Effects of experimental warming and increased ultraviolet B radiation on the Mediterranean plankton food web
Effects of experimental warming and increased ultraviolet B radiation on the Mediterranean plankton food web
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DOI：
10.4319/lo.2011.56.1.0206
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发表时间：
2011-01
影响因子：
4.5
通讯作者：
F. Vidussi;B. Mostajir;E. Fouilland;E. Le Floc’h;J. Nouguier;C. Roques;P. Got;D. Thibault-Botha;T. Bouvier;M. Troussellier
中科院分区：
文献类型：
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作者：
F. Vidussi;B. Mostajir;E. Fouilland;E. Le Floc’h;J. Nouguier;C. Roques;P. Got;D. Thibault-Botha;T. Bouvier;M. Troussellier
在地中海沿岸的一个站点，在春季浮游生物食物网的温度和紫外线B辐射（UVBR，280-320 nm）的增加的反应进行了实验研究。使用8个系泊中围生态系统比较天然浮游生物食物网响应（对照中围生态系统）与模拟预期未来局部温度和UVBR增加的三种处理，如下：（1）水温增加3°C，（2）入射UVBR增加20%，（3）水温同时增加3°C和入射UVBR增加20%。浮游生物的食物网是耐UVBR升高，只有中等的影响浮游生物丰度和结构。相反，变暖导致浮游生物食物网结构和功能发生重大变化。具体而言，原生浮游动物（纤毛虫和鞭毛虫）的丰度增加，桡足类从无节幼体到成体的发育时间缩短。在温暖的围隔中，出现的桡足类成年阶段中途通过实验导致纤毛虫减少，因此在异养鞭毛虫增加。一个意想不到的结果是，在实验中途，变暖减少了异养细菌的丰度。这些结果表明，在变暖的营养级联效应。成年桡足类的增加减少了纤毛虫，反过来又有利于消耗细菌的异养鞭毛虫。变暖还导致净氧产量增加，表明净初级生产力增加。
The responses of the plankton food web to increases in temperature and ultraviolet B radiation (UVBR, 280–320 nm) were experimentally investigated at a coastal Mediterranean site during spring. Eight moored mesocosms were used to compare natural plankton food web responses (control mesocosms) with three treatments simulating expected future local temperature and UVBR increases, as follows: (1) 3°C increase in water temperature, (2) 20% increase in incident UVBR, and (3) simultaneous 3°C increase in water temperature and 20% increase in incident UVBR. The plankton food web was resistant to elevated UVBR, having only moderate effects on plankton abundances and structure. In contrast, warming induced significant shifts in the plankton food web structure and function. Specifically, the abundance of protozooplankton (ciliates and flagellates) increased and the development time of copepods from nauplii to adults decreased. In the warm mesocosms, the emergence of copepod adult stages midway through the experiment resulted in a decrease in ciliates and consequently in an increase in heterotrophic flagellates. One unexpected result was that warming reduced the abundance of heterotrophic bacteria midway through the experiment. These results indicate a trophic‐cascade effect under warming. The increase in adult copepods diminishes ciliates and in turn favors heterotrophic flagellates that consume bacteria. Warming also induced an increase in net oxygen production, indicating an increase in net primary production.