It is an odd phenomenon that when looking for pictures of a forest canopy, they are always in the fall/autumn. Go figure. I guess a tree canopy when all green is disinteresting. I don't know why there are plenty of variations in the color green. Chlorophyll. Consumerism definitely has it's focus.
The Northern Hardwood Forest is the most northern deciduous forest community. It is dominated by three species of trees, Yellow Birch, Sugar Maple and American Beech.
The easiest way to identify native species from non-native species is to know what one is looking at. This is not difficult. The idea is to learn the basic identification method for each of these main trees and it will be a strong working knowledge of what to look for on a nature walk.
These tree species are NOT indicator species. They should be found in abundance and healthy. Indicator species serve as alert to things that are wrong with the young forest. Indicator species of any type are to serve as an early warning system to ward off any problems that would lead to a forest that will be lost to disease or non-native invasive species that literally choke out the native species.
The Northern Hardwood Forest is a transition forest from that of Oak-Hickory Forest to the south and the Boreal Forest to the north. Along the periphery of the Northern Hardwood Forest can be an overlap of species from other forests in differing climates. These are not invasive so much as species adaptation. In scientific terms what is experienced at peripheral areas of forest can be a PLASTIC adaptation. PLASTIC is a genetic dynamic that naturally allows survival although not in an ideal climate. It is the range of the species genetic viability that will allow some minor overlap of adjacent forest systems. There will be no genetic interaction by other species to the primary forest system.
The Yellow Birch, Sugar Maple and American Beech are all canopy species. There are understory species, but, that is a different discussion.Note: The word deciduous means the trees shed their leaves annually. This is called autumn. This is also different from the habitat of pine trees.
