Quantum Forest

After writing a letter to Tasmanian Times I received quite a long and self-centered reply from someone just briefly mentioned in my missive. Environmental issues tend to be quite controversial, with some people not being able to make a distinction between the ideas under discussion and the people behind them. It is just one more complication thrown into the mix… I sent the following reply:

I was surprised to receive such a long reply after my passing mention to water issues in a previous letter. My reference to water only suggested the fact that I have never seen a full description of the models used by Dr Leaman nor the software used to support his widely publicised statements. Given that, I could hardly comment on the scientific merits of his work or ‘rubbish’ his reputation. In contrast, I have seen descriptions and software implementations of the models developed by the CRC for Catchment Hydrology (CRC-CH), introduced by Dr Leaman in his letter. I am sorry if Dr Leaman considered my statement as part of a campaign to defame him. It seems that he is confusing my questions about research with personal criticism, a very inconvenient confusion for a researcher.

I have attended a couple of presentations by people from the CRC for Catchment Hydrology (CRC-CH). From those I understood that the business of predicting water flows from catchments is relatively complex. In addition, I also realised that the vegetation models included in hydrological models are still fairly general.

I am not a geologist, geophysicist or hydrologist, but only a simple forester. In spite of that, I can think of a few ‘rules of thumb’ concerning water flows and forests. Vegetation will affect water flow depending on species, age, position within the catchment, stand density, silvicultural management, etc. Furthermore, within a catchment there will be a mosaic of situations concerning vegetation-types, ages and changes of land use. Thus, a reasonable model for water flows should consider these factors, in such a way to take into account the temporal and spatial changes in vegetation cover. I also believe that the most important condition to have accurate predictions of the effects of plantations and other vegetation changes is to have good predictions of future vegetation changes. Should I presume that Dr Leaman has all those figures at his disposal?

Coming back to research done by the CRC-CH, I found a publication entitled ‘Predicting the effects of large-scale afforestation on annual flow regime and water allocation: an example for the Goulburn-Broken catchments’ published in June 2003 and available on its web site (http://www.catchment.crc.org.au). In this case, I can access the final report, scientific papers supporting the models used and the software implementation for the models. Thence, I have all the elements for making up my mind about the report.

If Dr Leaman wants to ensure proper communication of his model, may I suggest that he makes available the data, models and software on the internet? I am sure that there will be many people willing to host his files for no cost. This would certainly give everybody the opportunity to examine the models, and make up their minds about model validity.

In summary, my original intention was to question the bases for many claims presented in the media — always hungry for apocalyptic stories — so we can have a productive discussion about the best way to manage our forests for the benefit of Tasmanians. As a final point, I remember a comment made by my parents when I was ten years old (yes, a long time ago): ‘target the ideas but not the person. Personal attacks are a sign that you ran out of arguments’. This could not be more helpful today, because this debate is not about individuals and their egos but about alternative views of the future for Tasmania as a whole.

Enough said.