Over the past 100 years, New Zealand has developed a significant exotic forest resource that now provides the foundation for one of the largest industry sectors in New Zealand’s economy. Alongside the commercial benefits of New Zealand’s exotic forest resource sit an array of community and environmental values, not least is the contribution of these resources to New Zealand’s impact on global climate change. Recognising these values has prompted the New Zealand Forest owner’s Association (NZFOA) to commission Interpine to develop a system to monitor the condition of New Zealand’s forest over time. Stimulated by concerns about forest decline, forest condition monitoring (FCM) systems have become widespread throughout Europe and North America since the 1980s. However, in New Zealand there has been no systematic approach to monitoring the condition of New Zealand’s plantation forest estate until now.



Forest decline in a European Spruce (Picea abies) forest caused by insect infestation

What will we be measuring?

In FCM systems tree and forest condition are used as indicators of forest health. The criteria assessed must be scientifically valid and economically viable to collect. Crown condition has become the most widely used indicator or tree health and has become the cornerstone of the majority of FCM programmes around the world. Primarily assessed through the measurement of defoliation and crown transparency crown condition monitoring will represent the core of New Zealand’s FCM system. Working in collaboration with experts from Germany and researchers from Scion, Interpine have produced a data collection field manual for the New Zealand FCM program which includes an extensive photographic guide to the classification of defoliation and crown transparency in Pinus radiata. This is the first time a guide of this type has been produced for plantation species growing in New Zealand conditions.



A Pinus radiata tree infested with Dothistroma septoporum


Where will we be measuring?

Interpine have developed a sampling design for the FCM project on behalf of the NZFOA. All the FCM plots are located on a grid system which is overlaid across the whole country, this ensures that plots provide good coverage of the entire country and will not lead to bias in FCM estimates. In collaboration with the Ministry for the Environment (MFE) Interpine are about to undertake the third round of measurement for the Land Use and Carbon Analysis System (LUCAS) project which aims to provide a national inventory of the carbon stock contained within New Zealand’s forests. The LUCAS plots are located on a grid system with the bottom left hand corner located at a location off the South West coast of New Zealand. This presented a golden opportunity for Interpine to collaborate with NZFOA and MFE and carry out crown condition assessments on the trees within the LUCAS plots.


 The FCM plots in New Zealand are based around a 8km grid network across the entire country.

What will the data be used for?

The data collected during the FCM program over a number of years will allow us to monitor any changes in the condition of New Zealand’s plantation forest. This could be vital in providing us with information in changes to our forest caused by pathogens, insects or pollution. We will also be able to use this information to contribute to trans-national initiatives which aim to document changes in forest condition at an international level. However this survey will not provide information on the forest condition changes in specific forest estates or regions; this would require additional plots to be established according to a suitable sampling regime.

If you would like more information on forest condition monitoring or are interested in setting up a program for your estate then please contact our Rotorua head office.