Modeling the Role of Novel Ecosystems in Runoff and Soil Protection: Native and Non-native Subtropical Montane Forests

In recent decades, anthropogenic activities have led to the emergence of novel ecosystems. These are often dominated by non-native species, altering forest composition and functions. This study examines the impacts of land cover changes on runoff and erosion within a subtropical Andean watershed. It focuses on new forests dominated by different tree species (native and non-native trees). Employing the Soil and Water Assessment Tool (SWAT), the research integrates thirty years of meteorological, topographic, and edaphic data. It aims to model, quantify, and compare surface runoff and soil loss under two distinct land cover configurations observed in 1988 and 2017. The results indicate non-linear associations: a 10% increase in forest coverage led to a 3% decrease in monthly streamflow and an 11% reduction in soil erosion. Runoff varies significantly between forests dominated by native versus non-native species. Additionally, among non-native forests, those dominated by evergreen species have proven more effective in reducing runoff and soil loss than deciduous forests used for livestock grazing. Understanding the impact of land cover changes and novel ecosystems on water and soil regulation is crucial for informing management and conservation strategies.