Relationship between spatial strategies and morphological attributes in a Uruguayan grassland:: a functional approach

In a native grassland in Uruguay subjected to continuous grazing by cattle, four permanent plots of 40 x 40 cm were established. Plots were divided into 16 x 16 cells and the presence of species was recorded seasonally during two years. The spatial dynamic of the dominant species was defined through three parameters: persistence, short-distance spread and long-distance spread. The association between the spatial strategies and certain morphological attributes that were presumed to be important to the spatial behaviour of the species, was examined using Correspondence Analysis. Four types of spatial strategies were observed: (1) persisting over the year in the same cell without showing any type of mobility; (2) continuously growing due to the solid advancing front of ramets, persisting or not persisting (3) in the same cells; and (4) multi-strategy with high persistence and both high short- and long-distance spread. Among the selected attributes, the erect/prostrate habit, the capacity of vegetative propagation by means of bulbs, rhizomes or stolons, the ratio length/width of leaves and the season of active growth were the characteristics most closely associated with the spatial strategies.