David Griffiths and Raelene Ritchie make valid points about the drop in numbers at the Australian National Botanic Gardens (''Gardens losing their bloom for visitors'', May 19, p6) when they cite drought, the focus on Tidbinbilla and lack of advertising and of collaboration with other institutions.
Other factors have been the focus on the Canberra arboretum and the reduction in funding and staff at the ANBG. It would also help if the gardens became a statutory authority with an expert advisory board and if the director's position were upgraded.
Why aren't the gardens part of the itinerary for schools visiting Canberra? Should they not also be seeing at first hand the diversity of Australian native plants and some of the birds, reptiles and perhaps mammals? They might get an inkling of what biodiversity means and its significance. The Consultation Draft for Australia's Biodiversity Conservation Strategy 2010-2020, p.21 states ''Ex situ conservation (i.e. conservation of biodiversity outside of its natural habitat) can provide important insurance against biodiversity loss and a means to conserve species whose numbers have dwindled in their native habitat.
''Measures could include seed and gene banks, and living collections in ... botanic gardens.'' Exactly.
Those of us who treasure the ANBG don't want to see them turned into a theme park or circus to attract visitors.
Judy Kelly, Aranda
Plant for the future
Plantations of softwoods and blue gums, subsidised by taxpayers, including as managed investment schemes, were introduced to stop overlogging Australia's native forests. Instead, in the past ten years companies such as the Eden woodchip mill have doubled exports of native forest woodchips to Japan to one million tonnes per year.
They were supplied with ever-cheaper chip logs by the Victorian and NSW governments. NSW Forests admitted losing $14 million last year on chip logs; Victoria is selling chip logs at as low as $2.50 per tonne less than an icecream! MIS, promoted by floundering Timber Corp and Great Southern, were obviously shaky; however, state governments have also helped destroy the viability of investments in these companies.
It's time to stop woodchipping native forests and move to plantations for virtually all Australia's timber needs.
Prue Acton, Wallagoot, NSW
Climate caution
D. Zivkovic (Letters, May 18) tries to dismiss Al Gore's An Inconvenient Truth because a British court found some inaccuracies.
However, Zivkovic fails to mention that the court also acknowledged that Gore's central thesis that climate change is mainly attributable to man-made emissions of greenhouse gases was completely sound and was strongly backed up by peer-reviewed science.
Ian Plimer's Heaven and Earth has yet to be subjected to judicial analysis, but the scientific response to the book has been devastating.
Several detailed assessments are available online (see http://tinyurl.com/plimer as a starting point), but this observation from climate scientist Barry Brook sums it up nicely: ''Ian Plimer's book is a case study in how not to be objective. Decide on your position from the outset, and then seek out all the facts that apparently support your case, and discard or ignore all of those that contravene it.''
Global warming is not a certainty; in a complex system like climate it's all about the balance of probabilities.
The trouble is that the impacts of global warming are potentially so severe that, even if there was only 10 per cent risk of a rise of over two degrees this century, it would warrant massive precautionary efforts to avoid the risk.
Matt Andrews, Aranda