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| Titel |
Forecasting plant phenology: evaluating the degree-day method for Betula pendula and Padus racemosa spring phases in Latvia |
| VerfasserIn |
Māra Bitāne, Andis Kalvāns, Gunta Kalvane |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250080678
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| Zusammenfassung |
| A phenological and meteorological data series for period 1960-2009 were used to evaluate
the usefulness of the degree-day approach for forecasting beginning of leaf unfolding and
flowering for two tree species – silver birch Betula pendula and bird cherry Padus racemosa
in Latvia (Kalvane et al, 2009).
The degree days – sum of the active temperatures accumulated after the winter calm
period – were calculated for a range of base temperatures (0, 3, 5, 7 and 10oC). The results
were compared to the timing of the phenological events observed at eight stations in order to
evaluate year-to-year as well as regional variations.
Different base temperatures gave surprisingly similar results. The most appropriate
threshold temperatures was found to be +7Ë C for both the budburst and flowering of silver
birch, +3oC for the budburst of bird cherry and +5oC for flowering of bird cherry.
Giving the most appropriate estimated base temperatures, it is found that the budburst
of the Betula pendula takes place when 70 degree-days after the winter calm is
accumulated and the flowering takes place when 85 degree days are accumulated.
The respective degree day values for the Padus racemosa are 117 and 164. The
conclusions should be considered as indicative because the exact locations of the
phenological observations originating from the network of the volunteers are not known
exactly.
The research is supported by the European Union through the European Social Fund
Mobilitas grant No MJD309 and grant No. 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060.
Key words: phenology, degree day, Betula pendula, Padus racemosa, Latvia
References:
Kalvane, G., Romanovskaja, D., Briede, A., Baksiene, E. 2009. Influence of the climate
change to the phenological changes in Latvia and Lithuania. Climate Research. Vol. 39,
209-219. |
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