Plant growth rates and seed size: a re-evaluation

Lindsay A Turnbull, Christopher D Philipson, Drew W Purves, and AndOthers

Abstract

Abstract Small-seeded plant species are often reported to have high relative growth rate or RGR. However, because RGR declines as plants grow larger, small-seeded species could achieve higher RGR simply by virtue of their small size. In contrast, size-standardized growth rate or SGR factors out these size effects. Differences in SGR can thus only be due to differences in morphology, allocation, or physiology. We used nonlinear regression to calculate SGR for comparison with RGR for 10 groups of species spanning a wide range of life forms. We found that RGR was negatively correlated with seed mass in nearly all groups, but the relationship between SGR and seed mass was highly variable. We conclude that small seeded species only sometimes possess additional adaptations for rapid growth over and above their general size advantage.

Details

Publication typeArticle
Published inEcology
Pages1283-1289
Volume93
Number6
PublisherEcological Society of America

Previous versions

Lindsay A Turnbull, Cloe Paul-Victor, Bernhard Schmid, and Drew W Purves. Growth rates, seed size and physiology - Do small-seeded species really grow faster?, Ecology, January 2008.

C.E. Timothy Paine, Toby R Marthews, Deborah R Vogt, Drew Purves, Mark Rees, Andy Hector, and Lindsay A Turnbull. How to fit nonlinear plant growth models and calculate growth rates: an update for ecologists, Methods in Ecology and Evolution, British Ecological Society, September 2011.

Lindsay A Turnbull, Mark Rees, and Drew W Purves. Why equalising trade-offs aren’t always neutral, Ecology Letters, October 2008.

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