Retrospective data on male and female flower output over a period of 18 years in the European forest tree Abies alba Mill. from 14 forests in South-Eastern France

This publication reports the production of male and female reproductive structures (strobili or cones) in silver fir (Abies alba Mill.), a major forest tree species of European mountainous area. It contains male and female cone production data of 72 trees from 14 South-Eastern French populations using a retrospective counting over 18 years (total of 3839 data points). Data were acquired in 1987 and 1988 on cut branches from different parts of canopies with the goal of analyzing the damage done by the moth Choristoneura murinana Hübner. Sampled trees were selected from populations were the insect was present. Despite this focus, sampled trees were selected at random among mature, dominant trees independently of their defoliation stage. In Abies alba, leaves remain alive for at least a decade and male and female strobili scars remain visible for at least 20 years. However, as twigs become scarcer with age due to mortality and decay, we only considered the 15 most recent years (thus the period after 1970). Branch age was calculated retrospectively from the most recent annual growth unit, taking advantage of the fact that Abies alba is monocyclic. In general, two different branches from opposite directions were sampled at each level in the canopy, thus sampling different light intensities. The strobili that mature year n grow on year n-1 shoots. Male strobili appear below the shoot, mostly on low and mid-canopy branches while female strobili appear above the shoot, mostly on high canopy branches. This type of data can be used to identify ontogenic and architectural factors influencing male and female cone production. It can also be used to identify masting years and the ecological and climatic factors that drive them at a time when global temperatures had not yet strongly accelerated their warming. The publication contains four files. One data file with all populations and trees and three metadata files describing the sampling sites, the sampling size and the variables.