Long-term phyto-, ornitho- and ichthyophenological time-series analyses in Estonia.

摘要

Long-term phenological time series were analysed for their use in assessing the effects of climate change in Estonia. The data were also used for the methodological study of the possible limitations of using phenological time series in climate trendanalyses. These limiting factors can influence the results of studies more than the real impact of climate changes, which may have a much smaller numeric value. The study is based on 132-year series of the arrival of the skylark (Alauda arvensis) and the white wagtail (Motacilla alba), a 78-year series of the blossoming of the wood anemone (Anemone nemorosa), the bird cherry (Padus racemosa [Prunus padus]), apple trees (Malus domestica) and lilacs (Syringa vulgaris), and a 44-year series of the spawning of pike (Esox lucius) and bream (Abramis brama). Blossoming dates of Corylus avellana, Acer platanoides and Sorbus aucuparia were also used for extreme years. The study of the phenological time series shows that Estonian springs have advanced 8 days onaverage over the last 80-year period; the last 40-year period has warmed even faster.