Carrus Aotea Pine Tree Harvest and Site Rehabilitation
An exercise in situation-specific solutions
As part of the earthworks for Stage 10 of the Aotea subdivision, about 7 rows of pine trees over a 400m length needed to be removed over 1-2 years.
The problem was that the site is extremely visible to SH1 and to most areas overlooking the Porirua Harbour. While wanting the pines to be underplanted, Porirua City also needed to retain the screening properties of the trees throughout the harvesting process. Public interest was also high.
Carrus had certainly presented us with a creative challenge!
We figured that if we could thin the pines, and stage their removal, we might be able to retain the screening while creating an environment for the mitigation planting to thrive.
However the second objective of under-planting in a pine environment was also problematic. Pines create an acidic soil, making it difficult for anything else to grow.
So we surveyed the trees and picked out the ones that were the most dense. By doing this, we were able to take out 80 trees while retaining full screening of the earthworks behind. Despite removing half of the trees, it wasn’t easy to see that any had been taken.
Then we ripped the soil beneath, to allow planting amongst the tree roots, but first, we added lime to the soil, to neutralise it ready for the planting.
Although the planting plan had to be highly designed, the outcome was satisfying; staged pine removal plan in place, soil pH altered, under-planting carried out, site maintenance underway (we currently oversee the maintenance as required), and plants doing their growing thing… all while meeting the aim of minimising the visual impacts of the subdivision earthworks and the tree harvesting operation.