Variabilidad de la capacidad de intercambio catiónico en los ecosistemas de la zona noroccidental del parque nacional Llanganates

Abstract

The aim of this research was to evaluate the variability of the cation exchange capacity (CEC) in the ecosystems located in the northwest area of the Llanganates National Park (PNL), applying a non-probabilistic convenience sampling, 19 and 23 sampling points in Panzarumi and Sunfopamba were respectively considered, where 1-kilogram soil samples were collected at 30 and 60 centimeters in depth, then the ammonium acetate method was applied, and the sodium exchangeable cations (Na+),potassium (K+), calcium (Ca++), and magnesium (Mg+) and magnesium (Mn+) were extracted, the procedure consisted on collecting 5 g of dry and sieved sample, which was mixed with 25 mL of IM ammonium acetate, this mixture was vigorously shaken, Then the filtered solution was stabilized during 24 hours for its vacuum filtration. The filtered solution was volumetrically diluted to 100 mL by using ultrapure water, this allowed obtaining a sample which was ready for its analysis in the atomic absorption spectrophotometer. On the other hand, the aluminum concentration (AI++) was determined with the use of Palintest rapid test method, while the hydronium ions (H+) were obtained from the pH. The results obtained showed that the CEC reached concentrations up to 47 meq/100 g of soil in the Panzarumi paramo grassland ecosystem, this result reflected a very high availability of aluminum according to the Food and Agriculture Organization of the United Nations (FAO), while in Sunfopamba, the same ecosystem, revealed a maximum of 16 meq/100 g of soil. Thus, it was concluded that the conservation status in Panzarumi is higher than the one in Sunfopamba due to the remarkable variation of the CEC, so it is recommended to implement the study throughout the protected area, during the dry and rainy seasons to determine its influence on other ecosystems as well as the soil quality.