Plant-Based Sensing for Monitoring Soil Water Conditions in Vegetated Slopes

Wet and dry extremes induced by climate change are affecting soil mechanical behaviour, and consequent serviceability and stability of earthworks. Nature-based solutions using plants have been suggested as an environmentally friendly means to mitigate landslide hazards because of the hydrological and mechanical reinforcement provided by plants. This paper explores a new function of this nature-based solution named plant-based sensing (PbS), which utilises plant ecophysiological responses to monitor plant stress indicators that can be linked to soil matric suction. PbS aims to comprehend the fundamental understandings of plant ecophysiology, soil-plant hydraulics, and unsaturated soil mechanics under the influences of environmental stresses, to further exploit the engineering function of plants. PbS may be integrated into slope monitoring systems substituting the expensive needs for sensor installations on the slopes. Initial studies in geotechnical engineering have explored PbS by identifying plant morphological traits that are pertinent to soil matric suction; however, real-time monitoring remains a challenge. Therefore, this paper underscores the necessity for interdisciplinary collaboration to advance PbS technique in geotechnical discipline. By reviewing existing research, this paper identifies areas for future work and emphasizes the importance of integrating plant physiological and ecological insights into geotechnical engineering practices to enhance slope monitoring and management strategies.