MULTIVARIATE-ANALYSIS IN THE QUANTITATIVE-EVALUATION OF SOILS FOR REFORESTATION IN THE SIERRA-NEVADA (SOUTHERN SPAIN)

Soil characteristics that most strongly influence the outcome of the e valuation of soils for referestation were determined with multivariate analysis. R-mode factor analysis was used to relate results of the so il survey with those of the soil evaluation. We studied the area of th e Sierra Nevada mountains in southern Spain. Soil variables were measu red in 163 soil profiles, collected in a survey of the two soil enviro nments of the Sierra Nevada: the calcareous and silicic zones. Four fa ctor analyses showed that sand, clay, gravel and organic carbon conten t, and pH were the most useful soil characteristics in evaluating site keys that affect tree and shrub growth (nutrient availability, rootin g space and soil water availability). In the calcareous zone, hue, val ue and chroma color, and pH, were easily determined soil characteristi cs that established and classified the suitability of forest sites. In the silicic zone, hue, value and chroma, and altitude were the charac teristics found most useful in evaluating forest sites.