Nutrient concentration and allometric models for hybrid eucalyptus planted in France

Context

Short rotation coppice (SRC) of hybrid Eucalyptus has been developed in France for almost 30 years for the production of pulp and paper and, since a few years, for energy purposes. In the traditional pulp production, only the stems are harvested, whereas the whole biomass may be harvested for energy purposes. Thus, a range of different harvest scenarios need to be considered with higher plantation densities or younger age of harvest for example.

Aims

The objective of this study was to build models to estimate biomass and nutrient content of eucalyptus at different ages and so to estimate the production and the nutrient exportation of a SRC, depending on the different harvest scenarios.

Methods

Over 250 trees were sampled in 16 stands at ages from 1 to 15 years. For each tree, biomass of different compartments and nutrient contents were recorded.

Results

A complete set of equations for the four compartments (wood, bark, branches, and leaves) of aboveground biomass and for nutrient concentration was set up.

Conclusion

Biomass and its allocation to different compartments and nutrient concentrations depended on the dimension and/or the age of the tree. In particular, nutrient concentration decreased with increasing tree diameter.