Ramet demography of Aechmea distichantha (Bromeliaceae) in two contrasting years in the understory and open areas of a South American xerophytic forest

Ignacio Martín Barberis,José María Cárcamo,Juliana Albertengo,Luciano Galetti,Graciela Klekailo,Juan Ignacio Cárcamo

doi:10.1590/2175-7860202071014

Ignacio Martín Barberis, José María Cárcamo + Show 4 more

Open Access

https://doi.org/10.1590/2175-7860202071014

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Abstract

Abstract The Schinopsis balansae forests of the Wet Chaco are characterized by convex areas with woody vegetation and plain areas with herbaceous vegetation. In the Wet Chaco, Aechmea distichantha is a terrestrial bromeliad that forms dense colonies in the understory and open areas of these forests. The aim of this study was to analyze the spatial and temporal variations in population dynamics of this bromeliad species. We monitored ramets growing in sun and shade conditions during two contrasting years. We analyzed the spatial and temporal variations in survival, flowering, and ramet production. Variations in survival, flowering, and ramet production were more marked between years than between habitats. During the year with wetter and milder temperature conditions, survival and ramet production were higher than during the drier year with more extreme temperatures. Survival of vegetative ramets was less variable than survival of young and reproductive ramets. In the colder year, lower winter temperatures reduced the populations in all stages, being more important in the open areas. Our results highlight the importance of low temperatures on A. distichantha demography at this xerophytic forest located at the southernmost distribution range of this bromeliad species.

Highlights

Habitat heterogeneity has long been recognized as one of the main factors affecting plant distribution in many terrestrial ecosystems (Scheiner & Willig 2011)
Even though there is a continuous gradient in resource availability and environmental conditions (Cogliatti-Carvalho et al 1998, 2001), the environmental differences between contrasting shaded and open areas, like understory and treefall gaps, may affect plant growth and survival, and plant population dynamics (Barberis & Tanner 2005; Fortini et al 2010; Kuptz et al 2010; Dalling et al 2012; Myster 2012)
The dynamic of Aechmea distichantha populations was more affected by the environmental conditions of a year than by the habitat where the ramets grow: survival and ramet production were higher in the wetter and mild-temperature year, whereas fruiting was higher in the drier year

Summary

Introduction

Habitat heterogeneity has long been recognized as one of the main factors affecting plant distribution in many terrestrial ecosystems (Scheiner & Willig 2011). Even though there is a continuous gradient in resource availability and environmental conditions (Cogliatti-Carvalho et al 1998, 2001), the environmental differences between contrasting shaded and open areas, like understory and treefall gaps, may affect plant growth and survival, and plant population dynamics (Barberis & Tanner 2005; Fortini et al 2010; Kuptz et al 2010; Dalling et al 2012; Myster 2012). A conspicuous feature of several tropical and subtropical forests in America is the presence of dense populations of bromeliad species in their understories (Benzing 2000; Ticktin & Nantel 2004; Barberis & Lewis 2005; Brancalion et al 2009; Rocha et al 2015), which may colonize treefall gaps and forest edges (Scarano et al 2002; Sampaio et al 2004; Skillman et al 2005; Cavallero et al 2009). Only a few of these studies analyzed the effects of different habitats on bromeliad population structure and dynamic (Sampaio et al 2004, 2005)

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