Demography of red clover seeds in mixed-sown meadows

Abstract

To clarify the reproduction probability of red clover (Trifolium pratense L.) in meadows for herbage cutting, the demography of this legume was studied in a meadow in the central mountainous district of Japan. The present study shows the demography of deposited red clover seeds in a meadow, where timothy (Phleum pratense L.) predominated and herbage had been harvested for making hay or silage in early June and late August of a year. The densities of deposited seeds, buried seeds and seedlings were monitored to determine their survival. Deposited seeds were collected using seed traps, buried seeds were monitored seasonally by sampling them from topsoil and seedlings were counted in ten permanent 1×1 m quadrats. Many permeable and hard seeds of red clover were deposited on the soil surface of the meadow during the mechanical operation of the second haymaking in mid- to late August. Of the population of deposited permeable seeds, 0·16 germinated and 0·84 were lost in the present autumn. Conversely, of the population of deposited hard seeds, 0·11 germinated in the succeeding spring, 0·83 were lost and 0·06 remained as hard seeds until the succeeding autumn. The deposited permeable and hard seeds could contribute to the persistence of red clover population when their seedlings survived for seed setting in the meadow.