RAPID: Spatial scale of flowering and seed production in Posidonia oceanica - the influence of clonal structure

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

The sea grass Posidonia oceanica, a clonal species, is the dominant habitat forming, foundation species in coastal areas of the Mediterranean Sea. This species also provides additional ecosystem services through its role in stabilizing shorelines and immense primary productivity. Over the last century and particularly over the last 50 years, P. oceanica meadows have been contracting, in large part due to anthropogenic factors, and there has been considerable effort directed at restoration of degraded meadows. These efforts have almost always involved the transplantation of rhizomes, under the assumption that expansion and local replenishment of meadows would occur via vegetative growth. These efforts have met with little success. The PIs challenge the prevailing assumption that sexual reproduction for this clonal species is largely unimportant to population demography and rescue. They will take advantage of a recent and on-going mass flowering of P. oceanica at several sites in the northern Mediterranean. Preliminary data from one of the sites show spatial patterns of flowering within the sea grass communities. If these patterns are related to clones, identified through genetic analysis, that knowledge could be of great help in conserving and restoring local populations of this species. It would also shed light on a fundamental question about the relative functioning of sexual and asexual reproductive modes in a long-lived species. Flowering events such as the ones now taking place are both rare and unpredictable, making this an unusually good opportunity for this project. Broader Impacts: This work began as a student project under the direction of the PIs, and the two female undergraduate students involved in the initial project will play a primary role in the research described in this proposal, under appropriate supervision and with new training in molecular techniques. Results will provide new insights that could be very useful in conservation and restoration biology.