Definition of post-planting acclimatisation of Pinus radiata through relative height growth rate

Monthly height growth of Pinus radiata D. Don seedlings after planting was monitored in two locations in the Western Cape Province of South Africa over a period of two years. Two stages in seedling development were defined and modelled with mathematical functions: (i) an acclimatisation stage when relative height growth rate (RGRHT) showed a simple linear increasing trend after planting, and (ii) a post-acclimatisation stage when RGRHT followed a decreasing trend. The acclimatisation period was defined as the time between planting and intersection of the two regressions. This method may prove useful for evaluation of regeneration procedures at operational level.