Artrópodos fitófagos y entomófagos asociados a la vegetación responden diferencialmente a la fragmentación del Chaco Serrano

GONZÁLEZ, E.; SALVO, A.; VALLADARES, G. R.

Revista de la Asociación Argentina de Ecología de Paisajes

Asociación Argentina de Ecología de Paisajes

Año: 2011 vol. 2 p. 48 - 55

1853-8045

Currently, the rate of biodiversity loss is very high, with habitat fragmentation being one of the main causes. Arthropod richness and abundance frequently decrease in small forest fragments, and predators are more susceptible than herbivores. Also, fragment edges usually have greater diversity than interiors because they represent transition areas with adjacent crops. In this paper, we explored such trends in arthropod communities associated with three native plants (Cestrum parqui, Croton lachnostachyus and Eupatorium hookerianum) of Chaco Serrano in Córdoba, whose coverage dropped 94% in the last 30 years. We collected manually all arthropods present on 5 plants in the edge and 5 in the interior (for each species) of 12 forest remnants. We estimated abundance and richness of arthropod families, which were classified as phytophages and predators / parasitoids. Linear regressions were used to analyze the area effect and paired "t" test for edge effect. Eighty one families of arthropods (N=4644) were identified. The abundance of phytophagous families was independent of area and position, but their richness was positively related to area and was higher on the edge. For predators, both abundance and richness were lower in small fragments, and presented no differences between positions. These results confirm, for the system of study, the negative effects of area loss on species richness, affecting both functional groups. The reduction of predators in smaller remnants could free the phytophages from top-down control, offsetting any direct negative effects of fragmentation. Similarly, the greater diversity of phytophages on the edge may be associated with a contribution from the matrix of adjacent crops