Invasion impact by Pteridium arachnoideum (Kaulf.) Maxon (Dennstaedtiaceae) on a neotropical savanna

Abstract

Whether management intervention is required to control biological invasions depends primarily on demonstrating species losses resulting from such invasions. Brackens of the Pteridium genus are currently regarded as a problem species that act as important ecological filters in the assembly of invaded communities. We investigated the effects of Pteridium arachnoideum invasion on the diversity, structure, floristic composition, and functional traits of cerradão in Assis, São Paulo, Brazil. We compared an invaded site with an adjacent non-invaded site. Bracken constrained the establishment of tree species, resulting in a community structure remarkably distinct from the non-invaded area. The density and basal area of the arboreal community were higher in non-invaded areas, but large trees were more frequent in the invaded areas. However, bracken did not reduce tree species diversity. Both richness and diversity were higher in the invaded area, indicating that over time, tree species richness and diversity naturally recovered, albeit slowly, in the invaded area. Therefore, one cannot attribute the loss of richness in the Cerrado vegetation to bracken invasion. Hence, we argue that, in this system, eradication of this invasive species is not likely to be cost effective, and thus, it should be a low management priority.

Striking genetic homogeneity in the widespread South American bracken

“…By contrast, the Southern Hemisphere has received much less attention. In the case of the South American diploid P. esculentum ( P. e. arachnoideum ), most of the research has focused on its ecology (e.g., Alonso‐Amelot and Rodulfo‐Baechler, 1996; Hartig and Beck, 2003; Portela et al, 2009; Silva Matos et al, 2012), phytochemicals, and phytotoxins (e.g., Rosero Negrete, 2013; Furlan et al, 2014) or is related to the behavior of the species as a weed (e.g., Dorantes, 2014; Guerin and Durigan, 2015; Xavier et al, 2023). The taxon is characterized by petiole bases with adventive roots, large fronds usually ~2 m long (sometimes reaching 4.5 m long), free lobes between the distal segments (or only decurrent lobes), simple distal segments <5 cm long, and a complex laminar indument composed of two or three kinds of hairs, abaxially on the segments: catenate hairs on costae and costules, arachnoid or acicular hairs on veins, and gnarled hairs on the laminar tissue between the veins, giving it a farinaceous appearance (Thomson and Martin, 1996; Thomson and Alonso‐Amelot, 2002; Schwartsburd et al, 2018).…”

Floristic data to support conservation in the Amazonian canga

“…Cockayne (Dennstaedtiaceae) is widely distributed both on the edges of the trails and near the canga, occupying the space opened up by frequent, sometimes criminal fires. This fern is referred for some Brazilian regions and in other countries as a problem plant because, besides producing vast quantities of biomass, it rapidly expands its rhizome making the re-establishment of native vegetation extremely difficult (Guerin & Durigan 2015). Effective control measures for these invasive and native problem species in Serra da Bocaina need to be included in management plans for PNCF.…”

Restoration Strategies in an Area Invaded by Pteridium aquilinum (L.) Kuhn

“…A similar result was observed by Cervasio et al (2009), who tested methods of bracken control in Italy, verifying the efficiency of harrowing since the number of individuals was reduced and the natural regeneration of native species induced. Pteridium aquilinum is a rhizomatous plant (Guerin & Durigan, 2015). In general, the rhizomes and their rhizophores are deeply buried, allowing the bracken to withstand environment adversities, acting as a storage organ, besides having expansion properties, facilitating the colonization and fixation of the plant in the environment (Atkinson, 1989).…”