Publication Date:
2011-11-24
Description:
Genetic differences in 13 C (isotopic composition of dry matter carbon) have been evidenced among poplar genotypes at juvenile stages. To check whether such differences were maintained with age in trees growing in plantations, we investigated the time course of 13 C as recorded in annual tree rings from different genotypes growing at three sites in southwestern France and felled at ~15–17 years. Wood cores were cut from tree discs to record the time course of annual basal area increment (BAI). The isotopic ratio 13 C was recorded in bulk wood and in extracted cellulose from the annual rings corresponding to the period 1996–2005. Discrimination against 13 C between atmosphere and tissues ( 13 C) was computed by taking into account the inter-annual time course of 13 C in the atmosphere. Annual BAI increased steadily and stabilized at about 8 years. An offset in 13 C of ~1 was recorded between extracted cellulose and bulk wood. It was relatively stable among genotypes within sites but varied among sites and increased slightly with age. Site effects as well as genotype differences were detected in 13 C recorded from the cellulose fraction. Absolute values as well as the genotype ranking of 13 C remained stable with age in the three sites. Genotype means of 13 C were not correlated to annual BAI. We conclude that genotypic differences of 13 C occur in older poplar trees in plantations, and that the differences as well as the genotype ranking remain stable while trees age until harvest.
Print ISSN:
0829-318X
Electronic ISSN:
1758-4469
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
