Plant size, flowering synchrony and edge effects: What, how and where they affect the reproductive success of a Neotropical tree species

Abstract

Plant reproductive success is supposedly influenced by phenology and individual size, which may be modified under edge effects. We tested if reproductive success, estimated by fruit set, in Senefeldera verticillata (Euphorbiaceae) is related to flowering synchrony and tree size, including plant height and circumference at breast height. The study was carried out in the interior and in edges of clearings for gas pipelines and electric lines of a lowland rainforest in south-eastern Brazil. Monthly observations were performed during one reproductive season, of 19 individuals that grew at edges of electric lines and gas pipelines and at forest interior. Reproductive success was significantly higher at forest interior than at gas pipeline area; there was no significant difference between gas pipeline and electric line areas or between forest interior and electric line area. In the forest edges, only plant height was positively related to plant reproductive success. This is probably related to crown exposure to sunlight, which enhances flower production. At forest interior, reproductive success was positively influenced by the synchrony of flowering activity among neighbouring individuals. In contrast, flowering synchrony based on phenophase intensity negatively impacted reproductive success. Senefeldera verticillata shows temporal dioecy and is mainly pollinated by small social bees, and the high degree of flowering synchrony at low intensity may increase the number of mating partners and therefore enhance its reproductive success. Inside the forest fragments, individuals with thicker trunks showed lower reproductive success, which may be related to a loss of reproductive capacity of older individuals. Our results evidenced the complexity of responses experienced by tropical plants subjected to forest fragmentation because of linear clearings.

Reproductive phenology of Sambucus nigra subsp. canadensis in the Abies religiosa temperate forest of the Magdalena river basin, Mexico City

“…This coincides with our results, because small values of synchrony were registered in the three micro-environments. Since patterns of flowering and fructification are a reflex of the opportunities for pollination and dispersal (Augspurger 1983, Pires et al 2014 and taking into account the predictions proposed by Post et al (2001), for species under anthropic disturbances, the small values of synchrony indexes of S. nigra subsp. canadensis suggest that pollinators and dispersers are available during most of the year and they do not present a marked seasonality.…”

Influence of plant–pollinator interactions on the assembly of plant and hummingbird communities

“…Moreover, our results highlight that flowering intensity (i.e. flower availability), a variable that was included in our measure of synchrony, may be more critical to plant fitness than overall flowering time length, although studies on climate regulation of reproductive phenology concentrate on the latter (see Freitas & Bolmgren 2008;Pires, Silva & Freitas 2014).…”

The influence of El Niño and edge effects on the reproductive phenology and floral visitors of Eschweilera tetrapetala Mori (Lecythidaceae), an endemic species of the Atlantic Forest of northeastern Brazil

“…Th ere is indisputable evidence that edge eff ects resulting from forest fragmentation can modify the richness and abundance of tropical arboreal species (e.g., Oliveira et al 2004;Pires et al 2014;CoutoSantos et al 2015). Th e phenology and reproductive success of plant species occurring near forest edges can be strongly aff ected by their diff erent environmental conditions (Aguilar & Galleto 2004;Athayde & Morellato 2014).…”