Adaptive vegetation management is time-consuming and requires long-term colony monitoring to obtain reliable results. Although vegetation management has been widely adopted, the only method existing at present for evaluating the habitat conditions under management involves observations over a long period of time. The presence of reactive oxygen species (ROS) has long been used as an indicator of environmental stress in plants, and has recently been intensely studied. Among such ROS, hydrogen peroxide (H₂O₂) is relatively stable, and can be conveniently and accurately quantified. Thus, the quantification of plant H₂O₂ could be applied as a stress indicator for riparian and aquatic vegetation management approaches while evaluating the conditions of a plant species within a habitat. This study presents an approach for elucidating the applicability of H₂O₂ as a quantitative indicator of environmental stresses on plants, particularly for vegetation management. Submerged macrophytes and riparian species were studied under laboratory and field conditions (Lake Shinji, Saba River, Eno River, and Hii River in Japan) for H₂O₂ formation under various stress conditions. The results suggest that H₂O₂ can be conveniently applied as a stress indicator in environmental management.