Vegetation monitoring on recently reclaimed landfills

Background/Question/Methods The SUDOKWON Landfill in Incheon, Korea, is one of the biggest sanitary landfill in the world. Even though the place needs many treatment and examination, only horticultural studies have been held and ecological research was required. Research was concentrated at 1st landfill Site where reclamation was finished in 2003 and has formed 8 terraced layers to examine succession process. 25 quadrats per layer were looked over (3 times a year) to decide Importance Value and dominant species. And present species for each layer was also examined. Seedbank was also surveyed by seedling emergence method. With 10 replication of seedbank for each layer, potential vegetation of landfill was investigated. By collecting 3 years of data, regeneration pattern and proble! ms of planting was noticed. To solve exotic species problems of the landfill, several methods (harvesting, removing flower stalks, competition with native species and scattering seeds of native species) were tried. Generally, landfill area has low organic matter contents in the soil. To improve soil conditions for better vegetation growth, synthesized fertilizer and recycling of macrophytes in the leachate channel with sludge were tried for normalization of the plant coverage and succession process. Results/Conclusions 26 order 137 species (herb) was recorded in 1st site. At the top area where has been most recently molded (layer 8) showed many species may be introduced by soil seedbank and didn't show any dominancy but existed by small patches. The upper layers (layer 6-7) were dominated by 3-4 species such as vine species and leguminous species. The middle layers (layer 3-5) showed increasing dominancy of many species and high biomass. The vegetation of the lower area (layer 1-2) was simplified again by biennial exotic species dominance. These particular changes of vegetation is considered as the result of thinning and mowing of the landfill so that natural succession didn't occur and perennial plants with much investments on roots has merits during the cutting. Du! e to the special environment the high ratio of exotic plants and perennial plants were appeared. To manage dominant exotic plants in landfill area, we induced succession of native plants. As a result, cutting flower stalk at blooming period showed significant decrease in exotic species. And compost made with macrophytes and discharged sludge using effective microorganism complex showed better plant growth (herb) and photosynthesis rate.