This study conducted a preliminary biodiversity assessment of flora and fauna along the Maluyo River ecosystem, covering upstream, midstream, and downstream sections. Habitat conditions and environmental characteristics were documented to support ecological evaluation. Species were identified through initial field assessments using standardized ecological techniques and taxonomic references. Data were organized and analyzed to determine patterns of species diversity and ecosystem condition. Findings provide baseline information for biodiversity monitoring and contribute to future conservation and management strategies in the river ecosystem. There are 47 diverse floral and vegetation and 16 faunal species observed along the downstream, mid stream and upper stream part of the Maluyo riverbank in Santol La Union, Philippines. The biodiversity of flora and fauna along the Maluyo River plays a significant role in the ecological, economic, and social development of the Municipality of Santol. Ecologically, it supports environmental stability by preventing erosion, improving water quality, maintaining habitat balance, and reducing risks of flooding and land degradation. Economically, river resources provide food, livelihood opportunities, agricultural support, and potential uses for medicinal and useful plants. Socially, biodiversity enhances community well-being, environmental awareness, and opportunities for conservation education and eco-tourism. Overall, conserving the river’s biological resources is essential for sustainable development, livelihood security, and long-term ecological resilience in Santol.
