title: Anthropogenic oligotrophication via liming: Long-term phosphorus trends in acidified, limed, and neutral reference lakes in Sweden.
abstract: Restoration of acidified lakes by liming does not, in many cases, improve productivity to a pre-acidified state. We hypothesize that the poor recovery detected in many of these lakes is due to constrained in-lake phosphorous (P) cycling caused by enhanced precipitation of metals in higher pH, limed waters. Long-term (1990-2012) data for 65 limed, circum-neutral (pH 6-8), and acidified lakes in Sweden were analyzed to determine trends for P and potential drivers of these trends. Limed lakes not only had lower mean values and stronger decreasing trends for total P than non-limed lakes, but they also had the highest percentage of decreasing trends (85 %). A P release factor (Hypolimnetic P/Epilimnetic P) was developed to elucidate differences in internal P cycling between lake groups. Consistently, lower P release factors in limed lakes show limitation of internal P cycling during summer months that may be a factor limiting P bioavailability and thus productivity of these systems.
authors.affiliation: Waterways Centre for Freshwater Management, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.
authors.forename: Qian
authors.initials: Q
authors.lastname: Hu
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Huser
mesh_terms: D004784:Environmental Monitoring; D005068:Eutrophication; D006863:Hydrogen-Ion Concentration; D060106:Lakes / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*; D012621:Seasons; D013548:Sweden; D014877:Water Pollution, Chemical / Q000009:adverse effects*
chemical_list: D010758:Phosphorus