摘要: An analysis is presented of 46 ice break up and 15 free season phenology data series obtained largely through volunteer monitoring efforts in Southern Ontario. Observations spanned the years 1853-2001. Available included dates formation as well number days a year. A high degree temporal coherence between lakes was observed (137/365 pairwise correlations significant at P < 0.05). Significant monotonic trends towards earlier longer seasons were across region both entire last thirty data. Trends may be associated with end Little Ice Age. The significantly study area have important implications for other parts Canada where climate change effects are predicted to more extreme than South-Central