Linking Restoration and Ecological Succession (Springer ... - Inecol

98 Joachim Schrautzer et al.
Figure 5.3 Mowed foreground and abandoned background (successional stage III with
dominant Urtica dioica) wet meadow (Molinietalia) in Schmalensee, central Schleswig-
Holstein, Germany.
wet meadow), labeled Sere B, and for 4B (eutrophic wet meadow), labeled Sere
C. Stage 1 of each of the abandoned sites had a land-use history of cattle grazing
and mowing for hay.
All stage II sites are wet sites and are characterized by an increase in tall clonal
species such as Calamagrostis canescens, Carex acutiformis, Carex acuta, Filipendula
ulmaria, Glyceria maxima, Juncus acutiflorus, Juncus subnodulosus,
or Phalaris arundinacea. These species were already present in stage I, but
became dominant only after abandonment.
In sere (A), stage III develops from stage II through immigration and establishment
of herbaceous species (Phragmites australis). In seres (B) and (C),
ruderal species such as Urtica dioica, Galium aparine, and Galeopsis tetrahit
agg. increase in dominance (Fig. 5.3). These species seldom occur in vegetation
of stage I. Stage IV in all seres results from the immigration and establishment
of woody species (Alnus glutinosa, Betula pubescens).
Site factors and vegetation parameters in all investigated seres differed in a
characteristic way (Table 5.4). Groundwater tables increase and groundwater
amplitudes decrease from stages I to II and vice versa from stages III to IV.
Standing crop and LAI increase significantly from stages I to III (cf. Schrautzer
and Jensen 2006). The lowest standing crop (105 g m −2 ) and LAI (2.5) values
were detected in stands of stage I of sere A.
Even though the vegetation trends for the abandonment seres have been
shown in several successional studies, it is impossible to predict the time when
one successional stage passes over to the next. This is due to differences in
surrounding vegetation and land-use history resulting in a specific seed bank
composition and potentials for the immigration of new species. However, data
from the Biological Station of Steinfurt (unpublished) show the transition from
stage I up to stage III occurs more quickly at eutrophic sites than at mesotrophic