Ant-plant associations in different forests in Venezuela

Abstract

Associações Formiga-Planta em Diferentes Florestas na Venezuela RESUMO -Avaliou-se a hipótese de que a distribuição da abundância e o número de espécie de dois tipos diferentes de plantas mirmecófi las são infl uenciadas diferentemente pela diversidade e pela abundância de formigas. Em oito fl orestas naturais diferentes na Venezuela nós estimamos a riqueza de espécies e a abundância de plantas, de formigas no solo e no dossel, os danos às folhas e os nutrientes do solo. Os resultados mostram que as plantas com domácias para alojar formigas e plantas com nectários extrafl orais (PEFN) têm relacionamentos diferentes com formigas e sofrem confi namentos ecológicos diferentes. As plantas com domácias atraem um grupo mais específi co de formigas do que as PEFN. Os resultados são consistentes com a hipótese de que as domácias são adaptações que ajudam a planta a aumentar o acesso a nutrientes escassos para a defesa de herbívoros. PEFN atraem uma variedade maior da espécie de formigas do que as plantas com domácias, e a abundância de formigas parece limitar a escala ecológica de PEFN. A atração das formigas como mecanismo para reduzir a herbivoria, como feito por PEFN, não parece ser superior aos mecanismos alternativos de prevenção de herbivoria usados por outras plantas. Contrário a muitos estudos anteriores, as formigas mostraram-se geralmente mais diversas no solo comparado ao dossel. PALAVRAS-CHAVE: Mirmecofi ta, mirmecófi loABSTRACT -We evaluated the hypothesis that the abundance and species distribution of two different kinds of myrmecophilous plants is infl uenced differently by the ant diversity and abundance. In eight different natural forests in Venezuela we estimated the species richness and abundance of plants, ants on the soil and on the canopy, the leaf damage of plants and soil nutrients. The main results of the study show that plants with domatia (PD) and plants with extrafl oral nectaries (PEFN) have different relationships with ants and suffer from different ecological constraints. PD attract a more specifi c group of ants than PEFN. Our results are consistent with the hypothesis that domatia are adaptations that help plants to increase rare nutrient uptake rather than for herbivore defense. We found that PEFN attract a larger variety of ant species than PD, and ant abundance seems to limit the ecological range of PEFN. The attraction of ants as a mechanism to reduce herbivory, as done by PEFN, does not seem to be superior to alternative anti-herbivore mechanisms used by other plants. Contrary to many former studies, we found that ants are generally more diverse on the soil compared to canopies.

Evidences that human disturbance simplify the ant fauna associated a Stachytarpheta glabra Cham. (Verbenaceae) compromising the benefits of ant-plant mutualism

“…Although B. heeri was present but presents no aggressiveness (Rico-Gray and Oliveira, 2007). Camponotus crassus is considered a dominant arboreal ant and natural sugary secretion consumer (DelClaro andOliveira, 1999, 2000;Fagundes et al, 2012;Goitía and Jaffé, 2009;Rico-Gray and Oliveira, 2007). This means that its large size, aggressiveness, presence of attack mechanisms (namely acidoporo ejector of formic acid), and territorial behavior are key characters that make this species suitable for defense of plants and removing and driving away herbivores and thus reducing herbivory, ensuring the benefits of mutualism (Fagundes et al, 2012;Freitas and Oliveira, 1992).…”

Peer Review #2 of "Diversity and distribution of extra-floral nectaries in the cerrado savanna vegetation of Brazil (v0.1)"

“…Data on which of these species have extra-floral nectaries was obtained from Neotropical floras (Oliveira & Marquis, 2002;Pennington & Ratter, 2006), an online database (Keeler, 2008), and several journal articles (Oliviera & Leito-Filho, 1987;Oliviera & Oliviera-Filho, 1991;Diaz-Castelazo, et al, 2004, 2005Oliviera & Fraitas, 2004;Marazzi et al, 2006;Machado et al, 2008;Goita & Klaus, 2009;Schoereder et al, 2010, see Supplementary Table 1). Currently, 1-2% of plant species have been confirmed to possess EFN and it is estimated that a further 1-2 % of species remain to be discovered with EFN (Weber & Keeler 2012).…”

Biodiversity and Ecosystem Functioning in Tropical Habitats — Case Studies and Future Perspectives in Atlantic Rainforest and Cerrado Landscapes

“…Extrafloral nectar is a liquid resource, composed by glucose, sucrose and fructose, and containing sometimes amino acids and proteins [122]. EFN-bearing plants are more visited by ants than plants without them [123], and ants that use extrafloral nectar as a resource may establish a generalist association of protection in exchange for food [114,119]. Therefore, the benefits arising from this interaction may explain its success [124].…”