Nuevos avances en el conocimiento de las causas y consecuencias del fenómeno de vecería en especies de Quercus

Foto bellotas_Nacho_PuechabonMost of Mediterranean woody plant species, such as Quercus, exhibit a large interannual variability in seed production (a broadly-known phenomenon called masting), with important differences among individuals within the same year. However, very little is known about the causes and consequences for population dynamics of this potentially large – often ignored – between-individual variability.

Researchers of the IRNAS-CSIC led by Ignacio M. Pérez-Ramos have tried to answer the question: why seed production is so variable among individuals of a same population? For this purpose, they have quantified seed production over ten consecutive years in two Mediterranean oak species – the deciduous Quercus canariensis and the evergreen Q. suber – that coexist in forests of southern Spain (´Los Alcornocales` Natural Park).

In general, results from this study suggest that individual seed production (both in terms of seed productivity and inter-annual variability) is strongly dependent on soil resource heterogeneity, and highlight the necessity of considering this source of variability among individuals given its potential repercussion for recruitment and population dynamics. Thus, trees inhabiting moister and more fertile soils were more productive and exhibited a higher interannual variability in seed production than those growing in more resource-limited sites. As a principal consequence for population dynamics, results from this study demonstrated a satiating effect on granivorous insects at the tree level, which was evident in those years where between-individual variability in acorn production was higher.

This study has been recently published in Plos One.

Pérez-Ramos IM, Aponte C, García LV, Padilla-Díaz CM, Marañón T (2014) Why is seed production so variable among individuals? A ten-year study with oaks reveals the importance of soil environment. PLoS ONE 9(12): e115371. doi: 10.1371/journal.pone.0115371

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