Latitudinal patterns in ocean C:N:P reflect phytoplankton acclimation and macromolecular composition

• 成果类型: Article
• 署名作者: Liefer, Justin D.; White, Angelicque E.; Finkel, Zoe V.; Irwin, Andrew J.; Dugenne, Mathilde; Inomura, Keisuke; Ribalet, Francois; Armbrust, E. Virginia; Karl, David M.; Fyfe, Matthew H.; Brown, Christopher M.; Follows, Michael J.
• 署名单位: Mount Allison University; University of Hawaii System; University of Hawaii Manoa; Dalhousie University; Dalhousie University; University of Rhode Island; University of Washington; University of Washington Seattle; Mount Allison University; Massachusetts Institute of Technology (MIT)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9042
• DOI: 10.1073/pnas.2404460121
• 发表日期: 2024-11-12
• 关键词: zone chlorophyll front; elemental stoichiometry; nutrient limitation; resource-allocation; community structure; growth-rate; marine; nitrogen; ratios; carbon

摘要

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 1/3rd 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.