Reproductive Allocation of the Habitat-Forming Intertidal Macroalga <i>Ascophyllum nodosum</i> Decreases at Its Northern Distribution Edge.

ABSTRACT: The habitat-forming intertidal brown alga Ascophyllum nodosum has its colder northern distribution limit at 69°N in Disko Bay, Greenland. Its reproductive effort has never been assessed there despite expected northward expansion with climate change. We analyzed reproductive allocation and phenology at the northern distribution edge and across the geographical distribution range through field studies at three Greenland sites and one Danish site, supplemented with a literature survey. Because Ascophyllum is long-lived and forms annual segments through apical growth, old shoots sampled in the reproductive season revealed receptacle formation with segment age, from the tip to the base of the shoots. We confirmed the fertility of the northernmost populations, as zygotes formed fro

SUBMITTER: Albuquerque C 

PROVIDER: S-EPMC12457723 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature