 |
| Titel |
Tree Growth Responses to Climate Change at the Upper Treeline in the Mountains of Western Tuva |
| VerfasserIn |
Mariam Kolunchukova, Andrey Reznikov, Kirill Chistyakov |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250114007
|
| Publikation (Nr.) |
 EGU/EGU2015-15713.pdf |
|
|
|
|
|
| Zusammenfassung |
| The response of forest to climate change is most pronounced at higher elevations due to
the limitation of growth by temperature and precipitation. Modern instrumental
measurements show temperature increase during the 20th century that causes rising of
upper boundary of forests in the mountain regions. Climate-driven upward tree
migration in the region of Altai-Sayan Mountains has been demonstrated in a number of
investigations. The purpose of this research was an analysis of the impact of main
climatic factors on tree growth and current treeline dynamics under the climate
changes in the mountains of Western Tuva. Tree-ring width chronologies were built
based on larch samples (Larix sibirica) of living trees from the upper treeline, the
chronologies were compared, their statistics were estimated, and correlation with
temperatures and precipitations were analyzed. Tree growth is dominated by two major
factors – moisture supply and summer temperatures. It is generally hypothesized
that tree growth at the lower treeline is precipitation limited while at the upper
treeline is normally controlled by temperature. However in the upper forest belt
temperature can influence tree growth negatively as well as positively. Correlations
between chronologies and climatic factors revealed different climatic influences on
radial growth along a north-south gradient in the study area. Within northern wetter
areas tree ring width correlates positively with summer temperatures and negatively
with precipitation, so temperature increase leads to rise of upper treeline. Within
southern drier areas tree ring width correlates positively with precipitation and
negatively with rising summer temperatures. The analysis showed that in this case the
tree growth is determined by combination of optimal temperature and maximum
precipitation. The results provide evidence of critical importance of temperature and
precipitation in the upper forest belt and will be used in subsequent analysis of temporal
and spatial forest dynamics within the upper mountain forest belt of Altai-Sayan
Mountains. |
|
|
|
|
|
|