Ecological factors affecting the fruiting success of a Tibouchina trichopoda (DC.) Baill. (Melastomataceae) flower

Abstract

Ecological factors aff ecting the fruiting success of a Tibouchina trichopoda (DC.) Baill. (Melastomataceae) fl ower ABSTRACTTh e abundance and distribution of resources for pollinators modulate the reproduction of plants. Th is study attempted to determine whether and how the fruiting success of Tibouchina trichopoda fl owers varies due to plant size, number of fl owers produced, distance between individuals and cardinal orientation of the fl owers. From July 2009 to February 2010, we conducted monthly evaluations of 21 plants in an area of regenerating forest within the Atlantic Forest biome, located near the municipality of Antonina, in southern Brazil. Floral density was monitored weekly. During the study period, the species bloomed twice: once during the cool, dry season, showing an extended fl owering period with scattered fl owering individuals; and once during the hot, rainy season, showing a brief fl owering period with a high density of fl owering individuals. Plant size was not found to infl uence fruiting success. Th ere was greater production of fl owers and fruits during the brief fl owering period. Th e extent of the fl oral display positively aff ected the fruiting success of the fl owers, the eff ect being greater when the density of fl owers was low and tending to stabilize at higher densities. Th e northern-facing portions of tree crowns produced more fl owers and therefore had greater fruiting success than did the southern-facing portions. However, the proportion of fruits produced per fl ower was the same.

Breeding system and pollination of Pleroma trichopodum DC. (Melastomataceae): a potential species for the restoration of Atlantic Forest in southern Brazil

“…Although an enhanced display of flowers attracted more pollinators to focal trees, this was not related to variation in visitation rate per flower (Mitchell et al 2004), as previous detected for other species (Klinkhamer & Jong 1990;Grindeland et al 2005). In this way, we did not confirm that enhanced fruiting success in P. trichopodum plants with more flowers, as detected in a previous study (Maia et al 2013), could be due to enhaced visitation of pollinators to each flower.…”

“…Here we argue that P. trichopodum might also provide pollinator assurance to plants that are growing under its canopy or in its proximity, thus functioning as a magnet species (Molina-Montenegro et al 2008). Furthermore, previous studies with P. trichopodum report two flowering seasons: an extended flowering period with scattered flowering individuals during the less rainy season; and a brief flowering period with a high density of flowering individuals during the hot, rainy season (Maia et al 2013). In this way, P. trichopoda might also be considered a bridging plant since it provides floral resources over a long temporal span and in periods of the year with contrasting climates (Dixon 2009).…”

“…1), which, until recently, was named Tibouchina trichopoda (Meyer et al 2010). Pleroma trichopodum is a pioneer tree adapted to environments saturated with water (Meyer et al 2010;Maia et al 2013), and is abundant in areas undergoing early natural regeneration in southern Brazil (Cardoso 2014;Warring et al 2016). Although it has potential for use in the restoration of Atlantic Forest, knowledge of its reproductive and pollination biology is incomplete, particularly regarding its pollinators and mating system.…”

“…Although it has potential for use in the restoration of Atlantic Forest, knowledge of its reproductive and pollination biology is incomplete, particularly regarding its pollinators and mating system. For instance, it is known that large floral displays by this species are related to enhanced reproductive success (Maia et al 2013), but whether this is associated with increased floral visitation is unknown. Individuals of P. trichopodum occurring in natural regeneration areas were selected to address three major questions: (1) Is P. trichopodum dependent on pollinators and mates for reproduction?…”

Effect of rosette size, clonality and spatial distribution on the reproduction of Vriesea carinata (Bromeliaceae) in the Atlantic Forest of Paraná, southern Brazil

“…This may be a result of spatial structuring of the environment in which the plants grow, in terms of humidity, substrate and light availability, since local abiotic conditions are usually involved with variation in reproductive efforts (Ågren et al 2008). Even small variation in tree crowns due to light availability may change the number of flowers produced by a plant (Maia et al 2013). Indeed, Aechmea distichantha bromeliads growing under sunny conditions had a larger reproductive effort than those in shaded conditions, when controlled for bromeliad size (Scrok & Varassin 2011).…”