Developmental Patterns of the Invasive Bramble (Rubus alceifolius Poiret, Rosaceae) in Reunion Island: an Architectural and Morphometric Analysis

Abstract

The aim of this study was to identify the developmental stages of Rubus alceifolius and to determine one or more characteristic morphological markers for each stage. The developmental reconstitution method used involved a detailed description of many individuals throughout the different stages of growth, from germination to the development of an adult shoot capable of fruiting. Results revealed that R. alceifolius passes through five developmental stages that can be distinguished by changes in several morphological markers such as internode length and diameter, pith diameter and plant shape. This analysis indicated that R. alceifolius has a heteroblastic developmental pattern, midway between that of a bush and a liana. Moreover, results showed that this species taps environmental resources early in its development, i.e. foliarization is high (the foliar component overrides the caulinary component) and an autotrophic stage is rapidly reached, whereas it 'explores' the environment during the adult stage, i.e. axialization is substantial (the caulinary component overrides the foliar component) and autotrophy occurs at a later stage. The morphological markers identified could benefit land-use managers attempting to control this species before it reaches its optimum developmental stage.

Effects of canopy gap size on recruitment and invasion of the non-indigenousRubus alceifoliusin lowland tropical rain forest on Réunion

“…Rubus alceifolius has a growth form intermediate between a shrub and a liana (Baret et al . 2003a), and once established can grow rapidly upwards into the canopy (Baret et al . 2003a); in addition, it colonises open areas by vigorous vegetative reproduction (successive terrestrial layering), forming dense monospecific patches that prevent indigenous plants from regenerating (Baret et al .…”

Pith: a marker of primary growth in Picea abies (L.) Karst.

“…Nicolini et al 2001;Guédon et al 2007), whereas pith size is very rarely studied. For instance, Baret et al (2003) used changes in pith size in combination with other morphological markers to identify the developmental stages of the invasive bramble (Rubus alceifolius). In the present study, variables representative of primary growth (i.e.…”

Architecture and size relations: an essay on the apple (Malus × domestica, Rosaceae) tree

“…Although these criteria and the architectural models that they define are at first qualitative, the relationships to the size of organs (axis, leaf, inflorescence) have been addressed through ''Corner's rules'' (Corner, 1949;Hallé et al, 1978): axial conformity (the thicker the stem, the bigger the leaves and the more complicated their form) and reduction in size on ramification (the greater the ramification, the smaller the branches and their appendages). Various attempts have been made to study the correlations between dimensions of organs, at both the vegetative (e.g., leaf and stem size: Barcellos et al, 1986;Bond and Midgley, 1988;Brouat et al, 1998;Baret et al, 2003) and vegetative-reproductive (e.g., stem and inflorescence size: Lauri et al, 1996;Lauri and Trottier, 2004) levels.…”

“…The development of a plant follows a morphogenetic progression from the young, nonflowering individual to the senescing one and involves a succession of states, including reproductive and vegetative events (Nozeran et al, 1971;Nozeran, 1984;Borchert, 1976). The latter case may be illustrated well by morphological changes such as stem diameter (Allsopp, 1965), length and duration of growth units (Borchert, 1976), or the ratio between the axis and leaf components of the leafy shoot, i.e., axialization (Lauri and Térouanne, 1991;Lauri and Kelner, 2001;Baret et al, 2003). The concept of morphogenetic progression of interest in a modelling context (De Reffye et al, 1991;Barthélémy, 2003) may be illustrated by our results.…”