Well, there seems to have been a flurry of posting about water, global warming and environmental impacts recently. Some posts posts show how much information, misinformation and thorough bulls&*t is out there, being spouted by just about everyone, government, politicians, greens, interest groups, mums dads and even my brother and sister-in-law. These two quotes seem to ask very similar questions, but, believe it or not, they are worlds apart. Rob's question is difficult to answer well - forest management (or specifically timber harvesting if you like) affects water yield. The questions that this statement raises usually avoided by both greens and bureaucrats alike, is how is it affected, how much is water yield affected and how does this change over time and how does different silviculture techniques affect wtaer outcomes, both now and in the future. FL's questions are far more based in green dogma and begins to scratch the surface of some of the exceptionally poor information that gets out there, how it is interpreted and how it gets used. Timber harvesting is not land clearing. Land clearing infers that the existing ecosystem is managed post harvesting to become pasture or different land use and ecosystem type. Just not true. Clearfell and or seed tree harvesting occurs in areas where dominant tree species tend to be shade intolerant and have developed regeneration/regrowth/restocking techniques to cope with either low intensity disturbance or very high intensity/bradscale disturbance. They tend to be fire sensitive. Understorey species tend to be colonisers rather than regenerators (generally speaking). Smaller group selection in these forests lead to a change in forest type - that is the dominant species will tend to change to shade tolerant trees that outcompete the other trees since they don't need as much sun. In general, in Victoria, fire is used to provide a good seed bed to regenerate the same forest type (coupe burning produces and ash bed effect, removes shade producing plants and changes soil properties to be more receptive to ash regrowth) Group selection harvesting, shelterwood, or single tree selection in ash forest types results in poor or no regeneration, but can be used in other forest types (red gum, box-ironbark, some low elevation mixed species forests et al) However, if you want to maintain water yield, other forest management techniques amy provide better results for water yield. But that involves a conscious decision to manage forests for that particular outcome. Things to provide discussion - Harvest old growth - it's old and dying anyway! But let's make sure there are forests there to provide succession to that age class (currently in Victoria, that is a problem). How old is old growth anyway? Sustainable harvest means that you regenerate the areas you harvest. Does this really happen, and where? Firewood - the hidden cost? VEAC and the Redgum report - 4 billion litres for flooding! Clearfell, Seed tree, group selection, shelterwood, single tree selection - what's it all mean? Why do greenies always argue with you when you're at the pub having a few quiet drinks? Resource information - what's out there? Rainforest - what is it, where is it, how do you find the edge? Wood chips and pulp - the most efficient use of a tree. Wood or water? Why not both? There'll be dozens more! Personally, I like the one about sustainable harvesting and regeneration. It's a hidden issue that gets absolutely ignored by the greens (which I find disgusting) and by the government (which is also just as terrible) Screw bottled water! Our forest make the best water and all you have to do is turn the tap! Cheers Neil PS I'm off to a wedding in QLD, so I may not be able to get back to any particular thing till Monday! PPS Sorry for the length - but I've had no complaints yet!