Aerial images of the high summits of the Spanish Central Range reveal significant changes in vegetation over the period 1957 to 1991. These changes include the replacement of high-mountain grassland communities dominated by Festuca aragonensis, typical of the Cryoro-Mediterranean belt, by shrub patches of Juniperus communis ssp. alpina and Cytisus oromediterraneus from lower altitudes (Oro-Mediterranean belt). Climatic data indicate a shift towards warmer conditions in this mountainous region since the 1940s, with the shift being particularly marked from 1960. Changes include significantly higher minimum and maximum temperatures, fewer days with snow cover and a redistribution of monthly rainfall. Total yearly precipitation showed no significant variation. There were no marked changes in land use during the time frame considered, although there were minor changes in grazing species in the 19th century. It is hypothesized that the advance of woody species into higher altitudes is probably related to climate change, which could have acted in conjunction with discrete variations in landscape management. The pronounced changes observed in the plant communities of the area reflect the susceptibility of high-mountain Mediterranean species to environmental change.

Aim  Biological invasions are a major component of global change with increasing effects on natural ecosystems and human societies. Here, we aim to assess the relationship between plant invader species attributes and the extent of their distribution range size, at the same time that we assess the association between environmental factors and plant invader species richness. Location  Spain, Mediterranean region. Methods  From the species perspective, we calculated the distribution range size of the 106 vascular plant invaders listed in a recently published atlas of alien plant species in Spain. Range size was used as an estimation of the degree of invasion success of the species. To model variation in range size between species as a function of a set of species attributes, we adopted the framework of the generalized linear mixed models because they allow the incorporation of taxonomic categories as nested random factors to control for phylogenetic relationships. From the invaded site perspective, we determined invader plant species richness as the number of species for each 10 × 10 km Universal Transverse Mercator (UTM) grid. For each grid cell, we estimated variables concerning landscape, topography, climate and human settlement. Then, we performed a generalized linear mixed model incorporating a defined spatial correlation structure to assess the relationship between plant invader richness and the environmental predictors. Results  From the species perspective, wind dispersal and minimum residence time appeared to favour invasion success. From the invaded site perspective, we identified high anthropogenic disturbance, low altitude, short distance to the coastline and dry, hot weather as the main correlates to UTM grid cell invader richness. Main conclusions  According to these results, an increasing importance of man‐modified ecosystems and global warming in the Mediterranean region should facilitate the expansion of plant invaders, especially wind‐dispersed species, leading to the accumulation of invasive species in some sites (i.e. invasion hot spots).

The alien plant species and the ecological factors that facilitate their invasion to a coastal strip in the Baix Camp region (Tarragona, NE Spain) were studied. A detailed inventory of the area showed that 20% of the plant species, most of them from the American Continent, were aliens, many of which were strongly invasive.At the habitat level, the relationships between the invasive behaviour and a number of autecological, ecological and habitat variables were analysed by means of logistic analyses. In the best model five variables were related to alien plant invasions: climatic affinity, disturbance of the invaded habitat, route of introduction, soil moisture during summer, and life form. To elucidate the environmental factors that could be responsible for alien plant invasions at a regional scale, the number of alien taxa and the environmental features at 13 localities of the western Mediterranean area were analysed. The warm lowlands, subjected to low annual rainfall and high population density, exhibited the greatest reception capacity for alien plants.It is concluded that various specific environmental features -high mean temperatures, the abundance of riparian systems, the existence of biotopes with favourable water balance which harbour a great richness of alien species and the high human pressure to which the enclave is subjected, combined with the ecological requirements of the alien species and certain species attributes (biotype) can interact at different scales and have caused the over-representation of alien plants.

showed that achenes produced in the cold climates of North America normally contain 70% or more linoleic Knowledge of the effects of temperature and geographic variables acid in oil while those produced in more southern lation the oleic acid content of sunflower (Helianthus annuus L.) oil allows us to predict the type of oil that will be produced in a particular tudes show levels as low as 30%.area. This study was designed to establish a simple empirical model,The genetic modification of sunflower oil fatty acids which uses available variables of previously established effects, to eshas also been a subject of research. Soldatov (1976) obtimate the final oleic acid composition of sunflower oil. Over two growtained a stable sunflower mutant by dimethyl sulfateing seasons, sunflower seeds were collected from Spain's main producinduced mutagenesis that gave rise to oil levels exceeding areas, and the oleic acid concentration of oil extracted from these ing 80% oleic acid. This high-oleic mutant showed no samples was analytically determined. The effects of two types of varisubstantial variation in fatty acid composition in reables (geographical position and temperature) on oil oleic acid content sponse to changes in environmental conditions (Fick, were determined according to three models based on the input vari-1984). ables: latitude, longitude, and altitude (Model I); mean minimum and Sunflower cultivars differ in the sensitivity of their maximum temperatures during the phenological stages of sunflower seed development and maturation (Model II); and a combination of oil properties to the environment. This sensitivity has both types of data (Model III). Through stepwise regression, it was es-been exploited both from a theoretical perspective, such tablished that best results were obtained using the temperature model as by enzyme inactivation induced by temperature changes (Model II) and the variables' mean minimum development and mean under natural conditions, as well as from an applied minimum and maximum maturation temperatures (r 2 ϭ 0.99, P Ͻ standpoint because it is possible to produce oil of differ-0.001, n ϭ 88). Of the three variables included in this model, the ent characteristics at different latitudes. mean minimum maturation temperature provided the closest estimate Robertson et al. (1978) showed that fatty acid compoof percentage oleic acid content. This regression model was statistically sition was highly correlated with latitude. Although they validated and is proposed as a method for crop managers to estimate found that saturated fatty acids showed scarce variation oleic acid content based on local temperatures. associated with the environment, oleic acid ranged from 14 to 50% between north and south while linoleic acid levels changed from 41 to 75% in the reverse direction.329

Abstract. The alien plant species and the ecological factors that facilitate their invasion to a coastal strip in the Baix Camp region (Tarragona, NE Spain) were studied. A detailed inventory of the area showed that 20% of the plant species, most of them from the American Continent, were aliens, many of which were strongly invasive. At the habitat level, the relationships between the invasive behaviour and a number of autecological, ecological and habitat variables were analysed by means of logistic analyses. In the best model five variables were related to alien plant invasions: climatic affinity, disturbance of the invaded habitat, route of introduction, soil moisture during summer, and life form. To elucidate the environmental factors that could be responsible for alien plant invasions at a regional scale, the number of alien taxa and the environmental features at 13 localities of the western Mediterranean area were analysed. The warm lowlands, subjected to low annual rainfall and high population density, exhibited the greatest reception capacity for alien plants. It is concluded that various specific environmental features – high mean temperatures, the abundance of riparian systems, the existence of biotopes with favourable water balance which harbour a great richness of alien species and the high human pressure to which the enclave is subjected, combined with the ecological requirements of the alien species and certain species attributes (biotype) can interact at different scales and have caused the over‐representation of alien plants.