Recent climatic trends in Castilla and León (Spain) and its possible influence on the potential natural vegetation

Abstract

Abstract.-Precipitation and mean temperature trends at monthly, seasonal and annual time scale for Castilla and León during the period 1961-2004 were analysed in the present study. The main aims of this paper were to find out if these tendencies differ from those pointed out for this region in a previous research for the period 1961-1997 and to establish, based on bioclimatic models, possible changes on the potential natural vegetation of this territory if these trends do not change in future. Magnitude of trends was derived from the slopes of the regression lines while the statistical significance was determined by the Mann-Kendall test. Magnitude and sign of rainfall and temperature trends over the last four decades have been essentially the same than those concerning to the period 1961-1997. It can be concluded that if these trends keep in future areas with temperate climate could increase in this region. In this situation, deciduous forests could extend their distribution limits, thus replacing some semi-deciduous and evergreen ones.Key words : bioclimatology -Castilla and León -climatic trends -potential natural vegetation -Spain.Résumé.-On examine ici les tendances de précipitation et température moyenne mensuelle, saisonnière et annuelle pour la plus grande région de l`Espagne (Castilla et León) pendant la période 1961-2004. Le première objectif était découvrir si ces tendances ont été différentes de celles précisées pour cette région dans une recherche précédente pour la période 1961-1997 et en même temps d'établir, en fonction des modèles bioclimatiques, les changements possibles sur la végétation potentielle de ce territoire. L'intensité de cette tendance a été déduite des pentes de lignes de régression par l´utilisation de la méthode des moindres carrés et la signification statistique a été aussi déterminée par le test non paramétrique Mann-Kendall. Le sens des tendances de précipitations au cours des quarante-quatre dernières années est le même que celui de la période 1961-1997. En conclusion, si ces tendances continuent dans le futur, les secteurs de climat tempéré pourraient augmenter dans cette région. En consé-quence, les forêts à feuilles caduques pourront accroître leur aire en remplaçant un certain nombre de forêts à feuilles semi-caduques et persistantes.

Spatial analysis of mean temperature trends in Spain over the period 1961–2006

“…This increase has been statistically significant in 100% of Spain. Our results are in accordance with what has been reported by several authors who have noted an increase between 0.1 and 0.4°C/decade for the whole of the country or smaller territories (Kutiel and Maheras, 1998;Piñol et al, 1998;Parry, 2000;Brunet et al, 2001a,b;Klein Tank et al, 2002;Pausas, 2004;Sigró, 2004;Brunet et al, 2005;del Río et al, 2005;Morales et al, 2005;Cruz and Lage, 2006;Brunet et al, 2007;Castro-Díez et al, 2007;Brunet et al, 2009;del Río et al, 2009;Ileana and Castro-Díez, 2010). Summer and spring have been the seasons with the greatest contribution to annual trends.…”

“…Map prediction confirmed that temperature has tended to significantly increase in 100% of the country over the period 1961-2006 0.34°C/decade on average. Rises of temperature in this season are in line with proposals of several authors: Kutiel and Maheras (1998), Brunet et al (2001aBrunet et al ( ,b, 2007, Sigró (2004), Morales et al (2005), del Río et al (2005Río et al ( , 2009), Cruz and Lage (2006), Salat andPascual (2006), Capilla (2008) and Ileana and Castro-Díez (2010). Nevertheless it has been noted that magnitudes reported in this paper are generally lower than proposed by some of these authors.…”

“…These areas have been mainly located in western parts of Spain. Positive tendencies in these months have been also found by Sigró (2004) for Catalonia, del Río et al (2005Río et al ( , 2009 (2001a, 2007) and Ileana and Castro-Díez (2010) for whole Spain. Our results are also in agreement with those mentioned for the Mediterranean Basin (Kutiel and Maheras, 1998;Brunet et al, 2001a;Sigró, 2004;Salat and Pascual, 2006;Capilla, 2008).…”

“…The highest magnitude of trends in the year (up to 0.7-0.8°C/decade) has been found in this month. Cruz and Lage (2006) and del Río et al (2009) have also pointed out increases of temperature in June. Two main areas with positive significant trends covering about 32% of Spain have been noted in July: one in southwestern parts of the country and another one in the Mediterranean fringe extending to inner areas.…”

“…Many studies have focused on Spanish temperature over the last fifteen years at national, regional or local level: Esteban-Parra et al (1995) in the northern Spanish Plateau; Brunet et al (2001a), Serra et al (2001), Sáenz et al (2001), Sigró (2004), Cruz and Lage (2006), Salat and Pascual (2006) and Martínez et al (2010) in the north of Spain; Morales et al (2005) and del Río et al (2005Río et al ( , 2007Río et al ( , 2009 in Castile and León; Piñol et al (1998), Kutiel and Maheras (1998), Pausas (2004), Miró et al (2006) andCapilla (2008) in eastern Spain; Galán et al (2001) in the southern Plateau; Esteban-Parra et al (1997), Castro-Díez et al (2007) and Ordoñez (2008) in Andalusia; Homar et al (2010) in the Balearic Islands or Oñate and Pou (1996); Parry (2000), Xoplaki et al (2003Xoplaki et al ( , 2006, Prieto et al (2004), Brunet et al (2001bBrunet et al ( , 2005Brunet et al ( , 2006Brunet et al ( , 2007Brunet et al ( , 2009), Ileana and Castro-Díez. (2010) and Camuffo et al (2010) for whole country.…”