Comparing germination success and seedling traits between exotic and native pioneers: Cecropia pachystachya versus Macaranga gigantea

Abstract

Cecropia is a pioneer genus from the Neotropics, whilst Macaranga is an ecological analog with a center of distribution in Southeast Asia. In the past few decades, introduced populations of Cecropia spp. have spread rapidly in Singapore, Malaysia, and Indonesia. In Singapore, Cecropia pachystachya now occupies habitats that would have been expected to be occupied by Macaranga gigantea. We conducted germination experiments under 0, 20, 50, and 70 % shading and measured the survival rates and functional traits of the seedlings of these two species from material collected in Singapore. Seeds of C. pachystachya germinated in 3-12 days, whereas seeds of M. gigantea germinated from day 13 onwards. Germination success for C. pachystachya was between 90.3 % under fulllight conditions and 55.8 % under 50 % shading, while for M. gigantea only 69.1 % of seed germinated under full-light conditions and germination completely failed when seeds were shaded by 20 % or more. The seedlings of C. pachystachya also had higher survival rates, faster shoot and root biomass accumulation, larger leaves, and lower total water content than those of M. gigantea. Thus overall, C. pachystachya possesses traits that may provide a competitive edge over the native M. gigantea and will be advantageous for its spread given the increasing proliferation of disturbed landscapes in tropical Southeast Asia.

Comparing the reproductive biological characteristics of the alien invasive Coreopsis lanceolata to those of the non‐invasive alien congener Coreopsis tinctoria

“…Studies that compare congener successful and non‐successful alien species are more appropriate, as this minimizes the differences among species in their life‐history traits and evolutionary history. Hence, the differences between these species are key to gaining insights into which traits are associated with invasiveness (Bevill & Louda, 1999; Burns, Ashman, Steets, Harmon‐Threatt, & Knight, 2011; Kunin & Gaston, 1993; Powell et al, 2011; Raphael, Chong, Yap, & Tan, 2015).…”

Physiological responses to extreme hydrological events in the Pantanal wetland: heterogeneity of a plant community containing super‐dominant species

“…; Raphael et al. ). In particular, C. americana , L. parvifolia and V. divergens produce copious amounts of seed that ripen between Oct and Jan (Lorenzi ), which is before seasonal flooding but after the beginning of the rainy season when soil moisture is adequate for germination.…”

“…While the propensity for invasion success of these super-dominant species could not be solely explained by their physiological performance, their ability to thrive in both flooded and upland habitats may interact with other phenological and/or life-history characteristics that may explain their ability to expand and persist in novel habitats. First, all of the super-dominant species studied here are pioneer species that have large reproductive output and rapid growth rates in disturbed environments (Pott & Pott 1994;Lorenzi 2009), and in turn, many invasive species tend to be pioneer species (Lambdon et al 2008;Raphael et al 2015). In particular, C. americana, L. parvifolia and V. divergens produce copious amounts of seed that ripen between Oct and Jan (Lorenzi 2009), which is before seasonal flooding but after the beginning of the rainy season when soil moisture is adequate for germination.…”

Diploendozoochory in Neotropical fish makes seed germination unlikely

“…The species of Cecropia are widely distributed in the Neotropical region. They grow rapidly and are abundant in the early stages of succession (Raphael et al, 2015). Their fleshy fruits are consumed by many animals which are responsible for the dispersal of their small seeds (Lorenzi, 2017).…”