Metal stress and decreased tree growth in response to biosolids application in greenhouse seedlings and in situ Douglas-fir stands.
To assess physiological impacts of biosolids on trees, metal contaminants and phytochelatins were measured in Douglas-fir stands amended with biosolids in 1982. A subsequent greenhouse study compared these same soils to soils amended with fresh wastewater treatment plant biosolids. Biosolids-amended field soils had significantly higher organic matter, lower pH, and elevated metals even after 25 years. In the field study, no beneficial growth effects were detected in biosolids-amended stands and in the greenhouse study both fresh and historic biosolids amendments resulted in lower seedling growth rates. Phytochelatins - bioindicators of intracellular metal stress - were elevated in foliage of biosolids-amended stands, and significantly higher in roots of seedlings grown with fresh biosolids. These results demonstrate that biosolids amendments have short- and long-term negative effects that may counteract the expected tree growth benefits.
University of Washington Tacoma, 1900 Commerce St., Campus Box 358436, Tacoma, WA 98402, USA. ecline@uw.edu
Erica T
ET
Cline
Quyen T N
QT
Nguyen
Lucy
L
Rollins
James E
JE
Gawel
D019216:Metals, Heavy / Q000378:metabolism*; D054811:Phytochelatins / Q000378:metabolism; D028224:Pseudotsuga / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology; D012037:Refuse Disposal; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D012722:Sewage / Q000032:analysis; D012989:Soil Pollutants / Q000378:metabolism* / Q000494:pharmacology; D013312:Stress, Physiological; D014197:Trees / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology
D019216:Metals, Heavy; D012722:Sewage; D012989:Soil Pollutants; D054811:Phytochelatins