Analogue Forestry

The idea and wish to plant a 'natural' forest is a common one, but often this becomes a big compromise, an opposing consideration, to the wish to have a high quality forest producing good millable timber.

The idea of analogue plantation forestry is to design for timber production, and by-products such as firewood, while also designing for biodiversity, forest understorey, and future natural regeneration, trying to incorporate these qualities of natural forest into a designed planted forest.

These designs and species combinations need to be unique, specifically suited to the site layout, soil variations, climate, indigenous vegetation [1], and intended future management.

Then for community projects there is the additional challenge of making the design simple enough to be communicated to and applied by tree planting volunteers at a community tree planting day. Lots of planting plans have gone haywire at this stage!

There are very few publicly available designs for analogue forestry. I have made the Planting Plan and Plant Order Summary for the 2006 Stage 1 planting of the Violet Town Community Forest available for this reason. Species combinations were assembled, and given to planters with instructions such as 'plant this combination of species in every third row, between those two flags'. The flags were indicating soil type boundaries.

The planting days were productive, enjoyed by all, and managed to engage about 30 people each day while successfully applying the general intent of the planting plan.

Severe drought in 2006 required follow up watering, but with very little sub-soil moisture for the newly planted trees to chase, and with a severe late frost on 18th October [2], survival was about 60%. This was a good result in the circumstances.[3]

David Arnold, March 07

For details contact David Arnold on (03) 5798 1679

1. Most of the plants used for this project were indigenous, as the local box species eucalypts have many of the desired qualities for this planting. Non-local plants such as Sugar Gum, Spotted Gum and River She-Oak were also included for the specific qualities they have, that none of the local species had to the same extent.

The decision to use a lot of local species was influenced by community interest in enhancing habitat for native birds and animals, and in re-establishing local vegetation.

A discussion about the relative merits of hardy Mediterranean oak species is underway for future plantings.

2. The 18th October late frost was very damaging to the Sugar Gum and Spotted Gum, which are non-local species included as potential high quality sawlog species, but which are frost tender when young.

These two species are long established and well proven locally, but in 2006 proved to be vulnerable to that unexpected late frost. I have planted them widely, and very successfully, over the last ten years, generally taking about the second week of September as being safely ‘after frost’ for most regional sites. However with extreme climate events becoming more extreme and more common due to climate change, these kinds of ‘rules of thumb’ need to be reconsidered.

3. Control of grass and herbage competition for newly planted trees and shrubs can be one of the main factors determining survival. One benefit of the dry conditions was that there was no competition, because there was no surface soil moisture. Mechanical ground preparation in August of ploughing and rotary hoeing was all the grass control required.