Phytoremediation is a low cost, solar-energy driven technique that uses plants to cleanup contaminated environments. The presence of plants can help control and contain pollutants by preventing wind, rain, and groundwater flow from carrying contaminants deeper underground and to surrounding areas. Trees act like a pump, drawing groundwater up through their roots to keep it immobilized.
Beyond trees there are many types of plants that can help protect the spread of noxious metals, pesticides, explosives and oil. Some of the best are willow and poplar trees, hemp, sunflower, ‘Indian’ grass and mustard.
There are also a range of plant behaviors that do more than just hault the spread of undesired substances. Plants can metabolize contaminants (phytodegredation); produce biochemicals that can sequester nearby contaminants (phytosequestration), stimulate microbes living in surrounding soils to digest contaminants (rhizodegradation) and store contaminants in their roots, stems, or leaves (phytoaccumulation). This is particularly useful for removing metals from soil. In some cases, the metals can even be recovered for reuse by incinerating the plants in a process called phytomining - pretty incredible.
Even though LINNÉ uses plants exclusively grown in clean environments, such as the one pictured here, I felt compelled to share notes on this restorative technology. Being in the presence of such majestic trees I suppose just begs the question, what can’t plants do?