Reproductive collapse in European beech results from declining pollination efficiency in large trees

Bogdziewicz, Michał, Kelly, Dave, Tanentzap, Andrew J, Thomas, Peter, Foest, Jessie, Lageard, Jonathan and Hacket‐Pain, Andrew (2023) Reproductive collapse in European beech results from declining pollination efficiency in large trees. Global Change Biology, 29 (16). pp. 4595-4604.

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Abstract

Climate warming increases tree mortality which will require sufficient reproduction to ensure population viability. However, the response of tree reproduction to climate change remains poorly understood. Warming can reduce synchrony and interannual variability of seed production ("masting breakdown") which can increase seed predation and decrease pollination efficiency in trees. Here, using 40 years of observations of individual seed production in European beech (Fagus sylvatica), we showed that masting breakdown results in declining viable seed production over time, in contrast to the positive trend apparent in raw seed count data. Furthermore, tree size modulates the consequences of masting breakdown on viable seed production. While seed predation increased over time mainly in small trees, pollination efficiency disproportionately decreased in larger individuals. Consequently, fecundity declined over time across all size classes, but the overall effect was greatest in large trees. Our study showed that a fundamental biological relationship-correlation between tree size and viable seed production-has been reversed as the climate has warmed. That reversal has diverse consequences for forest dynamics; including for stand- and biogeographical-level dynamics of forest regeneration. The tree size effects suggest management options to increase forest resilience under changing climates.

Item Type:	Article
Uncontrolled Keywords:	climate change, fecundity, forest regeneration, geitonogamy, mast seeding, pollen limitation, seed predation, seed production, tree size
Divisions:	Faculty of Science and Engineering > School of Environmental Sciences
Depositing User:	Symplectic Admin
Date Deposited:	15 May 2023 07:54
Last Modified:	21 Sep 2023 13:28
DOI:	10.1111/gcb.16730
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3170354