The proportions of carbon (C), nitrogen (N), and phosphorus (P) in surface ocean particulate matter deviate greatly from the canonical Redfield Ratio (C:N:P = 106:16:1) in space and time with significant implications for global carbon storage as this matter reaches the deep ocean. Recent work has revealed clear latitudinal patterns in C:N:P, yet the relative importance of ecological, physiological, or biochemical processes in creating these patterns is unclear. We present high-resolution, concurrent measurements of particulate C:N:P, macromolecular composition, environmental conditions, and plankton community composition from a transect spanning a subtropical-subpolar boundary, the North Pacific Transition Zone. We find that the summed contribution of macromolecules to particulate C, N, and P is consistent with, and provides interpretation for, particulate C:N:P patterns. A decline in particulate C:N from the subtropical to subpolar North Pacific largely reflects an increase in the relative contribution of protein compared to carbohydrate and lipid, whereas variation in C:P and N:P correspond to shifts in protein relative to polyphosphate, DNA, and RNA. Possible causes for the corresponding trends in C:N and macromolecular composition include physiological responses and changes in community structure of phytoplankton, which represented approximately 1/3 rd of particulate C across the transect. Comparison with culture experiments and an allocation-based model of phytoplankton macromolecular composition suggest that physiological acclimation to changing nutrient supply is the most likely explanation for the latitudinal trend in C:N, offering both a mechanistic interpretation and biochemical basis for large-scale patterns in C:N:P.

中文翻译：

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海洋 C：N：P 的纬度模式反映了浮游植物的驯化和大分子组成


海洋表层颗粒物中碳 （C）、氮 （N） 和磷 （P） 的比例在空间和时间上与规范的红场比 （C：N：P = 106：16：1） 有很大差异，当这种物质到达深海时，对全球碳储存产生重大影响。最近的工作揭示了 C：N：P 中明显的纬度模式，但生态、生理或生化过程在创建这些模式中的相对重要性尚不清楚。我们展示了来自横跨亚热带-亚极地边界（北太平洋过渡带）的横断面的颗粒 C：N：P、大分子组成、环境条件和浮游生物群落组成的高分辨率同时测量。我们发现大分子对颗粒 C、N 和 P 的总贡献与颗粒 C：N：P 模式一致，并提供了对颗粒 C：N：P 模式的解释。从亚热带到亚极地北太平洋颗粒物 C：N 的减少在很大程度上反映了蛋白质相对于碳水化合物和脂质的相对贡献增加，而 C：P 和 N：P 的变化对应于蛋白质相对于多磷酸盐、DNA 和 RNA 的变化。C：N 和大分子组成相应趋势的可能原因包括浮游植物的生理反应和群落结构的变化，这大约占整个样带中颗粒 C 的 1/3。与培养实验和基于分配的浮游植物大分子组成的模型进行比较表明，对不断变化的营养供应的生理适应是 C：N 纬度趋势的最可能解释，为 C：N：P 的大规模模式提供了机制解释和生化基础。