Nitrogen addition alters arbuscular mycorrhizal fungi and soil bacteria networks without promoting phosphorus mineralization in a semiarid grassland.

Mycorrhiza interplays with the microbiome in adaptation to environmental fluctuation, yet how arbuscular mycorrhizal fungi (AMF) and the associated microbiome respond to nitrogen addition remains poorly understood. Here, we addressed this gap by conducting amplicon sequencing of AMF 18S rRNA and bacterial 16S rRNA operons, along with shotgun metagenome sequencing, using soil samples collected from a semiarid grassland that has received nitrogen inputs for 11 years at different levels. We found that the nitrogen response of the AMF community was characterized by a negative association whereby increasing nitrogen addition leads to higher beta diversity and lower alpha diversity.

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.

Increased nitrate uptake by plants in response to nitrogen addition and mowing in a temperate grassland.

Background And Aims: Plants absorb different forms of nitrogen (N) from the soil, which influences biodiversity and ecosystem functioning. However, how N uptake responding to different N addition rates and traditional mowing practices remains largely unexplored.

Methods: A field experiment was carried out to examine the effects of six N addition rates (0, 2, 5, 10, 20, and 50 g N m-2 yr-1) and mowing on N uptake.

Nitrogen addition decouples the microbial necro-mass from soil organic carbon formation in a temperate grassland.

Increasing anthropogenic nitrogen (N) inputs has profoundly altered soil microbial necro-mass carbon (MNC), which serves as a key source of soil organic carbon (SOC). Yet, the response pattern of MNC and its contribution to SOC across a wide range of N addition rates, remain elusive. In a temperate grassland with six years' consecutive N addition spanning seven rates (0-50 g N/(m·year)) in Inner Mongolia, China, we explored the responses of soil MNC and its contribution to SOC.

Properties of 3D-printed continuous silk fiber-reinforced poly(caprolactone).

In this study, poly(caprolactone)/continuous mulberry silk (PCL/MS) composite filaments were prepared the pre-impregnation method and were employed for FDM technology. The MS was treated with alkali. The tensile properties and morphology of PCL/MS composite filaments were investigated using a universal mechanical testing machine and a scanning electron microscope.

Microbial Immobilization Shapes the Non-Linear Response of Allochthonous Nitrogen Retention to Grassland Acidification Within Soil Aggregates.

Soil nitrogen (N) retention plays a crucial role in determining the ecosystem capacity to buffer anthropogenic N inputs and provides a sustainable N supply. However, the effect of acidification, driven by atmospheric deposition of N and sulfur (S), on the retention and fate of allochthonous N across soil aggregate size classes remains poorly understood. We utilized a soil-acidification gradient induced by 0-50 g S m year addition to investigate N recovery in soil N pools within aggregates 21 days after labeling in a Eurasian meadow.

Phytolith formation and its contribution to soil organic carbon sequestration in an Inner Mongolia grassland under long-term nitrogen deposition.

Nitrogen (N) deposition can enhance plant growth but may also disrupt soil nutrient balances and cause soil acidification, potentially affecting silicon (Si) uptake. Si is vital for phytolith formation and the sequestration of phytolith-occluded carbon (C) (PhytOC). Understanding how N deposition influences these dynamics is crucial, given their roles in C sequestration and ecosystem functions.

Multiple Nutrient Additions Homogenize Multidimensional Plant Stoichiometry in a Meadow Steppe.

Human activities are altering terrestrial ecosystem biogeochemistry globally by augmenting the availability of multiple biologically essential nutrients, thereby potentially altering plant internal concentrations (i.e., stoichiometry) across a diverse array of elements.

Quantity Versus Quality: Links Between Soil Organic Matter and Bacterial Community Composition Along a Geoclimatic Gradient.

Soil organic matter (SOM) quantity drives soil bacterial community composition from the regional to global scale. Qualitative characteristics of SOM are known to affect soil bacterial communities in manipulation experiments. However, it remains unresolved how strongly SOM characteristics affect soil bacterial community composition at the macroscale.

Grassland bud and shoot demographic responses to single and recurrent droughts vary across an aridity gradient.

Clonal demographic traits play important roles in regulating community dynamics. Yet, it remains unclear how the responses of these clonal traits to drought might depend on previous drought exposure, and how drought responses vary among grasslands. We conducted a repeated drought experiment across four grasslands along an aridity gradient in northern China.

Stronger Response of Plant N:P to Nitrogen Enrichment When Considering Roots.

Nitrogen (N) enrichment leads to an imbalance of N and phosphorus (P) in plants by enhancing plant N:P, with consequences for ecosystem processes and function. However, the evidence for a plant N-P imbalance is predominantly from studies on aboveground tissues. It remains unclear whether imbalanced aboveground responses would be paralleled by similar responses in roots, which contribute to nearly 70% of total biomass in grasslands globally.

Dominant species drove the balance between biodiversity and productivity in mown grasslands under nitrogen fertilization.

Annual mowing, a main management strategy of grasslands, would reduce primary productivity, though might increase plant diversity. Nitrogen (N) fertilization is widely used to raise productivity in global pastures, but always results in biodiversity losses. It is thus a challenge to balance the divergent impacts of mowing and N fertilization on biodiversity and productivity.

Contrasting drought sensitivity of Eurasian and North American grasslands.

Extreme droughts generally decrease productivity in grassland ecosystems with negative consequences for nature's contribution to people. The extent to which this negative effect varies among grassland types and over time in response to multi-year extreme drought remains unclear. Here, using a coordinated distributed experiment that simulated four years of growing-season drought (around 66% rainfall reduction), we compared drought sensitivity within and among six representative grasslands spanning broad precipitation gradients in each of Eurasia and North America-two of the Northern Hemisphere's largest grass-dominated regions.

Plant growth strategies and microbial contributions to ecosystem nitrogen retention along a soil acidification gradient.

Nitrogen (N) retention is a critical ecosystem function associated with sustainable N supply. Lack of experimental evidence limits our understanding of how grassland N retention can vary with soil acidification. A N-labeling experiment was conducted for 2 years to quantify N retention by soil pathways and plant functional groups across a soil-acidification gradient in a meadow.

3D printing of continuous cotton thread reinforced poly (lactic acid).

This paper purposed to prepare poly (lactic acid)/continuous cotton thread (PLA /CCT) filaments by using prepreg method, and investigated the properties of PLA/CCT filament and their 3D printed composites. Firstly, a prepreg device was home-made to immerse CCT with PLA melts. The effects of the dragging speed and tensioning equipment on the quality of PLA/CCT filament was investigated.

Methane emissions from the riverine sandy wetlands on the Mongolia Plateau.

Methane (CH) processes and fluxes have been widely investigated in low-latitude tropical wetlands and high-latitude boreal peatlands. In the mid-latitude Mongolia Plateau, however, CH processes and fluxes have been less studied, particularly in riverine wetlands. In this study, in situ experiments were conducted in the riverine sandy wetlands of the Mongolia Plateau to gain a better understanding of CH emissions and their influencing mechanisms.

Long-term grazing reduces soil fungal network complexity but enhances plant-soil microbe network connectivity in a semi-arid grassland.

Grazing plays a significant role in shaping both aboveground vegetation and belowground microbial communities in arid and semi-arid grasslands, which in turn affects ecosystem functions and sustainability. Therefore, it was essential to implement effective grazing management practices to preserve ecological balance and support sustainable development in these delicate environments. To optimize the traditional continuous grazing policy, we conducted a 10-year seasonal grazing experiment with five treatments in a typical grassland in northern China: no grazing (NG), continuous summer grazing (CG), and three seasonal grazing treatments (G57 in May and July, G68 in June and August, and G79 in July and September).

Differential responses of soil phosphorus fractions to varied nitrogen compound additions in a meadow steppe.

Nitrogen (N) addition can greatly influence soil inorganic phosphorus (Pi) and organic phosphorus (Po) transformations. However, whether and how the N compound forms may differentially affect the soil P fractions remain unclear. Here, we investigated the responses of soil Pi (labile Pi, moderately-occluded Pi, and recalcitrant Pi) and Po fractions (labile Po and stable Po) to varying addition rates of three N compounds ((NH)SO, NHNO, and urea) in a meadow steppe in northern China.

Tradeoff between productivity and stability across above- and below-ground communities.

An 11-year nitrogen addition experiment reveals that for both plants and soil microorganisms, the ruderal strategists had higher productivity but lower stability, while the tolerant strategists had higher stability and lower productivity, leading to the tradeoff between productivity and stability within and across above- and below-ground communities.

Environment and microbiome drive different microbial traits and functions in the macroscale soil organic carbon cycle.

Soil microbial traits and functions play a central role in soil organic carbon (SOC) dynamics. However, at the macroscale (regional to global) it is still unresolved whether (i) specific environmental attributes (e.g.

Research on a Support-Free Five-Degree-of-Freedom Additive Manufacturing Method.

When using traditional 3D printing equipment to manufacture overhang models, it is often necessary to generate support structures to assist in the printing of parts. The post-processing operation of removing the support structures after printing is time-consuming and wastes material. In order to solve the above problems, a support-free five-degree-of-freedom additive manufacturing (SFAM) method is proposed.

Interannual fluctuations in precipitation shape the trajectory of ecosystem respiration along a grazing exclusion chronosequence in a typical steppe in Inner Mongolia.

Grazing exclusion (GE), as an effective strategy for revitalizing degraded grasslands, possesses the potential to increase ecosystem respiration (R) and significantly influence the capacity of grassland soils to sequester carbon. However, our current grasp of R dynamics in response to varying durations of GE, particularly in the context of precipitation fluctuations, remains incomplete. To fill this knowledge gap, we conducted a monitoring of R over a 40-year GE chronosequence within Inner Mongolia temperate typical steppe across two distinct hydrologically years.

Hydrogen-independent CO reduction dominates methanogenesis in five temperate lakes that differ in trophic states.

Emissions of microbially produced methane (CH) from lake sediments are a major source of this potent greenhouse gas to the atmosphere. The rates of CH production and emission are believed to be influenced by electron acceptor distributions and organic carbon contents, which in turn are affected by anthropogenic inputs of nutrients leading to eutrophication. Here, we investigate how eutrophication influences the abundance and community structure of CH producing and methanogenesis pathways across time-resolved sedimentary records of five Swiss lakes with well-characterized trophic histories.