Seed bank composition in a secondary forest in the Lower Delta of the Paraná River (Argentina)

Abstract

Th e native forests once occupying the coastal levees of the Lower Delta islands of the Paraná River (in Argentina) have been replaced by commercial forests. Many of those forests have been abandoned, resulting in secondary forest formation that is subject to numerous invasive exotic species. A priori observations suggest that successional trends do not lead to recovery of the original forest. Th e aim of the present study was to analyze the role of invasive exotic species in these environments and the likelihood of recovery of the original forest cover. Th erefore, we examined the composition of the seed bank and of the standing vegetation, as well as the population structure of tree species. Secondary forests are described as being in an intermediate successional stage, with few exotic species (mainly trees) but with a high abundance of standing vegetation and seed banks. Th ese exotic species will likely continue to successfully predominate in diff erent forest strata over the next stages. Because of the low density of native tree species, it is diffi cult to predict their future persistence. In conclusion, ecological restoration strategies will be needed in order to increase native tree species richness and biodiversity of the forests in the Lower Delta of the Paraná River. Acta Botanica Brasilica 27(1): 40-49. 2013.

Diversity, composition and richness of soil seed banks in different forest communities at Dotalugala Man and Biosphere Reserve, Sri Lanka

“…Hopfensperger (2007) revealed that the least similarity (31%) between the standing vegetation and its associated seed bank in forest ecosystems, after reviewing 108 studies carried out between 1945 and 2006. Kalesnik et al (2013) also observed similar results in a study carried out in a secondary forest in Argentina. Mature forests generally consist of a small seed bank composed of species not present in the standing vegetation due to the fact that most shade-tolerant species do not develop persistent seed banks (Nakagoshi 1985;Thompson 1998).…”

Recovery of floristic diversity and basal area in natural forest regeneration and planted plots in a Costa Rican wet forest

“…, Barnes & Chapman ), a depleted soil seed bank due to previous land use (Kalesnik et al . ), seed and seedling predation (Holl & Lulow , Jones et al . , Cole ), unsuitable microsites for seed establishment (Holl , Holl & Aide ), and competition from established species (Duncan & Chapman , but see Elgar et al .…”

Composición del banco de semillas e invasión de Ligustrum lucidum en bosques costeros de la provincia de Buenos Aires, Argentina

“…De acuerdo a Kalesnik et al (2012), este valor se correspondería a un estado sucesional intermedio en bosques conservados. Sin embargo, este valor podría evidenciar un grado de invasión avanzado en bosques invadidos, con una alta presencia de las especies exóticas dominantes del dosel en el banco de semillas.…”

“…La baja diversidad y riqueza registradas para el ligustral y el bosque implantado, junto con índices de invasión superiores al 75 % y coberturas de especies exóticas cercanas al 100 %, indica que el proceso de invasión provocó la alteración de la estructura y funcionamiento de estos bosques dominados por L. lucidum, y podrían ser considerados como neoecositemas (Kalesnik et al 2012).…”

“…por especies nativas pioneras mientras que en ambientes altamente antropizados, los bosques pueden estar constituidos casi enteramente por especies exóticas, reduciendo la posibilidad de las especies nativas de recuperarse (Kalesnik et al 2012). En este sentido, el grado de asociación o la relación entre la composición del banco de semillas y la de la vegetación ha sido utilizado para predecir el potencial regenerativo de una comunidad vegetal luego de un disturbio (Albrecht y Pilgram 1997).…”