Palaeoclimatic Estimates for the Late Pliocene Based on Leaf Physiognomy from Western Yunnan, China

Authors : SANPING XIE, BAINIAN SUN, JINGYU WU, ZHICHENG LIN

Pages : 251-261

Doi:10.3906/sag-1209-11

View : 16 | Download : 5

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Based on leaf physiognomy of the Late Pliocene Tuantian megaflora from the Mangbang Formation of Tengchong County in western Yunnan, a quantitative reconstruction of palaeoclimate was performed with Leaf Margin Analysis insert ignore into journalissuearticles values(LMA); methodology and the Climate-Leaf Analysis Multivariate Program insert ignore into journalissuearticles values(CLAMP);. The latter produced the following parameters: mean annual temperature insert ignore into journalissuearticles values(MAT); from 17.2 to 17.7°C; warmest month mean temperature insert ignore into journalissuearticles values(WMMT); from 25 to 25.5°C; coldest month mean temperature insert ignore into journalissuearticles values(CMMT); from 9.5 to 10.8°C; length of growing season insert ignore into journalissuearticles values(GRS); from 9.5 to 9.7 months; growing season precipitation insert ignore into journalissuearticles values(GSP); from 1834.3 to 1901.2 mm; mean monthly growing season precipitation insert ignore into journalissuearticles values(MMGSP); from 222.4 to 230.5 mm; precipitation during the three consecutive wettest months insert ignore into journalissuearticles values(3-WET); from 892.1 to 917.8 mm; precipitation during the three consecutive driest months insert ignore into journalissuearticles values(3-DRY); from 474.5 to 512.8 mm; relative humidity insert ignore into journalissuearticles values(RH); from 76.7 to 77.8%; specific humidity insert ignore into journalissuearticles values(SH); from 10.7 to 10.8 g/kg; and enthalpy insert ignore into journalissuearticles values(ENTHAL); from 31.8 to 32 kj/kg. However, the MAT obtained from the Chinese LMA regression at 18.7°C, is slightly higher than that from CLAMP. The integrated analysis of these data and three adjacent pollen floras in western Yunnan suggests that the Gaoligong Mountains insert ignore into journalissuearticles values(a southern portion of the Hengduan Mountains); were only raised to modest altitudes in the Late Pliocene.
Keywords : Hengduan Mountains, leaf physiognomy, monsoon, palaeoclimate, Pliocene, western Yunnan