Hahne and Melles: Climate and Ve~etation History ofthe Taymyr Peninsula
417
from Lama Lake, the Older Dryas is characterized by a distinct decrease in AP values, the
absence of shrub vegetation, and a spread of Artemisia. At Levinson-Lessing Lake, in contrast,
Artemisia is reduced in favour of high Cyperaceae values, which point to higher precipitation
and an increase of moist habitats.
During the Aller¢d interstadial (LL 4 and L 4), a considerable spread of shrub birches and
willows took place in the Lama Lake area on the southern Taymyr Peninsula. Shrub birches
also increased at Levinson-Lessing Lake. In the second half of the Aller¢d period, they may
have occupied higher altitudes of the Byrranga Mountains. Pollen concentrations 2 - 5 times
higher than those of today in the diagram from Levinson-Lessing Lake evidence favourable
climatic conditions. A decrease of AP concentrations in the middle of this period is recorded in
both diagrams, thus indicating a short-term climatic deterioration of regional rather than local
character.
The Younger Dryas stadial (LL5 and L5) in both profiles is characterized by a distinct
decrease in Betula values and an increase of Cyperaceae. This may be due to a cold but
relatively moist climate which eliminated or, at Lama Lake, at least strongly reduced the birch
boscages. The Late WeichselianlHolocene transition in both cores exhibit high values of Dryas
(Dryas octopetala and D. punctata), with maxima during the colder periods Oldest, Older, and
Younger Dryas. This succession is comparable with Europe, where macrofossils of Dryas led
to the naming of these events.
Holocene
The beginning of the Preboreal period in the diagrams from both Levinson-Lessing Lake and
Lama Lake (PAZs LL6 and L6) is characterized by rapidly increasing birch values. At the end
of this period, shrub birches occurred in considerable amounts in the Levinson-Lessing Lake
area, and light forests of tree birches were developed at Lama Lake. A small climatic
deterioration within the Preboreal is indicated by reduced AP values in the Lama Lake core but
was not recorded in Levinson-Lessing Lake. This event may coincide with the "Pereslavl
Event" described by Khotinskiy (1984) for northern Central Siberia, or the "Preboreal
Oscillation" recorded in the GRIP ice core from Greenland as well as in various terrestrial
records in Europe (Bjorck et aI., 1996).
The transition from the Preboreal to the Boreal period (LL 7 and L 7) in both diagrams is
characterized by a decrease of birch pollen in favour of alder and other AP. At LevinsonLessing Lake, the Boreal shrub-birch tundra gave way to a shrub-alder-birch tundra during the
Preboreal period, and the light birch forest at Lama Lake was replaced by a dense larch forest.
The late Preboreal and the Boreal periods clearly represent the Holocene climatic optimum on
the Taymyr Peninsula. This is evidenced not only by the pollen assemblages during this time
interval, but also by very high pollen concentrations, which are up to an order of magnitude
higher than current levels in Levinson-Lessing Lake (Figure 3). This interpretation is in good
agreement with a radiocarbon-dated strong warming shortly after 10 ka BP in the Labaz Lake
area (Siegert et aI., this volume), and a Holocene temperature maximum between 10.2 and 9.0
ka BP reported for the Severnaya Zemlya Archipelago (Makeev, 1983; Figure I). It also
coincides with the occurrence of trees at their range limits in northwestern Canada between 10.0
and 8.5 ka BP (Spear, 1993). In other areas of Russia and in western Europe, in contrast,
determinations of the Holocene climatic optimum often place it somewhat later, in the Atlantic
period (e.g., Klimanov, 1989).
For northern Scandinavia, summer temperatures of 4°C above current temperatures are
suggested for about 9.0 ka BP (Birks, pers. comm. 1997). A similar temperature increase can
be expected for the Holocene climatic optimum at Levinson-Lessing Lake from the occurrence
of a shrub tundra. It would have resulted in mean temperatures of ca. 10°C for July and August
417
from Lama Lake, the Older Dryas is characterized by a distinct decrease in AP values, the
absence of shrub vegetation, and a spread of Artemisia. At Levinson-Lessing Lake, in contrast,
Artemisia is reduced in favour of high Cyperaceae values, which point to higher precipitation
and an increase of moist habitats.
During the Aller¢d interstadial (LL 4 and L 4), a considerable spread of shrub birches and
willows took place in the Lama Lake area on the southern Taymyr Peninsula. Shrub birches
also increased at Levinson-Lessing Lake. In the second half of the Aller¢d period, they may
have occupied higher altitudes of the Byrranga Mountains. Pollen concentrations 2 - 5 times
higher than those of today in the diagram from Levinson-Lessing Lake evidence favourable
climatic conditions. A decrease of AP concentrations in the middle of this period is recorded in
both diagrams, thus indicating a short-term climatic deterioration of regional rather than local
character.
The Younger Dryas stadial (LL5 and L5) in both profiles is characterized by a distinct
decrease in Betula values and an increase of Cyperaceae. This may be due to a cold but
relatively moist climate which eliminated or, at Lama Lake, at least strongly reduced the birch
boscages. The Late WeichselianlHolocene transition in both cores exhibit high values of Dryas
(Dryas octopetala and D. punctata), with maxima during the colder periods Oldest, Older, and
Younger Dryas. This succession is comparable with Europe, where macrofossils of Dryas led
to the naming of these events.
Holocene
The beginning of the Preboreal period in the diagrams from both Levinson-Lessing Lake and
Lama Lake (PAZs LL6 and L6) is characterized by rapidly increasing birch values. At the end
of this period, shrub birches occurred in considerable amounts in the Levinson-Lessing Lake
area, and light forests of tree birches were developed at Lama Lake. A small climatic
deterioration within the Preboreal is indicated by reduced AP values in the Lama Lake core but
was not recorded in Levinson-Lessing Lake. This event may coincide with the "Pereslavl
Event" described by Khotinskiy (1984) for northern Central Siberia, or the "Preboreal
Oscillation" recorded in the GRIP ice core from Greenland as well as in various terrestrial
records in Europe (Bjorck et aI., 1996).
The transition from the Preboreal to the Boreal period (LL 7 and L 7) in both diagrams is
characterized by a decrease of birch pollen in favour of alder and other AP. At LevinsonLessing Lake, the Boreal shrub-birch tundra gave way to a shrub-alder-birch tundra during the
Preboreal period, and the light birch forest at Lama Lake was replaced by a dense larch forest.
The late Preboreal and the Boreal periods clearly represent the Holocene climatic optimum on
the Taymyr Peninsula. This is evidenced not only by the pollen assemblages during this time
interval, but also by very high pollen concentrations, which are up to an order of magnitude
higher than current levels in Levinson-Lessing Lake (Figure 3). This interpretation is in good
agreement with a radiocarbon-dated strong warming shortly after 10 ka BP in the Labaz Lake
area (Siegert et aI., this volume), and a Holocene temperature maximum between 10.2 and 9.0
ka BP reported for the Severnaya Zemlya Archipelago (Makeev, 1983; Figure I). It also
coincides with the occurrence of trees at their range limits in northwestern Canada between 10.0
and 8.5 ka BP (Spear, 1993). In other areas of Russia and in western Europe, in contrast,
determinations of the Holocene climatic optimum often place it somewhat later, in the Atlantic
period (e.g., Klimanov, 1989).
For northern Scandinavia, summer temperatures of 4°C above current temperatures are
suggested for about 9.0 ka BP (Birks, pers. comm. 1997). A similar temperature increase can
be expected for the Holocene climatic optimum at Levinson-Lessing Lake from the occurrence
of a shrub tundra. It would have resulted in mean temperatures of ca. 10°C for July and August