西双版纳区域气候变化对植物生长趋势的影响

目前全球变暖已经致使地球上生物群系的格局发生了显著的变化。高纬度地区的植物生长由此变得更加活跃,而热带地区植物生长的趋势仍然是一个具有争论的问题。西双版纳热带植物园地处中国西南地区,20世纪70年代以来,这里气候发生了显著的变化,其气温以每10年0.18℃的速度上升。本研究利用西双版纳热带植物园中的48种热带植物（28科）的株高生长数据（1974～2003年）来分析其对西双版纳区域气候变化的长期变化响应,通过对株高与气候因子的相关分析选出对植物株高生长影响最大的气候因子。结果表明,植物在研究期间的株高生长年间波动比较强烈,但没有表现出明显的趋势;植物的株高生长主要受到干热季（3、4月份）的日照时数（负）与月均最低气温（正）所影响,而干热季正是这些植物每年开始萌叶的时期;另外,降雨并没有对引种植物株高生长产生显著的影响;从2个关键因子的长期变化趋势来看,西双版纳气候变化将有利于保护植物的生长,进而将有利于植物园内热带植物的保护与保存。

Effects of the Regional Climate Change on the Plant Growth Trend in Xishuangbanna

So far as we know,global warming has notably changed the patterns of the biomes on earth. As the increasing activity of plant growth in high latitudes has been confirmed,the plant growth trend in tropics is still a controversial question concerned. Xishuangbanna Tropical Botanical Garden is located in southwestern China,and the climate here has changed significantly during the past a few decades. As the temperature rose averagely 0.18℃ per ten years since 1970s,how would the plants here respond？ Here we used the long-term height plant growth data （1974-2003） of 48 tropical conserved species from 28 families in the botanical garden to present their inter-annual variation of growth responding to the regional climate change. Correlation analysis between the inter-annual climatic factors and the plant heights were performed to reveal the key climatic factors. Result shows as followed. For the conserved species in Xishuangbanna,inter-annual mean plant height varies strongly along years since 1974; however,no significant trend is shown. Height growth of the introduced species is mainly impacted by the sunshine duration （negative） and mean minimum temperature （positive） in dry-hot season （March and April）,which is the period when these plants begin to flush leaves. Yet,rainfall is not included in these key factors. In the perspective of the trends of the 2 key factors,growth of the plants in the botanical garden is expected to be benefited. And this will also benefit the conservation work for tropical plants in the botanical garden.