Fitness analysis of seed and vegetative reproduction of clonal tree Symplocos laurina

Abstract

There are two ways for Symplocos laurina to propagate: clonal reproduction and sexual reproduction. S. laurina adopted different ways to propagate and occupy space in different environments: under conditions with abundant water, nutrient resources, and lower light such as in an evergreen broad-leaved or a bamboo forest; survival rates and the ability of both clonal and sexual seedlings to occupy space, were relatively high. But clonal ramets took advantage both in terms of number and space. Therefore, clonal propagation predominated in such an environment. However, in habitats lacking sufficient nutrition and with higher light intensity, survival rates and space-occupying ability of two kinds of seedlings (sexual and asexual produced) were low and the space would be preempted by grown-up plantlets. A bottleneck in sexual propagation appeared at the stage from seed to seedling, while in clonal propagation it appeared during the period from an asexual plantlet to a ramet. The way S. laurina invaded space was like that of a plantlet settled in a place and then occupied the space rapidly by clonal growth under conditions of abundant water and nutrient resources and lower light such as in an evergreen broad-leaved forest or a bamboo forest. Clonal seedlings showed a great advantage in the initial stages, but this advantage disappeared after 15 years.