QUOTE=gost]
I recall reading a paper published in the eighties that suggested that native peoples here in the Pacific NW of N. America (where I live) had terraformed large tracts of land in the area around modern day Fort Lewis, about 75 miles or so south of Seattle. These large cleared areas were called "prairies" by the European settlers and had been thought to be natural formations. Scientists studying the area, however, were surprised to discover that these clearings were in fact man-made, created by "burning off" the temperate rain forest cover and encouraging the growth of certain plant species that the native peoples then harvested.
We have so much yet to learn.[/QUOTE]
Same thing in Australia but the Aborigines had about 50-70,000 years maybe more to change the environment.
Captain cook when he "discovered" Australia commented on the many fires he saw on the East Coast.
Early Botanists had no idea that the bio-diversity, the total environment had been man made! This has been a very recent an amazing revelation.
The theory is that Aborigines used "Firestick" farming to encourage the growth of grasses; this attracted herbivores(kangaroos etc) which they hunted.
Much Australian Flora now will not germinate without fire or at least smoke.
You can sometimes even buy "smokey water' to soak your native seed in so they will germinate!
Soils here are poor so the burning would have added some fertiliser and perhaps charcoal to the soil.
any most are sensitive to excess phosphorus and should be fertilized with special "native Plant" fertilsers low in phosphorus.
Our farmers use masses of Suppephosphate in order to grow wheat
This is from the CSIRO
http://www.publish.csiro.au/paper/S96060.htm
Phosphorus requirements of Australian native plants
Kevin A. Handreck
Abstract
Many Australian plants have highly developed abilities for acquiring and conservatively using P.
This is seen as an evolutionary response to the combined environmental pressures of fire, soil P levels that are in the lower part of the range for world soils, and low and eratic rainfall.
In natural Australian ecosystems, more than 50% of the P in the A horizon is in organic combination.
Organic matter is the main source for the growth of perennial plants, so the only successful assessments of ‘available’ P measure labile organic P and microbial P.
However, the inorganic P of ashbeds is essential to the rapid establishment of fire ephemerals and tree seedlings in natural ecosystems
. Almost all Australian plants develop associations with mycorrhizal fungi, or produce hairy roots, as ways of increasing P uptake. Highly developed abilities to redistribute P from ageing to young tissues enable Australian plants to have a low P requirement per unit of biomass production
--
Michael
