Ferns are tough - among the hardiest of plants. Ferns are generally the first plants to sprout on a new lava flow.
Bioremediation
Ferns are used for bioremediation - to clean up soil contamination at hazardous waste sites.
An example is the Blue Ridge Mountains of Virginia, where ferns remove arsenic from soil at a former apple orchard. During the 1970s, chemicals including DDT and lead arsenates were routinely sprayed on apple trees. By the time of their ban in the early 1970s, the site was seriously affected. There are still parts of the site contaminated with unacceptable levels arsenic.
One approach is "dig and haul" removal of the soil. However, "phytoremediation," e.g. with ferns, can help heal the soil. The plants extract the contaminant out of soil.
The Chinese Brake Fern, Pteris vittata, is a fern which readily accumulates arsenic from the soil.
Depending on conditions and the growing season, the ferns can extract up to 40-50 mg/kg arsenic from the soil. The arsenic is concentrated in the fern leaves, which can be removed and disposed of safely, according to regulations. This may mean one or two truckloads of waste, rather than 60 or 70 truckloads soil - and the soil is returned to its safe, healthy, productive state.
A company called Edenspace has an "exclusive license" to use Pteris vittata for phytoremediation - a curious example of intellectual property "rights" over a pre-existing lifeform.
Ferns as food
In some countries, such as Indonesia, the young shoots from the center of fern plants are cooked as a vegetable. They have an interesting, distinctive taste.
Of course, ferns used in bioremediation must not be used for food!
Further reading
- [The Hearty Fern – Tough Survivor and Humble Servant], USEPA.
