• Shepard, Robert K.
  Department of Forest Management, University of Maine
  

During the latter portion of the 1980s and the early 1990s wood-fueled electric generating companies in Maine expressed strong interest in the application of wood ash and paper companies strong interest in the application of papermill sludge to forest lands. This interest stimulated the initiation of field studies at different locations in Maine in conjunction with the Cooperative Forestry Research Unit of the University of Maine and interested companies. The general purpose of these studies was to investigate the effects softwood ash and sludge on tree growth and soil properties. Most studies were established in recently harvested areas planted to black spruce or red pine. All studies have completed a minimum of five growing seasons since their inception. This paper describes three studies that provide contrasting results. The emphasis is on the effects of the sludge and ash on tree growth and foliar element concentrations. The results for each study are presented separately.