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Drought occurs naturally all over the world. Global warming has led an increase in the areas affected by this phenomenon. The study of drought involves the analysis of indicators and indices used to assess changes in the hydrological cycle of a region. A large number of indices developed for drought monitoring are based on meteorological and hydrological variables. This research has applied the Ombroxeric Index for the first time in California. It is based on the concept of ombroxericity: a condition of the territory characterised from an ombrothermic point of view, which can develop in relatively humid areas/zones, depending on the time scale of the study (i.e. monthly, seasonal or annual basis). Temperatures and precipitation from 180 meteorological stations have been considered for a period of observation from 1980 to 2016. In order to know the evolution of this index, a modified trend analysis based on the Mann-Kendall test and a modified Sen slope analysis were used. Empirical Bayesian Kriging was applied as an interpolation technique. Results are presented in both surface and contour maps. California showed a wide range of ombroxeric levels that went from upper strong dry in northern zones, to lower weak arid. Trend results showed an increase in bioclimatic drought throughout the whole State. In addition, summer showed the highest levels on the Ombroxeric Index. An increase in drought trends was observed at the seasonal level, being more pronounced in summer and spring. In both cases are increases in the central (+5 and +3.6 units year−1 respectively) and the southern (+4 and +4.5 units year−1 respectively) areas of the State. Increasing frequency and severity of droughts could have implications for the management of water resources and the survival of Californian vegetation types, such as conifers.

Rising temperatures and changes in precipitation patterns under climate change scenarios are accelerating the depletion of soil moisture and increasing the risk of drought, disrupting the conditions that many plant species need to survive. This study aims to establish the bioclimatic characterisation, both qualitative and quantitative, of ten native Californian Pinales for the period 1980-2019, and to determine their habitat suitability by 2050. To achieve this, an exhaustive search of the Gbif database for records of ten conifer taxa was carried out. To conduct the bioclimatic characterisation of the studied taxa, we worked with the monthly values of average temperature and precipitation for the period 1980-2019 from 177 meteorological stations. Linear regressions was performed in order to compile the future evolution of California's climate. Suitable areas and optimal areas were defined at the present time (1980-2019) and its future projection (2050). We applied Boolean logic and, in this investigation, the Conditional Logic Operator (CON) was used to determine the possible species presence (one) or absence (zero) for each of the 15 variables analysed. In general, most of the conifers studied here will experience a reduction in their habitat range in California by the year 2050 due to climate change, as well as the displacement of species towards optimal areas. Furthermore, the results have highlighted the applicability of bioclimatology to future conditions under climate change. This will aid conservation managers in implementing strategic measures to ameliorate the detrimental impacts of climate change, thereby ensuring the ecological integrity and sustainability of the affected conifer species.

A phytosociological analysis of the Iberian Quercus faginea forests was carried out. For this purpose, 291 relevés were studied. A multivariate analysis consisting of a numerical classification based on the floristic composition of the relevés, was performed. The coherence and explanatory value of the current syntaxa are reviewed. As a result, the diversity of Iberian gall oak forests is resolved into 15 associations characterised according to their floristic, biogeographical, bioclimatic and synecological data supported by the statistical analyses. Thirteen have been described previously, and two new associations are proposed: Glandoro diffusae-Quercetum fagineae and Helianthemo mollis-Quercetum fagineae. A new combination, a lectotypification and a nomenclatural correction are also proposed. The Ios2 (ombrothermic index of the warmest bimonth of the summer quarter), Itc (compensated thermicity index) and Ic (continentality index) indexes proved to be fundamental to explain the syntaxonomic differentiation of the forests in the study. We consider that the differentiation and precision in the definition of clear syntaxonomic entities is vital to prioritize objectives in the conservation of these singular forests, and to ensure their adequate management in the context of the Habitats Directive.

The ombroxeric index (OXI), a drought-indicative bioclimatic index based on the Rivas-MartínezWorldwide Bioclimatic Classification System (WBCS), was used in this work to establish theombroxericity trends in a defined study area: the province of Leon (Spain). On the basis oflarge time-scale climatological gridded databases (MOPREDAS and MOTEDAS), with datafrom 1951 to 2010 at monthly, seasonal an annual study level, a Mann-Kendall test-basedtrend analysis was carried out and a geostatistical interpolation procedure, EmpiricalBayesian Kriging (EBK), was applied. Statistically significant increases were revealed in themonths of March and June, as well as in the summer period. These increments are greaterin the southernmost areas and could be related with changes in some teleconnectionpatterns. With this up-to-date approach, besides being aware of the direct bioclimate-altering consequences of the climate change, the prediction of the implications in thevegetation is made possible, due to the typological-predictive character of the model ofclimate-vegetation reciprocity provided by the WBCS.

The microscopic morphology of the leaves of six varieties of Vitis vinifera taken in the León Denomination of Origin is studied: the varieties Albarín Blanco, Malvasía, Mencía, Prieto Picudo, Tempranillo and Verdejo Blanco. The morphology is studied in two leaf fragments (basal and distal) related to the midvein, and parameters such as the thickness of the mesophyll and the stomatal density are measured. There are no works on the microscopic characteristics of the Prieto Picudo variety. All the varieties have the structural characteristics typical of V. vinifera varieties used for commercial purposes. The leaf blades are dorsiventral and hypostomatic with anomocytic stomata. There are two types of trichomes in the abaxial epidermis: some prostrate with a woolly appearance and others upright on which the previous trichomes rest. There are no significant differences between the values for the basal and distal samples of the leaf blade. The Prieto Picudo variety has the thinnest leaf blade and with the lowest stomatal density. It is assumed that the thicker the spongy parennchyma – which implies more intercellular spaces – and the higher the stomatal density, the greater the vulnerability of these varieties to infection by Plasmopara viticola. There are no scientific studies on this subject in the DO León, and very few with the Prieto Picudo variety. One of these studies reports the Prieto Picudo variety as being highly susceptible to the fungus, in which case the starting hypothesis could be rejected and the opposite hypothesis proposed: the thinner the spongy parenchyma and the lower the stomatal density (which are the peculiarities of the Prieto Picudo variety), the greater the vulnerability to P. viticola. However, there are inconsistencies in the works on mildew in the bibliography, possibly because not all the possible variables involved on vulnerability to the fungus are considered.

The aim of this research is to enlarge knowledge of space-time evolution of precipitation in California over the last decade on a monthly, seasonal and annual time-scale. This study also analyses the relationship between precipitation and teleconnection patterns with most influence on Californian climate. The homogeneity of the data from the selected stations was verified and finally 165 meteorological stations were used with an obser- vation period that ranged from 1980 to 2019. In order to evaluate trends and statistical significance, both the non-parametric Mann-Kendall test and modified Sen’s slope method were used. Correlation analysis using the partial non-parametric Spearman Test (95% confidence level) was performed to find out relationships between precipitation and nine teleconnection patterns in the State of California. Spatial analysis was achieved using Empirical Bayesian Kriging (EBK). Finally, this research, as a novelty, shows regionalisation of California State as a function of significance in the correlation of precipitation with teleconnection patterns. To achieve this, Principal Component Analysis (PCA) and Agglomerative Hierarchical Cluster analysis (HCA) was performed. Results show a positive precipitation trend in winter and negative precipitation trend in late summer and autumn. The teleconnection patterns more correlated with precipitation are El Ni ̃no along Southern Oscillation (ENSO), Antarctic Oscillation (AAO) and North Atlantic Oscillation (NAO). Four areas were discerned outlining the Mojave Climate Region (Area 4) by having ENSO as the teleconnection pattern that best account precipitation.

In 2018, Spain was the third largest producer and the leading exporter of wine in the world. Viticulture is an important economic activity in the Castilla y León region, and is an element capable of halting the flight from the countryside and favouring demographic settlement in rural areas. A new integrated methodology for characterizing and delimitating areas suitable for vineyard cultivation is proposed here. The approach combines traditional climate indices with others used in bioclimatology and with soil variables, and applies various statistical analyses to select the predictors that best characterize the vineyards. These predictors are then integrated in species distribution models and a geographic information system. The methodology was tested in the Denomination of Origin León (hereafter DO León) in northwest Spain. Ten single models using the maximum entropy modelling algorithm were run for each of the six wine-grape varieties. Single-model projections built as a consensus of the ten models into an ensemble-forecasting approach were later used to generate maps of suitable areas for each variety. The results confirm the delimitation of the DO León as a Denomination of Origin. The bioclimatic variables Compensated Thermicity Index and Continentality Index and the soil variables pH, Clay Content, Soil Retention Capacity and Soil Saturation Humidity are defining for all the varieties studied. Garnacha and Mencía were the most different varieties in relation to their bioclimatic and soil requirements. Suitability maps revealed that the DO could be extended into neighbouring areas up to 30 km around it. The proposed methodology is a useful tool for agronomic and oenological management; it allows a more effective selection of sites for new vineyards, improves vineyard management, and can even be used to protect territories with a historical and cultural heritage of grape cultivation, thus favouring demographic settlement in rural areas and avoiding depopulation.

Global change is expected to impact on the distribution and abundance of forests. Spain represents the south-western limit of distribution for several types of deciduous forests and, as part of the Mediterranean Basin, it has all the characteristics to be affected by climate change. This study analyses the effects of climate change on habitat suitability and vulnerability in four categories of deciduous forests: Fagus sylvatica L., Quercus petraea (Matt.) Leibl., Quercus robur L. and Betula celtiberica Rothm. and Vasc. The approach combines an ensemble platform for species distribution models (SDMs) using three algorithms applied to four global circulation models (GCMs) driven by two representative concentration pathways (RCPs). Bioclimatic, biogeographic, soil and topographic variables were taken into consideration as predictors to build 320 single distribution models. Ensemble-forecasting models were then produced for each forest category and RCPs by computing a consensus of single-model projections. The adapted proposal of the Intergovernmental Panel on Climate Change (IPCC) was also applied to deal with the uncertainty and notify the likelihood of the outcomes. The results revealed generalized losses in habitat suitability compared to current conditions for all the forest categories, which were more drastic for the RCP 8.5 emission pathway. Exceptions worth noting are forests of Fagus sylvatica (likelihood 25%-50%) and Quercus robur (likelihood 75%-100%) in the Orocantabrian biogeo-graphic subprovince, and Quercus petraea formations in the Cantabrian Atlantic subprovince (likelihood 25%- 50%). Betula celtiberica would suffer the largest losses of habitat suitability under the climate change scenarios analysed. The vulnerability analysis confirmed that the deciduous formations least affected by climate change in future will be the Orocantabrian forests, while the Pyrenean and Oroiberian communities are the most vulnerable. The models developed in this study provi

Se lleva a cabo un estudio floristico de los taxones existentes en la zona, de cada uno de los cuales se aporta la distribuccion a nivel provincial y se realizan comentarios de diversa indole. Ademas, de algunos grupos se realizan estudios taxonomicos siguiendo las tecnicas de la taxonomia numerica, asi como palinologicos, morfologicos al m.E.B., de fertilidad, etc. Se estudia la vegetacion desde los puntos de vista fitosociologico y sinfitosociologico y se lleva a cabo la division biogeografica del territorio. Se aportan tambien los siguientes mapas de cartografia tematica: topografico, geologico, edafologico, geomorfologico, ombroclimatico, de vegetacion actual y de series de vegetacion de la zona, todos ellos a escala 1:50.000, y el ombroclimatico de la provincia de palencia a escala 1:200.000, de los cuales los seis ultimos son originales. Tambien se realiza el estudio climatico y bioclimatico de la provincia de palencia mediante un programa informatico inedito y se incluyen las fichas de indices y diagramas.

Se analizan las comunidades de la clase Asplenietea trichomanis en la provincia de León, indicando de cada una de ellas sus peculiaridades florísticas, estructurales, corológicas y dinámicas.

Se aportan citas nuevas o interesantes para la provincia de León. Señalamos con un asterisco (*) los taxones que constituyen novedad provincial. Además, se mencionan otros para los que CASTROVIEJO & al. (eds.), Flora iberica, vol. VII (I)-VII (II). 1999-2000, no indican la sigla provincial, en cuyo caso hacemos referencia a las citas bibliográficas conocidas.

Se lleva a cabo un estudio floristico de los taxones existentes en la zona, de cada uno de los cuales se aporta la distribuccion a nivel provincial y se realizan comentarios de diversa indole. Ademas, de algunos grupos se realizan estudios taxonomicos siguiendo las tecnicas de la taxonomia numerica, asi como palinologicos, morfologicos al m.E.B., de fertilidad, etc. Se estudia la vegetacion desde los puntos de vista fitosociologico y sinfitosociologico y se lleva a cabo la division biogeografica del territorio. Se aportan tambien los siguientes mapas de cartografia tematica: topografico, geologico, edafologico, geomorfologico, ombroclimatico, de vegetacion actual y de series de vegetacion de la zona, todos ellos a escala 1:50.000, y el ombroclimatico de la provincia de palencia a escala 1:200.000, de los cuales los seis ultimos son originales. Tambien se realiza el estudio climatico y bioclimatico de la provincia de palencia mediante un programa informatico inedito y se incluyen las fichas de indices y diagramas.

Se analizan las comunidades de la clase Asplenietea trichomanis en la provincia de León, indicando de cada una de ellas sus peculiaridades florísticas, estructurales, corológicas y dinámicas.

Se aportan citas nuevas o interesantes para la provincia de León. Señalamos con un asterisco (*) los taxones que constituyen novedad provincial. Además, se mencionan otros para los que CASTROVIEJO & al. (eds.), Flora iberica, vol. VII (I)-VII (II). 1999-2000, no indican la sigla provincial, en cuyo caso hacemos referencia a las citas bibliográficas conocidas.

E.n el presente trabajo se estudian fitosociológicamente los matorrales de la clase Cytisetea scopario-striati en la provincia de León. Se propone la nueva subasociación Cytiso-scoparii-Genistetum polygaliphyllae lavanduletosum pedunculatae.

A taxonomic study of the genus Draba L. Sect. Aizopsis DC. in the lberian Peninsula is carried out based on numerical taxonomy techniques as well as on the analysis of sorne morphological features by meaos of S.E.M. Recognized are the following taxa: n dedeana Boiss. & Reuter subsp. dedeana, D. dedeana subsp. mawii (Hook. f.) Romo, D. zapaterii Wk., D. diazii spec. nov., D. lebrunii (P. Mont.) Laínz, D. hispanica Boiss. subsp. hispanica, D. hispanica subsp. /aderoi subsp. nov., D. aizoides L. subsp. aizoides, D. a izo id es subsp. estevei subsp. nov., n cantabriae (Laínz) Lainz subsp. cantabriae and D. cantabriae subsp. izcoi subsp. nov.

Se describen las características edáficas (textura, eolorimetría, pH, porcentaje de carbonatos, materia fina, materia orgánica, nitrógeno total y relación C/N) de las distintas asociaciones de cardales (Cirsio chodali Carduetum carpetani, Carduo nutantis-Cirsietum chodali, Onopordetum acantho-nervo

Se estudian las comunidades dominadas por grandes cardos anuales, incluibles en la clase Onopordetea acanthii, describiéndose una nueva asociación Carduo nutantis-Cirsietum chodati Rivas-Martínez & F. Prieto y analizándose las siguientes asociaciones: Cirsio chodati-Carduetum carpe¡ani, Ono,oordetum acanzho-nervosi, Carduo bourgeani-Silybetum mariani y Cardao carpetani- Onopordetum acanthii de las que se describen diversas subasociaciones.

Se contribuye al conocimiento de la flora palentina haciendo referencia a consideraciones corológicas y taxonómicas de interés, y se citan por primera vez para la provincia: Crepis albida subsp. albida, Diplotaxis erucoides, Iris xiphium, Lycium europaeum, Suaeda vera y Trifolium squamosum.

Se analizan fitosociológicamente las comunidades de malas hierbas de cultivo en la provincia de León, y se describen tres nuevas asociaciones: Holosteo umbellati-Veronicetum persicae ass. nova, Centaureo cyani-Raphanetum microcarpi ass. nova y Ceratocephalo falcatae-Androsacetum maximae ass. nova; asi como diversas subasociaciones, y se aportan datos corológicos y ecológicos de otras asociaciones ya descritas.

Fragmenta chorologica occidentalia

En el presente trabajo se analiza el comportamiento biageográfico yfitosociológico del endemismo altocarrionés Draba lebrunii (P. Monts.) Lafnz, y se concluye que caracteriza a las nuevas comuntdades: Drabo lebrunii-Armerietum cantabricae (Elyno-Seslerietea) y Festuca hystricis-Thymeíum mastigopliorí drabetosum lebrunii (Ononido-Rosmarinetea>, propias de los suelos calcáreos del Subsectar Altocarrionés (Sector Campurriano-Carrianés, Provincia Oracantábrica, Región Furosiberiana>, del piso subalpino la primera y del altimontano y subalpina la segunda

Sobre la presencia de "Erysimum cheiranthoides" L. subsp. "cheiranthoides" en la Península Ibérica

En el presente trabajo se aportan datos corológicos y ecológicos sobre algunas fanerógamas, que se citan por primera vez para la flora leonesa, tales como: Atriplex patula L., Lepidium latifolium L., Lotus tenuis Waldst. E Kit. ex Willd. var. tenuis, Hypericum androsaemum L., Thymus x sennenii Pau, Verbascum blattaria L., Carduus bourgeanus Boiss. E Reuter, Picnomon acarna (L.) Cass., Onopordum nervosum Boiss., Centaurea aspera L. De otras se indican nuevas localidades.

Se aporta un catálogo constituído por 29 taxones pertenecientes a 10 familias y encuadrados en 13 góneros. De cada taxon se señala su distribución provincial en base a las menciones bibliográficas constatadas, así como a los materiales depositados en el Herbario del Departamento de Biología Vegeta l. de la Facultad de Biología de la Universidad de León (LEB), presentando el mapa corológico provincial de cada uno en cuadriculas UTM de 10 Km de lado. LYCOPODIACEAE

En el presente trabajo ofrecemos una relación de plantas herborizadas en la provincia de León y algunas localidades próximas de Valladolid y Zamora, señalando con un asterisco (*) aquéllas que son novedad para la provincia en la que se citan. Otras constituyen menciones que amplían el areal significativamente y de ellas se aportan datos corológicos en base a citas conocidas de provincias colindantes, o se rescatan menciones antiguas. En el género Trifolium L. se lleva a cabo una revisión corológica general de los táxones presentes en la provincia de León en base al material existente en LEB. Todos los táxones mencionados se encuentran depositados en el Herbario LEBJaime Andrés Rodríguez, del Departamento de Biología Vegetal de la Universidad de León.

En el presente trabajo se establece la tipologia fitosociológica de la vegetación nitrófila de la provincia de León, desde el rango de clase hasta el de subasociación. Se incluyen las asociaciones reconocidas, hasta el momento, en estos territorios, tanto las publicadas de forma efectiva como las aún inéditas. Los rangos superiores (Clase, Orden y Suborden) se definen de un modo conciso y, tanto para ellos como para las alianzas y subalianzas, se señalan, además, los táxones caracteristicos y diferenciales que se encuentran en los territorios a 10s que se circunscribe el presente estudio. De cada asociación se menciona su distribución, utilizando las unidades biogeográficas establecidas, asi como el piso o subpiso bioclimatico en el que se desarrolla y las series de vegetación en las que se ubica, todo ello referido a la provincia de León. Se aportan dos cuadros sinópticos en 10s que SC relacionan las caractcristicas biogeográficas, bioclimáticas, fenológicas y seriales de todas las asociaciones existentes en el territorio.

Fagus sylvatica forests are considered to be of Community interest according to Directive 92/43/EEC. Climate change predictions for Spain point to a warming scenario, coupled with decreasing rainfall, which may have an impact on their future distribution particularly at the extremes of its distribution area. Species distribution models incorporating bioclimatic, topographic and phytogeographic variables were used as predictors to assess their habitat suitability under current conditions and a climate change projection. Ten single models were generated and an ensemble-forecasting model was subsequently built by computing a consensus of single-model projections. The results revealed that ombrothermic indices are the main factors controlling the distribution of Spanish beech forests. They are highly vulnerable to climate change and could suffer a decline in their habitat suitability if climate trends observed are maintained in the future. The least favoured areas for them will be located close to the limit between the Temperate and Mediterranean climates, where they could suffer a loss of habitat suitability. Conversely, suitable new areas could be found mainly in western areas of the Cantabrian Range and in the Central Pyrenees.