Demographic consequences of greater clonal than sexual reproduction in Dicentra canadensis

Abstract

Clonality is a widespread life history trait in flowering plants that may be essential for population persistence, especially in environments where sexual reproduction is unpredictable. Frequent clonal reproduction, however, could hinder sexual reproduction by spatially aggregating ramets that compete with seedlings and reduce inter‐genet pollination. Nevertheless, the role of clonality in relation to variable sexual reproduction in population dynamics is often overlooked. We combined population matrix models and pollination experiments to compare the demographic contributions of clonal and sexual reproduction in three Dicentra canadensis populations, one in a well‐forested landscape and two in isolated forest remnants. We constructed stage‐based transition matrices from 3 years of census data to evaluate annual population growth rates, λ. We used loop analysis to evaluate the relative contribution of different reproductive pathways to λ. Despite strong temporal and spatial variation in seed set, populations generally showed stable growth rates. Although we detected some pollen limitation of seed set, manipulative pollination treatments did not affect population growth rates. Clonal reproduction contributed significantly more than sexual reproduction to population growth in the forest remnants. Only at the well‐forested site did sexual reproduction contribute as much as clonal reproduction to population growth. Flowering plants were more likely to transition to a smaller size class with reduced reproductive potential in the following year than similarly sized nonflowering plants, suggesting energy trade‐offs between sexual and clonal reproduction at the individual level. Seed production had negligible effects on growth and tuber production of individual plants. Our results demonstrate that clonal reproduction is vital for population persistence in a system where sexual reproduction is unpredictable. The bias toward clonality may be driven by low fitness returns for resource investment in sexual reproduction at the individual level. However, chronic failure in sexual reproduction may exacerbate the imbalance between sexual and clonal reproduction and eventually lead to irreversible loss of sex in the population.

Synergistic Effect of Anthropogenic Disturbances on Offspring Demography of <i>Pentadesma butyracea</i> (Clusiaceae), a Threatened Tree Species in Benin (West-Africa)

“…High humidity can limit clonal recruitment [27]. This is consistent with the increase of clonal proportion with the increase of light and decreases with humidity [26] [28]. Also, the intensity of fire was reduced in large gallery forest.…”

“…Vegetative reproduction is common among flowering plants. It may be essential to the persistence of the plant species population, especially in environments where sexual reproduction is unpredictable [26]. Moisture conditions can favor plant asexual reproduction [27].…”

“…The vegetative offspring growth may vary according to the environmental regime [28]. Vegetative offspring are more robust, grow faster [29] and contribute to the population growth rate than sexual offspring [26]. All these advantages of clonal offspring are due to the maternal effect [30] at the early development stage.…”

Spatio-temporal variability of Gladiolus imbricatus L. populations in different plant communities near Kraków

“…The previous observations showed the clonal growth in Gladiolus cultivars (Rameau & Gouyon, 1991) and its great enhancement after the clipping of leaves and inflorescences (Memon et al, 2009) or the adding of fertiliser (Ali et al, 2014;Saeed et al, 2014;Khattab et al, 2016). Successful clonal growth was also observed in other tuberous taxa such as Dicentra canadensis (Lin et al, 2016) and Crocus sativus (Negb et al, 1989).…”

Spatial genetic structure of an endangered orchid Cypripedium calceolus (Orchidaceae) at a regional scale: limited gene flow in a fragmented landscape

“…Honnay and Bossuyt 2005;Bossuyt and Honnay 2006;Van Geert et al 2008). However, reduced sexual reproduction resulting from environmental changes (e.g., loss of pollinators or genetically compatible mates in fragmented habitats) may lead populations to shift towards a predominately clonal reproductive strategy (Barrett 2015;Lin et al 2016). Due to a low frequency of seed production and dispersal, clonal plants may be less effective in spreading into new habitat patches and respond more slowly to habitat change than non-clonal species, which may result in local extinction (Buckley and Frecleton 2010;Zobel et al 2010;Wiberg et al 2016).…”