The influence of atmospheric circulation on plant phenological phases in central and eastern Europe

Abstract

The objective of this study is to analyse relationships between the start dates of spring phenological phases and largescale atmospheric circulation patterns. The timing of phenological phases in temperate zones is driven by temperature, and temperature regime is generally determined by atmospheric circulation. The database analysed consists of the first dates of flowering of coltsfoot (Tussilago farfara L.), of birch (Betula pendula Roth.) leaf unfolding and of flowering of lilac (Syringa vulgaris L.); the North Atlantic oscillation (NAO) and the Arctic oscillation (AO) indices, frequencies of the circulation forms classified by Vangengeim and Girs, and of the groups of Grosswetterlagen presented by Hess and Brezowsky. The study area covers central and eastern Europe, and the period considered is 1951-98.The results show that the influence of the westerly airflow is more pronounced in the winter half-year, and weakens and even disappears as spring advances. Phases have the highest correlation with NAO and AO indices during winter (December-March) and the first three months of the year (January-March), which have correlations stronger than −0.5 in the Baltic Sea region. Among the phenological phases, flowering of coltsfoot is the most strongly correlated with the NAO and AO indices, followed by leafing of birch and flowering of lilac. Airflow from the north and from the east has a greater influence in springtime, particularly in the northernmost and southernmost regions of the study area.

Spatial structure of the 8200 cal yr BP event in northern Europe

“…The tree taxa that show strong responses to the 8200 cal yr BP event, Alnus, Corylus, and Ulmus, start flowering in early spring, in central Europe often in February-March and in southern and central Fennoscandia in March-April (Jäger et al, 1996;Kasprzyk et al, 2004). The start of their flowering and plant development is in general dependent on air temperature (Wielgolaski, 1999;Aasa et al, 2004) and if an abrupt change to cold winters and cold (Hammarlund et al, 2003Seppä et al, 2005), Rouge , and Tibetanus (Hammarlund et al, 2002). See Fig.…”

Divergent patterns of impact of environmental conditions on life history traits in two populations of a long-distance migratory bird

“…Advances in spring arrival date have also been associated with NAO in winter for both short-and long-distance migratory birds in Europe North America (MacMynowski et al 2007). A positive NAO index is linked to improved ecological conditions in central and northern Europe as a result of advanced spring phenology (Aasa et al 2004;Menzel et al 2005), but is linked to dry anomalies in the Mediterranean basin (Hurrell 1995;Hurrell and Van Loon 1997). For these reasons, there is a priori a much greater chance that the NAO will affect the migrants that spend a long part of their migratory journey passing through Europe, i.e., the Danish population.…”

Trends of the thermal growing season in China, 1951–2007

“…flowering, leafing, breeding, leaf fall) are linked to temperatures, respond to changing temperatures with shifts in their phenophases. An overwhelming number of phenological data indicate shifts towards earlier start of the GS in the latter part of the 20th century, and this has been coupled to warming associated with the North Atlantic Oscillation, NAO (D'Odorico et al, 2002;Menzel, 2003;Aasa et al, 2004), warming in spring (Cayan et al, 2001;Chmielewski and Rötzer, 2001a,b;Chmielewski et al, 2004) and increases in minimum temperatures, longer frost-free periods or earlier last spring freeze dates (AbuAsab et al, 2001;Scheifinger et al, 2003;Schwartz et al, 2006). This focus on the GS start in phenological studies is due to (1) the largest changes having been noticed in spring and (2) the relatively large uncertainty in timing the end of the GS.…”