Effects of acidification on benthic community structure and benthic processes in Little Rock Lake, Wisconsin
Acid precipitation and the resulting acidification of susceptible lakes has been a topic of great interest for two decades. Much of the public concern about this issue relates to changes that occur within the water column, e.g. elevation of metal concentrations and loss of desirable game fish. However, the extent of such changes and mechanisms whereby they occur depend strongly on processes occurring within the lake’s sediments and at the sediment/water interface. Much of our knowledge on these changes has been inferred from lake surveys and laboratory studies. This paper describes the responses of benthic community structure and functions (decomposition and element recycling) in a small, softwater (low alkalinity) lake that is undergoing experimental acidification. Most previous studies of the effects of acidification on decomposition have involved streams or forests. The effects of decreased decomposition may be more extreme in lakes (especially seepage lakes), where inflows of ions and nutrients from the watershed are small or absent, than in lotic systems, which have these inflows. Slower decomposition in seepage lakes could lead to large effects on element cycling rates.