Does nectar production reduce herbivore pressure on Passiflora species in tropical lowland rainforests in Costa Rica? / Puede la producción de néctar reducir la presión de herbivoría en especies de Passiflora (Passifloraceae) en un bosque tropical de Costa Rica?
- Author(s)
- Maria Thurner, Veronika Mayer
- Abstract
Mutualistic ant-plant associations are common and important elements of tropical ecosystems. The most common antplant associations are loose mutualisms due to the presence of extrafloral nectaries (EFN). Such loose mutualisms are also found in the genus Passiflora. From some EFN-bearing Passiflora species, it is already known that ants help to significantly diminish herbivore pressure. It is not known (1) whether Passiflora plants react to herbivore damage with differences in nectar production to attract more ants, (2) if shoot growth depends on ant presence, and (3) to what extent Passiflora species with EFN rely on ants as defence against herbivores. To this end, observations were performed on eight different Passiflora species which differ in EFN number and size and in the quantity of nectar production. Exclusion experiments and observations of ant activity and nectar production with and without disturbance events were used to clarify the open questions. Results show that the presence of EFNs has an influence on the fitness of some Passiflora species and that nectar production and ant activity change after artificial injuries in most of the species observed. The results show further that EFN-bearing Passiflora species profit from the facultative relation with the ants present in a given habitat and have established a good balance between costs and benefits resulting from the mutualism.
- Organisation(s)
- External organisation(s)
- Diözese Linz
- Pages
- 599-606
- No. of pages
- 8
- Publication date
- 2008
- Austrian Fields of Science 2012
- 106008 Botany, 106030 Plant ecology, 106047 Animal ecology
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/38e30f44-280a-439d-8723-330f156e9db9