Provided that more confidence can be placed in the results obtained by having
analysed large numbers of yield measurements in relation to the respective
bio-physical site conditions, the development of site classes as known for
timber yields, may be considered at a later stage. These site classes could
serve as a measure of the relative productive capacity of sites of defined
quality for the productive use of the tree species under study, based on
the mean annual yield that is attainable at a given stage of development of
the trees.