Forests and koalas – in the real world

Last week ABC national radio ran a story titled ‘A beautiful rainforest turned into woody weeds’. It showed three photos, starting with a Sassafras tree in a Tasmanian logging coupe, before logging and burning, its stump immediately after and what is growing back ten years on. The story was pulled the day after it went on line.
While I hate to think political influence could lead to the ABC being censored, it is possible that aspects of the photos and story upset some. Logging rainforest for example, although this upset only occurs when some one else notices. Using the timber for woodchips may be another, although both major political parties in Tassie support logging for ‘specialty timbers’ in World Heritage areas. So perhaps the most damaging photo was what grew back, in this case the wattle Acacia dealbata, replaced the ‘mixed’ rainforest and eucalyptus forest that previously grew at the location.

Locally, the photo below shows part of a eucalyptus left behind when mixed rainforest was logged on private land. Eucalyptus trees didn’t grow back at this location and since then BMAD has killed most of the rest.

logged 81

Co-incidentally, the ABC also reported that the Victorian Department of Environment, Land Water and Planning have cleared Vic forests of logging rainforest in east Gippsland. As it turned out there is more than one definition of ‘cool temperate mixed forest’, so Vic forests got off the hook, due to the ambiguity. However the department identified another issue, ‘ the need for greater protection of isolated old trees’.

Again locally, the threats posed to isolated old trees include windthrow, lightning strikes, fire and as indicated in the following photo, die-back associated with dry weather and drought. Simply protecting the trees from deliberate logging and burning hasn’t helped. The point being that while maintaining current management remains a government priority, forest decline due to ‘natural’ causes will remain off the agenda.

dead ib In his submission to the federal koala inquiry some years back,  koala recovery person Chris Allen said, ” . . . Towards the end of the most recent drought the quality and extent of forest canopy
improved markedly in many areas. Although dieback may be a significant threat in the long-term, currently we are in a remission phase, and this should assist surviving Koalas access suitable browse at least in the next few years.”

Noting that long term is generally considered to be somewhat more than a few years, the SMH recently reported on studies at ‘1,300 forest sites worldwide using data on severe droughts beginning in 1948.’  The research found  ‘ trees took an average of two to four years after the end of a drought to return to normal growth rates and store greater amounts of carbon dioxide’.

The lead author for the study said ” . . . In most of our current models of ecosystems and climate, drought effects on forests switch on and off like a light. When drought conditions go away, the models assume a forest’s recovery is complete and close to immediate. That’s not how the real world works.”

For koalas a four year recovery time frame after drought coincides with the timing of local leaf sampling and subsequent analysis, reported in the most recent paper ‘Nutritional Correlates of Koala Persistence in a Low-Density Population’ (Stalenberg et.al, 2014). So it seems likely that the sampling occurred when the remaining koala feed trees were providing the best possible nutrition.

Now six years after the sampling, data to support the notion that trees still provide the best possible nutrition, despite the passage of time, is not available. Similarly there is a lack of evidence that relevant government agencies are working to ensure nutritional requirements are being maintained and improved, or that trees planted on cleared land will provide better nutrition.

Seems a shame that governments are yet establish real world environment, social or economic frameworks, for koalas or people.

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