More trees per hectare lifts income

STUDIES HAVE SHOWN THAT WE MAY have been understocking our forests in recent years, costing our industry millions of dollars in lost income and lost opportunity.

A team at Scion has been looking at next generation silviculture regimes that will help forest owners maximum productivity and value from their estates, using genotype studies and the environment where the trees are planted.

Using this information, they have created a model that can determine the best trees to plant to suit the environment and then work out the optimal post-thinning stand density, including whether to prune or not, and how this impacts on crop value.

According to research presented to the Forest Growers Research conference in Christchurch by Scion’s Heidi Dungey, John Moore and Michael Watt, it seems we may have been thinning our stands too much in recent years.

They have concluded that increasing stocking rates by 100 stems per hectare could result in increases of up to $5,300 per hectare in gross value. That would translate to as much as $349 million over the course of a 28-year forest life.

These results have been made possible thanks to conducting large plot trials with the assistance of forest owners.

Future trials will be needed to work out better silviculture regimes, which could deliver seed lot and site-specific silvi regimes to help maximise productivity.

NZL