| Growth-climate responses of various sub-tropical tree species in Ailao Mountains, southwestern China |
| Paper ID : 1041-ADA2013 |
| Authors: |
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Fan Ze-Xin *1, Achim Bräuning2, Aster GEBREKIRSTOS3 1Menglun Town, Mengla County, Yunnan Province 666303, P.R. China 2Kochstrasse 4/4, D-91354 Erlangen 3Institute of Geography, University of Erlangen-Nurnberg |
| Abstract: |
| Climatic conditions in the Chinese monsoon regions are changing, affecting local hydrological and land- use systems. The Ailao Mountains of central Yunnan (southwestern China) lie in the region of Asian summer monsoon. Evergreen broadleaved forests flourish in this mountain area, with a humid summer and cloudy winter climatic conditions. Using dendrochronological techniques, we explored the effects of inter- and intra- annual climate variations on radial growth of various tree species growing in the subtropical forests. Monthly tree growth dynamics were recorded by bad metal dendrometers. High resolution dendrometers (Ecomatik, DR) were installed on tree stem at breast height for 10 tree species. Daily stem expansion and shrinkage and radial increment were registered at 10 minutes intervals. Daily amplitudes of stem diameter variations and daily and monthly net growth rates were determined and related to climatic variables. Sap flow rate were measured using Granier-type heat dissipation methods. Seasonal cambial growth dynamics were compared tree water status registered by sap flow measurements. Tree ring-widths chronologies were developed for various tree species according standard dendrochronological techniques. Our results showed daily- to monthly growth-climate relationships of tree species in the subtropical mountains, and intra-annual growth dynamics are in consistent with tree water status. Most of the studied tree species had visible ring boundary and cross-dateable, thus suitable for dendrochronological studies. Correlation analyses with regional climate data revealed that trees growing in the mountain cloudy forest are sensitive to climate change. We found high dendroclimatological potential in the subtropical evergreen forests. Further exploration should focus on long-term climate reconstruction, as well as modeling growth-climate response of different species, especially under future climate change. Long-term changes of intrinsic water-use efficiency (water consumed by a tree per g produced biomass) shall be studied by stable carbon isotopes trends in wood cellulose. |
| Keywords: |
| Ailao Mountains, Sub-tropical cloudy forest, Dendrometer, Sap flow, Cambium activity, Growth-climate responses |
| Status : Abstract Accepted |
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