Effect of different vegetation restoration patterns on community structure and co-occurrence networks of soil fungi in the karst region.

Introduction: The Grain for Green Project (GGP) by the Chinese government was an important vegetation restoration project in ecologically fragile and severely degraded karst regions. Soil fungi play a facilitating role in the cycling of nutrients both above and below the ground, which is crucial for maintaining ecosystem function and stability. In karst regions, their role is particularly critical due to the unique geological and soil characteristics, as they mitigate soil erosion, enhance soil fertility, and promote vegetation growth.

Visualization and standardized quantification of surface charge density for triboelectric materials.

Triboelectric nanogenerator (TENG) operates on the principle of utilizing contact electrification and electrostatic induction. However, visualization and standardized quantification of surface charges for triboelectric materials remain challenging. Here, we report a surface charge visualization and standardized quantification method using electrostatic surface potential measured by Kevin probe and the iterative regularization strategy.

Thermal degradation of greenhouse gas SF at realistic temperatures: Insights from atomic-scale CVHD simulations.

Sulfur hexafluoride (SF), recognized as a potent greenhouse gas with significant contributions to climate change, presents challenges in understanding its degradation processes. Molecular dynamics simulations are valuable tools for understanding modes of decomposition while the traditional approaches face limitations in time scale and require unrealistically high temperatures. The collective variable-driven hyperdynamics (CVHD) approach has been introduced to directly depict the pyrolysis process for SF gas at practical application temperatures, as low as 1600 K for the first time.

Elevated Mercury Deposition, Accumulation, and Migration in a Karst Forest.

The karst forest is one of the extremely sensitive and fragile ecosystems in southwest China, where the biogeochemical cycling of mercury (Hg) is largely unknown. In this study, we investigated the litterfall deposition, accumulation, and soil migration of Hg in an evergreen-deciduous broadleaf karst forest using high-resolution sampling and stable isotope techniques. Results show that elevated litterfall Hg concentrations and fluxes in spring are due to the longer lifespan of evergreen tree foliage exposed to atmospheric Hg.

DFT study of SF adsorption by Pd-doped hydroxyl-terminal modified TiCT MXene.

Context: SF gas has a strong greenhouse effect, and how to treat SF in an environmentally friendly way has been a hot topic of current research. In this paper, the adsorption behavior of SF on the surface of Pd-doped hydroxyl-terminated modified TiCT (i.e.

Density functional theory studies of TiCTMXene nanosheets decorated with Au for sensing SF/Nnitrogen-containing decomposition gases.

SF/Nmixture is an alternative gas of SF, which is already used in electrical equipment. When a malfunction occurs , SF/Nwill decompose and further react with trace water and oxygen to produce nitrogen-containing gases such as NO, NO, NO and NF. It is necessary to monitor these gases to ensure the safe operation of the equipment.

Construction of response surface model for photoacoustic-based HS measurement system and significance analysis of multiple influential factors.

Herein we first introduce the relationship between the photoacoustic (PA) signals' intensity of hydrogen sulfide (HS) versus multiple parameters of optical path conditions, following by the construction of response surface method (RSM)-based models of the PA signals' intensity versus the distance l from the laser head to the convex lens, the distance l from the convex lens to the PA cell (PAC), and the distance l from the geometric center line of the light beam to the acoustic sensor. After that, we perform the significance analysis. The results show that the RSM model with a third-order configuration is relatively preferred.

Degradation Behaviors and Mechanism of Nitrile Butadiene Rubber Caused by Insulating Medium CFO.

CFO is a promising insulating medium in the manufacturing of environmentally friendly gas-insulated switchgears (GISs). The fact that it is not known whether it is compatible with sealing materials used in GISs limits its application. In this paper, the deterioration behaviors and mechanism of nitrile butadiene rubber (NBR) after prolonged exposure to CFO are studied.

Spatial heterogeneity of soil available medium- and micro-elements in evergreen-deciduous broadleaved forest in karst.

Understanding the spatial heterogeneity of soil available medium- and micro-elements in karst area can provide a valuable theoretical guideline for soil nutrient management of karst ecosystem. We collected soil samples at a soil depth of 0-10 cm using grid sampling (20 m×20 m) in a 25 hm (500 m×500 m) dynamic monitoring plot. We further analyzed the spatial variability of soil medium- and micro-elements and their drivers, with classic statistics analysis and geo-statistics analysis.

TiCT as a Sensor for SF/N Nitrogen-Containing Fault Decomposition Characteristic Products: A Theoretical Study.

The SF/N gas mixture is an alternative gas to SF. SF/N will decompose and generate nitrogenous characteristic gases, such as NO, NO, NO, and NF, when exposed to long-term partial discharge. The adsorption models of TiCT (T=O, F, OH) and NO, NO, NO, NF were constructed, and the most stable adsorption structure was selected in this paper.

Effect of Different Grain for Green Approaches on Soil Bacterial Community in a Karst Region.

Soil bacteria participate in nutrient cycling above and below ground to promote ecosystem stability and health. However, the relationship of soil bacteria and environmental factors following the Grain for Green (GfG) program remains poorly understood in southwest China. Soil samples were collected from seven Grain for Green sites that had been revegetated for 15 years.

Foundation species across a latitudinal gradient in China.

Foundation species structure forest communities and ecosystems but are difficult to identify without long-term observations or experiments. We used statistical criteria--outliers from size-frequency distributions and scale-dependent negative effects on alpha diversity and positive effects on beta diversity--to identify candidate foundation woody plant species in 12 large forest-dynamics plots spanning 26 degrees of latitude in China. We used these data (1) to identify candidate foundation species in Chinese forests, (2) to test the hypothesis--based on observations of a midlatitude peak in functional trait diversity and high local species richness but few numerically dominant species in tropical forests--that foundation woody plant species are more frequent in temperate than tropical or boreal forests, and (3) to compare these results with data from the Americas to suggest candidate foundation genera in northern hemisphere forests.

Soil and fine roots ecological stoichiometry in different vegetation restoration stages in a karst area, southwest China.

The cyclic process of carbon (C), nitrogen (N), and phosphorus (P) elements is an important factor affecting the function of the forest ecosystem. However, the relation between soil and root stoichiometric ratios, especially in karst areas with extremely fragile geology and intensive human disturbance has rarely been investigated. In the current study the concentrations of C, N, and P and their stoichiometric characteristics were investigated using sequential soil coring under different stages of vegetation restoration (primary forest, secondary forest, shrubland and grassland) and soil layer (0-10 cm, 10-20 cm, 20-30 cm) in fine root and soil samples.

Climate, Life Form and Family Jointly Control Variation of Leaf Traits.

Variation in leaf traits may represent differences in physiological processes and environmental adaptative strategies. Using multivariate analyses, we investigated 13 leaf traits to quantify the trade-off in these traits and the trait-climate/biome relationships based on the China Plant Trait Database, which contains morphometric and physiological character information on 1215 species for 122 sites, ranging from the north to the tropics, and from deserts and grasslands to woodlands and forests. Leaf traits across the dataset of Chinese plants showed different spatial patterns along longitudinal and latitudinal gradients and high variation.

Seasonal Changes and Vertical Distribution of Fine Root Biomass During Vegetation Restoration in a Karst Area, Southwest China.

In karst ecosystems, plants absorbing smaller amounts of nutrients, owing to shallow soil, show limited growth. In addition, fine roots (diameter < 2 mm) contribute to the regulation of nutrient cycles in terrestrial ecosystems. However, the spatial and temporal variations of fine root biomass in different vegetation types of the karst region remains poorly understood.

Spatial Patterns and Drivers of Microbial Taxa in a Karst Broadleaf Forest.

Spatial patterns and drivers of soil microbial communities have not yet been well documented. Here, we used geostatistical modeling and Illumina sequencing of 16S rRNA genes to explore how the main microbial taxa at the phyla level are spatially distributed in a 25-ha karst broadleaf forest in southwest China. , dominated by and , was the most abundant phylum (34.

Spatial distribution of tree species in evergreen-deciduous broadleaf karst forests in southwest China.

Understanding the spatial distribution of tree species in subtropical evergreen-deciduous broadleaf karst forest is fundamental to studying species coexistence and karst species diversity. Here, complete spatial randomness and heterogeneous Poisson process models were used to analyze the spatial distribution patterns of 146 species with at least one individual per ha in a 25-ha plot in southwest China. We used canonical correspondence analysis (CCA) and the torus-translation test (TTT) to explain the distributions of observed species.

Nitrogen uptake and transfer in a soybean/maize intercropping system in the karst region of southwest China.

Nitrogen (N) deficiency occurs in over 80% of karst soil of southwest China, which restricts regional agricultural production. To test whether N fixed by legumes becomes available to nonfixing companion species, N fluxes between soybean and maize under no, partial, and total restriction of root contact were measured on a karst site in southwest China. N content and its transfer between soybean and maize intercrops were explored in a 2-year plot experiment, with N movement between crops monitored using N isotopes.

Biogeographical patterns of biomass allocation in leaves, stems, and roots in China's forests.

To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China's forests using both the national forest inventory data (2004-2008) and our field measurements (2011-2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass.

[Soil fertility characteristics under different land use patterns in depressions between karst hills].

Soil samples were collected from the depressions between karst hills by grid sampling method (5 m x 5 m), soil pH, soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) in surface layer (0-20 cm) under different land use patterns (burning, cutting, cutting plus root removal, enclosure, maize plantation, and pasture plantation) were measured, the main factors of influencing the soil fertility was identified by principal component analysis (PCA), and the relationships between soil nutrients and microorganisms were demonstrated by canonical correlation analysis (CCA). The results showed that the soil was slightly alkaline (pH 7.83-7.