Bromus tectorum invasion in South America: Patagonia under threat?

SPEZIALE K.L.; LAMBERTUCCI S.A.; EZCURRA C.

WEED RESEARCH

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2014 vol. 54 p. 70 - 77

0043-1737

Bromus tectorum (cheatgrass) is an aggressive invasivespecies posing threats to native ecosystems includingincrease in fire frequency, alteration of water andnutrient cycles and exclusion of native species. Assuch, it is important to monitor this species worldwide.However, outside the United States, it has been poorlystudied. We studied this species at two scales: (i) at alocal scale, evaluating the species presence and itsdeterminants, along the ecotonal area between thesteppe and the forest within north-western Patagonia,to reveal whether B. tectorum is actually invading naturalecosystems in areas comparable with thoseinvaded in USA, and (ii) at a regional scale, through asearch of literature and herbaria databases on B. tectorumin South America, to determine the current knowndistribution of the species in this subcontinent. Resultsindicate that it is already invading north-western Patagoniain Argentina, mainly in the semi-arid part of theregion, and that precipitation influences the invasionprocess. We found that for South America, B. tectorumhas been only documented in southern Argentinaand Chile. Given the similarities to other invadedregions, the possibility of invasion for Patagonia hasbeen predicted but not prevented. It is important tostudy changes in the invasion level where it is alreadyestablished, and to encourage managers with preventionand control strategies. Combining this informationwith lessons from places with extensive periods ofinvasion could help to initiate management of the speciesin areas where the invasion process is beginningand before the species spreads widely.