Limnological effects of wood ash application to the subcatchments of boreal, humic lakes

• Published in: Journal of environmental quality 2002-05, Vol.31 (3), p.946-953
• Main Authors: TULONEN, Tiina, ARVOLA, Lauri, OLLILA, Susanna
• Format: Article
• Language: English
• Subjects: Alkalinity; Animal, plant and microbial ecology; Applied ecology; Applied sciences; Biological and medical sciences; Calcium - analysis; Conductivity; Continental surface waters; Earth sciences; Earth, ocean, space; Ecotoxicology, biological effects of pollution; Electric Conductivity; Engineering and environment geology. Geothermics; Environmental assessment; Environmental risk; Exact sciences and technology; Fertilizers - analysis; Finland; Fresh Water; Fresh water environment; Freshwater; Fundamental and applied biological sciences. Psychology; Geochemistry; Humans; Hydrogen-Ion Concentration; Lakes; Leaching; Mineralogy; Natural water pollution; Nitrogen - analysis; Phosphorus - analysis; Phytoplankton; Pollution; Pollution, environment geology; Silicates; Water chemistry; Water geochemistry; Water Pollutants, Chemical - analysis; Water quality; Water treatment and pollution; Wood; Zooplankton
• ISSN: 0047-2425; 1537-2537; 1537-2537
• DOI: 10.2134/jeq2002.0946

To assess environmental risks of wood ash, limnological effects of ash application to the drainage basins of two small, humic lakes and one reference lake in southern Finland were examined in this three-year study. Treated areas corresponded to 12 and 19% of the total catchment and the amount of wood ash added was 6400 kg ha(-1). Immediate effects of wood ash on lake water were investigated in three tank experiments each lasting 1.5 wk. In tank experiments, addition of wood ash increased pH, alkalinity, conductivity, and Ca and P concentrations of humic lake water, while growth of phytoplankton decreased. After wood ash application to the subcatchments, pH, alkalinity, conductivity, and concentrations of K+, SO4(2-), and Cl- slightly increased, both in inflowing waters and in the lakes, but no increased leaching of Ca, N, or P from the treated subcatchments occurred. Phytoplankton biomass increased in both experimental lakes in comparison with the reference lake. In the lake with 19% application rate to the catchment, zooplankton biomass also increased. The results indicate that, over the short term, a small-scale ash treatment to a forested drainage basin will not necessarily cause significant changes in the water quality of boreal humic lakes, but at higher application rates, changes in water chemistry and biology are more evident.