Analysis of gradients using Landolt indicator values in Valle Maira pastures (Piedmont, Italy)

Abstract

The paper describes how ecologic gradients can be evaluated using the Landolt indicator values. The goal of this analysis is to reach a better interpretion of the ecologic ranges of significative typologies of pasture in the Western Alps (Valle Maira, Piedmont): mosaic vegetation of the upper alpine belt, Festuca paniculata vegetation type, Nardus stricta – Trifolium alpinum – Carex sempervirens vegetation type. Vegetational patterns have been selected using an increasing degree of grazing disturbance, in order to test the reliability of the analysis. The paper presents diagrams of ecologic distribution accordingly to the gradients for each type of selected vegetation. Ecological partioning is intelligibly evident for vegetation patterns in which abiotic factors are predominant. Sample spaces tend to dissolve and overlap when vegetation is perturbed by grazing, though they are still well distributed along gradients. The approach provides good results and could be applied in future to larger zones in the Western Alps.