Squeo, F. A., N. Olivares, S. Olivares, A. Pollastri, E. Aguirre, R. Aravena, C. Jorquera and J.R. Ehleringer. 1999. Grupos funcionales arbustos deserticos del norte de Chile, definidos sobre la base de las fuentes de agua utilizadas. Gayana Bot. 56(1):1-15.

Primary productivity and vegetation structure in arid ecosystems are determined by water availability. In studies conducted in the coastal dryland of north-central Chile (29°43'S; 71°14'O, 300 m), the mechanisms to use different water sources by shrub species, in two contrasting rainfall years were compared. Information on phenological studies, root architecture and water sources used by shrubs through the use of stable isotopes are discussed. Six functional groups based on water uptake and water use are recognized. The functional groups were defined based on their habits (deciduous and evergreen), their root systems (shallow, dimorphic and deep), and their ability to use different water sources (surficial and/or deep). Because of the differential impact of the goat overgrazing on different funtional groups, this would result on a lower utilization of surficial waters. A management and/or restoration plan should maximize the use of all water sources available to recover the primary productivity and the system stability.