At most Arctic or alpine loca-
tions, there is no single limiting key factor but rather a
combination of several (Figure 15.3). The application
of site - specifi c seed or plant material can be successful
only when the appropriate period for application is
respected (Figure 15.4). The following presents a short
overview of the most commonly used restoration tech-
niques within Arctic-alpine environments. In addition
Substrate s tabilization
Substrate stabilization is a particular requirement in
restoration of Arctic-alpine ecosystems with (1) a high
'relief energy' (i.e. difference of minimum altitude
from the maximum altitude in a sampled area), (2)
vulnerability to wind erosion and (3) thawing perma-
frost. Commonly known methods for substrate stabili-
zation (e.g. Zeh 2007) are generally applicable with the
exception of sites with thawing permafrost. When con-
cerning geotextiles, however, the use of nondegradable
synthetic fi bres and wire netting should be, where
possible, avoided. Under given climatic conditions,
galvanized-iron netting and synthetic netting degraded
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