Number and weight of seeds and reproductive strategies of herbaceous plants

Abstract

The paper brings data set of seed reproduction of about 500 wild herbaceous species of Central Europe and presents a number of produced seeds in a new way. Number of seeds — reproductive capacity of a population (RCP) was defined as a number of seeds produced by one species per 1 m2 at its one-hundred-per-cent cover per one season. About 23% of seed weight variability and about 26% of variability in RCP were explainable on a family level. The trade-off between RCP and seed weight was confirmed both within families and also among families. Both characteristics had higher variability on a family level and on lower taxonomic levels than on subclass and class levels. Species with an annual life cycle have a larger number of seeds than perennials. Geophytes and species without lateral spread have a tendency to produce a large amount of relatively weighty seeds in comparison to other life forms, and to species with vegetative lateral spread. Species with seeds dispersed by wind usually have a large number of lightweight seeds. Multivariate analyses confirmed some tendencies of reproductive traits which correspond to the definition of C-, S-, R- strategies by Grime — “verification” of the RCP as ecological trait. The R- strategy was well distinguished from the C- and S- strategies by reproductive traits, whereas C- and S- strategies are very similar to each other. Species with insect pollination agent often correspond to C- strategy, wind agent to S- strategy, and species with self-pollination to R- strategy.