SOIL MINERALOGY AND ITS RELATIONSHIP WITH CACTI SPECIES IN SOUTHEASTERN CHIHUAHUA, MÉXICO

Abstract

The relationship between minerals of soil and cacti may be an indicator of the distribution of these plants. The aim of this study was to determine the mineralogical composition of soils and its relationship with cacti in southeastern Chihuahua. Soil sampling was conducted in 2009 at 34 sites, samples were then analyzed by X-ray diffraction. Data were analyzed with ANOVA and Student t test to determine the relation among types and percentage of minerals, soil types and cacti species. The laboratory analyses identified 15 minerals, quartz, calcite, albite and sanidine being the dominant and correlated with the presence of 32 cacti species, Opuntia engelmannii, O. imbricata and O. leptocaulis being the most frequent. There were more cacti on tuffs and limestone derived soils compared to basalts and granites derived soils. The Student’s t test provided evidence (p < 0.05) of the significant relationship between sanidine with O. leptocaulis and O. macrocentra. Bayer’s theorem indicated that calcite, quartz and sanidine were related to O. engelmannii (31.99 %), O. macrocentra (27.86 %) and O. leptocaulis (28.13 %), respectively. Summarizing, sanidine, calcite and quartz were the minerals related to cacti; cacti were more diverse on tuff, rhyolite and limestone derived soils and scarce in basalt, alluvial and conglomerate derived soils