title: Investigation of temperature and aridity at different elevations of Mt. Ailao, SW China.
abstract: Our current understanding is that plant species distribution in the subtropical mountain forests of Southwest China is controlled mainly by inadequate warmth. Due to abundant annual precipitation, aridity has been less considered in this context, yet rainfall here is highly seasonal, and the magnitude of drought severity at different elevations has not been examined due to limited access to higher elevations in this area.In this study, short-term micrometeorological variables were measured at 2,480 m and 2,680 m, where different forest types occur. Drought stress was evaluated by combining measurements of water evaporation demand (E p) and soil volumetric water content (VWC). The results showed that: (1) mean temperature decreased 1 °C from 2,480 m to 2,680 m and the minimum temperature at 2,680 m was above freezing. (2) Elevation had a significant influence on E p; however, the difference in daily E p between 2,480 m and 2,680 m was not significant, which was possibly due to the small difference in elevation between these two sites. (3) VWC had larger range of annual variation at 2,680 m than at 2,480 m, especially for the surface soil layer.We conclude that the decrease in temperature does not effectively explain the sharp transition between these forest types. During the dry season, plants growing at 2,680 m are likely to experience more drought stress. In seeking to understand the mountain forest distribution, further studies should consider the effects of drought stress alongside those of altitude.
authors: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China.
authors: Guangyong
authors: G
authors: You
authors: Yiping
authors: Y
authors: Zhang
authors: Yuhong
authors: Y
authors: Liu
authors: Douglas
authors: D
authors: Schaefer
authors: Hede
authors: H
authors: Gong
authors: Jinbo
authors: J
authors: Gao
authors: Zhiyun
authors: Z
authors: Lu
authors: Qinghai
authors: Q
authors: Song
authors: Junbin
authors: J
authors: Zhao
authors: Chuansheng
authors: C
authors: Wu
authors: Lei
authors: L
authors: Yu
authors: Youneng
authors: Y
authors: Xie
mesh_terms: D000531:Altitude; D002681:China; D055864:Droughts; D008834:Microclimate; D012987:Soil / Q000032:analysis; D013696:Temperature; D014197:Trees; D014867:Water / Q000032:analysis
chemical_list: D012987:Soil; D014867:Water