Fourth Study Conference on BALTEX Scala Cinema Gudhjem

in the northern zone and on the eastern edge of the area
studied, coinciding with the open area covered by tundra
vegetation. Within these, the lowest values (30 cm) are
found in the part with the highest wind speed. In the forest -
where the wind speed is lower and thus is also drifting of the
snow - the snow accumulation was greater, 70-120 cm. The
largest snow depths (130-140 cm) were found in the
transition between the forest and the open area, where the
snow accumulated from snowfall and a large amount was
transported and deposited by the wind. Inside of the forest
the snow depth showed a uniform distribution.
4. Discussion and conclusions
The analyses of the manual and radar snow measurement
indicate some differences between the snow depths. These
differences are generated by the more frequent data
capturing (every 5 m) by radar than with the manual
measurement (50m) and thus the radar could detect small
variations in the ground and snow cover. On the other hand,
obstacles situated under the snow cover could introduce
imprecision into the radar measurements.
The distribution of snow accumulation varied in relation to
the type of vegetation and wind velocity, while the influence
of elevation was less demonstrable, because of the flat
features of the experimental site (the maximum variability of
the isolines is only 20 m). The snow drifting in the open
tundra resulted in a 30 cm thinner snow cover and almost
half of water equivalent compared to the spruce forest
values. In similar conditions in Canada (northern Québec) to
those of the studied site, the snow cover showed a 20-40 cm
decrease in the deforestation zone (Arseneault and Payette
1992); the zone was probably caused by a post-fire
exclusion of conifers and by the substitution of those by
lichen-tundra vegetation unable to trap drifting snow. The
forest edge constitutes a distinct snow-depth category with
its highest snow thickness, caused by the deposition of the
transported snow.
Beside the influence of vegetation on the distribution of
snow accumulation, the influence of snow on the vegetation
may not be ignored. In the region studied, near the
borderline of the forest, any changes in surface conditions
may create negative feedbacks, which prevent or retard the
returning of the vegetation to its original state. The
accumulation of snow and the microclimatological
conditions induced by the variations in snow cover and local
meteorological conditions (radiation, temperature,
evaporation and wind) cause differences in growth
- 34 -
conditions. The reduced snow cover on the open tundra
results in more unfavourable climatic and soil conditions
for the recovery of the forest. Snow could also give plants
protection against the large number of reindeer - 12 080 a
year (Kemppainen et al. 2001) - that are herded in the
Tuntsa region. Reindeer grazing and trampling causes
negative feedback on the vegetation. In the unforested
area, where snow drifting is more accentuated and the
snow accumulation is lower, reindeers can significantly
retard or even prevent the regeneration of vegetation.
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