¿Por qué la producción de semillas es tan variable en las especies mediterráneas de Quercus?

Q-suber-seedsUnderstanding the proximate factors that govern the widespread mast-seeding process (i.e., the large interannual variability in seed production) is a question of considerable ecological and evolutionary interest that remains poorly understood. The identity and effect of these factors may vary among coexisting species that differ in leaf habit, potentially resulting in temporally asynchronous patterns of seed production, with potential repercussions for recruitment and dynamics of these species.

Researchers of the IRNAS-CSIC, led by Ignacio M. Pérez-Ramos, and the University of Cornell (USA) have tried to answer the question: why is seed production so variable in Mediterranean oak species? For this purpose, they have quantified seed production over ten consecutive years in two oak species – the deciduous Quercus canariensis and the evergreen Q. suber – that coexist in forests of southern Spain (´Los Alcornocales` Natural Park). Simultaneously, they have reviewed the literature on environmental drivers of mast-seeding in Mediterranean oaks, distinguishing between evergreen and deciduous species.

Results from this study indicate that weather plays a crucial role as a proximate driver of mast-seeding in Mediterranean oaks. Based on these findings, it can be hypothesized that the current abundance of co-occurring species that differ in leaf habit could be altered under future climate change scenarios. Thus, the decline of seed production with drier conditions will be potentially greater in deciduous species, particularly those inhabiting wetter sites. Alternatively, the expected warmer temperatures could negatively affect evergreen species as a consequence of their more conservative strategy of biomass allocation. Information provided by this study suggests that understanding how species with different functional or phenological attributes adjust their reproductive abilities to weather may enable us to infer the effects of ongoing environmental changes on population recruitment and dynamics.

This study has been recently published in Journal of Ecology:

Pérez-Ramos, I. M., Padilla-Díaz, C.M., Koenig, W. D. & Marañón, T. (2015) Environmental drivers of mast-seeding in Mediterranean oak species: does leaf habit matter? Journal of Ecology 103, 691–700 (doi: 10.1111/1365-2745.12400)

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