Workshop 1 : Besse 2021

Water is essential to plant life and plays a crucial role in their development, growth rate, carbon assimilation capacity and survival in the face of drought induced by climate change. The physiology of the hydraulic system of plants is the disciplinary field that studies the capacity of plants to extract and transport water through their tissues. This discipline enables us to understand plant growth and resistance to drought, but could also provide valuable information on fire dynamics, vulnerability to pathogens and variations in crop production.

In a recent review article (Tansley Review) published in the journal New Phytologist, a multidisciplinary team of researchers in fire ecology, plant pathology, agriculture and vegetation dynamics consolidated the latest advances in plant hydraulics and identified how this field can address crucial questions in each discipline. In fire ecology, for example, hydraulics can help assess fire risk and understand fire dynamics as a function of tree water status. In plant pathology, a lower hydraulic capacity influences the response of plants to pathogens, just as pathogens can affect water transport capacity by damaging the conducting tissues (xylem). This could explain the massive outbreaks of pathogens following drought. In agriculture, the response to water stress is directly linked to the water transport capacity of plants, providing crucial information on how crops will cope with climate change or respond to the multiple issues surrounding water resources through specific irrigation treatments (e.g. deficit irrigation).

This review article highlights how the physiology of the hydraulic system of plants could improve the adaptation of agro-ecosystems to climate change, by being integrated, for example, into systems for forecasting natural risks in forests, or into varietal improvement programmes in agriculture.