Habitat Fragmentation and Species Loss across Three Interacting Trophic Levels: Effects of Life-History and Food-Web Traits

• Published in: Conservation biology 2009-10, Vol.23 (5), p.1167-1175
• Main Authors: CAGNOLO, LUCIANO, VALLADARES, GRACIELA, SALVO, ADRIANA, CABIDO, MARCELO, ZAK, MARCELO
• Format: Article
• Language: English
• Subjects: abundancia natural; amplitud trófica; Animal, plant and microbial ecology; Applied ecology; Argentina; Biodiversity; Biological and medical sciences; body size; Conservation biology; Conservation, protection and management of environment and wildlife; Ecosystem; Extinct species; Extinction, Biological; Food Chain; Food chains; Fundamental and applied biological sciences. Psychology; General aspects; Habitat conservation; Habitat fragmentation; Habitats; Insects; leaf miners; Leafminers; minadores de hojas; natural abundance; nivel trófico; parasitoides; Parasitoids; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Plants; pérdida de especies; relación especies-área; Species; Species extinction; species loss; Species Specificity; species-area relationship; tamaño corporal; trophic breadth; trophic level; Trophic levels
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1111/j.1523-1739.2009.01214.x

Not all species are likely to be equally affected by habitat fragmentation; thus, we evaluated the effects of size of forest remnants on trophically linked communities of plants, leaf-mining insects, and their parasitoids. We explored the possibility of differential vulnerability to habitat area reduction in relation to species-specific and food-web traits by comparing species-area regression slopes. Moreover, we searched for a synergistic effect of these traits and of trophic level. We collected mined leaves and recorded plant, leaf miner, and parasitoid species interactions in five 100-m² transects in 19 Chaco Serrano woodland remnants in central Argentina. Species were classified into extreme categories according to body size, natural abundance, trophic breadth, and trophic level. Species-area slopes differed between groups with extreme values of natural abundance or trophic specialization. Nevertheless, synergistic effects of life-history and food-web traits were only found for trophic level and trophic breadth: area-related species loss was highest for specialist parasitoids. It has been suggested that species position within interaction webs could determine their vulnerability to extinction. Our results provide evidence that food-web parameters, such as trophic level and trophic breadth, affect species sensitivity to habitat fragmentation.