Seasonality of reproduction of epiphytic bryophytes in flooded forests from the Caxiuanã National Forest, Eastern Amazon

Abstract

This work aimed to recognize the reproductive biology of the epiphytic bryofl ora of phorophytes of Virola surinamensis (Rol. ex. Rottb.) Warb. in várzea and igapó forests in the Caxiuanã National Forest, to answer the following question: The reproductive period of the bryophyte species is infl uenced by the environment due the climatic seasonality present in fl ooded forests, being higher the occurrence of the sexual and asexual reproduction in the rainiest months? The bryophytes were identifi ed and analyzed for the type of reproduction, sexual system and reproductive structures. In total, 502 samples of bryophytes were analyzed, resulting in 54 species, of which 34 were fertile. The comparison of the fertility of the species in different environmental conditions (dry or rainy, and igapó or várzea forest) was assessed using the chi-square test. The fertility of the seven studied species could not be defi ned by a pattern, considering the forest type and the seasonality. However, two species were associated to the forest type and two further species to the seasonality, showing that, for some bryophyte species, invest in constant fertility may be favoring the maintenance of their populations in tropical forests.

Fenologia reprodutiva de Ochrobryum Mitt. (Leucobryaceae, Bryophyta) no Brasil

“…Esse gênero segue o padrão compatível com a flora briofítica tropical, na qual, em períodos chuvosos percebese o aumento da reprodução sexuada. Cerqueira et al (2016) descreve que para as briófitas tropicais a ausência de uma estação tipicamente fria e seca é o que condiciona a expressão sexual em algumas espécies da brioflora.…”

“…A fenologia reprodutiva tem possibilitado dar respostas aos "porquês" de cada fase no ciclo biológico dos vegetais, ao compreender como esses organismos reagem às condições do meio ambiente e explicar o seu sucesso adaptativo/reprodutivo (Fenner 1998, Laaka-Lindberg 2005, Maciel-Silva 2011, Cerqueira et al 2016.…”

“…Nos trópicos, por sua vez, as estações do ano são marcadas por períodos mais chuvosos (verões) e por períodos de maior estiagem (invernos). Assim, é a disponibilidade hídrica no ambiente que favorece ou não o desenvolvimento da maioria das espécies vegetais (Fenner 1998, Reys et al 2005, Bergamaschi 2007, Cerqueira et al 2016.…”

Species richness and composition of epiphytic bryophytes in flooded forests of Caxiuanã National Forest, Eastern Amazon, Brazil

“…As the low frequency, high frequency can also be associated with reproductive strategies of bryophytes, which reproduce not only sexually, but asexually as well (Löbel and Rydin 2009, Frey and Kürschner 2011, Maciel-Silva and Válio 2011, Maciel-Silva et al 2013, Cerqueira et al 2016. Various means of asexual reproduction represent a successful strategy allowing species to maintain the equilibrium between populations, given the difficulties imposed by the environment preventing sexual reproduction (Laaka-Lindberg 2000).…”

“…Various means of asexual reproduction represent a successful strategy allowing species to maintain the equilibrium between populations, given the difficulties imposed by the environment preventing sexual reproduction (Laaka-Lindberg 2000). Among epiphytic bryophytes, this strategy is widely adopted, especially by liverworts, as the colonization through new gemmae facilitates the establishment on vertical substrates (Glime 2007, Bastos 2008, Cerqueira et al 2016. The lack of dispersion limitation among epiphytic bryophyte communities from Amazonian lowland forests indicated a predominance of niche-assembly rules over dispersal-assembly rules according to Motade-Oliveira et al (2009).…”