Plant life histories Flashcards
What is meant by the term ‘life history evolution’?
adaptive change in life history in response to selective pressure
Life history evolution involves how species adapt their reproductive strategies and growth patterns in response to environmental challenges.
What is a life history tradeoff?
an increase of one function decreases the function of other
Examples of life history tradeoffs include allocating resources to different functions such as growth, reproduction, and survival.
Give three examples of life history tradeoffs.
- Allocating more resources to roots increases drought survivorship but reduces growth and reproduction
- Genetic constraints prevent early-flowering large plants
- Producing nutritious seeds benefits seedlings but increases seed predation
These tradeoffs illustrate the balance species must maintain in resource allocation.
Give an example of a bet hedging strategy in a life history.
Seed dormancy: where few seeds germinate while others are “sleeping” for “just in case” situations to increase their survivorship
This strategy allows some seeds to remain viable in changing environmental conditions.
What is the relationship between present and future reproduction for monocarpic species?
reproduce once in their lifetime, investing all their resources into a single reproductive event
Monocarpic species focus their energy on one reproductive cycle, which can lead to high resource investment.
What is the relationship between present and future reproduction for polycarpic species?
reproduce multiple times, balancing current and future reproduction
Polycarpic species have a more flexible reproductive strategy, allowing them to adapt to varying environmental conditions.
What is masting?
synchronized mass production of seeds in some but not all years
Masting can help ensure that not all seeds are predated in years of high production.
Why could it make sense for a species to germinate only after seeds have been scared by fire?
because fire predicts a low density of competitors, providing better conditions for growth
This strategy takes advantage of cleared space and reduced competition post-fire.
Under what circumstance is seed dormancy advantageous to population growth?
preventing germination during unfavorable environmental conditions, buffers population fluctuations it increases the long-term growth rate
Seed dormancy allows a population to withstand adverse conditions until the environment improves.
Under what circumstances would it be advantageous to synchronize seed production within populations?
helps escape seed predation (predator satiation) or enhances fertilization efficiency in wind-pollinated species
Synchronization can overwhelm predators or ensure better fertilization success.
Under what circumstances would it be advantageous to be an annual plant?
seasonally harsh environments, rapid reproduction before the onset of unfavorable conditions maximizes fitness
Annual plants can complete their life cycle quickly in unpredictable environments.
What is meant by the term ‘life history’?
sequence of developmental events in a species’ lifetime
Life history encompasses all stages from birth to reproduction and death.
