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 Redwood research: The way ahead

New Zealand Tree Grower February 2007
Ian Nicholas, Paul Silcock and Luigi Gea

The recent resurgence of interest in redwoods largely stem from the opportunity to market New Zealand in the re-growth Californian redwood market. The Californian market has changed over the last two decades from old growth redwood to younger faster grown re-growth logs, this change has opened up export opportunities for NZ grown material.

The enthusiasm of farm forester Wade Cornell, researcher Mark Dean, and Jeremy Thomson, Rob Webster and Harry Saunders of NZ Forestry Ltd, and Jim Rydelius have all contributed to the knowledge on growing redwoods in New Zealand.

Research activities

Research in the 1970s evaluated establishment and genetics with one main genetic trial established in Rotoehu Forest in the Bay of Plenty in 1981, although genetic trials of giant sequoia Sequioadendron, were established in 1977.
Recent silvicultural and genetic research has been conducted on –

• Taper and bark equations for volume calculations
• The development of a growth model, 
• Pruning trials to test green crown removal and epicormic development
• Monitoring coppice growth
• Development of a permanent sample plot database, with 66 plots currently on a regular measurement programme
• Propagation of selected material from the provenance trial for clonal testing and the establishment of a clonal seed orchard
• Propagation in the lab of recalcitrant clones for the establishment of clonal archives and orchards
  

Farm forestry activities

Through the combined efforts of Professor Bill Libby of California and the Sequoia Action Group, in 2002 a series of self funded research packs were established on just over 50 farm forestry sites throughout the country. These research packs contained up to eight representatives of eight clones of Sequoia sempervirens, and are expected to provide valuable siting information, rather than formal clonal evaluation.

More recently farm forestry members have planted trials of the Kuser collection, which will help with a better understanding of these clones.

The NZFFA are also supporting redwood knowledge through the Sustainable Farming Fund project ‘Best practice with farm forestry timber species: NZFFA Electronic handbook series’, which is preparing a handbook on redwoods.

Another supporter of redwoods has been the Plantation Management Cooperative, supporting silvicultural trials and a research review.

Future research projects

Future work on redwoods will be dependant on continuous support from end users and from the Foundation for Research Science and Technology.
Possible projects include –

• Refining the breeding strategy, including a fast road to market approach 
• Genotype by environment studies
• Heartwood development models
• Research on endophytes for successful establishment of the species and for the production of Sequoiatones A and B metabolites as novel anticancer drugs
• Continuation of current silvicultural projects
• Sawing study of tended redwood logs to develop log and lumber quality predictive functions for plantation grown redwood
• Development of branch growth and mortality predictive tools
• Evaluation of stands for yield predictions
• Identification of superior clones
• Validation of durability scores for plantation grown redwood.
  

Ian Nicholas and colleagues are all with Ensis in Rotorua
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