光谱质量和光子照度对酸化环境中珊瑚代谢的影响

摘要

以霜鹿角珊瑚（Acropora pruinosa）、稀杯盔形珊瑚（Galaxea astreata）、盾形陀螺珊瑚（Turbinaria peltata）为研究对象，研究光照对酸化环境中的珊瑚钙化的调节作用。结果表明，光照条件下，随着pH降低，光照钙化率（GL）下降，且光子照度越低钙化率越低；酸化环境中，不同光谱低光强（LL）条件下GL、GL/GD（暗环境钙化率）比值小于高光强（HL）环境，GL变化率大于HL环境，稀杯盔形珊瑚尤为明显，酸化对石珊瑚GL的影响在高光强环境（HL）中受抑制。酸化环境中霜鹿角珊瑚总光合作用效率（PG）在 HL 条件下降低速率明显小于LL，稀杯盔形珊瑚和盾形陀螺珊瑚则无差异，光子照度对酸化环境中不同珊瑚的 PG调节效果不同；GL和 PG、GL变化率和PG变化率间的线性相关性显示HL加强了PG，且可能加强GL，由于PG可能受限于pCO2，且HL条件下，酸化减缓了pCO2对PG的抑制作用。低光子照度下珊瑚对酸化环境比较敏感。%We employed a multifactorial growth experiment to determine how light intensity and OA together modify the calcification ofAcropora pruinosa,Galaxea astreata andTurbinaria peltata. It was found that decreased pH(OA)-induced losses of calcification in the light (GL) especially under low-light growth conditions.The influence of light intensity upongross photosynthesis(PG)onses is coral species specific. Underlight-limited growth conditionsGL,GL / GDwith OAwas lowerthan that growth under high-light and with different spectral quality,but the change ofGL with OA was higher than that of under high-lightcondition,in particular forGalaxea astreata. Those results suggested that high-light growth conditions dampened the impact of OA uponGL. OA-induced change ofPG on light-saturated growth(LL)was significantly smaller than LL forAcropora pruinosa,and did not show a significant differences betweenhigh light(HL)and low light(LL)forGalaxea astreata,Turbinaria peltata. The reciprocal OA-induced change of GL with PG andchange ofGL withPG are consistent with the notion thatPG is enhanced by HL and GL is enhanced by PG,which is fundamentally limited by pCO2 availability (and hence relieved by OA) under HL. In total,thisstudy suggests that lower light availability will potentially increase the susceptibility of key coral species to OA.