Age, stage and senescence in plants

Caswell, Hal and Salguero-Gomez, Roberto (2013) Age, stage and senescence in plants. Journal of Ecology, 101 3: 585-595. doi:10.1111/1365-2745.12088

Author Caswell, Hal
Salguero-Gomez, Roberto
Title Age, stage and senescence in plants
Journal name Journal of Ecology   Check publisher's open access policy
ISSN 0022-0477
Publication date 2013-05
Year available 2013
Sub-type Article (original research)
DOI 10.1111/1365-2745.12088
Volume 101
Issue 3
Start page 585
End page 595
Total pages 11
Place of publication Oxford, United Kingdom
Publisher Wiley-Blackwell Publishing
Collection year 2014
Language eng
Formatted abstract
1. Senescence (an increase in the mortality rate or force of mortality, or a decrease in fertility, with increasing age) is a widespread phenomenon. Theories about the evolution of senescence have long focused on the age trajectories of the selection gradients on mortality and fertility. In purely age-classified models, these selection gradients are non-increasing with age, implying that traits expressed early in life have a greater impact on fitness than traits expressed later in life. This pattern leads inevitably to the evolution of senescence if there are trade-offs between early and late performance.
2. It has long been suspected that the stage- or size-dependent demography typical of plants might change these conclusions. In this paper, we develop a model that includes both stage- and age-dependence and derive the age-dependent, stage-dependent and age×stage-dependent selection gradients on mortality and fertility.
3. We applied this model to stage-classified population projection matrices for 36 species of plants, from a wide variety of growth forms (from mosses to trees) and habitats.
4. We found that the age-specific selection gradients within a life cycle stage can exhibit increases with age (we call these contra-senescent selection gradients). In later stages, often large size classes in plant demography, the duration of these contra-senescent gradients can exceed the life expectancy by several fold.
5. Synthesis. The interaction of age- and stage-dependence in plants leads to selection pressures on senescence fundamentally different from those found in previous, age-classified theories. This result may explain the observation that large plants seem less subject to senescence than most kinds of animals. The methods presented here can lead to improved analysis of both age-dependent and stage-dependent demographic properties of plant populations.
Keyword Ageing
ComPADRe III database
Matrix population models
Plant development and life history traits
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
School of Biological Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 21 times in Thomson Reuters Web of Science Article | Citations
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