Evolutionary Ecology
 | Vegetative dormancy in long-lived plants | |
Life history ramifications of adult dormancy in long-lived plants
Dormancy is a time when an adult plant does not sprout for one or more
consecutive years. While dormant, a plant cannot photosynthesize, nor can it
sexually reproduce. So, why be dormant?
Dormancy is a time when an adult plant does not sprout for one or more
consecutive years. While dormant, a plant cannot photosynthesize, nor can it
sexually reproduce. So, why be dormant?
Caption: Life history diagram for Cypripedium parviflorum, sans reproductive steps, per Shefferson
et al. (2003). Yellow arrows indicate transitions among mature plant stages. Curved arrows over
mature stages indicate self-loops.
et al. (2003). Yellow arrows indicate transitions among mature plant stages. Curved arrows over
mature stages indicate self-loops.
Dormancy occurs commonly in certain plant species. The actual number of plant
species in which this phenomenon occurs is unknown, but they are spread
throughout Kingdom Plantae. Populations of dormancy-prone species may have
dramatically different levels of dormancy, as dormancy may differ according to
such factors as climate, microsite heterogeneity, and plant size.
In some populations of the small yellow lady's slipper, roughly 1/3 of extant plants
are dormant in any one growing season. Dormancy-prone plants tend to have
lower survival, suggesting that dormancy may be maladaptive. However, plant
size correlates negatively with the probability of dormancy, and positively with the
probability of survival, suggesting that plants are more likely to go dormant when
they are young and small. Since clonal plants buffer themselves from the effects
of environmental stochasticity by growing more ramets and, in some cases,
larger root systems, dormancy may also serve this same purpose in plants
without the benefit of many ramets. Indeed, plants exposed to
experimentally-induced environmental stress tend to increase dormancy without
suffering increased mortality, at least in the short-term.
Dormancy should impact our fundamental assumptions about life history theory
in long-lived plants. The adaptive or maladaptive nature of dormancy in long-lived
plants rests on the assumption that fitness is most sensitive to adult survival in
long-lived organisms. Thus, the fact that no sexual reproduction takes place
during times of dormancy may not matter. However, reproduction should be more
important to fitness in shorter-lived organisms than in longer-lived organisms.
Intriguingly, initial explorations of this hypothesis suggest that indeed, the life
history context of dormancy changes between short-lived and long-lived species.
Dormancy is an exciting research subject. Please feel free to contact us to inquire
more about it.
species in which this phenomenon occurs is unknown, but they are spread
throughout Kingdom Plantae. Populations of dormancy-prone species may have
dramatically different levels of dormancy, as dormancy may differ according to
such factors as climate, microsite heterogeneity, and plant size.
In some populations of the small yellow lady's slipper, roughly 1/3 of extant plants
are dormant in any one growing season. Dormancy-prone plants tend to have
lower survival, suggesting that dormancy may be maladaptive. However, plant
size correlates negatively with the probability of dormancy, and positively with the
probability of survival, suggesting that plants are more likely to go dormant when
they are young and small. Since clonal plants buffer themselves from the effects
of environmental stochasticity by growing more ramets and, in some cases,
larger root systems, dormancy may also serve this same purpose in plants
without the benefit of many ramets. Indeed, plants exposed to
experimentally-induced environmental stress tend to increase dormancy without
suffering increased mortality, at least in the short-term.
Dormancy should impact our fundamental assumptions about life history theory
in long-lived plants. The adaptive or maladaptive nature of dormancy in long-lived
plants rests on the assumption that fitness is most sensitive to adult survival in
long-lived organisms. Thus, the fact that no sexual reproduction takes place
during times of dormancy may not matter. However, reproduction should be more
important to fitness in shorter-lived organisms than in longer-lived organisms.
Intriguingly, initial explorations of this hypothesis suggest that indeed, the life
history context of dormancy changes between short-lived and long-lived species.
Dormancy is an exciting research subject. Please feel free to contact us to inquire
more about it.
Copyright 2009 Richard P. Shefferson. All rights reserved.
Research Interests
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