2024-03-29T02:01:18Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/999682018-07-05T00:53:16Zcom_10261_11com_10261_6col_10261_390
2014-07-16T09:14:32Z
urn:hdl:10261/99968
Effect of mild winter temperatures on the earlywood formation of oaks (Quercus robur and Quercus pyrenaica) under oceanic climate in NW Spain
García-González, Ignacio
Pérez de Lis, Gonzalo
Chapela Rodríguez, David
Rozas Ortiz, Vicente Fernando
Comunicación presentada en Engelberg (Suiza) los días 19-23 de septiembre de 2011.
Quercus robur is a nemoral oak widespread all over Europe, and it is gradually replaced by species adapted to better tolerate summer drought towards the South of the continent. Among these, Quercus pyrenaica is a sub-Mediterranean tree, which constitutes the most typical tree species along the Atlantic-Mediterranean transition in the Iberian Peninsula. However, it is well-adapted to continental or mountain conditions, having a delay up to two months in leaf flushing as compared to Q. robur. Both oak species reach their distribution boundaries in NW Spain. Recent climate warming is intensifying summer drought in the region, and probably facilitating the displacement of Q. robur by Q. pyrenaica, better adapted to less water availability during the growing season. However, summer drought is especially remarkable at low altitudes, where Q. pyrenaica still has a much shorter active period than Q. robur because of its late bud break. In order to compare the behavior of these two oaks under such conditions, we carried out a wood anatomical study on the Island of Cortegada (National Park Atlantic Islands, NW Spain), where both occur together at sea level. Climate at the study site is mainly oceanic, with a very mild and rainy winter, but having a moderate summer drought. For each species, we developed chronologies of several anatomical variables derived from the earlywood vessels, which were compared between species, and also used to establish their relationships to climate. The results showed an important impact of winter temperatures on tree growth. Earlywood vessel formation of Quercus pyrenaica was mainly related by climatic conditions during dormancy and quiescence, and to a lesser extent, during the previous growing season, indicating that it is mainly controlled by the trade-off between carbohydrate storage and its consumption by respiration out of the vegetation period. Consequently, as ring-porous trees like oaks entirely rely on stored photosynthates to resume growth in spring, the occurrence of warm winters can be detrimental for their performance if assimilation in the active season does not compensate losses by respiration during the dormant period.
2014-07-16T09:14:32Z
2014-07-16T09:14:32Z
2011-09
2014-07-16T09:14:32Z
comunicación de congreso
Eurodendro Conference: 18 (2011)
http://hdl.handle.net/10261/99968
eng
openAccess
Swiss Federal Institute for Forest, Snow, and Landscape Research