The Impact Of Landfill Gas On The Growth Of Plants And The Approach Restoration Of Near-natural Vegetation

With the rapid development of urbanisation, the ecological environment problems resulted from landfill grow increasingly serious day by day. This issue that how to restore vegetation in landfill is can be faced to all people during sustainable development. Landfill is the major approach to deal with rubbish all the world, but which landfill gas, leachate and heavy metal produced in the process have great severe impact on urban ecosystem. Landfill gas is the key factor to plants. The difficult and important point are that how impact on plants, how to restore and afforestation on landfill and how to use sustainably landfill are also great importance to improve urban environment and ecology construction.This paper chosed Gucun landfill for object in Shanghai City, Baoshan District. Investigated the dynamics vegetation, and did experiment on it for landfill gas. Studied the impact of landfill gas on plants about biological characters and physiology characters. Combined with the plant status and the result of experiment, it put forward the near-natural vegetation process on the special habitat about landfill.The study result showed that:1) All 11 paints chosed near the vent were prohibited to grow. especially the survival of Distylium racemosum and Ligustrum lucidum were lowest nevertheless Broussonetia papyrifera,Ophiopogon japonicus,Cynodon dactylon were 100%. Broussonetia papyrifera were subjected non-obvious impact all groups. On leaf length, leaf width and plant height of Melia azedarach, Cynodon dactylon, Chlorophytum comosum'Jinbian'were declined. But Cynodon dactylon grew better after one month. Melia azedarach, Buxus sinica var. Parvifolia and Chlorophytum comosum'Jinbian' were showed obvious symptoms, Ligustrum sinense, Lycium chinense, Reinekia carnea were less obvious. Most plants far away from vent can survive.2) The chlorophyll of all 11 palnts chosed near the vent were different declined.But the content of Broussonetia papyrifera and Cynodon dactylon grew higher after one month, which meant the biological activities began to activate, nevertheless the chlorophyll content far away from vent changes little. Proline content grew higher by the damages sustained, espically Broussonetia papyrifera and Cynodon dactylon had most, which indicated the strongest resistance. Nevertheless the farer the less.3)This survey abouts Gucun landfill including 66 plants, which belonged to 64 generas and 28 families. The herb was the most kind, accounted for 86.3%. Only 1 alien species in all plants, Solidago canadensis. Espcially Broussonetia papyrifera and Cynodon dactylon around the gap of outlet landfill gas were strong-stress. The dominate species were Cynodon dactylon and Broussonetia papyrifera. Aimed at the more landfill gas in newly-closed landfill site, this paper put forward the model: heliophytes, fast-growing and anti-gas native plants and shallow-root pioneer herbs→medium anti-gas plants→umbraticolous and heliophytes, arbor-shrub-herb multiple-layered forest.