Dados do Trabalho

Título

WATER PERCOLATION IN NATIVE FOREST ECOSYSTEMS OF NOTHOFAGUS GLAUCA AND PINUS RADIATA FOREST PLANTATION IN THE COASTAL MOUNTAIN RANGE OF THE MAULE REGION.

Resumo

Percolation plays a significant role in the hydrological cycle as it directly impacts groundwater recharge. In light of the extensive and rapid land-use changes occurring in Chile's central-southern region, it is crucial to understand the differences between native Nothofagus glauca forests and exotic Pinus radiata plantations. Initially, we conducted an analysis of water balance variables using data collected from measuring instruments during the rainy seasons of 2018 and 2019. Our findings revealed that the soil moisture content of N. glauca was nearly double that of P. radiata. To estimate percolation, we utilized the HYDRUS-1D water transfer model and performed inverse simulations by incorporating observed soil moisture data to obtain the Van Genuchten pedotransfer parameters. The simulated soil moisture results showed satisfactory agreement, with R2 values of 0.68 for N. glauca in 2019 and 0.9 for P. radiata, demonstrating the model's ability to accurately represent water transfers in both ecosystems. However, when analyzing the simulated moisture content across soil horizons, we identified certain inconsistencies in parameter values. These discrepancies are likely attributed to the presence of rocks, which impact the horizon scale but not the overall soil profile. Significant disparities were observed in the estimated percolation between the two ecosystems. At a soil depth of 160 cm, percolation was higher in P. radiata, exceeding N. glauca by 8 and 14 mm in 2018 and 2019, respectively. Conversely, at a soil depth of 300 cm, percolation was higher in N. glauca, with a difference of 61 and 23 mm in the same years. These variations can be explained by soil management practices associated with forest plantations, which result in structural losses, favor preferential flows, reduce coarse porosity, and increase compaction at greater depths.

Palavras-chave

Water Transfers, Native Forest, Forest Management, Soil Physical Properties, Groundwater recharge

Instituição financiadora

Proyecto FONDECYT 1171560, 1210932

Agradecimentos

Área

Divisão 2 – Processos e Propriedades do Solo: Comissão 2.2 – Física do Solo