Examination of tree and root performance on closed landfills in Merseyside

摘要

A study of the above- and below-ground growth of alder (Alnus spp.), willow (Salix spp.) and poplar (Populus spp.) on 4 poorly restored landfill sites in Merseyside, northern England, was carried out in conjunction with measurements of physical sitecharacteristics. Soil gas analysis identified the incidence of high methane (CH4) and carbon dioxide (CO2) and low oxygen (O2) concentrations in the root zone at some of the sites. Statistical analysis revealed that tree roots were inhibited by high soil bulk density. Height growth was also inhibited by soil compaction, and high soil CO2 and low oxygen concentrations. The results demonstrate that satisfactory woodland can only be achieved if adequate physical soil conditions are obtained. However, thestudy also shows that useful woodlands may develop without a detailed and expensive restoration prescription.