Changes in Aquatic Macrophytes after Liming Thrush Lake, Minnesota

摘要: Thrush Lake, Minnesota, was treated with limestone in 1988 to evaluate the efficacy of protective base addition against loss sport fisheries a sensitive, mildly acidic lake. Prior treatment, lake stressed (pH 6.46, ANC 64 μeq/L) but not severely degraded by deposition and had macrophyte community typical lakes northeastern Minnesota low acid-neutralizing capacity (ANC). This paper describes changes observed aquatic plant communities during 5 years after as pH slowly returned pretreatment levels. Sphagnum platyphyllum, intolerant non-acid conditions, completely eliminated from The charo-phyte, Nitella, that originally shared dominance deep littoral zone S. decreased importance first 2 treatment. Two vascular plants, Potamogeton pusillus Najas flexilis, were found year treatment abundant for liming, probably response combination more neutral reduced cover Nitella. As Nitella again increased coverage depth range, concomitant decrease P. N. flexilis. moss, reinvaded 1993, its dramatic decline.