Germination Potential of Six Native Plant Species for Phytoremediation of Hydrocarbon Contaminated Peat Soils

Research on the remediation of hydrocarbon contaminated peatlands is limited; in particular, hydrocarbon effects on seed germination is critical for effective reclamation. This study examined germination responses of six wetland plant species under greenhouse and laboratory conditions. Seeds were exposed to hydrocarbon-contaminated peat soil and ground water under two light treatments (light, total darkness) for four weeks. Species specific responses in seed germination and germination velocity occurred under different light conditions and exposure to hydrocarbon-contaminated peat soil and water. Light significantly impacted germination, while hydrocarbon-contaminated peat soil and water had no effect. Glyceria grandis (83.5%) and Scirpus microcarpus (74%) had significantly higher germination rates even in contaminated treatments than Carex aquatilis (28%) and Typha latifolia (38%), which had modest germination. Modified Timson’s Index (germination velocity) was significantly greater in Scirpus microcarpus (21.90) and Glyceria grandis (19.20) than in other species after 30 days. Carex utriculata and Scirpus validus had ≤0.5% germination and ≤0.2 velocity. The overall species mean germination time was >9 days with a low (≤0.7) germination index. Ordination using several germination variables separated some species. These findings suggest Scirpus microcarpus and Glyceria grandis have high tolerance to hydrocarbon contamination and may be effective candidates for the phytoremediation and restoration of contaminated peatlands.