Assessing potential for recovery of biotic richness and indicator species due to changes in acidic deposition and lake pH in five areas of southeastern Canada.

摘要: Biological damage to sensitive aquatic ecosystems is among the most recognisable, deleterious effects of acidic deposition. We compiled a large spatial database over 2000 waterbodies across southeastern Canada from various federal, provincial and academic sources. Data for zooplankton, fish, macroinvertebrate (benthos) loon species richness occurrence were used construct statistical models lakes with varying pH, dissolved organic carbon content lake size. pH changes, as described predicted using Integrated Assessment Model (Lam et al., 1998; Jeffries 2000), based on range emission reductions set forth in Canada/US Air Quality Agreement (AQA). The scenarios tested include 1983, 1990, 1994 2010 sulphate deposition levels. Biotic developed five regions (Algoma, Muskoka, Sudbury, Ontario, southcentral Quebec, Kejimkujik, Nova Scotia) regression tree, multiple linear logistic analyses make predictions about recovery after reductions. produced different indicator regions, although some showed consistent trends regions. Generally, greatest occurred during final phase between all taxonomic groups Ontario average, recover greater extent than either Quebec or Kejimkujik area Scotia. Our results reconfirm that 5.5-6.0 an important threshold below which biota will remain major local regional environmental problem. This biodiversity trophic levels persist well into future if no further are implemented.