Title: Causes and consequences of unequal seedling production in forest trees: a case study in red oaks
Author: Moran, Emily V.; Clark, James S.;
Source: Ecology. 93(5): 1082-1094
Publication Series: Scientific Journal (JRNL)
Description: Inequality in reproductive success has important implications for ecological and evolutionary dynamics, but lifetime reproductive success is challenging to measure in long-lived species such as forest trees. While seed production is often used as a proxy for overall reproductive success, high mortality of seeds and the potential for trade-offs between seed number and quality draw this assumption into question. Parentage analyses of established seedlings can bring us one-step closer to understanding the causes and consequences of variation in reproductive success. In this paper, we demonstrate a new method for estimating individual seedling production and average percentage germination, using data from two mixed-species populations of red oaks (Quercus rubra, Q. velutina, Q. falcata, and Q. coccinea). We use these estimates to examine the distribution of female reproductive success and to test the relationship between seedling number and individual seed production, age, and growth rate. We show that both seed and seedling production are highly skewed, roughly conforming to zero-inflated lognormal distributions, rather than to the Poisson or negative-binomial distributions often assumed by population genetics analyses. While the number of established offspring is positively associated with mean annual seed production, a lower proportion of seeds from highly fecund individuals become seedlings. Our red oak populations also show evidence of trade-offs between growth rate and reproductive success. The high degree of inequality in seedling production shown here for red oaks, and by previous studies in other species, suggests that many trees may be more vulnerable to genetic drift than previously thought, if immigration in limited by fragmentation or other environmental changes.
Keywords: Coweeta LTER, North Carolina, USA, Duke Forest, North Carolina, USA, effective population size, fecundity, lognormal distribution, negative binomial distribution, parentage, Poisson distribution, Quercus, reproductive success
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
XML: View XML
Moran, Emily V.; Clark, James S. 2012. Causes and consequences of unequal seedling production in forest trees: a case study in red oaks. Ecology. 93(5): 1082-1094.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility