Male and female resposes to florivory in the perennial herb Silene dioica
(English)Manuscript (Other academic)
In dioecious species the two sexes differ in amount and timing of allocation to reproduction and as a consequence we would expect different sex specific responses to equal losses to herbivory. We studied the response of Silene dioica male and female plants to herbivory of two specialist insect herbivores Caryocolum viscariella and Delia criniventris that share the same food resource, the floral stems. We tracked the fates of marked individuals located in nine populations over eight consecutive years in a Bothnian archipelago. We found no differences in survival probabilities between attacked and non-attacked plants or between the sexes. We found that attacked plants of both sexes re-flowered to a higher extent compared to non-attacked plants. However, there was an inter-sexual difference in response to attack. Attacked females tended to re-flower more often than males and therefore showed a stronger compensatory response to this type of herbivore attack. The likely mechanism for this difference is that females in response to attack of floral stems early in season will save more resources than males and that these resources will be retained in the basal rosette to be used for future reproductive events. This suggests a positive effect on plant life time fecundity in females. However, there is also a negative effect of florivory on number of capsules produced as capsule production was halved in attacked compared to non-attacked females. The demographic implications of these direct and indirect effects of florivory remain to be understood.
Research subject Ecological Botany
IdentifiersURN: urn:nbn:se:umu:diva-21001OAI: oai:DiVA.org:umu-21001DiVA: diva2:210250