"Another good example would be a Ficus tree which can successfully grown in zone 4, outside during the summer, can never be styled in such a successful way as those styled in the tropics or asian climates where they grow naturally to become world class bonsai."
Not really accurate. As mentioned, Jerry Meislik grows spectacular tropical ficus bonsai in Montana.
http://www.bonsaihunk.8m.com/
Species native to southern areas of the U.S. can be successfully grown in a wide variety of place. Bald cypress native to La. can be planted in Northern Illinois and grow to a ripe old age. Live oak from Texas can be planted in Va. and get big (without the usual mistletoe and Spanish moss, though). There is an old one on the grounds of the National Arboretum in D.C.
I do agree the same species in different climate zones can have wildly different characteristics. Willow oak in East Texas is definitely not the same tree species I can collect here. I noted that on my Christmas visit there. The Willow oak (quercus phellos) in Tex. looks alot like live oak with shallowly lobed lance shaped leaves still on the trees in late December. The quercus phellos here in Va. has thinner lance shaped leaves that dropped long ago. I suspect the species interbreeds to some extent in Tex with other native oaks.
Anyway, I think this is highly variable, depending on species, locality and local genetic material of the plant.
Vance, if you're interested in live oak "fusiformis" ask a Texan bonsaiists to nab a one to ten gallon one from a local nursery someplace like Dallas or Austin. They are the predominant live oak sold for landscape in those places. I got a small, 1/2" diameter gallon live oak two summers ago, chopped it top and bottom and am in the process of growing in out. I wanted to see if a landscape tree was adaptable to this treatment. It is.
I've had a big collected oak from near Austin for years. It is my favorite tree. I want more
