Interannual variations of vegetation activity and hydrologic cycle observed in Eastern Siberia using stable isotopes of water
Abstract
East Siberian taiga is a unique ecosystem, which is established on permafrost. Climate there is extremely dry (about 250mm of annual mean precipitation). Soil moisture, water relating vegetation activities, stable isotope ratios of variety of water (precipitation, soil water, sap water, river water, etc) were observed at Yakutsk, Russia. Large interannual variation was observed in soil moisture and its stable isotopic composition, depending on summer rainfall. Observational results also shows that pulse of spring snowmelt makes seasonal variation in soil moisture, which superimposes on the interannual variation. Although the snow meltwater is not so important for interannual variation of soil moisture, it is extremely important for plant activities, because highest photosynthetic and transpiration activities soon after leaf unfolding are supported by the snow meltwater. Ice meltwater from permafrost is also very important as a direct water source for plants during drought. In other wards, function of soil for water storage stabilizes transpiration. Discrepancy of the period of transpiration by plants (maximum in June) and soil thaw may also derive another time-lag for hydrologic cycle, and water stress in late summer during dry year may also affect the activity of vegetation in the following summer.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFM.H51A0763S
- Keywords:
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- 1818 Evapotranspiration;
- 1823 Frozen ground;
- 1851 Plant ecology;
- 1863 Snow and ice (1827);
- 1866 Soil moisture