2002
  • Non-ICIMOD publication

Share

863 Views
Generated with Avocode. icon 1 Mask color swatch
10 Downloads

Larch timberline and its development in north China

  • Hongyan Liu
  • Zhiyao Tang
  • Junhu Dai
  • Summary

Alpine vegetation and timberline development were investigated on 4 high mountains in North China: Mt. Taibai (34°N, 108°E; 3767 m), Mt. Guandi (38°N, 111.5°E; 2831 m), Mt. Wutai (39°N, 113.6°E; 3058 m), and Mt. Xiaowutai (40°N, 115°E; 2882 m). The relationships between distribution of tree species and climatic factors on the uppermost parts of these mountains were established. As a result of the continental climate, their timberlines are composed of larch species, such as Larix chinensis on Mt. Taibai and Larix principis-rupprechtii on the other mountains. Two climatic indices, a warmth index (WI) and a humidity index (HI), were calculated for a differentiation of tree species near the timberline. A WI of 15°C mo has been commonly regarded as the limit for the timberline in East Asia. In addition, we suggest that the Larix timberline is formed when the HI is lower than 210. The understorey species of the forest patches inside the timberline and the L chinensis forest are similar on Mt. Taibai. These species are also distributed mostly in subalpine scrubs and meadows rather than in the Abies fargesii forest. This implies greater resistance to cold and drought in L chinensis than in A fargesii. Timberline movements were roughly reconstructed through analysis of sediments from the alpine zone of Mt. Taibai. A drier climate during 1830–1450 14C years BP resulted in a lower Abies timberline and was favorable for distribution of Larix, reflected by pollen diagrams and palaeolimnological evidence, such as grain size and total organic carbon. Percentages of Abies/Picea pollen recurred from 1450 to 680 14C years BP, implying an upward movement of Abies/Picea. Abies/Picea then moved downward, and the timberline was possibly replaced by Larix. In recent centuries, Picea/Abies has tended to move upward again.

  • Published in:
    Mountain Research and Development, Vol.22, No. 4
  • Language:
    English
  • Published Year:
    2002
  • External Link:
    External link