The small-scale pattern of Cynodon dactylon in Mediterranean pastures

The abundance of Cynodon dactylon was recorded in 50 plots presenting different geomorphological conditions and along a transect of 16 500 2×2 cm contiguous quadrats within a small basin 330 m in length, in the granite pediment of the Sierra de Guadarrama (Central Spain). Soil analyses were undertaken on samples from the 50 plots and the soil information matrix obtained was analysed using Principal Components Analysis and Discriminant Analysis. Results showed that in the Mediterranean pastures Cynodon dactylon was restricted to deep, well developed soils with relatively high values of cations, conductivity and organic matter, and could be used as an indicator of such soil conditions in these grasslands. The spatial pattern of the species was analysed using New Local Variances which revealed the existence of a small-scale pattern, ranging from 8 to 18 cm, present at all levels of the analysis. The size of small-scale patterns was positively correlated with species abundance and was interpreted as a relation between plant vigour and favourable soil conditions.I would like to thank Professor González Bernáldez for his interest and encouragement.