Diversity of the ground-dwelling ant fauna (Hymenoptera: Formicidae) of a moist, montane forest of the semi-arid Brazilian Nordeste

ABSTRACT

Although the so called "green islands" of the semi-arid Brazilian "Nordeste" are economically, socially, and ecologically important, relatively little is known about their biodiversity. We present the results of the first survey of the ground-dwelling ant fauna of a secondary forest in the Serra de Baturité (4° 05’ - 4° 40’ S / 38° 30’ - 39° 10’ W), among the biggest of the moist, montane forests of the state of Ceará, Brazil. From February to March 2001, samples were taken every 50 m along twelve 200 m transects, each separated from the others by at least 50 m and cut on either side of a recreational trail. Where possible, two transects were cut from the same starting point on the trail, one on either side. At each sample site two methods were used, as recommended in the ALL protocol a pitfall trap and the treatment of 1 m² of leaf litter with the Winkler extractor. The myrmecofauna of the Serra de Baturité is quite diverse individuals from 72 species, 23 genera, and six subfamilies were collected. The observed patterns of specific richness show the same tendencies noted in other tropical regions, particularly the frequency of capture distribution with many rare and few abundant species. Differences with the Atlantic and Amazonian forests were also observed, especially the relative importance of the Ponerinae and Formicinae subfamilies, indicating a possible influence of the surrounding "caatinga" (savanna-like ecosystem) on the myrmecofauna of the moist, montane forest

RESUMEN

Se presentan los resultados del primer inventario de la mirmecofauna del suelo en un parche de bosque montano húmedo del "Nordeste" semi-árido brasileño. Aunque estos parches o "islas verdes" son importantes económica, social, y ecológicamente, se conoce relativamente poco acerca de su biodiversidad. La investigación fue llevada a cabo en un bosque secundario en la Serra de Baturité, uno de los mayores del bosque montano húmedo del estado de Ceará, Brazil. La mirmecofauna de Serra de Baturité es muy diversa encontramos individuos de 72 especies, 23 géneros y seis fsubfamilias. Los patrones de riqueza específica muestran las mismas tendencias de otras regiones tropicales, particularmente en la distribución de frecuencia de capturas, con muchas especies escasas y unas pocas especies abundantes. También hay diferencias con los bosques atlántico y amazónico, especialmente en cuanto a la importancia relativa de las subfamilias Ponerinae y Formicinae, lo que indica una posible influencia de la "caatinga" (ecosistema semejante a la sabana) cercana en la mirmecofauna del bosque montano húmedo