Physiological and Spectral Responses of Sugar Maple (Acer Saccharum Marsh.) To Msw Leachate Spray Irrigation

Abstract

Foliar gas exchange, water relations and spectral properties of understorey sugar maple ( Acer saccharum Marsh. ) sapling leaves were studied in a natural forested ecosystem subjected to spray irrigation of municipal solid waste (MSW) landfill leachate and compared to similar measures taken from leaves of unirrigated saplings. Photosynthetic rates in irrigated saplings were reduced 34% to 53% in comparison to unirrigated sapling rates. Similarly, water use efficiency of sapling leaves subjected to direct leachate exposure dropped an average of 70%, while transpiration rates were similar to, and leaf temperatures were 20% higher than, those found in unirrigated leaves. Spectral patterns of understorey leaves, distorted because of the accumulation of leachate precipitate residues on the adaxial surface, demonstrated increased absorbance in the near infrared waveband and reduced reflection in visible wavebands compared to abaxial surfaces. The adaxial spectral properties of mid-canopy leaves (above maximum spray height) of mature sugar maple trees were not distorted by these residues and revealed spectra that suggested increased nitrogen uptake and benefit derived from leachate irrigation. These findings on leaf tissue integrity and energy budgets are discussed in terms of the implications for design of leachate treatment and disposal systems on land and for forest ecology in general.

Ecosystem Services, Physiology, and Biofuels Recalcitrance of Poplars Grown for Landfill Phytoremediation

“…Therefore, despite being beyond the scope of the current study, ∆-assisted, multi-trait selection of productive clones should be carefully considered in future efforts, focusing on both growth and high WUE [ 51 , 57 ]. Such efforts are important, as they take into account linkages between WUE and phytoremediation that are associated with potential stress impacts from landfill soil properties and contamination sources [ 10 , 31 , 32 , 33 , 34 , 35 ].…”

“…Thus, water use efficiency (WUE), which is strongly correlated with both δ 13 C stable carbon isotope ratios and carbon isotope discrimination (Δ) [ 29 , 30 ], is an important trait during genotype selection for phytoremediation. However, research using Δ in phytoremediation with trees is scarce [ 31 ], especially when considering potential stress impacts that are caused by landfill soil properties [ 32 , 33 ] and/or highly variable contamination sources [ 10 , 34 , 35 ] on plant water regimes during phytoremediation processes.…”

Physiological Responses of Red Maple Saplings To Sub-Irrigation With an Untreated Municipal Landfill Leachate

“…Precipitate coatings with qualitatively similar characteristics have been observed on roots of water oak (Quercus nigra L.) and green ash (Fraxinus pennsylvanica Marsh.) Large amounts of ferrihydrite, a type of iron oxyhydroxide, have been found in MSW leachates with high Fe concentrations (Shrive et al 1990, Bolton & Evans 1991. The composition of this plaque was believed to be an iron oxyhydroxide (Chen et al 1980, Macfie & Crowder 1987.…”

“…chemical oxygen demand (COD)] can be substantially reduced in the irrigants by adopting application methods such as spray irrigation, but direct contact of the leachate with foliage and the resulting residue accumulations are an undesirable side-effect (Shrive et al 1990). ammonia, volatile organic compounds (VOCs)] and conventional contaminants [e.g.…”