Edge effects decrease ant-derived benefits to seedlings in a neotropical savanna

Autor(es)

Christianini, Alexander V. ^[1] ; Oliveira, Paulo S. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Ciencias Ambientais, BR-18052780 Sorocaba, SP - Brazil

^[2] Univ Estadual Campinas, Dept Biol Anim, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ARTHROPOD-PLANT INTERACTIONS; v. 7, n. 2, p. 191-199, APR 2013.
• Citações Web of Science: 17

Resumo

Edge effects may lead to changes in mutualistic plant-animal interactions, such as seed dispersal, that are critical to plant regeneration. However, research into edge effects is neglected in the Brazilian cerrado, the largest neotropical savanna. We evaluated the consequences of edge effects in the cerrado for the regeneration of Erythroxylum pelleterianum (Erythroxylaceae), a shrub that benefits from seed dispersal by ants. We compared air temperature, relative humidity, and vapor pressure deficit, as well as the frequency and outcome of ant-diaspore interactions between cerrado edges and interiors. The inner portion of cerrado was likely to be moister than its borders, but seed production and germination did not differ between edge and interior of cerrado. Ants removed more seeds near fragment edges than at the interior. However, Myrmicinae ants dominated ant-fruit interactions at edges. These ants are likely to provide few benefits to the seeds. Seedlings of E. pelleterianum growing close to Ponerinae ant nests showed higher survival than seedlings growing away from nests in the interior of cerrado, but such effect disappeared near edges. Widespread seedling mortality due to a higher evaporative demand at edges may partially account for this effect. Furthermore, Ponerinae's nests also showed a lower residence time near edges, decreasing possible benefits derived from ant colony activity such as nutrient enrichment and protection against insect herbivores. Edge effects could change the structure and dynamics of vegetation in cerrado fragments, due in part to the collapse of the mutualistic interactions demonstrated here. (AU)

• Processo FAPESP: 11/18580-8 - Estudos sobre formigas neotropicais: interações com insetos herbívoros, ecologia comportamental e organização social
• Beneficiário: Paulo Sergio Moreira Carvalho de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 02/12895-8 - Interação entre formigas, frutos e sementes em solos de Cerrado: o papel de formigas na biologia de sementes e plântulas
• Beneficiário: Alexander Vicente Christianini
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 08/54058-1 - Ecologia e comportamento de formigas neotropicais
• Beneficiário: Paulo Sergio Moreira Carvalho de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular