A Key Marine Diazotroph in a Changing Ocean: The Interacting Effects of Temperature, CO2 and Light on the Growth of Trichodesmium erythraeum IMS101.
A Key Marine Diazotroph in a Changing Ocean: The Interacting Effects of Temperature, CO2 and Light on the Growth of Trichodesmium erythraeum IMS101.
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DOI：
10.1371/journal.pone.0168796
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Geider RJ
中科院分区：
文献类型：
--
作者：
Boatman TG;Lawson T;Geider RJ
Trichodesmium 是一种全球重要的海洋固氮生物，约占海洋生物 N2 固定的 60-80%，因此在海洋 N 和 C 循环中发挥着关键作用。我们对温度、pCO2 和光强度的综合相互作用如何直接影响红毛藻 IMS101 的生长速率进行了全面评估。我们的主要发现是： 低 pCO2 影响温度耐受下限 (Tmin)，但对生长最大的最适温度 (Topt) 或最高温度耐受极限 (Tmax) 没有影响；低pCO2对热生态位宽度的影响比低光更大； pCO2 对生长速率的影响在次优温度下比在超优温度下更为明显；温度和光照对光合效率（Fv/Fm）的影响比CO2更强；在Topt，最大生长速率随着CO2的增加而增加，但生长-辐照度曲线的初始斜率不受CO2的影响。在环境变化的背景下，我们的结果表明，(i) Trichodesmium IMS101 的营养充足生长速率将受到末次盛冰期 (LGM) 的低 pCO2 的严重限制，(ii) 未来 pCO2 的增加将增加温度范围在 Tmin 到 Topt 之间的区域的生长速率，但在 Topt 和 Tmax 之间的温度范围内的影响可以忽略不计，(iii) 温暖表面的面积增加 水域（> 18°C）使得地理范围从末次盛冰期到现在显着增加，并且随着持续变暖，该范围将继续扩大到更高纬度，但（iv）持续的全球变暖可能会排除Trichodesmium spp。到 2100 年，来自一些温度超过 Topt 的热带地区。
Trichodesmium is a globally important marine diazotroph that accounts for approximately 60 − 80% of marine biological N2 fixation and as such plays a key role in marine N and C cycles. We undertook a comprehensive assessment of how the growth rate of Trichodesmium erythraeum IMS101 was directly affected by the combined interactions of temperature, pCO2 and light intensity. Our key findings were: low pCO2 affected the lower temperature tolerance limit (Tmin) but had no effect on the optimum temperature (Topt) at which growth was maximal or the maximum temperature tolerance limit (Tmax); low pCO2 had a greater effect on the thermal niche width than low-light; the effect of pCO2 on growth rate was more pronounced at suboptimal temperatures than at supraoptimal temperatures; temperature and light had a stronger effect on the photosynthetic efficiency (Fv/Fm) than did CO2; and at Topt, the maximum growth rate increased with increasing CO2, but the initial slope of the growth-irradiance curve was not affected by CO2. In the context of environmental change, our results suggest that the (i) nutrient replete growth rate of Trichodesmium IMS101 would have been severely limited by low pCO2 at the last glacial maximum (LGM), (ii) future increases in pCO2 will increase growth rates in areas where temperature ranges between Tmin to Topt, but will have negligible effect at temperatures between Topt and Tmax, (iii) areal increase of warm surface waters (> 18°C) has allowed the geographic range to increase significantly from the LGM to present and that the range will continue to expand to higher latitudes with continued warming, but (iv) continued global warming may exclude Trichodesmium spp. from some tropical regions by 2100 where temperature exceeds Topt.