中科院西双版纳热带植物园的范泽鑫博士与德国气候学家Axel Thomas合作研究发现，云南省潜在蒸发散总体呈下降趋势，主要由于日照时数和平均风速的下降所致。近日，该研究结果发表在国际学术期刊《气候变化》上。

据介绍，潜在蒸发散反映了植被地段的蒸发和植物蒸腾的总和，是区域水量平衡和热量平衡的重要组成部分。

“我们利用国家气象台站资料，采用修正的Penman模型计算产生了云南省119个气象台站1961～2004年潜在蒸发散月值数据，并系统分析了云南高原过去半个世纪以来潜在蒸发散和相关气候因子的变化趋势和区域差异。”范泽鑫说。

研究发现，云南省潜在蒸发散总体呈下降趋势，特别是在春季和夏季，并明显表现于云南东部和北部地区。云南省年平均风速、日照时数和相对湿度呈下降趋势。其中，潜在蒸发散的下降主要由于日照时数和平均风速的下降所致。

同时，该研究还首次发现，各气象因子对潜在蒸发散的贡献大小不是恒定不变的。1970年以来，云南省日照时数的减少对潜在蒸发散下降的贡献增强，而温度升高的相对贡献逐渐减弱。

据悉，该研究更全面地了解了云南省区域气候变化的时空特征，为预测和评价全球变化背景下区域水分循环提供了参考数据。（来源：中国科学报 张雯雯）

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【细菌群落，盐度】Anna J Székely Mercè Berga and Silke Langenheder. Mechanisms determining the fate of dispersed bacterial communities in new environments. The ISME Journal 2013 7: 61–71 doi:10.1038-ismej.2012.80.

Recent work has shown that dispersal has an important role in shaping microbial communities. However little is known about how dispersed bacteria cope with new environmental conditions and how they compete with local resident communities. To test this we implemented two full-factorial transplant experiments with bacterial communities originating from two sources (freshwater or saline water) which were incubated separately or in mixes under both environmental conditions. Thus we were able to separately test for the effects of the new environment with and without interactions with local communities. We determined community composition using 454-pyrosequencing of bacterial 16S rRNA to specifically target the active fraction of the communities and measured several functional parameters. In absence of a local resident community the net functional response was mainly affected by the environmental conditions suggesting successful functional adaptation to the new environmental conditions. Community composition was influenced both by the source and the incubation environment suggesting simultaneous effects of species sorting and functional plasticity. In presence of a local resident community functional parameters were higher compared with those expected from proportional mixes of the unmixed communities in three out of four cases. This was accompanied by an increase in the relative abundance of generalists suggesting that competitive interactions among local and immigrant taxa could explain the observed ‘functional overachievement’. In summary our results suggest that environmental filtering functional plasticity and competition are all important mechanisms influencing the fate of dispersed communities.

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【微生物群落生态】Donovan H Parks and Robert G Beiko. Measures of phylogenetic differentiation provide robust and complementary insights into microbial communities. The ISME Journal 2013 7: 173–183 doi:10.1038-ismej.2012.88.