... 195–208© INRA, EDP Sciences, 2003DOI: 10.1051/forest:2003012Original article Needle longevity, shoot growth and branching frequency in relation to site fertility and within-canopy light conditions ... average needle age, shoot length growth, and branching frequency in response to seasonal averageintegrated quantum flux density (Qint) were investigated in Pinus sylvestris L. in a fertile site ... biomassinvestment in branches in low light. However, in our study,there was an increase in the fractional investment in needleswith increasing Qint in the fertile site, and no effect of Qint in the...