Response of Macroinvertebrates to Calcium Addition in the Adirondack Mountains, USAA

Acid deposition is a well-studied phenomenon in the lakes and streams of the northeastern United States and in northern Europe, but the effect of acid deposition on terrestrial communities is less well-known. I examined the effects of large-scale calcium addition on the communities of macroinvertebrates present in the litter layer of maple-beech forests in the Adirondacks, which are strongly affectred by acidic deposition due to poor buffering capacities in the soils. Lime was added to five treatment plots over the course of a year. Untreated deciduous and coniferous forests in Madison County, which has a well-buffered soil, were used as reference sites, and untreated plots in the coniferous Earlville State Forest were used as outgroups. Invertebrates were sampled in both Madison County and the Adirondacks. Discriminant analysis showed differences in calcium-rich invertebrate groups (Diplopoda, Arionidae, and Isopoda) between the three regions. All were now abundant in the calcium rich Madison County sites, indicating that the need for calcium to form extrernal structures (millipedes and isopods) or eggs (slugs) may be a factor in their distribution. One year after liming, invertebrate communities did not measurably differ between limed and control plots in the Adirondacksw. Physical factors of the litter (pH, percent organic matter, elemental composition, etc.) were measured to correlate invertebrate communities to thier microhabits