Despite Forest Service regulations, collectors continue to roll entire moss mats off of logs, rocks, and the forest floor and inadvertently remove lichens, insects and amphibians which live among the mosses. Mushrooms are also collected each year. As long as pickers take only the fruiting body of the mushroom they can be safely collected in large amounts. However, the harvested mushrooms are important to the plant's reproduction and as a rule of thumb should never be entirely removed from any one area. The greatest dangers to mushrooms are soil disturbance and destruction of their host plants.
Pollution is another threat to non-vascular plants.
For more than twenty years now we have known that many nitrogen-fixing lichens and mycorrhizae are highly sensitive to pollution. A low diversity of lichens in an area is a strong indicator of high levels of air pollution. Little protection is currently afforded to lower plants, but awareness is growing. This does not mean that they are legally protected however, and there are no non-vascular plants in Oregon with federal listing. To learn more about the lower plants, begin in your own backyard.