PNG FOREST GROWTH MODELLING SINCE 1975 Professor John Davidson10 commented that if one looks back over the past 20 years or so for PNG, plenty has been written by ACIAR, Universities and others on increasingly sophisticated methods of vegetation typing and stratification using better and better satellite imagery and GIS manipulation to report on areas allegedly deforested or degraded by whatever means but no one has been very fussed about accurately converting areas into wood volumes or biomass. John has not come across any reports of extensive sampling to produce new local PNG volume or biomass tables from raw plot data. On the one hand, some authors have resorted to quite simple conversions assuming a form factor of 0.5, plus perhaps species-specific parameters also borrowed from other authors, or more detailed assessments using generic equations published by others, among which e.g., Chave et al. (Tree allometry and improved estimation of carbon stocks and balance in tropical forests. Article in Oecologia Sept 2005.) is the most-often go-to source for “tropical wet forests” in PNG, e.g., This is from p93 Chave et al.: AGB = Above Ground Biomass (kg); D = trunk diameter (cm); H = tree height (m); ln = natural logarithm (log to the base e) Of 27 sites analysed by Chave et al. only one was from "New Guinea". Since 1975, most of the work by NFS on PNG natural rainforest growth functions has concentrated on permanent sample plots for natural rainforest in PNG rather than forest assessment for commercial purposes. It is of scientific interest here to correlate growth data and its methodologies over time. 1980 D Alder did an FAO Forestry Paper 22/2 vol 2 Rome titled Forest Volume Estimation and Yield Prediction. 1980 PNGRIS (Papua New Guinea Resource Information System) (Funded by AusAID and PNG). This project commenced in 1980 as a joint co-operative research project between the PNG Department of Primary Industry (DPI) (now Dept of Agriculture and Livestock) and CSIRO. It was envisaged as an inventory of natural resources, land use and population for the whole of PNG. PNGRIS publications (ISSN 1320-5765) include: PNGRIS No 6 Papua New Guinea inventory of natural resources. Population Distribution and Land use handbook. ISBN 0642196109. PNGRIS No 2 Forest Resources of Papua New Guinea ISBN 0642196036. CSIRO Division of Land Use Research Land research series No 35 Vegetation of Papua New Guinea ISBN 0643001387.
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Personal Communication 6th June 2021 Professor John Davidson TPNG Forests 1962-1980.
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