To: maceng2 who wrote (17875 ) 12/1/2007 5:34:12 PM From: Brumar89 Read Replies (1) | Respond to Interesting.Between 1850 and 1950 a long-term trend of gradual climate warming is observable, and during this same period the Marsham record of oak leafing dates tended to become earlier. Towards the end of the 19th century the recording of the appearance and development of plants and animals became a national pastime, and between 1891 and 1948 a programme of phenological recording was organised across the British Isles by the Royal Meteorological Society. Up to 600 observers submitted returns in some years, with numbers averaging a few hundred. ...... The 58-year data have been summarised by Jeffree (1960), and show that flowering dates could be as many as 21 days early and as many as 34 days late, with extreme earliness greatest in summer flowering species, and extreme lateness in spring flowering species. During this period, important contributions were made by individual dedicated observers. ........Writing in Science in 2002, Richard Fitter and his son Alistair Fitter found that "the average FFD of 385 British plant species has advanced by 4.5 days during the past decade compared with the previous four decades". They note that FFD is sensitive to temperature, as is generally agreed, that "150 to 200 species may be flowering on average 15 days earlier in Britain now than in the very recent past" and that these earlier FFDs will have "profound ecosystem and evolutionary consequences". en.wikipedia.org
