The orchid bee fauna (Hymenoptera, Apidae) of a core area of the Cerrado, Brazil: the role of riparian forests as corridors for forest-associated bees

Abstract

Abstract:The composition of local orchid-bee faunas (Hymenoptera, Apidae, Euglossina) in open-vegetation domains is poorly known, making the ecology and biogeography of the group difficult to understand. The aim of this work was to answer the following questions: i) Is the orchid-bee fauna composition, species richness and abundance in the cerrado (Brazilian savanna) sensu stricto similar to that of riparian forests immersed in that domain? ii) Do species from neighboring forest domains use riparian forests as mesic corridors into the Cerrado? Two sites in cerrado s.s. and two in riparian forests were sampled monthly, one day per month, during one year (Nov/2003-Oct/2004) in northwestern Minas Gerais state, Brazil. Six aromatic compounds (β-ionone, 1,8-cineole, eugenol, methyl trans-cinnamate, methyl salicilate and vanillin) were exposed from 8:00 AM to 4:00 PM to attract orchid bees. The results suggest that: i) The composition of the orchid bee fauna in the two kinds of environments is the same; ii) Riparian forests apparently have no role as mesic corridors for penetration of forest-dependent euglossine species into the core of the Cerrado Domain. Resumo: A composição das faunas locais de Euglossina (Hymenoptera, Apidae) em formações vegetais abertas é pouco conhecida, o que dificulta o entendimento da ecologia e biogeografia do grupo. O objetivo deste trabalho foi responder às seguintes perguntas: i) No domínio do Cerrado, a composição da fauna, riqueza em espécies e abundância de euglossinas em áreas de cerrado s.s. e em mata ciliar são semelhantes entre si? ii) Espécies de domínios florestais adjacentes utilizam as matas ciliares como corredores mésicos para dentro do Cerrado? Duas áreas de cerrado s.s. e duas de mata ciliar foram amostradas mensalmente, um dia por mês, durante um ano (nov/2003-out/2004), no noroeste do estado de Minas Gerais, Brasil. Seis compostos aromáticos (β-ionona, cineol, cinamato de metila, eugenol, salicilato de metila e vanilina) eram expostos das 8 às 16 horas para atrair as euglossinas. Os resultados encontrados sugerem que: i) As composições das faunas em áreas de cerrado s.s. e matas ciliares são iguais; ii) As matas ciliares aparentemente não atuam como corredores mésicos para a penetração, em áreas centrais do Cerrado, de espécies de euglossinas dependentes de florestas. Palavras-chave: Euglossina, mata ciliar, mata de galeria, savana, ecologia de paisagem.

Orchid bee fauna responds to habitat complexity on a savanna area (Cerrado) in Brazil.

“…The results of the present study, plus those obtained by Viotti et al (2013), Justino and Augusto (2012) Faria and Silveira (2011), Alvarenga et al 2007 andFaria (2004), in other areas of savanna (Cerrado) in Minas Gerais state, revealed a total of 16 orchid bee species for this region. So far there is no list for the orchid bee fauna in the Cerrado of Minas Gerais.…”

“…Despite Faria and Silveira (2011) explain the low richness and abundance of orchid bees in Cerrado areas, as a result from relative food scarcity, which, in turn, would be a consequence of a combination of low soil fertility and relatively low seasonal precipitation, our results are going in an opposite way. The Cerrado is a very rich floristic region with many different habitat types (Joly et al, 1999) and that habitat heterogeneity may provide the necessary resources for orchid bee species.…”

“…The species richness in Parque do Rio Preto is higher to those found in other inventories carried out in the Cerrado domain (e.g Nemésio & Faria, 2004;Alvarenga et al, 2007;Justino & Augusto, 2010;Faria & Silveira, 2011;Viotti et al, 2013) and in fragments of the semideciduous "low mountain rain forest", at elevations of 300-900 m, in the Atlantic forest domain (Rebêlo & Garófalo, 1997;Sofia & Suzuki, 2004;Nemésio & Silveira, 2010;Silveira et al, 2011;Ferreira et al, 2013). These forests are characterized by relatively open canopy, 15-25 m tall, and occur under climates with two well defined seasons, rainy and dry.…”

“…Habitat complexity, measured as a function of differences in multiple strata in forests, may be of great worth as a surrogate for the diversity of a range of arthropod groups including orchid bees. (Nemésio & Faria, 2004;Alvarenga et al, 2007;Faria & Silveira, 2011;Viotii et al, 2013). These studies have shown structural differences in bee communities from distinct biogeographical regions, particularly in relation to composition, richness and patterns of dominance.…”

Abelhas Euglossina (Hymenoptera: Apidae) Associadas À Monocultura De Eucalipto No Cerrado Mato-Grossense

“…Comparado a outros estudos (CARVALHO et al, 2006;ALVARENGA et al, 2007;FARIA;SILVEIRA, 2011), que fizeram amostragens, também no domínio de Cerrado e por um período mais longo, este estudo, em apenas quatro meses de coleta na estação chuvosa, obteve registro superior tanto em riqueza quanto em abundância de abelhas Euglossina. Essa condição indica que a extensão do plantio de eucaliptos e outros cultivos nesses locais ainda não foram suficientes para extinguir a grande diversidade das espécies de abelhas da região amostrada.…”