Invasive grasses and native Asteraceae in the Brazilian Cerrado

Author(s)

Almeida-Neto, Mario ^{[1, 2]} ; Prado, Paulo I. ^[3] ; Kubota, Umberto ^{[2, 4]} ; Bariani, Joice M. ^[5] ; Aguirre, Guilherme H. ^[2] ; Lewinsohn, Thomas M. ^[4]

Affiliation

^[1] Univ Brasilia, Depto Ecol, Inst Ciencias Biol, BR-70919970 Brasilia, DF - Brazil

^[2] Univ Estadual Campinas, Curso Posgrad Ecol, Inst Biol, Campinas, SP - Brazil

^[3] Univ Sao Paulo, Inst Biociencias, Depto Ecol, BR-05508900 Sao Paulo - Brazil

^[4] Univ Estadual Campinas, Lab Interacoes Insetos Plantas, Inst Biol, Dept Biol Anim, BR-13083970 Campinas, SP - Brazil

^[5] Univ Estadual Campinas, Curso Posgrad Genet & Biol Mol, Inst Biol, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: PLANT ECOLOGY; v. 209, n. 1, p. 109-122, JUL 2010.
• Web of Science Citations: 24

Abstract

Anthropogenic disturbances frequently modify natural disturbance regimes and foster the invasion and spread of nonindigenous species. However, there is some dispute about whether disturbance events or invasive plants themselves are the major factors promoting the local extinction of native plant species. Here, we used a set of savanna remnants comprising a gradient of invasive grass cover to evaluate whether the species richness of Asteraceae, a major component of the Brazilian Cerrado, is affected by invasive grass cover, or alternatively, whether variation in richness can be directly ascribed to disturbance-related variables. Furthermore, we evaluate whether habitat-specialist Asteraceae differ from habitat generalist species in their responses to grass invasion. Abundance and species richness showed unimodal variation along the invasive grass gradient for both total Asteraceae and habitat-generalists. The cerrado-specialist species, however, showed no clear variation from low-to-intermediate levels of grass cover, but declined monotonically from intermediate-to-higher levels. Through a structural equation model, we found that only invasive grass cover had significant effects on both abundance and species density of Asteraceae. The effect of invasive grass cover was especially high on the cerrado-specialist species, whose proportion declined consistently with increasing invasive dominance. Our results support the prediction that invasive grasses reduce the floristic uniqueness of pristine vegetation physiognomies. (AU)

• FAPESP's process: 98/05085-2 - Species and interaction diversity in plants and phytophagous insects
• Grantee: Thomas Michael Lewinsohn
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants