Invading plants at high altitudes on Tenerife especially in the Teide National Park

Eighty-three flowering plants are discussed as successful, failed or potential invaders of the Teide National Park, Tenerife, a caldera at 2000 m altitude and above with a largely endemic native flora. Two important methods of invasion are considered. Firstly, there was dispersal by pastoralism, goat-herding, an ancient practice which stopped over 30 years ago. Secondly, the development of mass tourism in the last 25 years has brought a fresh influx of alien plantS. Many of the 83 invaders discussed have had only transient occurrences, but 30 are well-established, 15 being grasses among which Bromus tectorum and Vulpia myuros are the most abundant. Chenopodium vulvaria and Poa pratensis are new to Tenerife and Dactylis glomerata subsp. hispanica is new to the Canary Islands. Control measures are outlined. Attempts have already been made to contain Avena barbata, hactuca serriola and Chenopodium species.