Does seed germination contribute to ecological breadth and geographic range? A test with sympatric Diplusodon (Lythraceae) species from rupestrian fields

Abstract

We tested the regeneration niche hypothesis by comparing the germination ecology of two sympatric Diplusodon species differing in their geographic range and microhabitat. Diplusodon orbicularis is an endemic shrub achieving high densities on sandy soils, whereas Diplusodon hirsutus has a wider geographic range and establishes on rocky outcrops. Seeds were set to germinate under constant temperatures of 15, 20, 25, 30 and 35°C under 12 h light/12 h dark conditions. Light induced germination in both species, but germination under darkness was also observed. Optimum conditions for germination were 25°C/light for both species. The lack of differences in soil temperatures between rocky outcrops and sandy soils provides evidence of no temperature-dependent microhabitat selection. Unexpectedly, germinability of the more widespread species was lower than that of the endemic congener. Higher germinability of D. orbicularis may account for higher densities when compared with D. hirsutus. Our results provide limited support for the role of germination in contributing to ecological breadth and geographic range.

Effects of NaCl stress on seed germination and seedling development of Brassica insularis Moris (Brassicaceae)

“…Coastal habitats are often characterised by harsh conditions, e.g. intense sun exposure, violent winds and high water deficit during the driest months (Ribeiro & Fernandes 2000;Oliveira Silveira et al 2012). Seasonal fluctuations of salinity on coastal cliffs strongly influence plant growth in these habitats, and the distance from the sea is one of the most important factors (Weber & D'Antonio 1999).…”

Germination responses of the invasive Calotropis procera (Ait.) R. Br. (Apocynaceae): comparisons with seeds from two ecosystems in northeastern Brazil

“…LAURA C. LEAL, MARCOS V. MEIADO, ARIADNA V. LOPES and INARA R. LEAL Studies on seed traits and germination behavior have been useful in the investigation of environmental factors affecting geographic distribution of native species (Abreu and Garcia 2005, Donohue et al 2010, Silveira et al 2011. Furthermore, such investigations are important tools for understanding colonization abilities and geographical distribution of exotic plants introduced in new habitats (Smith and Knapp 2001).…”

Contribución al conocimiento de las semillas de cinco especies forestales nativas y dos exóticas de Córdoba, Colombia

“…No obstante, en diferentes partes del mundo, varios estudios se han realizado sobre variabilidad gené ca, parámetros gené cos y el efecto de lotes mezclados de semillas en diferentes especies (Davidson et al, 1996;Murillo, 1998;Leishmann et al, 2000;Cordazzo, 2002;Costa et al, 2005;Rego et al, 2005;Varghese et al, 2006;Resende & Duarte, 2007;Tenorio-Galindo et al, 2008;Costa et al, 2009;Fofana et al, 2009;Rocha et al, 2011;Silva et al, 2012;Correa, 2012;Silveira et al, 2012;Correa et al, 2013;Souza & Fagundes, 2014). En general, los resultados han sido par culares y diferentes para cada especie, por ello se recomienda muy puntualmente analizar cada situación o caso por separado, con el objeto de tomar la mejor decisión de acuerdo con los obje vos puntuales que se busquen.…”