luthuan 1959 26 Nov. Mother Lode Trip New - we can state few assumptions. What was the initial state (pristine condition, etc.)? To this we must admit that we don't know. The most important factor to consider is the area of climatic changes. Rather always ones (in geologic time sense) might be due to an alteration from a glacial to an interstadial situation. Larger more subtle changes may due secular changes since an abrupt one. Unfortunately we do not have a very good record of past-pleistocene pollen strata, etc. to in California to determine the amount of climatic fluctuations (in the sense of the Antics). Let us then consider that it has been afew thousand years since there were any acute or dramatic secular changes - or at least that if there have been any secular changes in this interval someone must document them. I have no doubt that there have been - but this is another story. We can safely assume that the natural ecologic factors have remained constant -more or less. This is the old ganters "all things being equal. What changes were taking place the vegetation was adapting to it. Also, a matter difficult to assess would be the changes call them secular vegetational which took place with maturation of soils, etc. This is hovering about the halo of the Climax" theory. I do not intend that this method is a mainly static one - it is more of a conservative dynamic one - I realize the dangers & difficulties last in order to operate