当前，生物入侵已成为严重的环境问题，是全球变化的重要组成部分，入侵生态学尤其是与全球环境变化相结合，成为生态学研究的热点问题之一。杂志Biological Invasions 刊登了中科院西双版纳热带植物园生物入侵生态学组最新研究论文"Innate and evolutionarily increased advantages of invasive Eupatorium adenophorum over native E. japonicum under ambient and doubled atmospheric CO2 concentrations ”。
中科院西双版纳热带植物园生物入侵生态学组以紫茎泽兰原产地（墨西哥）种群、入侵地（中国）种群，以及本地近缘种白头婆为材料，利用哀牢山生态站的人工气候室，研究了三类植物对二氧化碳浓度倍增的响应差异，分析了紫茎泽兰生物入侵性的来源，及其入侵性随环境变化的演化。
研究结果表明，对大多数的生长性状而言，入侵地紫茎泽兰种群表现优于原产地种群，而原产地种群的紫茎泽兰又优于本地近缘种，表明紫茎泽兰既具有固有竞争优势，又在入侵地发生快速进化，从而成为一种“超级”入侵者。研究同时测定了一类重要的含氮化防物质生氰糖苷的含量，发现在入侵种群内，该物质含量显著低于原产地种群，表明紫茎泽兰在入侵过程中的确降低了化学防御的氮投入。这进一步验证了冯玉龙研究员提出的解释植物入侵机理的“氮分配的进化假说”。
另外，研究发现，二氧化碳浓度增加对三类植物的生长都有促进作用，且效果相当，所以单独的二氧化碳浓度增加可能并未加剧紫茎泽兰的生物入侵性。但是二氧化碳浓度增加的生态效应与其他环境因子，如氮水平等紧密耦合，因此后续研究正在进行中。（生物谷Bioon.com）
doi:10.1007/s10530-011-9940-y
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Innate and evolutionarily increased advantages of invasive Eupatorium adenophorum over native E. japonicum under ambient and doubled atmospheric CO2 concentrations
Yan Bao Lei, Yu Long Feng, Yu Long Zheng, Rui Fang Wang, He De Gong and Yi Ping Zhang
Both innate and evolutionarily increased ecophysiological advantages can contribute to vigorous growth, and eventually to invasiveness of alien plants. Little effort has been made to explore the roles of innate factors of alien plants in invasiveness and the effects of CO2 enrichment on alien plant invasions. To address these problems, we compared invasive Eupatorium adenophorum, its native conspecific, and a native congener (E. japonicum) under ambient and doubled atmospheric CO2 concentrations. Native E. adenophorum from Mexico grew slower than invasive E. adenophorum but faster than native E. japonicum under both CO2 concentrations. The faster growth rate of invasive E. adenophorum was associated with higher photosynthetic capacity and leaf area ratio. For invasive E. adenophorum, the higher photosynthetic capacity was associated with higher nitrogen (N) allocation to photosynthesis, which was related to lower leaf mass per area; the higher leaf area ratio was due to lower leaf mass per area and higher leaf mass fraction. Tradeoff between N allocations to photosynthesis versus defenses was found. CO2 enrichment significantly increased relative growth rate and biomass accumulation by increasing actual photosynthetic rate for all studied materials. However, the relative increase in growth was not significantly different among them. CO2 enrichment did not influence N allocation to photosynthesis, but increased N allocation to cell walls. The reduced leaf N content decreased N content in photosynthesis, explaining the down-regulation of photosynthetic capacity under prolonged elevated CO2 concentration. Our results indicate that both innate and evolutionary advantages in growth and related ecophysiological traits contribute to invasiveness of invasive E. adenophorum, and CO2 enrichment may not aggravate E. adenophroum’s invasion in the future.
