Aim of study: Designing adequate silvicultural systems for natural regeneration of a forest species requires sound knowledge of the underlying ecological subprocesses: flowering and fruiting, seed dispersal and predation, seed germination, seedling emergence and seedling survival. The main objective of the present work is to carry out a review on the current knowledge about the different subprocesses governing the regeneration process for the main Iberian Pinus species, in order to propose scientifically based management schedules.Area of study: The review focuses on the five main native Pinus species within their most representative areas in the Iberian Peninsula: Pinus nigra in Cuenca mountains, Pinus sylvestris in Sierra de Guadarrama, Pinus pinaster and Pinus pinea in the Northern Plateau and Pinus halepensis in Catalonia.Material and methods: Firstly, currently available information on spatiotemporal dynamics and influential factors is introduced for each subprocess and species. Secondly, current regeneration strategies are characterized and the main bottlenecks are identified. Finally, alternative silvicultural practices proposed on the light of the previous information are presented.Main results: Different climate-mediated bottlenecks have been identified to limit natural regeneration of the Iberian pine species, with seed predation and initial seedling survival among the most influential. New approaches focusing on more gradual regeneration fellings, extended rotation periods, prevent big gaps and program fellings on mast years are presented.Research highlights: Natural regeneration of the studied species exhibit an intermittent temporal pattern, which should be aggravated under drier scenarios. More flexible management schedules should fulfil these limitations.Additional keywords: seed production; seed dispersal; seed predation; germination; regeneration fellings.Correspondence should be addressed to Rafael Calama: rcalama@inia.es

Natural regeneration faces increasing difficulties in dry forests from the Mediterranean basin, including for normally well-regenerating species such as maritime pine (Pinus pinaster Aiton). In this paper, we studied female fertility, seed dispersal and spread rates in P. pinaster from the Spanish Northern Plateau, where natural regeneration failure is a main concern for forest managers. For this purpose we periodically collected data from seed traps and trees located at two core locations across several years. We found sig-nificant variation in interannual cone production, with the best seed trees being the same across years. In addition, we found highly skewed distributions of female reproductive effort and large fertility differ-ences across stands located few kilometres away. Annual seed dispersal kernels fitted lognormal or 2Dt models depending on the stand analysed, with median dispersal distances between 14 and 25 m. Kernels fitted for maximum dispersal periods showed an outstanding intraseasonal variation of median dispersal distances, from 10 to 54 m, in association to variable patterns of rainfall and maximum wind speed.The amount of seed produced appeared to be enough to guarantee the natural regeneration of the stands during the typical 20-year regeneration period. Colonisation simulations concluded that Med-iterranean maritime pine has a notable dispersion capacity, which is strongly influenced by levels of fecundity and, especially, by the number and frequency of long-distance dispersal events. The latter play a key role in tree dispersion processes through enlarging the occupied area and fostering the invasion of abandoned crop land.Mating system Seed rain Dispersal kernel Dispersion Sortie-ND Mediterranean region

Seed bank dynamics constitute a pool of natural regeneration, a complex and key process for stand persistence. The present work analyses post-dispersal predation on a density. These results demonstrate how seed rain, summer drought and micro-site conditions are crucial to understanding the effects of predation on the below-ground seed bank. Though greater than null, the final seed bank might be insufficient for successful natural regeneration due to high mortality caused by difficult germination and establishment conditions.

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