Ian,
With forests, artificial disturbances such as clearfelling and burning tend
more often to lead to an overall decrease in biodiversity. Old growth
forests reach a balance between old trees dying and new trees emerging.
Species attain dominance in patches due to a very complex microenvironment
within the forest based on canopy cover, soil chemistry water availability
and other factors. Natural disturbance has the power to alter this
seccessional balance, but clearfelling completely destroys it. Any natural
forest that grows back will attain a different seccessional balance, one
that will not necessarily be suited to any endangered species in the area.
Also, for many species of eucalypts, it takes nearly 100 years to begin
senescing, that is forming hollows big enough for our parrots to nest in.
More importantly, in the Tasmanian context, once forests are clearfelled and
burned they are then replaced by a monoculture of plantation trees,
definitely not an improvement as far as our fauna and flora are concerned.
I personally doubt forestry bodies argue for clearfelling because of
biodiversity benefits, but instead believe it is cheaper to harvest a whole
area at once, therefore their bottom line is greatly improved.
Sustainable forestry (and by this I mean selective harvesting) can occur,
but it requires a lot of trust in the bodies engaged. I point you to the
recent scandal in Victoria where the official forestry body was caught
harvesting trees they were not legally allowed to take. Sustainable
forestry requires that the people involved not only understand the
principles but actually believe in them enough to forgo the "extra profit"
to be had from breaking the rules.
Regards,
Chris
On Tue, May 12, 2009 at 2:47 PM, Ian May <> wrote:
> Hi all
>
> It should be recognised that sometimes domestic use of an area improves the
> habitat for bird diversity. For example. across the Cooper Ck of South
> Australia there are a number of wetlands that provide excellent refuge for
> many species of waterbirds. The lake margins provide extensive feeding
> areas for water birds including migratory waders but in many areas, when
> cattle grazing is excluded, some of the wetland margins become choked with
> dense short rushes and within a year or two after removing cattle from an
> area, the diversity of species to be seen often decreases. The habitat
> structure has been altered.
>
> It is possible that sustainable forestry practices have benefited Superb
> Parrots providing nesting trees have been protected.. If logging is to
> proceed, the debate should identify which forestry practice is best to
> maintain the diversity of the forest, selective logging or targeted small
> area clear felling?. Ignoring the politics of forest management, it needs
> to be recognised that these issues are rarely as straight forward as they
> first seem.
> At first glance it would appear that if a forest is to be logged selective
> logging should be the preferred method for most wildlife conservation
> reasons, especially if old growth trees with hollows are to be retained.
> However in some forests selective logging can permanently and significantly
> alter the habitat structure with all its ecological impacts on biodiversity.
> Selective small area clear felling may actually be preferable in some
> instances so long as the area cleared is kept small relative to the
> adjoining uncleared forest and is managed to avoid triggering a negative
> island affect. Clear felling can allow the forest to regenerate from the
> start, somewhat like the primary and secondary after affects of an intense
> bushfire and over a period of time when the forest has regrown, it will have
> re developed its original structure and most of its biodiversity..
>
> And no, I don't have shares in Gunns
>
>
> The following article is of interest
>
> http://www.tasmedia.org/node/286
>
>
> Regards
>
>
> Ian May
> St Helens Tas
>
>
> Carl Clifford wrote:
>
> Good to see the SPs are well managed by the local timber industry /8-)
>>
>>
>> On 11/05/2009, at 6:41 PM, Terry wrote:
>>
>> Another story has just come in on bigpond news.
>>
>> http://tinyurl.com/p7ekuw
>>
>> -------Original Message-------
>>
>> From: Carl Clifford
>> Date: 11/05/2009 12:24:35 PM
>> To: Rob Geraghty
>> Cc: Birding-Aus
>> Subject: Re: [Birding-Aus] Superb Parrot in the news
>>
>> The Sydney "Daily Telegraph" is also carrying the story, on the front
>> page. The article claims that 1000 jobs. It is also a lead story on
>> the Yellowgraphs online site, where there some interesting comments
>> posted. Looks like the CFMEU is really gunning for the poor old Superb.
>>
>> Carl Clifford
>>
>>
>> On 11/05/2009, at 8:56 AM, Rob Geraghty wrote:
>>
>>
>> http://www.abc.net.au/news/stories/2009/05/11/2566058.htm
>>
>> It's sad that the prevention of species loss is regarded as "ruining
>> inland Australia". I feel sorry for anyone who loses a job but
>> frankly Australia's lack of effort at sustainable forestry is pathetic.
>>
>> Rob
>> =======
>> Rob Geraghty
>>
>>
>>
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