The invasion of Pteridium aquilinum and the impoverishment of the seed bank in fire prone areas of Brazilian Atlantic Forest

Abstract

Several studies have documented that fires are widespread in the tropics. Because fire in the Atlantic Rain Forest is rare, fire events and their consequences at the community level have not been evaluated. This study describes the composition of different seed banks in areas of Atlantic Forest. The study was carried out in the National Park of Tijuca in the state of Rio de Janeiro. Four different areas were chosen considering their differences on fire history. Fifteen soil surface samples (23 cm (centimeter) diameter ·7 cm height at 5 cm deep) were obtained from random locations within each site. The dominant family at all study sites except in the most preserved one were Dennstaetiaceae, followed by Melastomataceae and Poaceae. The family Dennstaetiaceae was exclusively represented by Pteridium aquilinum (Klf.) Herter. There were no significant differences among areas when comparing the number of seedlings excluding P. aquilinum. However, the number of P. aquilinum was higher in the most disturbed area, while Melastomataceae and Rubiaceae were more frequent in a less impacted area. Our results suggest that the seed bank in disturbed areas of the Atlantic Forest possibly will not contribute for forest restoration after disturbance.

Variation in aboveground biomass and necromass of two invasive species in the Atlantic rainforest, southeast Brazil

“…in abandoned pastures, around forest edges and in other degraded areas are often dominated by productive grasses and ferns, and some of these species are invading the Atlantic Forest (Silva Matos et al 2002, Silva & Silva Matos 2006. Two species that are present in abundance in such situations are the grass Panicum maximum Jacquin (Poaceae) (Guinea Grass) and the fern Pteridium arachnoideum (Kaulf.)…”

Interference of Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) on the establishment of rainforest trees

“…Most studies on the impact of bracken on plant communities have been carried out in the temperate zone of the northern hemisphere, and almost nothing is known about the ecology of bracken in the sub-tropics and tropics (Gliessman, 1976apud den Ouden, 2000Silva Matos et al, 2005;Silva and Silva Matos, 2006). Here we report the results of an experiment designed to test the hypothesis that Pteridium interfered with tree colonisation.…”

“…This is also supported by the work of Royo and Carson (2006), who argued that the dense understorey layer in forests is one of the causes of impact on the floristic composition rather than some allelopathic effect. The work of Silva Matos et al (2005) and Silva and Silva Matos (2006), showed that the occurrence of wild fires and the consequent expansion of grasses and ferns within Atlantic Forest areas is hindering the establishment of secondary vegetation typically found along the natural successional process. Our results contribute to understanding the reasons of such dominance of bracken within this ecosystem and its influence on the establishment of pioneer and secondary tree species.…”

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

“…The lack of effective sources of propagules may lead to the stagnation of the ecosystem after invasion by bracken, requiring management intervention to facilitate the arrival of species (planting). Moreover, a natural reversal of the invasion may not occur if the target vegetation is susceptible to fires, considering that Pteridium increases in density in post-fire environments (Roos et al 2010;Silva & Matos 2006). Bracken may also have a more lasting effect on non-forest vegetation, given that shading of bracken by trees appears to be the major mechanism by which the biotic filter imposed by bracken can be overcome.…”

“…Characterized by large fronds and rapidly expanding rhizomes, brackens reduce the establishment of native vegetation (Marrs & Watt 2006), and act as an important ecological filter in the assembly of invaded communities (Matos & Belinato 2010). Species of Pteridium produce large quantities of dry biomass, increasing the frequency and intensity of wildfires (Ghorbani et al 2006;Portela et al 2009;Silva & Matos 2006), and can also alter the soil seed bank and hinder the establishment of native species due to allelopatic compounds (Gliessman & Müller 1978).…”