Nutrient input via gross rainfall, throughfall and stemflow in scrubland species in northeastern Mexico

Abstract

Introduction: Precipitation is an important factor in the input of nutrients to ecosystems. In some cases, rainfall can add elements that are not available due to area conditions. Objective: To compare the nutritional contribution in gross rainfall (Pi) and rainwater reaching the soil by throughfall (Pd) and stemflow (Ef) of scrubland species. Materials and methods: A total of 41 rainfall events were evaluated in northeastern Mexico in the period September 2016-September 2017. Precipitation volumes were recorded and their chemical composition were analyzed: pH, electrical conductivity and contribution of macronutrients (Ca, Mg and K) and micronutrients (Fe, Mn, Zn and Cu). Results and discussion: Pi accumulated 508.97 mm. Pd is the one that deposits more nutrients to the soil. The net contribution (Pd+Ef) indicated that Fe was the most deposited micronutrient with 2 938.29 g·ha-1·year - 1, of which Casimiroa greggii (S. Watson) F. Chiang contributed 31.59 %. The macronutrient with greater presence was Ca with 319.31 kg·ha-1·year - 1, being Acacia farnesiana (L.) Willd. the one that achieved greater flow of the mineral (22.66 %). pH and electrical conductivity were similar (Kruskal-Wallis, P > 0.05) in the three types of rainfall. Conclusion: The precipitation chemistry is modified after passing the canopy of each species, either to enrich or remove nutrient concentrations, playing an important role in the biogeochemical cycles of the ecosystem.