Recovery of acid damaged zooplankton communities: measurement, extent, and limiting factors

摘要

Anthropogenic acidification has affected biota in thousands of lakes in eastern North America and Europe. Tonmeasure the degree and extent of biological recovery following pH recovery in acidified lakes, many studies have assessednchanges occurring in acid-damaged zooplankton communities. In this review we synthesize studies of zooplankton recov-nery from regions severely affected by acidification. In doing so, we provide a critical overview of: (1) the design of studiesnused to detect recovery; (2) the status of communities in acidified regions; and (3) our current understanding of the factorsnthat limit recovery. The design of most studies assessing zooplankton recovery fall into three categories based on their se-nlection of data to be used for recovery benchmarks: (1) historical; (2) reference-lakes; and (3) temporal. Within these studyndesigns, the most commonly used metrics include species richness, indicator species, and relative species abundances.nMany studies have used species richness as the sole indicator of recovery; however, we argue that additional metricsnshould be considered in analyses to make conclusions more robust. Studies conducted in eastern North America and North-nern Europe have demonstrated significant, though often incomplete, recovery of zooplankton communities in lakes thatnreach a pH > 6.0. Data collected in central Europe indicate little recovery in the heavily affected Bohemian Forest lakes,nbut complete recovery of species richness in the moderately acidified Tatra Mountain lakes. Factors limiting biological re-ncovery, including slow chemical recovery, dispersal limitation, and community resistance, vary in importance among andnwithin regions, suggesting that region- and lake-specific management approaches may be required.