垃圾填埋场植被恢复及其环境影响因子的研究

对中山市一个关闭了5a左右的垃圾卫生填埋场进行植被恢复、土壤、填埋气和植物自然定居与植被恢复等方面的调查研究。结果表明：垃圾填埋场的土壤偏碱性，场内土壤的盐分、含水量、有机质和重金属等含量远远高于场外的对照土壤。填埋场的植被自然恢复得很好，总盖度达到98％，以草本植物为主，灌木为辅，另外还有少量的藤本植物和乔本存在。本次调查共记录高等植物74种，隶属63属30科。优势种为狗牙根，亚优势种包括苦楝、胜红蓟、蟛蜞菊、加拿大飞蓬、小牵牛、鸭跖草、少花龙葵、鸡矢藤、红斑一品红、牛筋草、类芦和田菁等12种植物。其中类芦、加拿大飞蓬和胜红蓟是本垃圾填埋场植被恢复先锋植物。场内的填埋气含量显著地高于对照样方，但与其它垃圾填埋场相比，其填埋气的含量较低，因此填埋气对植被恢复的限制作用也相对较小。影响本填埋场植被恢复的环境因子主要是土壤的营养成分、重金属和填埋气。最后，提出了对垃圾填埋场进行植被恢复时应采取的关键措施。图1表5参19。

VEGETATION RESTORATION ON A SANITARY LANDFILL AND ITS RELATIVE ENVIRONMENTAL FACTORS

Vegetaion restoration, landfill soil and gases were studied in Gouzikeng Landfill site in Guangdong, which had been closed for 5 a.The results showed that the surface soil of the landfill site appeared to be slightly alkali, and the contents of salinity, moisture, organic matter and heavy metals in the surface soil were very high, compared with the soil of control. Plant grew naturally very well there, with a total coverage of 98%. 74 species in 63 genera and 30 families were found on the landfill site, including 1 dominant species, Cynodon datylon, and 12 sub-dominant species, Ageratum conyzoides, Melia azedarach, Wedelia chinensis, Erigeron canadensis, Jacquemontia paniculata, Commelina communis, Solanum photeinocarpum var. photeinocarpum, Paederia scandens, Euphorbia sp., Eleusine indica, Neyraudia reynaudiana and Sesbania canabina. Among them, Neyraudia reynaudiana, Erigeron canadensis and Ageratum conyzoides were the pioneer species. The contents of landfill gases (CH 4 and CO 2) in the landfill site were obviously higher than those in the control. However, those were low when compared with those determined from Gin Drinkers' Bay Landfill in Hongkong, which had been closed for 10 a. Thus, harmful effects of landfill gas on the growth of the vegetation in Gouzikeng Landfill site were greatly reduced. Environmental factors limiting the vegetation restoration on Gouzikeng Landfill site mainly included low fertility, high contents of heavy metals and the presence of relatively high concentration of landfill gases. This paper also diccusses the methods for vegetation restoration on landfill sites. Fig 1, Tab 5, Ref 19