Gremios y diversidad de hormigas (Hymenoptera: Formicidae) en tres usos del suelo de un paisaje cafetero del Cauca-Colombia.

Abstract

Guilds and diversity of ants in three land uses from a coffee landscape at Cauca -Colombia. In the last 50 years, Colombian coffee production has undergone a great transformation from traditional plantations grown below the forest's shade, to vast extensions of coffee plantations consisting of free exposition to sun. These systems reduce native biodiversity and its associated ecosystem services. Simultaneously, shaded coffee plantations operate as potential shelter of such biodiversity, favoring its dispersal in the landscape, because they offer high-quality habitat for the movement of wild organisms through natural vegetation relicts. Therefore, it is important to document its biological value. In Colombia, Cauca department is the fourth coffee producer and although its cultures were mainly based on the model of using trees' shade on coffee shrubs, in last 10 years, sun coffee plantations have doubled their extension in this department and have almost equated the shaded coffee extension. Thus, it is necessary to document if these land use changes at landscape scale may derivate in consequences for the wild biota dwelling these productive systems. Given the above considerations, and in order to test for the biological importance of coffee plantations, the present study compares the effect of three land uses (sun coffee, shaded coffee and natural vegetation patches; eight of each one) in terms of ants' species richness and the abundance of their trophic guilds at Caldono municipality, between August 2015 and January 2016. Captures were carried out with pitfall traps, mini-Winkler sacs and direct capture. We found that ants' richness was higher in natural vegetation patches, followed by shaded coffee plantations and sun coffee plantations, in these last ones, the omnivore-generalist ants were more abundant, and ground-foraging arboreal ants were less abundant. We found that shaded coffee plantations, despite belonging to a transformed land use, have greater similarity with some natural vegetation patches. Using only ants from the lowest stratum (soil and understory), our findings confirm that shaded coffee plantations maintain an important part of the ant diversity of the locality, while sun coffee plantations offer less habitat quality to it. El café (Coffea arabica L. Rubiaceae) es una especie vegetal de gran importancia comercial en Colombia, cuya producción ubica este país como el tercero a nivel mundial, después de Brasil y Vietnam (ICO, 2017). Con el paso de los años, las variedades de los cafetos sembrados en Colombia -que en condiciones naturales de su sitio originario en África, crecen en el estrato bajo de bosques-, fueron progresivamente reemplazadas por variedades desarrolladas para resistir el pleno sol, sembradas a cielo abierto con arbustos bajos, en densidades de hasta 10 000 por hectárea, y ocasionalmente acompañadas por una o dos especies vegetales, también productivas (Borrero, 1986;Armbrecht, 2016). Esta forma de producción proviene de una concepción de agricultura industrial, que dep...

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Effects of environmental variables on the composition of ants (Hymenoptera: Formicidae) in Amazonian foothills forest

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