The plastic responses of plants to abiotic and biotic environmental factors have generally been addressed separately; thus we have a poor understanding of how these factors interact. For example, little is known about the effects of plant–plant interactions on the plasticity of plants in response to water availability. Furthermore, few studies have compared the effects of intra‐ and interspecific interactions on plastic responses to abiotic factors. To explore the effects of intraspecific and interspecific plant–plant interactions on plant responses to water availability, we grew
Water availability is an important abiotic factor, resulting in differences between plant species growing in xeric and mesic habitats. Species with populations occurring in both habitat types allow examination of whether water availability has acted as a selective force at the intraspecific level. Investigating responses to water availability with a dioecious species allows determination of whether males and females, which often have different physiologies and life histories, respond differently.
An experiment varying water availability was performed under an outdoor rain‐out shelter using plants from two mesic and two xeric populations of the dioecious plant
Compared to the two mesic populations, plants from the two xeric populations grew more slowly, were less likely to flower, took longer to flower, had thicker leaves, invested less in aboveground biomass and more in root biomass, produced fewer flowers and fruit, but were more likely to live. Many traits exhibited significant habitat type × treatment interactions. Compared to the xeric populations, males—but not females—from mesic populations had less root biomass and greatly reduced their flower production in response to low water availability.
Mesic and xeric populations responded in ways congruent with water availability being a selective force for among‐population divergence, especially for males.
- PAR ID:
- 10459537
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- American Journal of Botany
- Volume:
- 106
- Issue:
- 10
- ISSN:
- 0002-9122
- Page Range / eLocation ID:
- p. 1346-1355
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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