 |
| Titel |
Late Glacial to Holocene environments in the present-day coldest region of the Northern Hemisphere inferred from a pollen record of Lake Billyakh, Verkhoyansk Mts, NE Siberia |
| VerfasserIn |
S. Müller, P. E. Tarasov, A. A. Andreev, B. Diekmann |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1814-9324
|
| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 5, no. 1 ; Nr. 5, no. 1 (2009-03-06), S.73-84 |
| Datensatznummer |
250002247
|
| Publikation (Nr.) |
 copernicus.org/cp-5-73-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
| In this study, a radiocarbon-dated pollen record from Lake Billyakh (65°17' N, 126°47' E; 340 m
a.s.l.) in the Verkhoyansk Mountains was used to
reconstruct vegetation and climate change since about 15 kyr BP. The pollen
record and pollen-based biome reconstruction suggest that open cool steppe
(STEP) and grass and sedge tundra (TUND) communities with Poaceae,
Cyperaceae, Artemisia, Chenopodiaceae, Caryophyllaceae and Selaginella rupestris dominated the area from
15 to 13.5 kyr BP. On the other hand, the constant presence of Larix pollen in
quantities comparable to today's values points to the constant presence of
boreal deciduous conifer (CLDE) trees in the regional vegetation during the
Late Glacial. A major spread of shrub tundra communities, including birch
(Betula sect. Nanae), alder (Duschekia fruticosa) and willow (Salix) species, is dated to 13.5–12.7 kyr BP,
indicating a noticeable increase in precipitation toward the end of the Last
Glaciation, particularly during the Bølling-Allerød Interstadial.
Between 12.7 and 11.4 kyr BP pollen percentages of herbaceous taxa rapidly
increased, whereas shrub taxa percentages decreased, suggesting
strengthening of the steppe communities associated with the relatively cold
and dry Younger Dryas Stadial. However, the pollen data in hand indicate
that Younger Dryas climate was less severe than the climate during the
earlier interval from 15 to 13.5 kyr BP. The onset of the Holocene is marked
in the pollen record by the highest values of shrub and lowest values of
herbaceous taxa, suggesting a return of warmer and wetter conditions after
11.4 kyr BP. Percentages of tree taxa increase gradually and reach maximum
values after 7 kyr BP, reflecting the spread of boreal cold deciduous and
taiga forests in the region. An interval between 7 and 2 kyr BP is
noticeable for the highest percentages of Scots pine (Pinus subgen.
Diploxylon), spruce (Picea) and fir (Abies) pollen, indicating mid-Holocene spread of boreal
forest communities in response to climate amelioration and degradation of
the permafrost layer. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|