PARENT SESSION
Poster Session # 7: Restoration, Resource Management, and Conservation.
Monday, August 4 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.
Effects of mulch on edaphic conditions and seedling survival on a closed Ohio landfill.
Athy, Erin1, Keiffer, Carolyn2, 1 Miami University, Oxford, OH2 Miami University, Oxford, OH
ABSTRACT- Restoration of degraded lands, including closed landfills, is urgently needed; however, many restoration attempts fail due to poor soil conditions (e.g., compacted, low in nutrients and organic matter). Current agricultural strategies include applications of mulch, which are known to increase soil organic matter, increase soil moisture, moderate rhizosphere temperatures, and reduce herbaceous competition. Employing such practices on sites with similar soil limitations may increase tree survival and growth. This study evaluates the effect of mulch type and depth on tree seedling survival and edaphic conditions on Center Hill landfill, Cincinnati, OH. The area, a former gravel mine in the 1950s, was filled to capacity with urban and construction refuse until it was capped with 1.5m of compacted clay and 0.5m of fill dirt in the 1970s. A subsequent reforestation attempt with hybrid poplars failed (17.5% survival). In Spring 2002, five species of tree seedlings (Fraxinus pennsylvanica, Robinia pseudoacacia, Prunus serotina, Quercus macrocarpa, Populus spp.) were planted as bare root seedlings (n=1750) on each of 35 replicate plots, including non-mulched controls. Three types of mulch (hardwood chips, leaf, and mixed) were distributed in three depths (0, 5, 15 cm). Gravimetric soil moisture and temperature were taken monthly (May-September). Seedling survival varied by species, from Fraxinus (97%) to Prunus (11%). Populus, Prunus, and Robinia benefited by mulch additions; 15cm hardwood and mixed mulch improved survival of Prunus (p<0.005) while leaf mulch had little effect. Populus responded positively to the 15 cm application of any mulch (p<0.004), while Robinia was sensitive to specific treatments (p<0.004). Fraxinus and Quercus showed no significant differences in survival on mulched plots compared to the control. Data suggests that the 15 cm mulch treatment negatively impacted herbaceous growth (p<0.017) and lowered soil temperatures (p<0.0001). Soil moisture was not significantly different per treatment, attributed to drought conditions.
Key words: vegetation, seedling, landfill, restoration