Romero et al. 2010 (Article) Vriesea, animals, Nutrients

Nitrogen fluxes from treefrogs to tank epiphytic bromeliads: an isotopic and physiological approach

Author(s):—G.Q. Romero, F. Nomura, A.Z. Gonçalves, N.Y.N. Dias, H. Mercier, E.d.C. Conforto & D.d.C. Rossa F.

Publication:—Oecologia 162: 941–949. (2010) — DOI

Abstract:—Diverse invertebrate and vertebrate species live in association with plants of the large Neotropical family Bromeliaceae. Although previous studies have assumed that debris of associated organisms improves plant nutrition, so far little evidence supports this assumption. In this study we used isotopic (15N) and physiological methods to investigate if the treefrog Scinax hayii, which uses the tank epiphytic bromeliad Vriesea bituminosa as a diurnal shelter, contributes to host plant nutrition. In the Weld, bromeliads with frogs had higher stable N isotopic composition (
15N) values than those without frogs. Similar results were obtained from a controlled greenhouse experiment. Linear mixing models showed that frog feces and dead termites used to simulate insects that eventually fall inside the bromeliad tank contributed, respectively, 27.7% (§0.07 SE) and 49.6% (§0.50 SE) of the total N of V. bituminosa. Net photosynthetic rate was higher in plants that received feces and termites than in controls; however, this eVect was only detected in the rainy, but not in the dry season. These results demonstrate for the first time that vertebrates contribute to bromeliad nutrition, and that this beneWt is seasonally restricted. Since amphibian–bromeliad associations occur in diverse habitats in South and Central America, this mechanism for deriving nutrients may be important in bromeliad systems throughout the Neotropics.

Keywords:—Bromeliad-frog interactions, Digestive mutualism, Nutrient provisioning, Tillandsioideae, Scinax hayii