Swiss Cherry Tree Phenology 1721-2000 AD ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Swiss Cherry Tree Phenology 1721-2000 AD LAST UPDATE: 1/2013 (Observed values added for 2008-2012 AD) Original receipt by WDC Paleo 8/2008 CONTRIBUTOR: This Rutishauser, University of Bern IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2008-080 WDC PALEO CONTRIBUTION SERIES CITATION: Rutishauser, T. 2008. Swiss Cherry Tree Phenology 1721-2000 AD. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2008-080. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Rutishauser, T. 2003. Cherry Tree Phenology. Interdisciplinary Analyses of Phenological Observations of the Cherry Tree in the Extended Swiss Plateau Region and Their Relation to Climate Change. Diploma thesis, University of Bern, p. 122. (http://www.giub.unibe.ch/klimet/docs/diplom_trutishauser.pdf) ABSTRACT: The 'Cherry Tree Phenology' is an analysis of phenological cherry tree flowering observations. The data covers the extended Swiss Plateau region from Alps to the Basel area. The 280-year composite series includes a set of 14 different records of the 'flowering of the cherry tree' from 1721-2000. The contributions consist of observations from phenological networks as well as records by independent observers. This interdisciplinary study includes methods from phenological biology, plant physiology, climatology and history. The influence of global and climate change processes on the flowering dates of the cherry tree blossoms are described from different perspectives. In particular, the relation of pre-flowering mean temperature and the flowering date is assessed. When available, observations from phenological networks were averaged into yearly mean flowering dates in order to remove microclimatic and cultivar specific differences. A comparison between the yearly mean dates of the network observations and independent observations show that the series are well correlated for the 1951/1978-2000 period. Correlation coefficients range between r = 0.78 and 0.91. Mean and single flowering dates from 1721 to 2000 were corrected for altitude to a reference level of 550 m a.s.l. which is the median station height of the Swiss Phenological Network in the study area. The dates were adjusted by + (-) 2.5 days per 100 meters below (above) the reference altitude. The most important environmental impact factor for the cherry tree flowering date is temperature. For the 1951-2000 period, the most influential pre-flowering mean temperature period was assessed by comparison of the flowering date with monthly and seasonal means at the representative station (Zuerich-SMA). A comparison of monthly and combined monthly mean temperatures with the flowering date revealed that the February-April period were highest correlated (r = - 0.82). The correlation is even higher with a subperiod of the Liestal-Record (r= - 0.88). The negative sign describes the inverse physical dependence of the flowering date from temperatures. Thus, warmer mean February-April temperatures result in an earlier flowering date and vice versa. Based on this relationship a linear regression model, calculated from a predictor set of European monthly mean temperatures, was used to predict the annual flowering date. The correlation coefficient in the calibrating period 1951-1995 was r = 0.84. The comparison of the observed and reconstructed flowering date for the 1721-1995 period revealed a high common variability (r = 0.61). Systematic differences before 1900 can be attributed to differences in the definition of the phenological phase. The longterm mean of the observed flowering date 1721-2000 is April 21 (day of year 111) with a standard deviation of approximately ten days. For the reconstructed series 1721-1995 the mean flowering day is on April 26 (day of year 116) with a standard deviation of five days. In order to assess the quality of the observation series, subperiods of the contributing records were compared with the statistical reconstruction. Correlation analysis was applied to compare variability. Coefficients range from 0.38 to 0.91. Systematic differences are revealed by comparing mean values for the 14 subperiods. In addition, suprasegmental comparison was assessed by moving correlation analysis with a 31-year time window. Even though significant at 99 % level during the whole study period, three time windows showed a systematic lower moving correlation coefficient. Whereas the lower correlation during the 1827-1845 period can be attributed to unprecise observations, the other two periods (1755-1765, 1885-1895) seem to reveal a lower dependency of the flowering dates on spring temperature. Systematic differences between observed and reconstructed was additionally assessed with historical source analysis. It is shown that metadata such as biographical notes of the observer and detailed place and phenological phase descriptions, can explain some of the bias in the series. ADDITIONAL REFERENCES: Hansen, J., R. Ruedy, M. Sato, M. Imhoff, W. Lawrence, D. Easterling, T. Peterson, and T. Karl. 2001. A closer look at United States and global surface temperature change. J. Geophys. Res., 106(D20), 23,947-963. Luterbacher, J., D. Dietrich, E. Xoplaki, M. Grosjean, and H. Wanner. 2004. European seasonal and annual temperature variability, trends and extremes since 1500. Science, 303, 1499-1503. Mitchell, T.D. and P.D. Jones. 2005. An improved method of constructing a database of monthly climate observations and associated high-resolution grids. International Journal of Climatology, Volume 25, Issue 6, pp. 693-712, May 2005. doi: 10.1002/joc.1181 Rutishauser, T. and S. Studer. 2007. Klimawandel und der Einfluss auf die Frühlingsphänologie, Schweizer Zeitschrift für das Forstwesen, 158 (5), 105-111. Xoplaki, E., J. Luterbacher, H. Paeth, D. Dietrich, N. Steiner, M. Grosjean, and H. Wanner. 2005. European spring and autumn temperature variability and change of extremes over the last half millennium. Geophys. Res. Lett., 32, L15713. GEOGRAPHIC REGION: Swiss Plateau region, central Europe PERIOD OF RECORD: 1721-2007 AD FUNDING SOURCES: Swiss National Science Foundation (project "Past, Present and Future Climate Impact on Spring and Summer Vegetation - a Phenological Approach" contract 205321-105691/1) and through its National Center of Competence in Research on Climate (NCCR-Climate), projects PALVAREX and CAPRICORN and the Oeschger Centre for Climate Change Research, University of Bern, Switzerland. DESCRIPTION: Flowering dates of cherry (Prunus avium) Original data from Euroclimhist (www.euroclimhist.com) and MeteoSwiss. Approximate regional average location: 7°-9°E/47°-47°30N, 200-1000m a.s.l. Rutishauser (2003) gives technical details (http://www.giub.unibe.ch/klimet/docs/diplom_trutishauser.pdf) Please acknowledge original data owners: Euroclimhist (www.euroclimhist.com) and MeteoSwiss (www.meteoswiss.ch) Updates can be obtained from rutis@giub.unibe.ch NOTE: This file updated 30-January-2013 to add observed values for 2008-2012 AD DATA: Column 1: Year AD Column 2: Observed date of cherry flowering, number of days after January 1 [DoY] Column 3: Observed date of cherry flowering corrected w.r.t. an altitude reference level, number of days after January 1 [DoY] Column 4: Reconstructed flowering date from temperature predictor (Feb-Apr) stations of selected stations from Luterbacher et al. (2004, Science) and Xoplaki et al. (2005, Geophys. Res. Lett.), number of days after January 1 [DoY] Column 5: Observed Feb-Apr temperatures as the mean of selected grid-points (47°-47°30'N, 7°30-9°30'E) from Luterbacher et al. (2004), Xoplaki et al. (2005), Mitchell and Jones (2005, Int J Climatol) and Hansen et al. (2001, updated, J Geophys Res) [°C] YEAR OBS OBSCORR RECON TT24 1721 107 109 121 2.24 1722 84 86 113 4.82 1723 91 93 113 5.09 1724 112 114 117 3.61 1725 104 106 121 3 1726 113 115 119 3.1 1727 101 103 117 4.09 1728 97 99 113 5.03 1729 123 125 122 2.19 1730 112 114 114 4.43 1731 125 127 121 1.99 1732 102 104 111 5.18 1733 104 106 110 4.96 1734 93 95 108 6.25 1735 100 102 112 4.14 1736 98 100 116 4.39 1737 110 112 115 4.06 1738 104 106 113 4.47 1739 119 120 113 4.47 1740 142 143 135 0.15 1741 110 111 120 3 1742 117 118 121 2.55 1743 117 118 120 3.18 1744 111 112 120 2.48 1745 96 97 120 3.58 1746 110 111 125 2.17 1747 107 108 116 4.17 1748 118 119 128 0.97 1749 96 97 120 3.47 1750 117 118 108 5.66 1751 117 118 118 3.77 1752 111 112 118 3.9 1753 85 86 115 4.6 1754 117 118 125 1.77 1755 98 99 119 3.39 1756 105 106 116 3.84 1757 114 115 114 4.12 1758 103 104 117 3.76 1759 79 80 112 4.88 1760 99 100 116 4.17 1761 101 102 110 5.23 1762 107 108 116 3.88 1763 102 103 114 4.4 1764 95 96 116 3.44 1765 114 115 117 3.97 1766 116 114 117 3.62 1767 120 118 115 4.45 1768 106 104 118 3.65 1769 120 118 116 3.73 1770 133 131 123 2.31 1771 125 123 126 2.22 1772 103 101 114 4.79 1773 113 111 119 3.3 1774 96 94 111 5.03 1775 114 112 111 5.52 1776 105 103 111 5.38 1777 106 104 119 3.81 1778 103 101 117 3.79 1779 101 99 106 5.73 1780 118 116 116 3.84 1781 96 94 108 5.41 1782 124 122 124 2.07 1783 103 101 113 4.47 1784 127 125 126 1.92 1785 130 131 132 0.41 1786 113 115 118 3.18 1787 115 117 113 4.61 1788 111 113 115 5.13 1789 121 123 119 3 1790 112 114 113 3.94 1791 102 104 110 4.91 1792 102 104 111 5.15 1793 115 117 117 3.82 1794 91 93 102 6.81 1795 116 118 116 3.87 1796 112 114 117 3.61 1797 112 114 115 3.65 1798 106 108 112 4.65 1799 127 129 120 3.35 1800 113 115 116 3.5 1801 109 111 113 5.12 1802 114 116 114 4.56 1803 98 99 116 3.58 1804 113 114 121 2.65 1805 120 121 119 3.67 1806 107 108 117 3.93 1807 121 122 121 2.54 1808 125 126 127 0.96 1809 114 115 116 3.82 1810 109 110 118 3.8 1811 96 97 110 5.56 1812 120 121 119 3.5 1813 102 103 112 4.73 1814 107 108 123 2.26 1815 94 95 109 5.88 1816 117 118 122 2.52 1817 129 130 117 4.3 1818 112 113 115 3.98 1819 103 103 112 4.82 1820 108 108 115 3.86 1821 116 116 114 3.93 1822 105 105 106 6.32 1823 122 122 117 4.2 1824 124 124 117 3.84 1825 115 115 116 3.67 1826 91 91 111 5.17 1827 118 118 120 4.11 1828 110 113 113 4.71 1829 107 110 120 2.49 1830 79 82 116 4.61 1831 118 121 111 4.74 1832 106 109 117 4.09 1833 119 122 116 3.67 1834 110 113 117 4.01 1835 109 112 115 4.2 1836 112 115 116 3.93 1837 128 131 126 1.44 1838 121 124 126 2.07 1839 121 122 123 2.54 1840 114 115 119 2.75 1841 100 101 116 4.31 1842 NA 115 118 3.74 1843 133 134 116 4.04 1844 NA 115 118 3.98 1845 125 126 130 0.77 1846 107 108 109 5.17 1847 113 114 123 2.02 1848 107 108 112 4.58 1849 114 115 116 3.4 1850 130 131 115 4.01 1851 126 127 115 3.88 1852 116 117 120 2.98 1853 134 135 130 1.43 1854 100 107 116 3.92 1855 110 117 128 2.76 1856 102 109 114 3.73 1857 109 116 120 2.94 1858 111 118 125 3 1859 89 96 115 4.95 1860 118 125 123 1.44 1861 98 105 111 4.76 1862 89 96 108 5.07 1863 101 108 111 4.7 1864 105 112 120 3.57 1865 105 112 124 2.14 1866 98 105 111 4.84 1867 100 107 113 4.83 1868 101 108 114 4.56 1869 102 109 111 4.56 1870 111 118 127 3.02 1871 99 106 117 4.73 1872 95 102 109 5.32 1873 93 100 111 3.62 1874 102 109 113 4.42 1875 126 122 125 1.95 1876 130 126 114 4.11 1877 132 129 118 3.64 1878 126 123 115 4.51 1879 137 134 120 3.15 1880 122 119 110 4.74 1881 106 109 123 3.93 1882 97 100 114 5.15 1883 114 116 121 2.65 1884 94 97 109 4.12 1885 109 112 113 4.28 1886 109 112 121 2.54 1887 118 121 123 2.11 1888 121 124 126 1.33 1889 123 126 125 1.88 1890 107 110 120 2.89 1891 122 125 125 2.65 1892 102 105 120 2.85 1893 100 103 111 5.74 1894 106 111 107 5.02 1895 107 112 128 1.88 1896 106 111 115 4.7 1897 86 91 110 5.6 1898 106 111 112 3.53 1899 93 98 116 4.62 1900 113 118 119 3.08 1901 113 118 125 1.18 1902 102 107 116 4.14 1903 86 91 117 3.61 1904 104 109 113 4.22 1905 102 107 117 3.65 1906 103 108 120 2.53 1907 105 110 126 1.64 1908 119 124 119 2.12 1909 109 114 121 2.34 1910 105 110 114 3.6 1911 107 112 114 3.35 1912 86 91 109 5.14 1913 90 95 112 4.36 1914 99 104 112 5.39 1915 117 122 120 2.77 1916 97 102 113 4.22 1917 124 129 129 0.8 1918 103 108 112 4.05 1919 112 117 121 2.29 1920 90 95 109 5.5 1921 92 97 113 3.99 1922 111 116 119 3.14 1923 98 103 109 4.74 1924 115 120 122 2.71 1925 104 109 115 3.46 1926 99 104 103 6.05 1927 108 113 111 4.12 1928 105 110 109 4.55 1929 122 127 129 0.61 1930 109 114 111 4.1 1931 116 121 124 1.59 1932 120 125 123 1.17 1933 112 117 114 3.85 1934 106 111 107 4.57 1935 106 111 118 2.92 1936 100 105 111 3.96 1937 101 106 114 3.67 1938 91 96 114 3.55 1939 105 110 112 3.59 1940 112 117 122 3.51 1941 116 121 116 3.38 1942 114 119 122 2.96 1943 102 107 107 5.53 1944 109 114 122 2.02 1945 92 97 105 6.06 1946 96 101 106 5.79 1947 107 112 120 4.28 1948 88 93 106 5.43 1949 107 112 113 4.66 1950 100 105 112 4.58 1951 105 105 115 3.66 1952 109 109 113 4.3 1953 108 108 112 4.28 1954 124 124 119 3.13 1955 119 119 123 2.78 1956 120 120 129 -0.02 1957 105 105 106 6.18 1958 124 124 124 2.62 1959 107 107 108 5.64 1960 105 105 112 4.57 1961 98 98 104 6.66 1962 119 119 122 2.43 1963 122 122 121 2.3 1964 113 113 112 4.15 1965 122 122 121 2.04 1966 110 110 109 5.71 1967 113 113 113 4.48 1968 110 110 111 4.99 1969 119 119 121 2.8 1970 127 127 125 1.96 1971 114 114 115 3.29 1972 111 111 107 5.15 1973 124 124 121 2.17 1974 103 103 105 5.28 1975 119 119 116 4.07 1976 114 114 115 4.11 1977 111 111 110 5.42 1978 121 121 117 3.59 1979 126 126 116 3.77 1980 120 120 115 4.06 1981 114 114 113 5.18 1982 121 121 117 3.51 1983 115 115 115 4.05 1984 118 118 118 2.47 1985 123 123 120 3.38 1986 125 125 124 1.6 1987 118 118 119 3.36 1988 117 117 116 4.04 1989 105 105 107 5.71 1990 105 105 107 6.39 1991 115 115 115 4.03 1992 116 116 110 4.9 1993 114 114 114 4.52 1994 110 110 108 5.36 1995 112 112 111 5.18 1996 114 114 NA NA 1997 105 105 NA NA 1998 114 114 NA NA 1999 111 111 NA NA 2000 111 111 NA NA 2001 109 109 NA NA 2002 98 98 NA NA 2003 107 107 NA NA 2004 110 110 NA NA 2005 109 109 NA NA 2006 117 117 NA NA 2007 103 103 NA NA 2008 114 114 NA NA 2009 110 110 NA NA 2010 111 110 NA NA 2011 100 100 NA NA 2012 107 107 NA NA