Nicola Arndt und Matthias Pohl - Neobiota

the driest (like Ulmus and Corylus in the west), and of the wettest habitats (Alnus incana, Salix
pentandra and mires) have most frequently been used as criteria.
4 Conclusions
1. A division of the Arctic including five zonal units with almost equal temperature sum ranges seems
to function very well, with a very high correlation between the zones mapped, the criteria used (not
surveyed here) and the positive sum of monthly mean temperatures from 78 meteorological stations in
the European Arctic.
2. Regional changes in zonal boundaries of the Panarctic Flora Map can be made on Novaya Zemlya
and at the northern part of the White Sea area.
3. The polar tree line roughly coincides with the temperature sum of 36 o C in both oceanic and
continental areas, but regularly changes from 8-9 to 12-12.5 o C in mean July temperatures from the
westernmost to the eastern continental areas.
4. Meteorological stations are completely lacking from mountains in the study area, except near
Kirovsk in the Kola Peninsula, where a good local data set can be further studied for a comparison
with the latitudinal gradient.
5. Mean July temperatures are impossible to use for the delimitation of the boreal zonal units, but
temperature sums have a high positive correlation. A recommended system primarily based on
TUHKANEN (1985) defines a northern boreal zone between sums of 36-47 o C and a middle boreal zone
between 47 and 62 o C, both in oceanic and continental areas.
6. The Map of the Natural Vegetation of European adopts a much more broadly defined northern
boreal zone in Russia than for the Nordic countries, resulting in a poorer correlation with climatic data.
7. There is a strong need for a renewed study of the botanical criteria used to define the boreal
subzones in continental vs. oceanic areas, and across national boundaries in northern Europe.
References
AHTI, T.; HÄMET-AHTI, L. & JALAS, J. (1968): Vegetation zones and their sections in northwestern
Europe. – Ann. Bot. Fenn. 5: 169-211.
ALEXANDERSSON, H.; KARLSTRÖM, C. & LARSSON-MCCANN, S. (1991): Temperaturen och
nederbören i Sverige 1961-90. – Referensnormaler. SMHI Meteorologi Klimatsektionen nr. 81.
AUNE, B. (1993): Temperaturnormaler, normalperiode 1961-1990. – Det Norske Meteorol. Inst. Klima
Rapp. 02/93: 1-63.
BOHN, U.; GOLLUB, G. & HETTWER, C. [Bearb.] (2000): Karte der natürlichen Vegetation
Europas/Map of the Natural Vegetation of Europe. Maßstab/Scale 1:2.500.000. Teil 2/Part 2:
Legende/Legend, 153 S.; Teil 3/Part 3: Karten/Maps (9 Blätter/Sheets, Legendenblatt/Legend
Sheet, Übersichtskarte 1:10 Mio./General Map 1:10 million). – Münster (Landwirtschaftsverlag).
CAVM Team (2003): Circumpolar Arctic Vegetation Map. Scale 1:7,500,000. – Conservation of
Arctic Flora and Fauna (CAFF), Map No. 1. U.S. Fish and Wildlife Service, Anchorage, Alaska.
DAHL, E.; ELVEN, R.; MOEN, A. & SKOGEN, A. (1986): Vegetasjonsregionkart over Norge
1:1.500.000. Nasjonalatlas for Norge, Hovedtema 4: Vegetasjon og dyreliv, kartblad 4.1.1. –
Hønefoss (Statens Kartverk).
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