The question of native and non-native species arises aplenty in many circles. Here is a penetrating article on this topic from the NY Times.
“…just as America is a nation built by waves of immigrants, our natural landscape is a shifting mosaic of plant and animal life. Like humans, plants and animals travel, often in ways beyond our knowledge and control. They arrive unannounced, encounter unfamiliar conditions and proceed to remake each other and their surroundings.

