Holm oak savannas. Influence of weather on acorn production

Abstract

Carbonero, M.D., Fernández-Rebollo, P. 2014. Holm oak savannas. Influence of weather on acorn production. Ecosistemas 23(2): 45-63. Doi.: 10.7818/ECOS.2014.23-2.08

Acorn production in holm oak (Quercus ilex subsp. ballota (Desf.) Samp.) varies over the years, across areas and even between nearby trees. There are many variables that are involved in these differences, acting in different spatial and temporal levels too. We can identify endogenous and external factors as weather, pests and diseases, management or the habitat. In this work we analyze the influence of meteorology on acorn production and seed weight in an open woodland with high acorn crops. Acorn production was assessed in 50 trees during 2001-2006. The results indicated that weather conditions at early spring and autumn had a marked influence on acorn production. Summer and early autum affected acorn weight. So mild temperatures during March enhanced acorn crops, and lower temperatures in summer and early fall increased the weight of the acorns. In addition, this study has showed the heterogeneous response of trees to weather in terms of seed production.