Soil quality dynamics under tropical land-use change: implications for sustainable management

Land-use changes profoundly affect soil physical and chemical properties, influencing ecosystem functions and sustainability in tropical landscapes. This study evaluated soil properties across five land-use systems in Selangor, Malaysia: secondary forest, Pinus caribaea plantation, Swietenia macrophylla plantation, pasture, and oil palm plantation. Soil morphology, physicochemical attributes, mineralogical properties, and charge characteristics were assessed across soil depths. Principal Component Analysis (PCA) was employed to derive a PCA-based Soil Quality Index (SQI_PCA), integrating key soil indicators to quantify overall soil health. Results showed significant variations in soil texture, organic matter, total carbon, total nitrogen, cation exchange capacity, and exchangeable cations across land-use types and depths. Mahogany plantations exhibited the highest SQI_PCA, reflecting superior nutrient retention and organic matter accumulation, whereas secondary forests and pine plantations had the lowest indices, indicating greater soil degradation and acidity. Partial indices revealed that soils could be chemically fertile but physically degraded, highlighting the importance of multidimensional soil assessment. These findings underscore the influence of land-use practices on soil quality and provide valuable insights for sustainable land management and restoration strategies in tropical ecosystems.