Temperature and aridity regulate spatial variability of soil multifunctionality in drylands across the globe

Area of Science:

• Ecology
• Soil Science
• Climate Change Research

Background:

• The spatial variability of soil multifunctionality (SVM) and its drivers remain poorly understood globally.
• Dryland ecosystems, covering a significant portion of Earth's land surface, are particularly vulnerable to climate change.
• Previous research has not comprehensively assessed the impact of climate on SVM across diverse dryland environments.

Purpose of the Study:

• To globally assess the relationship between major climatic drivers (temperature, aridity) and SVM in terrestrial dryland ecosystems.
• To determine the relative importance of climatic, abiotic, and biotic factors in driving SVM.
• To investigate the direct and indirect pathways through which climate influences SVM.

Main Methods:

• Conducted a global survey of 236 dryland ecosystems across six continents.
• Calculated SVM as the averaged coefficient of variation for soil variables related to nutrient stocks and cycling.
• Employed structural equation modeling to analyze the influence of climate, soil texture, and plant cover on SVM.

Main Results:

• Increased temperature and aridity globally correlated with increased SVM.
• Climate influenced SVM directly and indirectly through vegetation patch reduction and increased soil sand content.
• Structural equation modeling showed higher predictive capacity for Nitrogen (N) variability compared to Carbon (C) and Phosphorus (P).
• Climate effects on N cycling were direct and indirect; effects on C and P were mainly indirect via plant attributes.

Conclusions:

• Future climate change may disrupt the spatial availability of essential nutrients (N, C, P) for soil organisms in drylands.
• Understanding climate-driven SVM is crucial for predicting ecosystem functioning under global change.
• Findings advance the understanding of SVM patterns and mechanisms in global drylands.