International Journal of Geobotanical Research (Abbreviation: Int. J. Geobot. Res.) is a scientific journal published by the Asociación Española de Fitosociología (AEFA). It is published two issues a year (at least). It is open to papers on Bioclimatology, biogeography, phytosociology, plant biology, plant conservation, plant taxonomy, vegetation and cli- matic change and any other plant research projects related to geobotany. Chief editor Ángel Penas Merino Department of Biodiversity & Environmental Management (Botany) Faculty of Biology & Environment Science University of León. León. Spain Email: [email protected] Co-editors Salvador Rivas-Martínez Carlo Blasi Phytosociological Research Center. Department of Plant Biology Los Negrales (Collado-Villalba). Madrid, Spain University of Roma "La Sapienza". Roma. Italy Ulrich Deil Pavel V. Krestov Biologisches Institut II / Geobotanik. Freiburgi. Br. / Germany Institute of Biology & Soil Science. Vladivostok / Russia Andraž Carni Stephen S. Talbot Scientific Research Center. Slovenian Academy of Sciences and Arts US Fish and Wildlife Service. Anchorage. USA Ljubljana. Slovenia Tomás Emilio Díaz González Javier Loidi Arregui Department of Biology of Organisms & Systems Department of Plant Biology and Ecology University of Oviedo. Oviedo. Spain University of the Basque Country. Bilbao. Spain José Carlos Augusta da Costa José Alejandro Velázquez Montes Instituto Superior de Agronomía. Lisboa. Portugal Geografía Ambiental. UNAM. Mexico D.F. Mexico Francisco Alcaraz Ariza Frédéric Bioret Department of Plant Biology. University of Murcia. Murcia / Spain Université de Bretagne occidentale. Brest. France Luis Herrero Cembranos Department of Biodiversity & Environmental Management (Botany) University of León. León. León.. Spain International Editorial Board Ramón Álvarez Esteban Javier Amigo Vázquez Department of Economy & Statistic. University of León. León..Spain University of Santiago de Compostela.Santiago de Compostela. Spain Michael G. Barbour Edoardo Biondi Department of Plant Sciences. University of California. Davis.USA Universitá Politécnica delle Marche. Ancona. Italy Paloma Cantó Ramos Bruno de Foucault University Complutense of Madrid. Spain Département de Botanique.Université de Lille. France Sara del Río González Blanca Díaz Garretas. University of León. León. Spain University of Málaga. Málaga. Spain Nikolai Ermakov Mario Fernandes Lousã Central Siberian Botanical Garden. Russia Instituto Superior de Agronomía. Portugal Leopoldo García Sancho Jean Marie Géhu University Complutense of Madrid. Spain Inter-Phyto. Nouvion. La Somme. France Carlos Francisco Gonçalves Aguiar Jorge Henrique Capelo Instituto Politécnico de Bragança. Bragança. Portugal National Institute of Biological Resources I.P. Oeiras.Portugal Jesús Izco Sevillano Pedro Luis Pérez de Paz Department of Botany. University of Santiago de Compostela. Spain Department of Plant Biology. University of La Laguna. Spain Paolo Mandrioli Ladislav Mucina Istituto di Scienze dell’Atmosfera e del Clima (CNR-ISAC). Bolonia. Department Enviromental & Aquatic Sciences. Curtin University of Tech- Italy nology. Perth. Australia Gonzalo Navarro Sánchez Yukito Nakamura Universidad Católica San Pablo de Bolivia. Cochabamba. Bolivia Department of Forest Science. Tokyo University of Agriculture. Japan Franco Pedrotti Jean Jacques Lazare Dipartimento de Scienze Ambientali. Universitá degli Studi di Came- Centre d’Etude et de Conservartion des Resources Végétales. Bayonne. rino. Camerino. Italy France Carlos José Pinto Gomes Richard Pott Department of Ecology. University of Evora. Portugal Institut für Geobotanik.Leibniz Universität Hannover. Germany Jesús Orlando Rangel Churio Martha Raynolds Instituto de Ciencias Naturales. Universidad Nacional de Colombia. Alaska Geobotany Center. Institute of Arctic Biology.University of Alaska. Bogotá. Colombia USA Daniel Sánchez Mata University Complutense of Madrid. Spain Technical Editors (Mapping) Ignacio Prieto Sarro Miguel Álvarez García Department of Geography. University of León. León. Spain Department of Geography. University of León. León. Spain ______________________________________________________________________________________________________________________ ISSN: 2253-6302 (print)/ISSN: 2253-6515 (on line). © EDITAEFA. Asociación Española de Fitosociología. Depósito Legal: LE-280-2011. Published 1 December 2013. Printed by Gráficas CELARAYN S.A. International Journal of Geobotanical Research VOLUME 3 NUMBER 1 DECEMBER 2013 CONTENTS Comparative analysis of precipitation trends in continental Spain over the period 1961-2010 ...................... 1-18 D. Ríos-Cornejo, Á. Penas & S. del Río Bioclimatic belts of Sierra Madre Occidental (Mexico): A preliminary approach .................................... 19-35 J. Giménez de Azcárate, M.A. Macías Rodríguez & F. Gopar Merino The salic pine forest of Tenerife: Morello fayae-Pinetum canariensis ..................................................... 37- 45 M.J. del Arco Aguilar, O. Rodríguez Delgado & P.L. Pérez de Paz A new contribution to syntaxonomy of sclerophyllous forests and pre-forests of Central Chile: Lithraeion causticae alliance.................................................................................................................. 47-67 J. Amigo & L. Flores-Toro International Journal of Geobotanical Research, Vol. nº 3. 2013. pp. 1-18 Comparative analysis of precipitation trends in continental spain over the period 1961-2010 David RIOS CORNEJO (1), Angel PENAS MERINO(2) & Sara del RÍO GONZÁLEZ (2) (1) Department of Biodiversity and Environmental Management (Area of Botany), Faculty of Biological and Environmental Scien- ces, University of León (Spain), Campus of Vegazana, s/n., E-24071 León. (2) Department of Biodiversity and Environmental Management (Area of Botany). Mountain Livestock Farming Institute (Join Cen- ter CSIC-ULE), Faculty of Biological and Environmental Sciences, University of León (Spain), Campus of Vegazana, s/n., E-24071 León. Abstract This work calculates and analyses monthly, seasonal and annual precipitation trends over continental Spain between 1961 and 2010, according to data from 144 weather stations widely distributed throughout the study area. The magnitude and sign of the trends were evaluated with Sen’s slope estimator and their statistical significances were determined with the non-parametric Mann-Kendall test. In general terms, the rainfall trends for the period and the study area are mainly non non-significant at the monthly, seasonal and annual timescales. By and large, we noted the highest number of weather stations with positive significant trends in September and October, whereas the highest number of stations with negative significant trends was observed in February, June, winter, summer and at the annual time- scale. The most pronounced decreases occurred in June (–18.58 mm/50years) and in summer (-27.67 mm/50years) in the south, which points to an intensification of mediterraneity in this area. We observed a sign asymmetry in significant rainfall trends during winter, spring and at the annual timescales between the north (negative) and the southeast (positive). Keywords: Climate change, rainfall trends, Spain, Mann-Kendall test, Sen’s slope Introduction most closely studied parameters due to its ability to quantify and indicate climate stability or change. In recent decades the scientific community has be- The main aim of this research is to conduct a time- come increasingly concerned about climate change and space analysis of the magnitude and statistical signifi- its possible consequences, and as a result, a large number cance of the rainfall trends observed in Spain over the of work have appeared on this issue: ATEAM (2004), last five decades (1961-2010) at the monthly, seasonal IPCC (2007), van der Linden & Mitchell (2009), García- and annual timescale. Ruiz et al. (2011), Kirilenko & Stepchenkova (2012), The spatial analysis of climate trends is crucial, since Pinault (2012), Wu et al. (2012), among others. climate variations can vary in a positive way over some Several authors have conducted studies into precipi- areas and in a negative way in others (Gallego et al. tation trends at the global, national, regional and local 2011, Ríos-Cornejo et al. 2012). level as part of the research into climate change: Brunetti et al. (2000), Busuioc et al. (2001), ATEAM (2004), Study area Chaouche et al. (2010), Tabari & Talaee (2011), Hen- riksson et al. (2012). The study area is continental Spain, comprising a There are also a substantial number of works on pre- land area of 491,258 square kilometers. Its geographic cipitation variations in Spain specifically, or in some of location is between latitudes 7° 41’ 18’’ in the north, and its regions: del Río et al. (2005, 2011), González-Hidalgo 35° 59’ 50’’ in the south, and longitudes 3° 19’ 5’’ in the et al. (2009), Altava-Ortiz et al. (2011), Gallego et al. east to 9° 18’ 19’’ in the west. (2011), Ruiz et al. (2011), Ruiz-Leo et al. (2013). The territory of Spain is characterized by major geo- Precipitation varies widely in Spain (Serrano et al. graphic contrasts. Its altitude ranges from 3,479 m (Mul- 1999b, Martínez et al. 2010, Camuffo et al. 2013), with hacén Peak, Betic System) and sea level, sometimes with very frequent seesaws of wet and dry phases: Gallego et abrupt differences in height. The average altitude is al. (2011) for the Iberian Peninsula; Rodrigo et al. (2000) about 660 m (Albentosa 1989). Spain has the second-