Drought and Salinity Stresses Response in Three Korean Native Herbaceous Plants and Their Suitability as Garden Plants

Native garden plants significantly contribute to the conservation of biodiversity and ecosystem functions in urban environments. This study aimed to identify the physiochemical differences among native herbaceous plants subjected to drought or salinity stress and to assess their potential as garden plants adaptable to outdoor conditions and global climate change. Physiological parameters, such as chlorophyll (SD; −86.7% and −61.5%, SS: −85% and −76.5%) and carotenoid (SD; −84.5% and −58.3%, SS; −80.5% and −76%), decreased in Melica grandiflora and Carex forficula in severe drought or salinity treatment. In contrast, Carex boottiana maintained high water-use efficiency (SD: +97.5%, SS: +262.9%) under severe drought or salinity conditions, with no significant changes observed in chlorophyll (SD: +9.5%, SS: −3.7%) or carotenoid levels (SD: +35.2%, SS: +0.3%) compared to the WW or UT conditions. Biochemical analyses indicated that C. boottiana exhibited lower or slightly higher levels of malondialdehyde in SS (−22.5%) and reactive oxygen species such as O₂⁻ (SD: +9.9%; SS: −9.4%) than those observed in the other species under severe stress conditions. Principal component analysis revealed clear differences in tolerance levels among the native species. C. boottiana demonstrated high adaptability to both drought and salinity stress, indicating its potential as a sustainable and resilient garden material for urban landscapes facing severe climatic challenges.