After a
long journey, the chapter four of the thesis of Oriol has been published in
Estuarine, Coastal and Shelf Science. In this paper we report an assessment of
shoot demography in the seagrass Cymodocea
nodosa at an unprecedented high-resolution temporal level. We attempted to
estimate shoot mortality and recruitment rates, that is, the rates at which the
units (say “individuals”) of the plant die and born. We found that recruitment
(“births”) were strongly correlated to light availability and were partially
supported by carbohydrate resources, that is, energy saved from the preceding
year. In contrast, mortality was correlated to high temperatures stimulating
respiratory demand and to shading among neighboring shoots. In addition to
this, the presence of macroalgae in eutrophic areas caused additional mortality
of shoots.
As
births exceeded deaths from March to August, the number of shoots, and then the
density and biomass of the meadows increased during that period. In contrast,
as deaths exceeded births from August to November, density and biomass of the
meadows decreased during that period.
In
summary, the strong seasonality in the number of shoots in these seagrass
meadows result from the different controls by environmental factors on births
and deaths, and in the seasonal uncoupling between these two factors.
Mascaró, O.
Romero, J. Pérez, M., 2014. Seasonal uncoupling of
demographic processes in a marine clonal plant. Estuarine Coastal and Shelf
Science, 142: 23-31.
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