Wildflowers in the Smokies face a number of human-instigated threats, including air pollution, off-trail hiking, and poaching.
Long term research conducted in the park shows that ground level ozone pollution is injuring at least 30 species of native plants. Ground level ozone, sometimes called "smog," is created when nitrogen oxides from automobiles and factories mix with sunlight and natural hydrocarbons. Black-eyed susan, tall milkweed, and coneflower are among the most vulnerable wildflowers.
Plant poaching appears to be on the rise in the Smokies. Some commercial poachers remove hundreds of plants each trip and make several trips annually. In recent years groups of poachers have been apprehended with well over 1,000 American ginseng roots. Aside from ginseng, the most popular targets are orchids and trilliums. Overzealous gardeners take a serious toll by removing showy wildflowers for transplanting back home and careless hikers trample delicate wildflowers when they leave established trails.
If you observe people digging plants in the park, report the activity to the nearest ranger station or call (865) 436-1230.