Estación de Fotobiología Playa Unión, Casilla de Correos No. 15 (9103) Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.
J Photochem Photobiol B. 2011 Apr 4;103(1):68-77. doi: 10.1016/j.jphotobiol.2011.01.013. Epub 2011 Jan 21.
During the late austral spring of 2009 we carried out experiments (4days of duration) with four cyanobacteria species, Anabaena sp., Nostoc sp., Arthrospira platensis and Microcystis sp., to assess the combined effects of temperature and solar radiation on photosynthesis performance and morphology. Two experimental temperatures (18°C and 23°C, simulating a 5°C increase under a scenario of climate change) and three radiation treatments (by using different filters/materials) were implemented: (i) P (PAR, 400-700nm), (ii) PA (PAR+UV-A, 320-700nm) and, (iii) PAB (PAR+UV-A+UV-B, 280-700nm). In general, samples under the P treatment had less decrease/higher recovery rates of effective photochemical quantum yield (Y) than those receiving UV-A or UV-A+UV-B. The effects of increased temperature were species-specific: At the end of the experiments, it was seen that increased temperature benefited photosynthetic performance of Anabaena sp. and Nostoc sp. but not of Microcystis sp. and A. platensis. Higher temperature was also associated to an increase in the chain area of Anabaena sp., and to bigger trichomes in A. platensis; however, no morphological effects were observed in Microcystis sp. In addition, in Nostoc sp. the increase in temperature counteracted the UVR impact on the reduction of the chain area. How these effects and mechanisms will affect the trophodynamics and production of aquatic ecosystems is still uncertain, but the specificity of the responses suggests that not all cyanobacteria would be equally benefited by temperature increases therefore affecting the balance and interaction among species in the water column.
在 2009 年晚春，我们进行了四项为期 4 天的实验，研究了四种蓝藻物种，即鱼腥藻、念珠藻、螺旋藻和微囊藻，以评估温度和太阳辐射对光合作用性能和形态的综合影响。我们实施了两种实验温度（18°C 和 23°C，模拟气候变化情景下 5°C 的升高）和三种辐射处理（使用不同的滤光片/材料）：（i）P（PAR，400-700nm），（ii）PA（PAR+UV-A，320-700nm）和，（iii）PAB（PAR+UV-A+UV-B，280-700nm）。一般来说，与接受 UV-A 或 UV-A+UV-B 的样品相比，P 处理下的样品具有较低的有效光化学量子产额（Y）下降/较高的恢复率。温度升高的影响因物种而异：在实验结束时，我们发现，温度升高有利于鱼腥藻和念珠藻的光合作用性能，但对微囊藻和螺旋藻没有益处。较高的温度还与鱼腥藻的链区面积增加以及螺旋藻的藻丝增大有关；然而，在微囊藻中没有观察到形态效应。此外，在念珠藻中，温度升高抵消了 UVR 对链区减少的影响。这些影响和机制将如何影响水生生态系统的营养动态和生产力仍然不确定，但响应的特异性表明，并非所有蓝藻都会因温度升高而同等受益，从而影响水柱中物种的平衡和相互作用。
