Vulnerability of soil food webs to chemical pollution and climate change.

Soil food webs are critical for maintaining ecosystem functions but are challenged by various stressors including climate change, habitat destruction and pollution. Although complex multitrophic networks can, in theory, buffer environmental stress, the effects of anthropogenic chemicals on soil food webs under climate change remain poorly understood. Here we propose that the effects of chemical pollution on soil communities have been largely underestimated, particularly for climate change-affected ecosystems.

Negative Impacts of Global Change Stressors Permeate Into Deep Soils.

Surface soils are highly vulnerable to multiple global change stressors associated with climate change and human activity; however, whether the impacts of this increasing number of stressors penetrate deeper soils remains virtually unknown. Here, we conducted a continental-scale survey of soil profiles (0-100 cm). Results showed that multiple stressors jointly affect multiple soil functions (from soil carbon sequestration to pathogen control) across top (0-30 cm), subsurface (30-60 cm) and deep soils (60-100 cm).

Distribution and Environmental Preference of Potential Mercury Methylators in Paddy Soils across China.

The neurotoxin methylmercury (MeHg) is produced mainly from the transformation of inorganic Hg by microorganisms carrying the gene pair. Paddy soils are known to harbor diverse microbial communities exhibiting varying abilities in methylating inorganic Hg, but their distribution and environmental drivers remain unknown at a large spatial scale. Using gene amplicon sequencing, this study examined Hg-methylating communities from major rice-producing paddy soils across a transect of ∼3600 km and an altitude of ∼1300 m in China.

Multidimensional Drivers of Mercury Distribution in Global Surface Soils: Insights from a Global Standardized Field Survey.

Soil stores a large amount of mercury (Hg) that has adverse effects on human health and ecosystem safety. Significant uncertainties still exist in revealing environmental drivers of soil Hg accumulation and predicting global Hg distribution owing to the lack of field data from global standardized analyses. Here, we conducted a global standardized field survey and explored a holistic understanding of the multidimensional environmental drivers of Hg accumulation in global surface soils.

Climatic seasonality challenges the stability of microbial-driven deep soil carbon accumulation across China.

Microbial residues contribute to the long-term stabilization of carbon in the entire soil profile, helping to regulate the climate of the planet; however, how sensitive these residues are to climatic seasonality remains virtually unknown, especially for deep soils across environmental gradients. Here, we investigated the changes of microbial residues along soil profiles (0-100 cm) from 44 typical ecosystems with a wide range of climates (~3100 km transects across China). Our results showed that microbial residues account for a larger portion of soil carbon in deeper (60-100 cm) vs.

Local temperature increases reduce soil microbial residues and carbon stocks.

Warming is known to reduce soil carbon (C) stocks by promoting microbial respiration, which is associated with the decomposition of microbial residue carbon (MRC). However, the relative contribution of MRC to soil organic carbon (SOC) across temperature gradients is poorly understood. Here, we investigated the contribution of MRC to SOC along two independent elevation gradients of our model system (i.