Environmental patterns and plant distribution along aprecipitation gradient in western Patagonia

BERTILLER, MÓNICA B.; ELISSALDE, NÉSTOR O.; ROSTAGNO, CÉSAR M.; DEFOSSÉ, GUILLERMO E.

JOURNAL OF ARID ENVIRONMENTS

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Manchester; Año: 1995 vol. 29 p. 85 - 97

0140-1963

Plant species distribution along a gradient of precipitation was analysed inwestern Patagonia. First, the affinity of 53 vegetation releves was tested byprincipal component analysis of the matrix of n x n binary correlations amongspecies cover values. Further, the relationship between plant cover (Festucapallescens, shrubs, and Stipa spp.) and the environmental factors (precipitation,soil texture, soil depth, altitude, landscape form, aspect, and disturbance) wasanalysed by stepwise regression analysis. Five homogeneous vegetation unitscould be identified at several different regions of the gradient. Soil characteristicsassociated to precipitation levels (i.e. texture, profile depth), but notprecipitation per se, were strongly related to the cover of F. pallescens and shrubspecies. A model of transitions in the composition of vegetation is introducedwhich includes soil variables, site conditions and the spatial distribution ofgrazing herds.