A Pleistocene legacy structures global variation in modern eelgrass ecosystems

J. EMMETT DUFFY; JOHN J. STACHOWICZ; PAMELA L. REYNOLDS; ERIK E. SOTKA; KEVIN A. HOVEL; CHRISTOFFER BOSTRÖM; KATHARYN E. BOYER; MATHIEU CUSSON; JOHAN EKLÖF; ASCHWIN H. ENGELEN; BRITAS KLEMENS ERIKSSON; F. JOEL FODRIE; JOHN N. GRIFFIN; CLARA M. HEREU; MASAKAZU HORI; A. RANDALL HUGHES; MIKHAIL V. IVANOV; MARLENE JAHNKE; PABLO JORGENSEN; CLAUDIA KRUSCHEL; KUN-SEOP LEE; JONATHAN S. LEFCHECK; PER-OLAV MOKSNES; MASAHIRO NAKAOKA; MARY I. O'CONNOR; NESSA E. O'CONNOR; ROBERT J. ORTH; BRADLEY J. PETERSON; HENNING REISS; KATRIN REISS; J. PAUL RICHARDSON; FRANCESCA ROSSI; JENNIFER L. RUESINK; STEWART T. SCHULTZ; JONAS THORMAR; FIONA TOMAS; RICHARD K. F. UNSWORTH; ERIN VOIGT; MATTHEW A. WHALEN; SHELBY L. ZIEGLER; JEANINE L. OLSEN

Portsmouth, New Hampshire

Congreso; 50Th Benthic Ecology Meeting (BEM 2022); 2022

Benthic Ecology Meeting Society

Distribution of Earth?s biomes is structured by the match between climate and plant traits, which in turn shape associated communities and ecosystem processes and services. But that climate-trait match can be disrupted by historical events, with lasting ecosystem impacts. As Earth?s environment changes faster than at any time in human history, a critical question is whether and how organismal traits and ecosystems can adjust to altered conditions. The ZEN network quantified the relative importance of current environmental forcing versus evolutionary history in shaping the growth form and associated community of eelgrass (Zostera marina), a widespread foundation plant of ecosystems along northern hemisphere coastlines, which experienced major shifts in distribution and genetic composition during the Pleistocene. We found that eelgrass growth form and biomass retain a legacy of the Pleistocene colonization of the Atlantic from the ancestral Pacific range and of more recent within-basin bottlenecks and genetic differentiation. This evolutionary legacy in turn influences the biomass of associated algae and invertebrates that fuel coastal food webs, with effects comparable to or stronger than effects of current environmental forcing. Such long-term lags in phenotypic adaptation and acclimatization among foundation species represent a potential choke point for ecosystems adjusting to rapid climate change.