Data Sources


The Plant-Phenological Online Database PPODB comprises plant-phenological observations collected in Central Europe between 1880 and 2009 with an emphasis on Germany. Most of the data presented here was kindly provided by the Deutscher Wetterdienst (German meteorological service, DWD), a public-law institution in the area of accountability of the German Federal Ministry of Transport, Building and Urban Development. Generally, access to the database is unrestricted and free of charge. For more details see Acknowledgments. The raw data can also be ordered directly from the DWD (www.dwd.de).
The PPODB comprises three main data sources,
  • phenological observations collected by the Deutscher Wetterdienst (German meteorological service, DWD) from 1951 to 2009. This data is referred to as 'DWD'-data and tables containing this data are named with the prefix 'DWD'.
  • the historical phenological database (HPDB) provided by the DWD, which is a collection of phenological observations from Central Europe, mainly Germany, covering the years 1880 until 1941 compiled from various sources. This data is referred to as 'HPDB'-data and tables containing this data are named with the prefix 'HPDB'.
  • To supplement the data for the time before 1951 and to fill the gap between 1941 and 1951 we digitalized phenological data that were available only in printed form. These data were collected by the volunteer network of the precursor of the DWD, the Deutscher Reichswetterdienst, and were published after world war II (Schnelle and Witterstein, 1952; Schnelle and Witterstein, 1964). These observations cover the years 1922 until 1944. Additionally, we digitalized phenological data that were published between 1951 and 1961 in the meteorological yearbooks of the DWD (DWD, 1951; DWD, 1953; DWD, 1960; DWD, 1961). All these historical data were stored in yet another historical phenological database (HIS), which for the first time is made publicly available. Only the meteorological yearbooks of the former US-Zone in Germany covered the whole time span from 1945 until 1951, whereas the meteorological yearbooks of the other occupied zones started publishing later, e.g. the British-Zone started 1949. Thus, continuous time series for the whole period from 1880 until 1999 could only be found for southern Germany. This data is referred to as 'HIS'-data and tables containing this data are named with the prefix 'HIS'.
The PPODB offers a unique data source, where, for the first time, plant-phenological observations from 129 years are brought together in one consistent database. Moreover, sophisticated outlier detection methods and quality checks are applied. For more information about the different databases, please refer to the documentation or (Schaber, 2002) and (Schaber and Badeck, 2005).
For a quick overview we compiled some summary statistics about the number of stations, phenological phases, observations and observation years for the different data bases :
Database plant type # stations # phases # plants # observations observation period
DWD wild 6.514 75 38 5.897.274 1951 - 2009
agro 6.410 (3.062) 140 (9) 25) 5.981.960 (63.457) 1951 - 2009
fruit 6.433 (2.715) 67 (11) 24 3.534.316 (159.863) 1951 - 2009
wine 1.176 (276) 27 (5) 4 100.609 (5.216) 1951 - 2009
all 6.544 334 91 15.514.159 1951 - 2009
HIS wild 1.195 56 29 138.419 1921 - 1955
agro 1 1.147 214 28 86.533 1921 - 1944
all 1.675 270 57 224.952 1921 - 1955
HPDB wild 1.099 97 38 109.782 1880 - 1941
agro 944 22 11 16.955 1880 - 1941
fruit 1.078 49 15 52.943 1880 - 1941
unclassified 2 1.161 296 290 122.015 1880 - 1941
all 1.184 1.566 296 284.236 1880 - 1941
combined data 3 wild 7.952 75 38 6.142.068 1880 - 2009
agro 7.807 140 25 6.064.664 1880 - 2009
fruit 7.859 67 24 3.623.751 1880 - 2009
vine 1.182 27 4 101,383 1951 - 2009
unclassified 2 1.808 1487 280 122.015 1880 - 1944
all 8.333 1.961 370 16.065.517 1880 - 2009
Numbers in brackets are respective numbers for plant varieties.
1 In the historical databases HIS agrological plants include fruits and vines.
2 Unspecified plant types refer to plant-phase combination that are not in the actual DWD database.
3 The Combined Data refers to the database where stations and corresponding observations from all three databases have been combined and merged.