Article

Over the past two millennia the Mediterranean region has been the recipient of many waves of plant introductions, some of which have produced major effects on the landscapes and lives of the peoples who inhabit its shores. The impacts of the introductions made by the Romans and the Moors are compared with those of the ‘Columbian exchange’ which led to a systematic and massive transfer and diffusion of plants, animals and diseases between the old and new worlds. The effects of the various introductions on both agricultural and urban landscapes are discussed as are the impacts on human diet and nutrition which had important demographic consequences and both deleterious effects on human health as well as providing plant-based medicines to cure some diseases such as malaria. Some of these effects are still being played out today. The social and economic consequences, although initially, scarcely perceptible, were quite profound in the subsequent centuries after the initial introductions. The landscapes and the economy of the region have also been affected in more recent times by changes in the way that the introduced crops are cultivated, such as intensification including irrigation and cultivation of fruit, salad crops and flowers in greenhouses or under plastic, crop substitutions such as sunflower (Helianthus) for olive, increased reforestation and plantation forests, often with exotic species such as Eucalyptus. Urban landscapes have been transformed as a consequence of the widespread introduction of ornamental subtropical species that are now almost their defining features. Finally, invasive alien species are an increasing threat to landscapes in several Mediterranean countries and likely to become more widespread in the face of climate change.