Aim: Most studies on invasibility consider the characteristics of the habitats colonized. However, the success of the establishment of exotic species can be conditioned by the characteristics of the donor communities. In this study, we analyse the extent to which the distribution of exotic herbaceous species in Chile is conditioned either by the climatic characteristics of the recipient area or by the environmental features of the source areas on the Iberian Peninsula.Location: Chile and the Iberian Peninsula (Portugal and Spain).Methods: For Chile, we characterized the exotic species according to their current Chilean distribution and their region of origin. For the Iberian Peninsula, we compiled the floristic composition of 11,702 relevés. We classified each relevé according to key habitat characteristics (bioclimate, soil nutrient status and type of community associated with human activities) and calculated the percentage of species in common with Chile in different climatic regions therein.Results: Over half of Chile's exotic species exhibited a geographic distribution related to the climate of the recipient area. The main donor communities were those associated with ruderal and arable land habitats, although their importance depended upon the climate in the recipient area. Correspondence was observed between the climatic characteristics of the communities in the source area and those of the recipient areas.Main conclusions: The results highlight the influence of the characteristics of habitats in the source area on the successful establishment of exotic species in Chile. The relationships between source and recipient area are scale dependent, climate constituting the main driver at broad scale. Within each climatic region, the communities associated with habitats presenting greater anthropic influence act as the main donors. Both features indicate the existence of filters that select species pre‐adapted to the climatic and habitat conditions in the recipient area.

Below-ground biomass might play an important role in the persistence of grasslands. The summertime water stress of Mediterranean grasslands very much accounts for annual plants in their communities. These plants die off in summer, and the soil seed bank ensures the grasslands' recovery every autumn. Temperature decreases with altitude, together with the proportion of annual and perennial herbs. This paper explores the vertical profile of this biomass in grasslands on the Iberian Peninsula along an altitudinal gradient and two geomorphological positions in each site. Both factors were considered to determine the development of below-ground biomass. We also took into consideration the experimental exclusion of livestock, considering that the presence or absence of herbivores may influence the aerial and underground structure of the grasslands. Using an allometric approach, we examined the relative distribution of below-ground biomass with depth and its temporal variation (“construction”). We found that there is a general allometric pattern in the vertical profile of variation of below-ground biomass in which density is inversely proportional to the depth of the stratum raised to the power of 1.8 (at high elevations) and 2.5 (low elevations). The construction process of these grasslands exhibits slight variations within a common pattern. Growth of the plant canopy can be temporally limited by the action of herbivores, a more complex underground structure thereby developing, with more strata and a more even biomass distribution. An adaptive reaction to the notable Mediterranean seasonal change appears to occur but, surprisingly, may depend upon altitude rather than upon the influence of herbivory.