Andean montane forests (AMF) are biodiversity hotspots that provide fundamental hydrological services as well as carbon storage and sequestration. In recent decades, southern Ecuador AMFs have been seriously threatened by increased logging and conversion to forest plantations with exotic species. In this context, our main objective was to evaluate the effects of AMF conversion to forest plantations on soil physicochemical properties in the buffer zone (Bz) of the Podocarpus National Park (PNP), in southern Ecuador. For this purpose, random samples were taken at a depth of 0–10 ​cm in four plots in each contrast zone and analyzed for bulk density, porosity, textural class, leaf litter depth, soil pH, as well as the contents of organic matter (SOM), soil organic carbon (SOC), total nitrogen, and available phosphorus and potassium.

The results indicate that the conversion of AMFs produces an increase in bulk density and a decrease in SOM, SOC, and total nitrogen contents, thus modifying soil properties, which could result in a decrease in water regulation capacity and produce an increased risk of soil erosion. This accelerates degradation processes, as well as threatens shortages of the drinking water supply.

This study can help decision-makers to implement soil management plans in the Bz of the PNP, based on the implementation of new regulations, where the conservation of AMF is promoted. In addition, it is recommended to apply environmental restoration strategies in the anthropized areas of the AMF, as well as in the areas with exotic eucalyptus and pine plantations.