UP study maps riverbank plants in Occidental Mindoro for conservation efforts

A University of the Philippines (UP) study has mapped the vegetation along the Amnay River in Occidental Mindoro, offering baseline data that researchers say could help guide conservation and rehabilitation efforts in one of the province’s sediment-affected river systems.

The study, led by Dr. Enrico Replan of the UP Diliman College of Science’s Institute of Environmental Science and Meteorology (UPD-CS IESM), examined plant communities along a 14-kilometer stretch of the Amnay River’s downstream corridor to determine how riverbank vegetation is shaped by flooding, sediment buildup, and local environmental conditions.

Riparian vegetation, or plants growing along riverbanks, plays a key role in preventing soil erosion, improving water quality, and providing habitat for wildlife, but is also highly sensitive to changes in river flow, sediment movement, and land disturbance.

“Riparian areas—those found along rivers—are very important because they help prevent soil erosion, improve water quality, and provide habitat for wildlife,” Replan said.

“By documenting the plants present, the study provided a baseline record that can help monitor environmental changes in the future,” he added.

The study covered about 509 hectares, including riverbanks and nearby vegetation extending inland, allowing researchers to observe how plant communities shift between flood-prone and more stable terrestrial zones.

Replan said the study was prompted by the lack of scientific documentation on the Amnay River’s riparian vegetation despite its ecological importance to surrounding communities.

“Given increasing environmental pressures such as land-use change and sedimentation, I felt it was important to establish baseline ecological data,” he said.

The study found that most vegetation along the river consisted of herbs and disturbance-tolerant species, particularly grasses and legumes, while trees and other woody plants were scarce and appeared only in isolated patches.

This resulted in what the study described as a relatively simple and fragmented vegetation structure along the river corridor.

The research also found that plant diversity varied depending on local conditions such as soil stability, vegetation cover, and distance from the river.

“Some species were highly adapted to periodic flooding and unstable soils, while others thrived further away from direct river influence,” Replan said.

“This spatial variation highlights how sensitive and specialized riparian ecosystems can be,” he added.

According to the study, the Amnay River shows how sediment-heavy tropical rivers can develop uneven and highly localized plant communities, underscoring the need for site-specific conservation and management strategies.

Replan said the findings could serve as a reference for future researchers and policymakers, particularly in monitoring environmental change and identifying native plant species suited for river rehabilitation.

The study, “Floristic Diversity of Riparian and Associated Vegetation Along the Amnay River (The Philippines),” was published in the journal Plant-Environment Interactions.—LDF, GMA News