Soil Functions: Connecting Earth's Critical Zone

Abstract

Soil is the central interface of Earth's critical zone—the planetary surface layer extending from unaltered bedrock to the vegetation canopy—and is under intense pressure from human demand for biomass, water, and food resources. Soil functions are flows and transformations of mass, energy, and genetic information that connect soil to the wider critical zone, transmitting the impacts of human activity at the land surface and providing a control point for beneficial human intervention. Soil functions are manifest during bedrock weathering and, in fully developed soil profiles, correlate with the porosity architecture of soil structure and arise from the development of soil aggregates as fundamental ecological units. Advances in knowledge on the mechanistic processes of soil functions, their connection throughout the critical zone, and their quantitative representation in mathematical and computational models define research frontiers that address the major global challenges of critical zone resource provisioning for human benefit. ▪ Connecting the mechanisms of soil functions with critical zone processes defines integrating science to tackle challenges of climate change and food and water supply. ▪ Soil functions, which develop through formation of soil aggregates as fundamental eco-logical units, are manifest at the earliest stages of critical zone evolution. ▪ Global degradation of soil functions during the Anthropocene is reversible through positive human intervention in soil as a central control point in Earth's critical zone. ▪ Measurement and mathematical translation of soil functions and critical zone processes offer new computational approaches for basic and applied geosciences research.

Strong slope‐aspect control of regolith thickness by bedrock foliation

“…Graham et al, 2010;Grant and Dietrich, 2017;Riebe et al, 2017). Regolith, as the subsurface part of the critical zone, is the basis of vital ecosystem services, including soil production, aquifer recharge, and baseflow discharge (Field et al, 2015;Banwart et al, 2019). It also provides a habitable substrate for terrestrial life.…”

Spatial structure, parameter nonlinearity, and intelligent algorithms in constructing pedotransfer functions from large-scale soil legacy data

“…Five different modelling approaches were used for 9 West Bengal-centric and 8 Odisha-centric ISL datasets and model performances were tested on WBT and ODT datasets. With separate surface and whole profile data treated as separate datasets, these modelling efforts led to having a total of 170 sets of R 2 and RMSE values along with estimated bias (Tables 2 and 3). In general, the performance of the MLR-and RR-based PTFs decreased with the increase in the geographical extent of the training dataset because of the increase in the nonlinear relationship among response and predictor soil properties.…”

“…Soil information systems are increasingly used in developing ecosystem-scale understanding of critical zone processes and ecosystem services 1 , 2 . More recently, a greater role is attributed to large-scale soil data for realizing the sustainable development goals of food security, water management, and other health threats 3 .…”

Selected Plant-Related Papers from the First Joint Meeting on Soil and Plant System Sciences (SPSS 2019)—“Natural and Human-Induced Impacts on the Critical Zone and Food Production”

“…To meet humankind’s growing needs for food, fiber, and bioenergy, crop and soil productivity will be vastly expanded in the next few decades, with substantial effects on the Critical Zone [ 5 ]. Therefore, during the Anthropocene, the Critical Zone is increasingly being affected by natural processes and human activities (e.g., land use intensification, climate change, desertification, pollution) [ 2 , 6 , 7 , 8 , 9 , 10 ], with consequences for food production, safety and security [ 9 ].…”