Bet Hedging Is Not Sufficient to Explain Germination Patterns of a Winter Annual Plant

AbstractBet hedging consists of life history strategies that buffer against environmental variability by trading off immediate and long-term fitness. Delayed germination in annual plants is a classic example of bet hedging and is often invoked to explain low germination fractions. We examined whether bet hedging explains low and variable germination fractions among 20 populations of the winter annual plant Clarkia xantiana ssp. xantiana that experience substantial variation in reproductive success among years. Leveraging 15 years of demographic monitoring and 3 years of field germination experiments, we assessed the fitness consequences of seed banks and compared optimal germination fractions from a density-independent bet-hedging model to observed germination fractions. We did not find consistent evidence of bet hedging or the expected trade-off between arithmetic and geometric mean fitness, although delayed germination increased long-term fitness in 7 of 20 populations. Optimal germination fractions were two to five times higher than observed germination fractions, and among-population variation in germination fractions was not correlated with risks across the life cycle. Our comprehensive test suggests that bet hedging is not sufficient to explain the observed germination patterns. Understanding variation in germination strategies will likely require integrating bet hedging with complementary forces shaping the evolution of delayed germination.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:202

Enthalten in:

The American naturalist - 202(2023), 6 vom: 14. Dez., Seite 767-784

Sprache:

Englisch

Beteiligte Personen:

Siegmund, Gregor-Fausto [VerfasserIn]
Moeller, David A [VerfasserIn]
Eckhart, Vincent M [VerfasserIn]
Geber, Monica A [VerfasserIn]

Links:

Volltext

Themen:

Bet hedging
Delayed germination
Journal Article
Life history evolution
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Seed banks

Anmerkungen:

Date Completed 04.12.2023

Date Revised 15.12.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1086/726785

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM365243078