January-February 2006 30 ECOLOGY, BEHAVIOR AND BIONOMICS Diversity of Bees and their Floral Resources at Altitudinal Areas in the Southern Espinhaço Range, Minas Gerais, Brazil VINÍCIUS A. ARAÚJO1, YASMINE ANTONINI2 AND ANA P.A. ARAÚJO3 1Lab. Histofisiologia Reprodutiva e Digestiva. Pós-Graduação em Entomologia. Univ. Federal de Viçosa, 36570-000 Viçosa, MG, [email protected] 2Instituto de Ciências Exatas e Biológicas, Depto. Ciências Biológicas, Univ. Federal de Ouro Preto, Ouro Preto, MG [email protected] 3Lab. Termitologia, Pós-Graduação em Entomologia. Univ. Federal de Viçosa, 36570-000, Viçosa, MG [email protected] Neotropical Entomology 35(1):030-040 (2006) Diversidade de Abelhas e suas Fontes Florais em Campos Altitudinais, na Porção Sul da Cadeia do Espinhaço, MG RESUMO - A porção sul da Cadeia do Espinhaço apresenta amplas áreas cobertas por campos altitudinais tropicais, quartizíticos ou metalíferos. Esses ecossistemas estão extremamente ameaçados, devido ao alto impacto antrópico, como a mineração e a urbanização. Nesse estudo inventariou-se a fauna e flora apícola durante um ano em uma área de campo rupestre (Serra de Ouro Branco) e durante dois anos em uma área de canga (Ouro Preto). Foram realizadas coletadas quinzenais de 8:00h às 17:00h. Foram coletados 677 indivíduos pertencentes a 91 espécies de abelhas de cinco famílias. Apidae foi a família mais rica e abundante, seguida por Halictidae e Megachilidae. As abelhas visitaram 46 espécies de plantas e as famílias mais visitadas foram: Asteraceae (n = 220), Malpighiaceae (n = 95), Melastomataceae (n = 94), Fabaceae (n = 78), e Solanaceae (n = 63). A região de Ouro Branco apresentou maior diversidade (H = 1,47) que Ouro Preto (H = 1,17). A baixa riqueza e abundância de abelhas, quando comparada a outras regiões de cerrado, podem ser atribuídas aos fatores ambientais das áreas de estudo: alta altitude, temperatura e disponibilidade de recursos florais. Áreas de canga e campo rupestre abrigam espécies raras e ameaçadas de extinção da fauna e flora. Áreas no sul do Espinhaço podem, entretanto, serem consideradas possíveis áreas de conservação biológica permanente. PALAVRAS-CHAVE: Apidae, cerrado, fauna de abelhas, conservação ABSTRACT - The Southern Espinhaço Range consists of large areas covered by quartzitic or metaliferous tropical altitudinal fields. The Espinhaço Range ecosystems are endangered by anthropic high impacts, particularly due to mining and urbanization. We conducted a one-year inventory of the bee flora and fauna at the quartzitic Ouro Branco Mountains and a two-year survey of the metaliferous Ouro Preto fields. The samples were collected twice a month, from 8:00 am to 5:00 pm. The bees (677) belonged to 91 species, five families. The family Apidae was the richest and most abundant, followed by the Halictidae and Megachilidae. The bees visited 46 flowering plant species; the most visited plants were the Asteraceae (n = 220), the Malpighiaceae (n = 95), the Melastomataceae (n = 94), the Fabaceae (n = 78), and the Solanaceae (n = 63). Diversity was higher in Ouro Branco (H = 1.47) than in Ouro Preto (H = 1.17). The low richness and abundance of bees in our research site when compared to other Brazilian “Cerrado” areas can be due to the high altitude, low temperature, and low availability of flowers we found. “Canga” and rupestrian areas house fauna and flora species that are rare and threatened by extinction. The southern Espinhaço areas can, therefore, be given the status of permanent biodiversity preservation area. KEY WORDS: Apidae, bee fauna, conservation January-February 2006 Neotropical Entomology 35(1) 31 Approximately 30,000 bee species with several 256 collecting hours at the Canga and 160 hours at the Ouro nidification habits and floral preferences are found in the Branco Mountains. The bees were trapped in entomological world (Roubik 1989, Michener 2000); in Brazil, an estimated nets as soon as they landed on or right after leaving the 3,000 species (Silveira et al. 2002) can be found. Most bees flowers. The bees were placed in a lethal vial and were killed; depend on floral resources such as pollen, nectar, and oil next, they were mounted with entomological pins and for food (Camargo & Roubik 1991). On the other hand, identified to the taxonomic level as possible. Control species flowering plants depend on bees as pollen vectors for their were brought to the entomological collection, Universidade sexual reproduction; this interaction is particularly important Federal de Ouro Preto (UFOP), Ouro Preto, MG. Although in tropical ecosystems (Buchmann & Nabhan 1996). the species Apis mellifera L. was abundant and its occurrence Although studies on bee fauna and flora have been registered, we did not capture any specimen. Two samples conducted in almost every region in Brazil, studies are still of each flowering plant species were collected for scarce in some parts of the country (Sakagami et al. 1967, identification and herborization. Some of the fertile material Laroca et al. 1982, Carmargo & Mazucato 1984, Pedro & was first herborized following the techniques described by Camargo 1991). In the State of Minas Gerais, bee fauna Mori & Pipoly (1984), and then deposited at the Herbário surveys conducted at the “Zona da Mata” (a forest area) Professor José Badini, Universidade Federal de Ouro Preto. (Cure et al. 1992, 1993; Silveira & Cure 1993, Antonini & We used the Shannon-Wienner diversity index to assess Martins 2003) and the “Cerrado” (a savannah area) (Silveira the diversity of bee species in both sampled areas. A simple & Campos 1995, Carvalho & Bego 1998) have contributed linear regression analysis tested the relationship between significantly for the better understanding of bees in the State. accumulated number of bee species (y variable) and number The southern Espinhaço Range, located in Minas Gerais, of months when sampling was conducted (x variable); the contains large Cerrado areas and is one of the richest biomes sampling site was the co-variable (Canga area and Ouro in the planet (Myers et al. 2000). In this region, the Cerrado Branco Mountains). The model was simplified to remove contains rupestrial and “Canga” areas with poor and thin non-significant variables using the generalized linear model soils, high insulation, and low humidity. These extreme as recommended by Crawley (2002) and processed with the situations make the region highly peculiar and endemic. software R (Ihaka & Gentleman 1996). Nonetheless, this biome has been considered one of the most critical and threatened, due to the high anthropic impact to Results which it is subjected (Mendonça & Lins 2000). In spite of the high diversity found in the Cerrado, studies We collected 677 specimens belonging to 91 bee species. on bee diversity in the southern Espinhaço Range were not At the Canga, we found 46 species belonging to 21 genera found. In our study, we aimed at learning about bee fauna and four families, a total of 325 individuals. At the Ouro and its flower resources and providing information to Branco Mountans, we found 66 species belonging to 28 transform the region into an ecological preservation unit. genera and four families, a total of 352 individuals (Table 1). Only 22 (24.2%) of the collected species were reported Materials and Methods for both areas (Table 1). When we include the species A. mellifera the total increases to 3006 individuals. We studied two different ecosystems in the southern At the Canga, the number of bee species collected Espinhaço Range: the hematitic Canga and the rupestrial increased until the 20th data-collecting month; after that, area in the Ouro Branco Mountains. the number tended to stabilize. In the Ouro Branco The hematitic Canga area is located at the Ouro Preto Mountains, however, the number of captured species municipality (43º30’ and 43º31’ W; 20º23’ and 20º24’ S). increased significantly until the 10th collecting month and The mountain peak in the area is approximately 1230 m. the collecting curve did not stabilize (Fig. 1) (χ2 < 0.001, gl From 1940 to 1950, the region, which is formed by a rigid- = 31). The Ouro Branco Mountains had a higher diversity substrate iron compound, was mined for bauxite. Grasses index (H = 1.47) than the Canga (H = 1.17). (20-50cm tall) completely cover the substrate and several Bee abundance and richness per family had similar Asteraceae, Malpighiaceae, Myrtaceae, Verbenaceae, and relationships in both areas. The Apidae was the richest and other species can also be found. most abundant family, followed by the Halictidae and the The Ouro Branco Mountains, located at the Ouro Branco Megachilidae. We found few specimens belonging to the municipality (43º46’ and 43º33’ W; 20º26’ and 20º30’ S), families Colletidae ad Andrenidae (Table 2). occupy approximately 65 km2, maximum altitude 1573 m. The most abundant bee species at the Canga were The mountains’ quartzitic surface rocks are mainly covered Bombus (Fervidobombus) morio (Swederus) (n = 65 by low-mountain pluvial forests and riparia, and also by specimens), Melipona quinquefasciata (Lepeletier) (n = 56), quartizitic and ferruginous fields (Alkmim 1987). Bombus (Fervidobombus) atratus (Franklin) (n = 51) and The bee samples were collected at 1250 m, every 15 days, Pseudaugochlora graminea (Fabricius) (n = 35). In the Ouro from August 2000 to August 2002 at the Ouro Preto Canga Branco Mountains, the most abundant species were Trigona and from October 2002 to July 2003 at the Ouro Branco spinipes (Fabricius) (n = 61), B. atratus (n = 40), Trigona Mountains. Two collectors obtained the samples from 2500 hyalinata (Lepeletier) (n = 30) and Tetrapedia sp.1 (n = m transects. From 8:00 a.m. to 5:00 p.m., each collector 18). remained at a flowering plant for five minutes, totalizing The bees visited 46 plant species belonging to 16 families 32 Araújo et al. - Diversity of Bees and their Floral Resources at Altitudinal Areas... Table 1. Bee species and their abundance and seasonal distribution, and number of plants visited at the “Canga” area and the Ouro Branco Mountains.