Demonstration trials

NZDFI demonstration species trials combine tree growth and productivity assessments with research into silvicultural management regimes, and extension activities.

The NZDFI demonstration trials complement our breeding trials.

Over 20,000 trees were established at 13 sites during 2010 and 2011, with a further 6 sites due for completion by the end of 2014.

The demonstration trials contain a wider range of species than the breeding trials. Species included are the Top 5 breeding trial species:

• E. argophloia
• E. bosistoana
• E. globoidea
• E. quadrangulata
• E. tricarpa.

The following ‘second-choice’ species are included at some sites:

• E. camaldulensis
• E. cladocalyx
• E. eugenoides,
• E. longifolia
• E. macrorhyncha
• E. notablis.

Pinus radiata is planted as a control species.

The sites range from the Bay of Plenty and Gisborne in the eastern North Island to Canterbury in the north-eastern South Island. The wide range of locations will allow us to compare performance and phenotypic variation in survival, growth and form between species.

The trials are being managed so we can measure medium-term productivity, allowing us to develop early growth and yield models for post and pole wood production.

Ruth McConnochie (NZDFI trial site manager) records trial data

Trial design – demonstration trials
Two to three replications of each of the species included at each site have been established in square plots of 49 trees (7 x 7) at 2.8m x 2.8 m spacing (1280 stems per hectare).