Size effects of microplastics on competition between crop and weed via soil microbes.

Microplastics (MPs) are widespread contaminants in agroecosystems, with potential implications for soil microbial communities, plant growth, and crop-weed interactions. This study investigates how MPs of different particle sizes influence crop-weed competition by altering soil microbial communities. Through a controlled greenhouse experiment, we examined the effects of 50 μm and 500 μm polyethylene (PE) MPs on competition between Eruca sativa (crop) and Amaranthus retroflexus (weed).

Unique plastisphere viromes with habitat-dependent potential for modulating global methane cycle.

Plastispheres, novel niches in the Anthropocene, harbor microbial communities with unique functional signatures. As the most abundant biological entity on Earth, viruses are key regulators of microbial community composition and metabolism. However, little is known about viral communities and their functions in the plastisphere.

Zoonotic pathogen-driven antibiotic resistance emerges in urban soils: A large-scale study in 13 cities across China.

Land-use changes drive the microbial community and associated soil resistome. Enrichment of risk antibiotic resistance genes (risk ARGs) is related to 4.95 million deaths across the globe each year, rendering them an urgent threat to human health.

Mycorrhizal allies: synergizing forest carbon and multifunctional restoration.

While forest degradation persists across many regions, restoration efforts have predominantly targeted aboveground carbon, often overlooking critical belowground ecosystem functions. Plant-mycorrhizal associations - key connectors between aboveground and belowground biodiversity - can help to enhance both carbon storage and forest multifunctionality; yet their explicit integration into restoration frameworks remains limited. By synthesizing recent advancements, we highlight the role of plant-mycorrhizal diversity in enhancing soil carbon pools and supporting multiple ecosystem functions.

Abrupt versus gradual application of pesticides: effects on soil bacterial and fungal communities.

Pesticides are a major anthropogenic input to the environment and a factor in global change that puts pressure on soil microbial communities. However, the effects of different rates of pesticide application on soils remain poorly understood. This study investigates how abrupt versus gradual pesticide applications influence soil bacterial and fungal communities.

Quantifying the Positive Effect of Ungulate Herbivory on Living Root-Derived Soil Organic Carbon Formation: Evidence From an Eight-Year Simulated Grazing Field Experiment With C Pulse Labeling.

Ungulate grazing encompasses multiple components, including defoliation, trampling, and excreta return, all of which affect soil organic carbon (SOC) dynamics by influencing the balance between rhizodeposition and the subsequent C input and release. However, it remains unclear how ungulate grazing regulates SOC through living roots, especially as evidence from the field is lacking. A CO pulse labeling experiment was conducted on an 8-year simulated grazing field experiment, involving separate or combined treatments of defoliation, excreta return, and trampling from grazing animals.

Plastic Biofilms as Hotspots of Nitrogen Cycling in Estuarine Ecosystems: Comparative Ecological, Genomic, and Transcriptomic Analysis Across Substrates.

Biofilms represent a ubiquitous microbial lifestyle that facilitates colonization, symbiosis, and nutrient cycling, shaping environmental chemical transformations. In the Anthropocene, the proliferation of artificial surfaces, particularly plastics, has introduced novel and artificial ecological niches for microbial colonization. However, the biogeochemical potential of biofilms on these emerging artificial substrates remains largely unknown.

Expanding the Root Economics Space With Root Nitrogen Reallocation.

Harnessing root nitrogen reallocation (RNR) to enhance plant productivity commences with positioning RNR in the root economics space, about which we still know little. We conducted an inclusive synthesis linking RNR to root traits, combined with a 2-year N-labelling field experiment, to position RNR in the root economics space under acidification. RNR was negatively correlated with specific root length (SRL) and mycorrhizal colonisation in the synthesis, suggesting that RNR is a conservative trait.

National Inventory of Plastic Mulch Residues in Chinese Croplands From 1993 to 2050.

Agricultural plastic mulch films are a major source of plastic pollution of croplands. In China, which uses about 68% of the plastic mulch film produced globally (ca. 1.

A Double-Edged Sword of Biodegradable Microplastics on the Soil Microbial Carbon Pump.

Understanding how microplastic pollution alters soil microbial communities and their influence on soil carbon processes is crucial to elucidating the associated pollutant-climate change feedback. However, previous studies have mainly focused on the effects of microplastics on soil carbon loss, and whether and how microplastics mediate microbial anabolism and subsequent contributions to soil carbon are largely unexplored. Here, we evaluated how conventional and biodegradable microplastic exposure simultaneously affects carbon mineralization and the accumulation of microbial necromass carbon in two types of soil with distinct nutrient levels.

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.

Airborne microplastics in leaves and food safety risks.

Global plastic production has surged. Li et al. provide evidence of an important aspect of terrestrial plastic pollution, highlighting leaf absorption of airborne plastics as a major route into plants.

Patterns and drivers of soil microbial carbon use efficiency across soil depths in forest ecosystems.

Subsoils below 30 cm store more than half of global soil carbon. Microbial carbon use efficiency (CUE) serves as a key indicator of microbial control over soil carbon turnover, but the general patterns and drivers of microbial CUE across soil depths remain poorly understood. Here, we report a decreasing trend in microbial CUE with increasing soil depths through large-scale soil sampling across 60 sites spanning tropical to boreal forests.

Concurrent anthropogenic stressors affect plant-soil systems with different plant diversity levels.

Plant diversity strongly influences ecosystem functioning. Due to human activities, ecosystems are increasingly threatened by the co-occurrence of numerous anthropogenic pressures, but how they respond to this multifaceted phenomenon is poorly documented, and what role plant diversity plays in this process has not been investigated so far. Here, plant-soil systems with different plant diversity levels (3 vs 9 species) were subjected to an increasing number of anthropogenic stressors (0, 1, 2, 5, and 8).

Toxicological effects of microplastic fibers from different disposable face masks on Caenorhabditis elegans.

During the COVID-19 pandemic, the widespread use of disposable face masks generated substantial waste, much of which ends up in terrestrial environments. However, the impact of this discarded material on soil ecosystems remains poorly understood. This study investigated the toxicological effects of microplastics derived from three types of disposable face masks (KF94, medical, and particulate respirator) and a polypropylene reference material on the soil nematode Caenorhabditis elegans (C.

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).

Soil microbial responses to multiple global change factors as assessed by metagenomics.

Anthropogenic activities impose multiple concurrent pressures on soils globally, but responses of soil microbes to multiple global change factors are poorly understood. Here, we apply 10 treatments (warming, drought, nitrogen deposition, salinity, heavy metal, microplastics, antibiotics, fungicides, herbicides and insecticides) individually and in combinations of 8 factors to soil samples, and monitor their bacterial and viral composition by metagenomic analysis. We recover 742 mostly unknown bacterial and 1865 viral Metagenome-Assembled Genomes (MAGs), and leverage them to describe microbial populations under different treatment conditions.

Global patterns of nutrient limitation in soil microorganisms.

The availability of nitrogen (N) and phosphorus (P) is essential for soil microbial activity and growth, yet global patterns of N and P limitation in soil microbial metabolism remain largely unknown. We modeled ecoenzyme stoichiometry data from 5,259 field observations of natural ecosystems to assess microbial N and P limitation in global surface soils. We found that microbial P limitation, which was especially strong at low latitudes, was more prevalent globally than microbial N limitation, which prevailed in cold environments.

Ungulate herbivory affects grassland soil biota β-diversity and community assembly via modifying soil properties and plant root traits.

Ungulate herbivory, a widespread and complex disturbance, shapes grassland biodiversity and functions primarily through three mechanisms: defoliation, trampling, and excreta return. However, the specific effects of these mechanisms on soil biodiversity and community assembly remain unclear. We conducted a 4-yr factorial experiment in the Eurasian steppe to investigate how defoliation, trampling, and excreta return influence soil bacterial, fungal, and nematode β-diversity and community assembly under moderate- and high-density ungulate grazing scenarios.

Effects of microplastic types and shapes on the community structure of arbuscular mycorrhizal fungi in different soil types.

Arbuscular mycorrhizal fungi (AMF) play a crucial role in soil ecosystems by enhancing nutrient exchange, stabilizing soil structure, and improving water movement in soils. Microplastics (MPs), synthetic polymers smaller than five mm, pose an emerging threat to AMF by altering soil structure and chemistry, potentially disrupting these essential functions. This study examined how ten different microplastic types and shapes influenced AMF communities within the context of Grime's C-S-R (competitor-stress tolerator-ruderal) framework.

Soil organic carbon stabilization is influenced by microbial diversity and temperature.

The stabilization of soil organic carbon (SOC) is influenced by soil microbes and environmental factors, particularly temperature, which significantly affects SOC decomposition. This study investigates the effects of temperature (ambient: 25 °C; elevated: 27.5 °C) and soil microbial diversity (low, medium, and high) on the formation of stabilized SOC, focusing on mineral-associated organic carbon (MAOC) and water-stable aggregates, through a 75-day model soil incubation experiment.

Soil properties explain the variability in tire wear particle effects in soil based on a laboratory test with 59 soils.

Tire wear particles (TWPs) are among the most prevalent microplastics in the environment, with potential detrimental effects on ecosystem health and functionality. While little is known how the effects of TWPs on soil physicochemical and microbial properties vary across different soil types, and if so, which factors contribute to this variability. To address this knowledge gap, we conducted a laboratory experiment involving soils from 59 grassland plots across two sampling regions in Germany, each experienced varying land-use intensities.

Beyond Dosage: The Need for More Realistic Research Scenarios to Understand Pesticide Impacts on Agricultural Soils.

Pesticides play a crucial role in modern agriculture, yet they pose considerable risks to soil health and ecosystem integrity. Current risk assessment research often relies on simplified models, focusing on single substances under standardized conditions and failing to reflect realistic exposure scenarios. We call for a paradigm shift toward incorporating agroecological research that evaluates pesticide effects under more complex and dynamic conditions, including mixtures, application frequency, diverse soil properties, and interactions with other environmental stressors.

Vertical distribution of microplastics in soil affects plant response to microplastics.

The impacts of microplastics on plants have been extensively researched, yielding a variety of responses: promoting growth, limiting growth, or causing no change in plants. Experimental studies, following basic principles of ecotoxicology, typically use a homogeneous distribution of microplastics in soils, where soil and microplastic are well-mixed. However, in the environment, plastic is not homogeneously distributed.

Effects of biodegradable microplastics on soil microbial communities and activities: Insight from an ecological mesocosm experiment.

Microplastics (MP) are being released into the environment at an increasing rate, causing extensive pollution in soils and affecting biota and processes. Although the use of biodegradable plastic has increased, its effects on the soil microbial community are not yet well understood. A controlled mesocosm experiment was conducted to investigate the response of soil microbial communities to increasing amounts of starch-polybutylene adipate terephthalate MPs (PBAT-BD-MPs) added to the soil.