title: The effects of a simulated acid precipitation on leaf litter quality and the growth of a detritivore in a buffered lotic system.
abstract: The effects of a simulated acid rain on leaf litter quality and the growth of a detritivore in a buffered lotic system were investigated. Exposure of Populus balsamifera L. saplings to a simulated acid precipitation prior to leaf abscission resulted in significant decreases in foliar nitrogen content and increases in carbon: nitrogen ratios. During decomposition of the leaf litter in a buffered lotic system, microbial activity was significantly reduced. Growth of Tipula commiscibilis Diane (Diptera: Tipulidae) larvae decreased significantly when fed conditioned leaves exposed to a simulated acid precipitation prior to abscission. Reductions in detritivore growth were correlated with lower potential quality of the leaf litter resulting from increased carbon: nitrogen ratios and reduced levels of microbial activity. Thus, even in well buffered freshwater ecosystems, acid precipitation can have significant indirect effects on microbial activity and macroinvertebrate growth.
authors.affiliation: Division of Ecology (Aquatic Ecology Group), Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada T2N 1N4.
authors.forename: A
authors.initials: A
authors.lastname: Garden
authors.forename: R W
authors.initials: RW
authors.lastname: Davies