Ecological Dynamics of Understory Vegetation in Managed Malaysian Oil Palm Ecosystems

Understory vegetation in oil palm plantations plays a crucial role in sustaining biodiversity, ecosystem health, and agricultural resilience; however, its diversity and distribution remain poorly understood. This study examined understory vegetation composition across the fringe, middle, and inner zones of oil palm plantations in the Banting, Selangor, using systematic quadrat sampling. A total of 1,630 individuals were identified, representing 31 species from five genera. The most dominant species were Nephrolepis acutifolia, Paspalum conjugatum, Ageratum conyzoides, and Nephrolepis cordifolia. Vegetation abundance was highest at the fringe (596 individuals), followed by the middle zone (557) and the inner zone (477). Diversity indices revealed that the middle zone supported the highest Shannon–Wiener Diversity Index (H’ = 2.43) and Margalef Richness Index (R’ = 4.11), while the inner zone exhibited the highest evenness (E’ = 0.60) but the lowest diversity (H’ = 1.97). Generalised Linear Models indicated significant differences in species distribution, particularly between fringe and inner zones (p < 0.001). Light availability and canopy cover were key drivers of vegetation patterns, with higher light penetration supporting greater diversity. These findings underscore the ecological significance of understory vegetation in managed oil palm systems and offer valuable insights for biodiversity conservation in agricultural landscapes.