Limits to reproduction and seed size-number trade-offs that shape forest dominance and future recovery
Authors: Qiu Tong , Andrus Robert , Aravena Marie-Claire , Ascoli Davide , Bergeron Yves , Berretti Roberta , Berveiller Daniel , Bogdziewicz Michal , Boivin Thomas , Bonal Raul , Bragg Don C. , Caignard Thomas , Calama Rafael , Camarero J. Julio , Chang-Yang Chia-Hao , Cleavitt Natalie L. , Courbaud Benoit , Courbet Francois , Curt Thomas , Das Adrian J. , Daskalakou Evangelia , Davi Hendrik , Delpierre Nicolas , Delzon Sylvain , Dietze Michael , Calderon Sergio Donoso , Dormont Laurent , Espelta Josep , Fahey Timothy J. , Farfan-Rios William , Gehring Catherine A. , Gilbert Gregory S. , Gratzer Georg , Greenberg Cathryn H. , Guo Qinfeng , Hacket-Pain Andrew , Hampe Arndt , Han Qingmin , Hille Ris Lambers Janneke , Hoshizaki Kazuhiko , Ibanez Ines , Johnstone Jill F. , Journé Valentin , Kabeya Daisuke , Kilner Christopher L. , Kitzberger Thomas , Knops Johannes M. H. , Kobe Richard K. , Kunstler Georges , Lageard Jonathan G. A. , LaMontagne Jalene M. , Ledwon Mateusz , Lefevre Francois , Leininger Theodor , Limousin Jean-Marc , Lutz James A. , Macias Diana , McIntire Eliot J. B. , Moore Christopher M. , Moran Emily , Motta Renzo , Myers Jonathan A. , Nagel Thomas A. , Noguchi Kyotaro , Ourcival Jean-Marc , Parmenter Robert , Pearse Ian S. , Perez-Ramos Ignacio M. , Piechnik Lukasz , Poulsen John , Poulton-Kamakura Renata , Redmond Miranda D. , Reid Chantal D. , Rodman Kyle C. , Rodriguez-Sanchez Francisco , Sanguinetti Javier D. , Scher C. Lane , Schlesinger William H. , Schmidt Van Marle Harald , Seget Barbara , Sharma Shubhi , Silman Miles , Steele Michael A. , Stephenson Nathan L. , Straub Jacob N. , Sun I-Fang , Sutton Samantha , Swenson Jennifer J. , Swift Margaret , Thomas Peter A. , Uriarte Maria , Vacchiano Giorgio , Veblen Thomas T. , Whipple Amy V. , Whitham Thomas G. , Wion Andreas P. , Wright Boyd , Wright S. Joseph , Zhu Kai , Zimmerman Jess K. , Zlotin Roman , Zywiec Magdalena , Clark James S. 
Published: May 2022

The relationships that control seed production in trees are fundamental to understanding the evolution of forest species and their capacity to recover from increasing losses to drought, fire, and harvest. A synthesis of fecundity data from 714 species worldwide allowed us to examine hypotheses that are central to quantifying reproduction, a foundation for assessing fitness in forest trees. Four major findings emerged. First, seed production is not constrained by a strict trade-off between seed size and numbers. Instead, seed numbers vary over ten orders of magnitude, with species that invest in large seeds producing more seeds than expected from the 1:1 trade-off. Second, gymnosperms have lower seed production than angiosperms, potentially due to their extra investments in protective woody cones. Third, nutrient-demanding species, indicated by high foliar phosphorus concentrations, have low seed production. Finally, sensitivity of individual species to soil fertility varies widely, limiting the response of community seed production to fertility gradients. In combination, these findings can inform models of forest response that need to incorporate reproductive potential.