Re: TH: mix them together, and scatter

Katherine in Tucson, Arizona wrote :

>Just a little reminder that there's a big, big difference between deserts
>that evolved gradually over the eons and have a full complement of plants,
>animals, insects etc. that happily and fruitfully live there; and the kind
>of desert_ification_ that often occurs as a result of poor agricultural,
>ecological, or social practices (overgrazing, overuse of water resources,

O.K. so the problem now must be, where do we draw the line between a
'natural' desert ecosystem and an anthropogencally derived system ? Very
difficult I suspect ! Also, how common are 'natural' deserts, if indeed
there are any ? Is the Sahara a result of purely natural forces ? 

Permaculture recognises that all animals garden. Poor agricultural practices
(as mentioned by Kathy) can be concidered as inappropriate gardening. If an
animal gardens is it natural ? If a person gardens, or performs agriculture,
is this unnatural ? If an introduced animal species gardens in a system to
which it is not native, but has been introduced, does it then perform an
unnatural, or inappropriate form of agriculture ? 

Where do you draw the line between an anthropogenic system, or culture which
is practising natural or unnatural patterns of living ? 

When we look at a species within a biomme, we say it has adapted, over time,
to this environment. More commonly, the species has adapted to a previous
environment which has since been altered by people, and is tollerant to this
new anthropogenically altered envronment. In such cases, the species is abapted.

Take for example the grouse which inhabits the peat upland moors of northern
Britain. In terms of flora and fauna, this ecosystem may be considered as a
desert, comparative to the diversity which existed there 10,000 years ago,
before the trees were felled by people. Although a native to the U.K. , the
grouse isn't adapted to this kind of environment, but rather tollerates it,
and is abapted.  

Another ripe example of abaptation may be the 2 million wilderbeest which
roam the Sarengetti plain. Supposedly natural Savahna systems are in fact
equally as much a result of human intervention (through fire management) as
the upland moors of Britain, or for that matter, desert in Northern America
produced through inappropriate agriculture. 

There is no balance in nature. All ecological systems are in a constant flux
of change.

In summary, are people, with all their diversity of complex agricultural and
social systems, still part of a natural evolution ? and are there any
systems on the planet that have been touched by Man that can really be
considered as natural ?

Just a thought, rob. 
                         Rob Squires of CTCSystems 
                    Gill Ellison - Age Concern St.Helens
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