I would say that although this forum is called "The Tropical Fruit Forum," from the beginning it's actually been The Subtropical Fruit Forum since it was formed by South Floridians, and then Southern Californians immediately came on board, with neither of these groups actually living in the tropics. It could easily have been called The Mango Forum (with Other Tropical Fruits)! 
I don't feel like people's location does matter to much but more where the plant in dicsussion originated regarding the category choosen (tropical or sub). Example, mulberry did not originate in the tropics and should not be discussed there unless someone is making a post specific about mulberry in the tropics.
It would seam a bit excluding to people with limited outside climate. People in the subtropics can create micro cliamtes with some effort, this is acutally a good way of learning more about a tree and would be invited in a tropical category, just growing a tropical originated tree in the subtropics does not take away the expereince learnt from observin the tree or it's fruit, it's still of tropical origin.
So tropo I wouln't be in favour for a forum folder that is in favour of people actually living in the tropical region.
I feel this is a tropical forum as the majority of the members are trying to grow tropical plants.
I was mostly talking about separating subtropical plants from the tropical folder, not the forum in it's whole.
It would ofcourse be quite epic with an automated translate feature for asian languages and vice versa english and then whole of indonesia, malaysia and thailand could join in. That would be AMAZING!