method_Menzel {vegperiod} | R Documentation |
Vegetation Start Method "Menzel"
Description
The method "Menzel" implements the algorithm described in Menzel (1997). The method is parameterized for 10 common tree species ( Larix decidua, Picea abies (frueh), Picea abies (spaet), Picea abies (noerdl.), Picea omorika, Pinus sylvestris, Betula pubescens, Quercus robur, Quercus petraea, Fagus sylvatica). It needs previous year's chill days.
Calculations
- counting chill days in Nov & Dec of previous year if previous year available else estimate previous year's chill days - count chill days in current year - determine critical temperature per days using regression equation fitted by Menzel 1997 - calculate HeatSum starting from Feb - vegetation start if HeatSum >= criticalTemp
References
Menzel, A. (1997) Phänologie von Waldbäumen unter sich ändernden Klimabedingungen - Auswertung der Beobachtungen in den Internationalen Phänologischen Gärten und Möglichkeiten der Modellierung von Phänodaten. Forstliche Forschungsberichte München.
[Package vegperiod version 0.4.0 Index]