Salt tolerance of woody phreatophytes for phytoremediation applications

摘要

A six-week-long test program was conducted to study the short-term response of live, unrooted phreatophyte cuttings of genus Populus and genus Salix to salinity in a controlled, greenhouse environment. The program tested four candidate woody phreatophytes prior to final species selection for a phytoremediation system at a former manufactured gas plant site in Charleston, SC. Growth was evaluated by biomass, shoot length, water consumption, and transpiration ratio. Hybrid poplar, P.charcowiensis x P.incrassata, exhibited vigorous growth at all treatment levels relative to the other species tested and was concluded to be the most salt tolerant relative to the other species under the test conditions. Another hybridpoplar, P. maximowiczii x P.trichocarpa, exhibited the least salt tolerance with growth severely affected by exposure to increased salinity conditions, mortality rates of 75 and 100 percent, respectively; low biomass; and short shoot length relative to the control plants. Salt stress of this species was recorded early in the study. Documented mortality, transpiration ratio, biomass and shoot length indicated S.matsudana x S.alba and P.deltoides x P.nigra were more salt tolerant than P. maximowiczii x P.trichocarpa.