Patterns and Sources of Variability in Biological Weighting Functions for UVR Inhibition of Primary Production in California Coastal Waters

在过去的20年中，UVR气候学的显著变化发生在所有纬度地区，除了热带地区，对沿海海洋学具有潜在的重大影响。有一个迫切需要了解和能够预测紫外线辐射对沿海初级生产的影响，部分是因为在生态系统动态中的核心作用固碳发挥，部分是因为各种各样的，但未经测试的情况下，生产模式的变化，以应对不断变化的紫外线辐射的气候学，部分出于对这些情况可能对沿海社会的潜在影响的关注。在先前的NSF资助下，我们已经证明了太阳紫外线辐射（UVR）对海洋初级生产的抑制在南大洋的浮游植物，大型藻类，石生微藻和冰藻中广泛存在。为了推进太阳紫外线辐射对初级生产的影响的光谱建模，我们测量了几个行动光谱或生物加权函数（BWF）的第一个量化的光谱敏感性的初级生产的紫外线辐射抑制在自然条件下。我们第一次记录了这些光谱算法的显著变化，并确定了但尚未测试这种变化的潜在实验，分析和自然来源。如果要知道紫外线辐射光学模型和紫外线辐射对初级生产的影响之间的预测联系，就需要这种知识。缺乏考虑紫外线辐射的影响破坏了初级生产模型的预测准确性，并忽略了调节作用，紫外线辐射在修改细胞过程中定义浮游植物的光生态学。不同生态系统中紫外线辐射挑战的性质可能不同，对食物网的相互影响可能有不同的平衡。1995年期间，对圣巴巴拉海峡表层浮游植物群落的可行性研究表明，紫外线辐射对表层初级生产率的影响可能很大，但变化很大。基于这些研究结果，并使用成熟的技术，我们将定义的模式和变异的BWF的初级生产在高度多样化的加州沿海沃茨的UVR抑制的来源，从而，先进的光谱建模的UVR依赖的初级生产。该研究项目的结果还将有助于确定UVA和UVB调节浮游植物多色生物学的机制，并提供有关全球UVB气候变化对浮游植物生态的潜在后果的见解。

Significant changes in UVR climatology have occurred all latitudes, except the tropics, during the last 20 years with potentially significant consequences for coastal oceanography. There is a pressing need to understand and be able to forecast UVR effects on coastal primary production; in part because of the central role carbon fixation plays in ecosystem dynamics, in part because of the various but untested scenarios suggesting changes in production patterns in response to changing UVR climatology, and in part out of concern for the potential impact these scenarios might have on coastal societies. With prior NSF funding, we have documented that inhibition of marine primary production by solar ultraviolet radiation (UVR) is widespread in phytoplankton, macroalgae, epilithic microalgae and ice algae in the Southern Ocean. To advance the spectral modeling of solar UVR effects on primary production, we measured the first of several action spectra or biological weighting functions (BWFs) quantify the spectral sensitivity of primary production to UVR inhibition under natural field conditions. We documented, for the first time, the significant variability in these spectral algorithms and identified but have not tested potential experimental, analytical and natural sources of that variability. Such knowledge is required if the predictive linkages between optical models of UVR and UVR effects on primary production are to be known. Lack of consideration of UVR effects undermines the predictive accuracy of primary production models and overlooks the regulatory roles that UVR plays in modifying cell processes that define the photoecology of phytoplankton. It is likely that the nature of the UVR challenges may differ in different ecosystems and the interactive effects on food webs may be balanced differently. A feasibility study of surface phytoplankton communities in the Santa Barbara Channel during 1995 indicate a potential for significant, but highly variable, UVR effects on surface primary production rates. Based on those findings and using proven techniques, we will define the patterns and sources of variability in BWFs for UVR inhibition of primary production in highly diverse California coastal waters and, thereby, advance spectral modeling of UVR dependent primary production. The results of this research project will also help identify the mechanisms by which UVA and UVB regulate the polychromatic biology of phytoplankton and provide insights regarding potential consequences of changing global UVB climatology on phytoplankton ecology.