Modeling vegetation interception under natural rainfall in yerba mate production systems

Modelagem da interceptação vegetal sob chuva natural em sistemas de produção de erva-mate

ABSTRACT

Interception loss plays an important role in rainfall partitioning, retaining significant amounts of water that would be directed to the soil. In this work, the objective was to measure interception by vegetation and evaluate the Rutter and Gash models to estimate the interception in different yerba mate production systems. The study was conducted the period from July/2019 to March/2020 in the municipality of Guarapuava, southern Brazil. The total rainfall, stemflow, and the throughfall were monitored in each rainfall event. Rutter and Gash interception models were applied. The interception losses estimated by Rutter and Gash models were considered satisfactory but, in general, underestimated. In the yerba mate monoculture system, an average interception loss of 15.6% was recorded, in the yerba mate agroforest, 21.4%, and, in the native Mixed Ombrophilous Forest, 16.2%. Rutter's model presented estimates close to the measured rainfall interception estimate for the yerba mate monoculture system and Gash's model for the agroforestry system and the native Ombrophilous Mixed Forest.

Keywords:
Throughfall; Stemflow; Rutter model; Gash model