Transitioning Exotic Plantations to Native Forest

A Report on the State of Knowledge

Prepared for Te Uru Rākau – New Zealand Forestry Service by Forbes Ecology, August 2021

The topic of transitioning exotic plantations to native forest is relatively new and there has been insufficient time and a lack of coordinated research to determine the actual timeframes required to transition exotic plantations to native forest. Related to this, we do not know what level of regeneration is required to successfully attain a transition to native forest or to what levels old-growth native forest canopy dominants will establish in relation to biotic and abiotic gradients. While we know that the performance of regeneration (e.g., structure, composition, growth and biomass) will differ along the main abiotic and biotic gradients, we have few empirical data from exotic plantations to demonstrate this. Work to attain empirical data is critical, as these data would allow management thresholds to be identified as well as informing carbon and forest dynamics models. The role for species other than radiata pine (e.g., exotic angiosperms), particularly when planted in polycultures designed to provide specific structural and functional elements is also unknown and is deserving of trials and investigation.