1. Is there tree senescence? The fecundity evidence.
- Author
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Qiu T, Aravena MC, Andrus R, Ascoli D, Bergeron Y, Berretti R, Bogdziewicz M, Boivin T, Bonal R, Caignard T, Calama R, Julio Camarero J, Clark CJ, Courbaud B, Delzon S, Donoso Calderon S, Farfan-Rios W, Gehring CA, Gilbert GS, Greenberg CH, Guo Q, Hille Ris Lambers J, Hoshizaki K, Ibanez I, Journé V, Kilner CL, Kobe RK, Koenig WD, Kunstler G, LaMontagne JM, Ledwon M, Lutz JA, Motta R, Myers JA, Nagel TA, Nuñez CL, Pearse IS, Piechnik Ł, Poulsen JR, Poulton-Kamakura R, Redmond MD, Reid CD, Rodman KC, Scher CL, Schmidt Van Marle H, Seget B, Sharma S, Silman M, Swenson JJ, Swift M, Uriarte M, Vacchiano G, Veblen TT, Whipple AV, Whitham TG, Wion AP, Wright SJ, Zhu K, Zimmerman JK, Żywiec M, and Clark JS
- Subjects
- Forests, Fertility, Models, Biological, Regeneration, Trees growth & development
- Abstract
Despite its importance for forest regeneration, food webs, and human economies, changes in tree fecundity with tree size and age remain largely unknown. The allometric increase with tree diameter assumed in ecological models would substantially overestimate seed contributions from large trees if fecundity eventually declines with size. Current estimates are dominated by overrepresentation of small trees in regression models. We combined global fecundity data, including a substantial representation of large trees. We compared size-fecundity relationships against traditional allometric scaling with diameter and two models based on crown architecture. All allometric models fail to describe the declining rate of increase in fecundity with diameter found for 80% of 597 species in our analysis. The strong evidence of declining fecundity, beyond what can be explained by crown architectural change, is consistent with physiological decline. A downward revision of projected fecundity of large trees can improve the next generation of forest dynamic models., Competing Interests: Competing interest statement: C.J.C. and J.C. are coauthors on a 2020 article; S.J.W. and J.C. are coauthors on a 2019 article; J.R.P. and J.C. are coauthors on a 2020 article; M.U., J.K.Z., and J.C. are coauthors on two 2019 articles; and M. Silman, W.F.R., and J.C. are coauthors on 2018, 2019, and 2020 articles.
- Published
- 2021
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