ensembles of Global Circulation Models-Regional Climate Models (GCM-RCM)
combined with the SRES A1B emission scenario. On the basis of the GCM-RCM
projections on temperature and precipitation changes, we set up two hypothetical
scenarios to be analysed in the context of climate-change related challenges for
habitats, and also for the socio-economic development of the Biebrza Valley. In the
last section of the chapter we discuss the interface between the potential environmental conservation of valuable wetland habitats and the management pressures of
various groups of stakeholders. Concise conclusions from our research are
highlighted in the last part of this chapter.
14.2 Environment and Management of the Biebrza Valley
Biebrza Valley and its wetlands have become a sink of the catchment of the River
Biebrza, which covers 7,120 km
2 , (almost 2.5 % of the total area of Poland).
Surrounded by glacial plateaus of the Wartian (Riss) Glaciation (Gonia ˛dzka and
Kolnen ´ska Plateau, Soko ´lskie Hills) and morphologic units of the Vistulian (Wurm)
Glaciation (Ełckie Lakeland and Augustowska Outwash Plain), the ice marginal
valley of Biebrza (Fig. 15.1) is one of the largest coherent wetland areas in Central
Europe. The majority of the valley is covered with peat (locally decently
decomposed due to former drainage), which rests on the sandy plain of the Biebrza
Ice Marginal Valley. The maximum thickness of the peat layer reaches from
approximately 3 m in the southern-most part of the valley, up to approximately
8 m in the northern part, in the so-called Upper Basin (Z ˙ urek 1984). Locally, the
continuous peat cover is perforated by sandy dunes, which play an important role in
sustaining the biodiversity of the wetlands. The temperate climate of the Biebrza
Valley with continental influences can be characterised by the average annual air
temperature of 6.6
C (Banaszuk 2004), with annual magnitudes of more than 55
C
(maximum and minimum values of air temperature measured in the Biebrza Valley
in 2011 reached 30.5
C and À25.6
C, respectively). The average annual sum of
precipitation calculated by Kossowska-Cezak (1984) for the Biebrza Valley equals
583 mm. On the basis of precipitation measurements in the Laskowiec rain gauge
(see Fig. 15.1) for the years 1996–2011, we estimate an average annual sum of
precipitation of 574 mm. The average sum of precipitation in the summer
(May–August) – a critical season for wetlands due to the high rate of evapotranspiration – equals 260 mm (data from the Laskowiec rain gauge). The constant
saturation of the valley, preconditioned by the hydrogeology and low slopes,
occasions the appropriate conditions for valuable wetland habitats and species.
Among the most important wetland habitats in the Biebrza Valley, there are
alkaline fens, mire meadows, transition mires and bogs with pine bog forest and
alder forests. All are listed in Annex I of the 92/43/EEC “Habitat Directive”. Due to
presence of unique plant species (e.g. Saxifraga hirculus, Liparis loeselii, Polemonium coeruleum, Swertia perennis, Betula humilis), those habitats have become
those of the highest ecological value and consequently of the highest conservation
status. The exceptionally rich fauna of the Biebrza Valley is represented by
212
M. Grygoruk et al.
combined with the SRES A1B emission scenario. On the basis of the GCM-RCM
projections on temperature and precipitation changes, we set up two hypothetical
scenarios to be analysed in the context of climate-change related challenges for
habitats, and also for the socio-economic development of the Biebrza Valley. In the
last section of the chapter we discuss the interface between the potential environmental conservation of valuable wetland habitats and the management pressures of
various groups of stakeholders. Concise conclusions from our research are
highlighted in the last part of this chapter.
14.2 Environment and Management of the Biebrza Valley
Biebrza Valley and its wetlands have become a sink of the catchment of the River
Biebrza, which covers 7,120 km
2 , (almost 2.5 % of the total area of Poland).
Surrounded by glacial plateaus of the Wartian (Riss) Glaciation (Gonia ˛dzka and
Kolnen ´ska Plateau, Soko ´lskie Hills) and morphologic units of the Vistulian (Wurm)
Glaciation (Ełckie Lakeland and Augustowska Outwash Plain), the ice marginal
valley of Biebrza (Fig. 15.1) is one of the largest coherent wetland areas in Central
Europe. The majority of the valley is covered with peat (locally decently
decomposed due to former drainage), which rests on the sandy plain of the Biebrza
Ice Marginal Valley. The maximum thickness of the peat layer reaches from
approximately 3 m in the southern-most part of the valley, up to approximately
8 m in the northern part, in the so-called Upper Basin (Z ˙ urek 1984). Locally, the
continuous peat cover is perforated by sandy dunes, which play an important role in
sustaining the biodiversity of the wetlands. The temperate climate of the Biebrza
Valley with continental influences can be characterised by the average annual air
temperature of 6.6
C (Banaszuk 2004), with annual magnitudes of more than 55
C
(maximum and minimum values of air temperature measured in the Biebrza Valley
in 2011 reached 30.5
C and À25.6
C, respectively). The average annual sum of
precipitation calculated by Kossowska-Cezak (1984) for the Biebrza Valley equals
583 mm. On the basis of precipitation measurements in the Laskowiec rain gauge
(see Fig. 15.1) for the years 1996–2011, we estimate an average annual sum of
precipitation of 574 mm. The average sum of precipitation in the summer
(May–August) – a critical season for wetlands due to the high rate of evapotranspiration – equals 260 mm (data from the Laskowiec rain gauge). The constant
saturation of the valley, preconditioned by the hydrogeology and low slopes,
occasions the appropriate conditions for valuable wetland habitats and species.
Among the most important wetland habitats in the Biebrza Valley, there are
alkaline fens, mire meadows, transition mires and bogs with pine bog forest and
alder forests. All are listed in Annex I of the 92/43/EEC “Habitat Directive”. Due to
presence of unique plant species (e.g. Saxifraga hirculus, Liparis loeselii, Polemonium coeruleum, Swertia perennis, Betula humilis), those habitats have become
those of the highest ecological value and consequently of the highest conservation
status. The exceptionally rich fauna of the Biebrza Valley is represented by
212
M. Grygoruk et al.