Reproductive capacity of Pinus nigra ssp. salzmannii in relation to mother plant age

Abstract

This paper analyses the possible reduction of fertility in Pinus nigra ssp. salzmanii as trees age in the managed forests of Cazorla mountain range (Southern Spain). Fertility was assessed by the combined values: frequency of empty seeds and viability of full seeds. Performance of one year seedlings was also evaluated. Plant material came from reproductive trees of up to 120 years old (the rotation period in the study area), and from older trees of over 1000 years old. The older tended to produce larger quantities of empty seeds than the younger ones, and their filled seeds tended to be lighter and slower to germinate. Nevertheless, the difference in these parameters shown by the trees studied was not so great so as to establish that ageing Salzmann pines are unable to regenerate managed forests. The growth of first year seedlings was positively correlated to seed weight and, therefore, negatively correlated to mother plant age. However, these factors could only account for a small amount of the variability in the size of first-year seedlings. Results suggest that reproductive function works normally in the very old (senescing) Salzmann pines, this being important in relation to the maintenance of biodiversity in the managed mountain forests of Southern Europe.