Investigating the Impact of El Niño–Southern Oscillation on Rangeland Productivity in the Limpopo Province, South Africa

ABSTRACT

The El Niño–Southern Oscillation (ENSO) is a major driver of climate variability that influences rainfall patterns and vegetation productivity across semi‐arid regions of southern Africa. Understanding how ENSO affects rangeland productivity is essential for improving climate adaptation and sustainable livestock management in Limpopo Province, South Africa. This study investigated the influence of ENSO on rangeland productivity between 1999 and 2024 across 10 representative sites in Limpopo Province. Dry Matter Productivity (DMP) derived from the Copernicus Global Land Service was analysed together with seasonal rainfall and the Oceanic Niño Index (ONI). Long‐term trends were evaluated using the Mann–Kendall trend test and Sen's slope estimator, while standardized anomaly analyses and ENSO phase comparisons were used to assess rainfall and vegetation variability. Rainfall trends were generally weak and statistically non‐significant, with a significant decrease detected only at Lephalale (τ = −0.34, p = 0.017), despite pronounced interannual variability. In contrast, significant increasing trends in annual DMP were observed at Mhinga (τ = 0.343, p = 0.015), Mooketsi (τ = 0.415, p = 0.003), and Marble Hall (τ = 0.394, p  = 0.005), with Sen's slope estimates ranging from 0.53 to 0.98 kg DM ha⁻¹ day⁻¹ year⁻¹ across these sites. Long‐term mean monthly DMP revealed a distinct seasonal cycle, with greening during early summer, peak productivity from January to April, and senescence during the dry winter months. ENSO phase comparisons showed that La Niña years were generally associated with above‐average November–December–January (NDJ) rainfall, whereas El Niño years exhibited below‐average rainfall. Higher February–March–April (FMA) DMP anomalies followed above‐normal NDJ rainfall conditions, while lower productivity occurred following below‐normal conditions. Spatial differences were evident, with the eastern and southern regions consistently exhibiting higher productivity than the drier northern and western regions. These findings demonstrate that ENSO influences rangeland productivity primarily through its effect on seasonal rainfall. Integrating ENSO‐based climate information with satellite‐derived vegetation monitoring can strengthen drought preparedness, improve seasonal grazing management, and support climate‐resilient rangeland management in semi‐arid South Africa.