Growing Trees on Completed Sanitary Landfills

Mounding as a Technique for Restoration of Prairie on a Capped Landfill in the Puget Sound Lowlands

“…Soil generally covers the impermeable material, although it is often shallow and may create problems associated with low soil volume and low permeability (Moffat & Houston 1991; Handel et al 1997; Parsons et al 1998). There may be excessive soil or surface water during the wetter part of the year, and drought may occur during the dry season (Leone et al 1983). This results in a stressful environment that may have few analogues in natural systems near the landfill (Gilman et al 1989; Pastor et al 1993; Kindscher & Tieszen 1998).…”

Laboratory-scale measurements of N2O and CH4emissions from hybrid poplars (Populus deltoides × Populus nigra)

“…In most cases, landfill biogas is initially comprised of up to 60% CH 4 and up to 40% carbon dioxide (CO 2 ), although other trace gases such as ammonia (NH 3 ), hydrogen (H 2 ), hydrogen sulphide (H 2 S), ethylene (C 2 H 4 ) and mercaptans can also be produced , Leone et al 1983. In most cases, landfill biogas is initially comprised of up to 60% CH 4 and up to 40% carbon dioxide (CO 2 ), although other trace gases such as ammonia (NH 3 ), hydrogen (H 2 ), hydrogen sulphide (H 2 S), ethylene (C 2 H 4 ) and mercaptans can also be produced , Leone et al 1983.…”

“…Similarly, international research efforts on alternative landfill covers have included studies on the effectiveness of vegetative landfill covers at reducing deep drainage (recharge) and overall leachate volumes in landfills (Licht et al 2001). On a global scale, research efforts have focused on the overall success of tree establishment on landfills (e.g., Flower et al 1981, Leone et al 1983, Moffat & Houston 1991, as well as the extent to which tree roots can adversely affect the integrity of landfill covers (e.g., Dobson & Moffat 1993). No known research published on the PTS cover or other alternative vegetative landfill cover types has dealt with the extent to which poplars × × × × may affect landfill biogas emissions.…”

“…Many factors limit the growth success of plants on decommissioned MSW landfills, but of significant interest for this study are issues related to the mixture of landfill biogases that are generated during the decomposition of biodegradable refuse. In most cases, landfill biogas is initially comprised of up to 60% CH 4 and up to 40% carbon dioxide (CO 2 ), although other trace gases such as ammonia (NH 3 ), hydrogen (H 2 ), hydrogen sulphide (H 2 S), ethylene (C 2 H 4 ) and mercaptans can also be produced (Flower et al 1981, Leone et al 1983. As this landfill biogas migrates through the cover, concentrations are reduced somewhat by downward diffusing air from the atmosphere and in some cases certain gas constituents are transformed by biochemical reactions in the soil (e.g., CH 4 oxidation).…”