The beech scheme has a significance that goes far beyond the West Coast of the South Island of New Zealand. It calls into question what we mean when we say we wish to live in a sustainable manner. We need resources to sustain ourselves, and we should welcome opportunities to harvest resources in ways that can be done in perpetuity without damaging the ecosystems from which the resources come.
Preservationists argue that humans should not be allowed to harvest wood from even a tiny fraction of our large beech estate, but to leave the forests unmanaged is not sustainable because of the influences of introduced pests. Possums, rats, stoats and wasps are degrading our native forest ecosystems as you read this. Pest control costs money. Exactly how much is required has not been well estimated yet, but it appears to be in the order of hundreds of millions of dollars per year. If we chose to preserve forests sustainably, then pest control would have to be financed by taxpayers. Meanwhile, the Department of Conservation (DoC) does not have the necessary financial resources, and so DoC's management of our indigenous forests is not sustainable.
Preservationists also argue that the planned harvest is not sustainable. Their evidence is beech growth model software provided by one researcher within Landcare that has been disowned by other ecologists within that same organisation. As a modeller, I can confirm that the software contains some elementary mistakes, and the effects of low-level harvesting that it predicts are simply not credible. Regeneration of beech forests is usually prolific after logging, a fact that the Landcare model software doesn't take into account. The picture at left shows regeneration of mountain beech in a gap. The software also implies that natural rates of mortality would be unchanged with harvesting, and this is not so.
There are some areas of uncertainty, but these can be checked early in the life of the scheme, long before any serious damage could be done. Firstly, patterns of natural tree death need further study, and although matrix models are a good start, they should be succeeded by models based on data from permanent sample plots and studies of gaps. These studies have already been initiated by TWC. Future models will probably need to be spatially explicit in order to better predict effects of low-level harvesting. Secondly, criteria for the identification of dying trees may need to be refined, and Prof. Vanclay suggested an easy way to accomplish this.
The submissions offered by scientists that are listed on this website are thorough, impressive, and provide a great deal of confidence that the scheme would be sustainable, albeit with some changes as research results became clearer. This is called adaptive management. It is pretty obvious that with such low levels of harvest (less than half the natural mortality rate), no lasting damage would be done while techniques were refined.
Gap-level harvesting operates in some other countries, even in beech forests. The picture at right shows a gap in a European beech forest in Denmark. The green carpet is all beech regeneration. Harvesting in this forest was much more intensive than that planned by TWC in our forests, but the example serves to show that the scheme has some basis in forestry experience, and that logging doesn't destroy forests if it is planned carefully.
The TWC project is also significant internationally. The world is destroying large areas of tropical forest, and New Zealanders regularly purchase imported manufactured goods that contain hardwood timber mined from these forests. By establishing our own, sustainably managed sources of hardwood timber, we can reduce our reliance on tropical hardwoods, and at the same time set a forest management example that is environmentally friendly and also far more acceptable to developing countries than calls for them to preserve their forests.
The beech scheme offers an opportunity to provide some high quality hardwood from a small portion of our beech forests, while maintaining levels of pest control far in excess of those that DoC could provide. It appears likely that the harvest could be done in a way that wouldn't disrupt the habitat; moreoever, by controlling pests we would actually enhance the habitat for our native fauna. It would reduce our reliance on tropical hardwoods while providing a practical alternative to destruction of tropical forests.
It is important for us to debate this issue, and it would be best for everyone if the RMA hearings on the scheme resumed.