3-PG is one of the most widely used forest growth models in the world.

Tools for modelling commercial environmental forestry

CSIRO has developed a series of tools to meet the increasing demand for accurate and reliable information in forestry and natural resource management.

• 12 September 2008 | Updated 14 October 2011

• Scenario Planning and Investment Framework (SPIF)
• 3-PG2 Model
• Framework for Land Use and Soil Hydrology (FLUSH)
• Carbon Balance model (CABALA)
• Full Carbon Accounting Model (FullCAM)

Through the Commercial Environmental Forestry program a number of capability and decision support tools have been developed to:

• reduce risk for investors in forestry and revegetation schemes
• make most cost-effective use of public and private funds.

These tools provide information on:

• growth
• carbon sequestration
• biodiversity enhancement
• salinity reduction
• water impacts.

Scenario Planning and Investment Framework (SPIF)

One of the main tools developed is the Scenario Planning and Investment Framework (SPIF) tool. This is a Geographic Information System (GIS) data manager used to compare layers of spatial information. Much of this information generated by calibrated process-based models for predicting tree growth, rates of carbon sequestration and their impacts on stream flows and quality.

3-PG2 Model

The Physiological Processes Predicting Growth (3-PG) model was developed to bridge the gap between conventional, mensuration-based growth and yield, and process-based carbon balance models. It predicts stem volume, tree diameter, basal area and rates of water use.

Additional work on the 3-PG model has resulted in the development of:

• a spatial application (3-PGS)
• an easy to use Excel version (3-PGjps)
• a visual basic version of the model that was modified to include the ability to simulate understorey vegetation, sequestration of carbon, and the impact of salinity and access to the ground water on growth, predicted either at a point or spatial scale (3-PG+).

The latest version, 3-PG2, include all of these developments as well as an improved water balance model.

Framework for Land Use and Soil Hydrology (FLUSH)

Framework for Land Use and Soil Hydrology (FLUSH) was developed to improve hillslope (farm scale) predictions of tree growth and impacts on water and salinity flows.

It can be used to compare the impact of revegetation on different locations in the landscape and so helps to prioritise sites for potential commercial environmental forestry.

Carbon Balance model (CABALA)

CArbon BALAnce (CABALA) is a stand-level carbon-balance model of plantation growth designed for silvicultural decision support. It requires readily available site and climatic data as inputs, and predicts the time-course of stand development, water use, and available soil water for trees.

It is particularly useful for predicting growth of trees planted in a wide range of layouts (blocks, rows, multiple rows) and following silvicultural interventions such as thinning and fertilisation.

Its primary outputs are:

• stand-biomass (foliage, branch, stem, bark, coarse root and fine root, forest floor litter)
• site water balance terms (interception, soil evaporation, run-off and deep drainage, transpiration, available soil water)
• distribution of nitrogen in trees and the soil.

CABALA also incorporates the effect of atmospheric carbon dioxide on growth, so is useful for growth predictions under a changing climate.

Full Carbon Accounting Model (FullCAM)

The Full Carbon Accounting Model (FullCAM) is a major component of the National Carbon Accounting Toolbox (NCAT).

FullCAM tracks carbon changes in biomass, litter, soil and harvest products under agricultural and/or forestry systems.

Through the Commercial Environmental Forestry program CSIRO researchers made many contributions to the development of FullCAM, including:

• calibration of soil carbon turnover, decomposition of litter, and temporal variations in partitioning of biomass
• calibration of density of stem wood under key plantation species
•  extensive reviews on allometrics, soil carbon, decomposition of litter
• calibrations for both key plantation species growing in regions of low-medium rainfall, as well as for various types of environmental plantings.

Learn more about CSIRO’s work in Forestry Management.