Demography and reproductive performance ofCalystegia soldanellaon a sandy seashore in Tuscany, Italy

Abstract

Calystegia soldanella (L.) R.Br. is a psammophyte growing in the coastal foredunes of temperate areas. We investigated its demography and reproductive performance, to improve the in situ and ex situ management of the species as an essential element in planning the stabilization of the shoreline. The studied population is located in northwestern Tuscany, Italy. Demographic data were recorded in 20 quadrats from May to October 2009. Self-pollination ability has been tested by wrapping flower buds in cotton lint. Seeds traits (length, width, depth, shape index, mass, and water content), flotation ability, and germination percentage have been determined on seeds collected from the study site. The presence of C. soldanella seeds in the soil seed bank has been investigated by sifting the sand of 30 soil core samples. Our results showed that ramet density decreases during summer, mainly owing to drought. Predation reduces ramet size especially in spring and autumn, but rarely fatally, having the greatest impact on flower removal and, therefore, in decreasing the population’s genetic variability. Self-pollination does not occur and the percentage of reproductive ramets increases with their size. Tested seeds were able to float on water and germinated to 100%. No C. soldanella seeds were observed in the soil core samples. While suggesting useful indications for the management of the investigated population, our results provide a guideline for a more comprehensive study about the management of C. soldanella.