Global environmental changes impact soil hydraulic functions through biophysical feedbacks

• Published in: Global change biology Vol. 25; no. 6; pp. 1895 - 1904
• Main Authors: Robinson, David A., Hopmans, Jan W., Filipovic, Vilim, van der Ploeg, Martine, Lebron, Inma, Jones, Scott B., Reinsch, Sabine, Jarvis, Nick, Tuller, Markus
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.06.2019
• Subjects: Agricultural production; Atmospheric models; Biological effects; biophysical feedbacks; Carbon cycle; Climate models; climatic factors; Drought; Ecosystem dynamics; Ecosystems; environmental change; Environmental changes; Environmental impact; floods; Freshwater; Heat waves; Heatwaves; hydraulic; Hydraulics; Hydrologic models; Hydrology; infiltration; infrastructure; Inland water environment; Land use; Markvetenskap; microbiome; Microbiomes; Microorganisms; Moisture content; Oceanografi, hydrologi, vattenresurser; Oceanography, Hydrology, Water Resources; Parameters; Plants (botany); Precipitation; Soil dynamics; Soil moisture; soil physics; Soil properties; Soil Science; Soil structure; Soil water; soil water content; Stability; state shift; Water content; water repellency; Wildfires; hydraulic; biophysical feedbacks; environmental change; soil water content; state shift; soil physics; infiltration; water repellency
• ISSN: 1354-1013; 1365-2486; 1365-2486
• DOI: 10.1111/gcb.14626

Although only representing 0.05% of global freshwater, or 0.001% of all global water, soil water supports all terrestrial biological life. Soil moisture behaviour in most models is constrained by hydraulic parameters that do not change. Here we argue that biological feedbacks from plants, macro‐fauna and the microbiome influence soil structure, and thus the soil hydraulic parameters and the soil water content signals we observe. Incorporating biological feedbacks into soil hydrological models is therefore important for understanding environmental change and its impacts on ecosystems. We anticipate that environmental change will accelerate and modify soil hydraulic function. Increasingly, we understand the vital role that soil moisture exerts on the carbon cycle and other environmental threats such as heatwaves, droughts and floods, wildfires, regional precipitation patterns, disease regulation and infrastructure stability, in addition to agricultural production. Biological feedbacks may result in changes to soil hydraulic function that could be irreversible, resulting in alternative stable states (ASS) of soil moisture. To explore this, we need models that consider all the major feedbacks between soil properties and soil‐plant‐faunal‐microbial‐atmospheric processes, which is something we currently do not have. Therefore, a new direction is required to incorporate a dynamic description of soil structure and hydraulic property evolution into soil‐plant‐atmosphere, or land surface, models that consider feedbacks from land use and climate drivers of change, so as to better model ecosystem dynamics. Global environmental changes impact soil hydraulic functions through biophysical feedbacks. Here, we argue that biological feedbacks from plants, macrofauna and the microbiome influence soil structure, and thus the soil hydraulic parameters and the soil water content signals we observe. Incorporating biological feedbacks into soil hydrological models is therefore important for understanding environmental change and its impacts on ecosystems.