Herbivory and habitat association of tree seedlings in lowland evergreen rainforest on white-sand and terra-firme in the upper Rio Negro

Abstract

Background: It has been proposed that the interaction between herbivory and soil nutrient availability drives habitat association of tree species in Peruvian Amazonia. Nevertheless, there is no empirical evidence that this interaction holds across other Amazonian regions.

Aims: We address this knowledge gap by testing whether the interaction between herbivory and soil nutrient contributes to habitat association of tree species in white-sand and terra-firme forests in the upper Rio Negro, Brazil.

Methods: We conducted a reciprocal transplanting field experiment in which we controlled for the presence of herbivores. We tested for differences in tree-seedling growth and herbivory among seven white-sand and seven terra-firme habitat-specialist species. Additionally, we assessed whether tree seedlings differed in their functional traits.

Results: We found no empirical evidence that an interaction between herbivory and soil nutrients shapes habitat association in white-sand and terra-firme forests of the upper Rio Negro. Tree seedlings showed higher mortality when growing in their non-typical habitat. Growth and herbivory were similar regardless of the presence or absence of herbivore protection and type of soil.

Conclusions: We suggest that the overall differences in soil nutrient status between white-sand and terra-firme forests in the upper Rio Negro are insufficient to trigger an interaction between herbivory and soil nutrient availability.

Keywords:

• Amazonia
• interaction between herbivory and soil nutrient availability
• habitat association of trees
• herbivory
• seedling traits
• terra-firme forests
• tree seedlings
• upper Rio Negro
• white-sand forests

Acknowledgements

We thank teachers and students of Escola Indígena Baniwa Coripaco Pamaáli (EIBC) for their support during the field work. We acknowledge Eliodoro Ramirez, Lourenço Ancieto and Romeu Brazao for their careful fieldwork. Adeilson Lopes and Laise Diniz from the Instituto SocioAmbiental (ISA) kindly favoured the collaboration with EIBC. Francismar dos Santos and Joás da Silva (ISA) and Ana Andrade from Instituto Nacional de Pesquisas da Amazônia (INPA) provided logistical support. Tania Pimentel helped with the soil analysis. We thank the Instituto Internacional de Educação do Brasil (BECA program), the Conselho Nacional Ciência e Tecnologia (CNPq – Brazil), the Alberta Menega Stichting and the Miquel Fonds for financing the research. We, furthermore, acknowledge Associação Indígena da Bacia do Içana (OIBI) and Fundação Nacional do Índio (FUNAI) for providing permission to conduct our research at the Terra Indígena do Alto Rio Negro (permission No. 0742/07). IBAMA authorised collection and exportation of the plant material (permission No. 08BR002437/DF). Finally, we thank two anonymous reviewers, Chris Baraloto, Marinus Werger, Martin Weiss and Paul Fine for their comments on previous versions of this manuscript.