| Water saturated soils can reduce the performance of planted willow clones in phytoremediation systems. Gas exchange in the root zone is inhibited under these conditions reducing growth. Seven different willow clones were compared for their performance (survival and above-ground biomass) under three different innovative site improvement techniques based on the concept of raised planting beds using: (1) cardboard tubes; (2) wooden, bottomless boxes; and (3) grassed berms. Survival was high for all clones (98% on average) and was not significantly improved by any of the treatments. Biomass production was significantly increased through the use of box and tube planters, as compared to grassed berms, and conventionally planted rooted and unrooted cuttings. Within the box and tube planters, clones 94003 ( S. purpurea) and 9882-25 (S. purpurea) exhibited the greatest success. Planting boxes are recommended for use in future phytoremediation sites within Fort Drum and other areas in the Northeast similar to the saturated seeps of this study site. It appears that Salix purpurea clones, especially clones 94003 and 9882-25, are best suited to the site conditions at Fort Drum, and warrant future study. |
