[Spatiotemporal Evolution Patterns of Grassland Degradation and Its Driving Factors on the Loess Plateau].

The vegetation restoration strategies on the Loess Plateau are progressively orienting towards natural regeneration, utilizing grasslands for ecological recovery. However, there is a dearth of precise, in-depth quantification of the long-term spatio-temporal patterns and driving factors of grassland degradation in this area. This study, based on AVHRR and MODIS NDVI data, employs Google Earth Engine （GEE）, grassland degradation indices, and spatio-temporal analysis to examine the vegetation cover and degradation patterns of the Loess Plateau's grasslands from 1986 to 2021.

Declining precipitation frequency may drive earlier leaf senescence by intensifying drought stress and enhancing drought acclimation.

Precipitation is an important factor influencing the date of foliar senescence, which in turn affects carbon uptake of terrestrial ecosystems. However, the temporal patterns of precipitation frequency and its impact on foliar senescence date remain largely unknown. Using both long-term carbon flux data and satellite observations across the Northern Hemisphere, we show that, after excluding impacts from of temperature, radiation and total precipitation by partial correlation analysis, declining precipitation frequency may drive earlier foliar senescence date from 1982 to 2022.

Soil moisture determines effects of climates and soil properties on nitrogen cycling: Examination of arid and humid soils.

While soil moisture has a significant effect on nitrogen (N) cycling, how it influences the dependence of this important biological process on environmental factors is unknown. Specifically, it is unclear how the relationships of net N mineralization (N) and soil moisture vary with soil properties and climates. In turn, how the relationships of N vs.

Rainfall partitioning characteristics and simulation of typical shelter forest in Chinese Mu Us Sandy Land.

Numerous shelter forests have been established to combat desertification in the Mu Us Sandy Land, China. Shelter forests modify the characteristics of the underlying surface and affect the regional water cycle by altering rainfall partitioning. Understanding the rainfall partitioning process and its controlling factors for indigenous and exotic species is crucial for vegetation restoration and sustainable soil water management.

Soil moisture decline in China's monsoon loess critical zone: More a result of land-use conversion than climate change.

Soil moisture (SM) is essential for sustaining services from Earth's critical zone, a thin-living skin spanning from the canopy to groundwater. In the Anthropocene epoch, intensive afforestation has remarkably contributed to global greening and certain service improvements, often at the cost of reduced SM. However, attributing the response of SM in deep soil to such human activities is a great challenge because of the scarcity of long-term observations.

Analysis of soil water use by exotic and native vegetation in a semi-arid area and their associated interspecific competition.

The exotic vegetation used in dryland vegetation restoration projects is characterized by its fast-growing and deep-rooted system, which enables it to expedite the restoration of ecosystem functions and enhance biodiversity. However, the interspecific relationship between exotic and native vegetation and soil water uptake in these restored ecosystems remains unclear, limiting our ability to evaluate the succession process and sustainability of restored ecosystems. In this study, stable isotope techniques and a proportional similarity index were used to investigate soil water use strategies and interspecific relationships between exotic and native vegetation.

Contrasting response of soil microbiomes to long-term fertilization in various highland cropping systems.

Soil microbiomes play important roles in supporting agricultural ecosystems. However, it is still not well-known how soil microbiomes and their functionality respond to fertilization in various cropping systems. Here we examined the effects of 36 years of phosphorus, nitrogen, and manure application on soil bacterial communities, functionality and crop productivity in three contrasting cropping systems (i.

Characteristics, sources and influencing factors of atmospheric deposition of microplastics in three different ecosystems of Beijing, China.

As the research on microplastics (MPs) has intensified, more attention has been paid to MPs deposition in the atmosphere. This study further explores and compares the characteristics, the possible sources and influencing factors of deposition of MPs in three different ecosystems: forest, agricultural and residential area in Beijing. It was found that the deposited plastics were mostly white or black fibres, with PET and RY as the main MPs types.

Haplotype study of the mitochondrial control region of broiler breeds with different growth rates.

This study discussed the haplotype characteristics of mitochondrial control region (D-loop region) of broiler breeds with different growth rates as well as the relationships between different haplotypes and growth performance. The D-loop region's sequence size of the 974 individuals from 20 broiler breeds ranged from 1,231 to 1,232bp, as a C base deletion at 859 bp. A total of 52 mutation sites and 72 haplotypes were detected, which were divided into four haplogroups, A, B, C and E.

Tracing the Sources and Fate of NO in the Vadose Zone-Groundwater System of a Thousand-Year-Cultivated Region.

Excess nitrate (NO) loading in terrestrial and aquatic ecosystems can result in critical environmental and health issues. NO-rich groundwater has been recorded in the Guanzhong Plain in the Yellow River Basin of China for over 1000 years. To assess the sources and fate of NO in the vadose zone and groundwater, numerous samples were collected via borehole drilling and field surveys, followed by analysis and stable NO isotope quantification.

Distribution characteristics and controls of soil organic carbon at different spatial scales in China's Loess Plateau.

Understanding the variations and controls of soil organic carbon (SOC) at different spatial scales can help in selecting edaphic and environmental covariates that enables us to model SOC more accurately. The present study investigated the distribution characteristics and controls of SOC content at various spatial scales, including a deep soil core (204.5 m) taken from land surface down to bedrock (plot scale), two toposequences with different slope aspects (slope scale), and eighty-six soil profiles along a north-south transect under different land uses (regional scale) in China's Loess Plateau.

Erosion reduces soil microbial diversity, network complexity and multifunctionality.

While soil erosion drives land degradation, the impact of erosion on soil microbial communities and multiple soil functions remains unclear. This hinders our ability to assess the true impact of erosion on soil ecosystem services and our ability to restore eroded environments. Here we examined the effect of erosion on microbial communities at two sites with contrasting soil texture and climates.

Vertical distribution of soil available phosphorus and soil available potassium in the critical zone on the Loess Plateau, China.

Soil available phosphorus (SAP) and soil available potassium (SAK) are important elements in the growth of plants. However, limited data are available regarding the vertical distribution of SAP and SAK in deep soil profiles. In this study, we investigated the vertical variations in SAP and SAK in the critical zone on the Loess Plateau (50-200 m), China, by using classical statistical and geostatistical methods.

Characterization and phylogenetic evolution of mitochondrial genome in Tibetan chicken.

The objective of this study was to characterize mitochondrial genome and investigate phylogenetic evolution in Tibetan chicken. In this study, four haplotypes were identified based on D-loop sequencing in Tibetan chicken ( = 40), and each representative of four haplotypes was selected for total mitochondrial genome sequencing and analyzed together with published mitochondrial genome data of red jungle fowl. Four haplotypes belonged to three previously published clades, i.

Impacts of shrub introduction on soil properties and implications for dryland revegetation.

The intensive introduction of shrubs to drylands can alter species composition and affect a series of biotic and abiotic processes. This topic has attracted increasing attention by researchers. To assess the response of soil properties to vegetation succession in arid regions of China, we measured the soil water content (SWC) to a depth of 5-m and determined soil properties of surface (0-5 cm) and subsurface (20-25 cm) layers in areas of natural grasses (NGs) and planted shrubs (PSs).

Distributions of arsenic and other heavy metals, and health risk assessments for groundwater in the Guanzhong Plain region of China.

The aim of this study was to evaluate the quality of shallow groundwater and deep groundwater in the Guanzhong Plain region of China, as well as the related health risk to humans. In total, 130 groundwater samples were collected comprising 116 from shallow groundwater (dug wells) and 14 from deep groundwater (drilled wells). The water samples were analyzed to determine the levels of As and 12 other heavy metals (Al, Cd, Mn, Cr, V, Fe, Ni, Cu, Zn, Co, Pb, and Mo).

Insight into the vertical characteristics of dissolved organic matter in 5-m soil profiles under different land-use types on the Loess Plateau.

Dissolved organic matter (DOM) is a natural chemical component of all soils and influences soil organic pollutant migration, nutrient cycling, and global climate change. Previous field studies have focused on a single ecosystem, such as cropland, grassland, or forestland. However, the potential effect of different land-use types on the vertical distribution of soil DOM quantity and quality remains unclear.

What is the mass of loess in the Loess Plateau of China?

The Loess Plateau of China (LP) has the largest and thickest loess deposits in the world. Quantifying the amount of loess in the LP is crucial for investigating the accumulation and erosion of loess, and determining the regional soil and water resource capacity. We used loess thickness data, a pedotransfer function for bulk density (BD), and the clay content data observed in 242 sites across the LP to derive the BD of loess and then estimate the loess mass and its distribution across the LP.

Deep soil water storage varies with vegetation type and rainfall amount in the Loess Plateau of China.

Soil-water storage in a deep soil layer (SWSD), defined as the layer where soil water is not sensitive to daily evapotranspiration and regular rainfall events, functions as a soil reservoir in China's Loess Plateau (LP). We investigated spatial variations and factors that influence the SWSD in the 100-500 cm layers across the entire plateau. SWSD generally decreased from southeast to northwest following precipitation gradient, with a mean value of 587 mm.

Mineral N stock and nitrate accumulation in the 50 to 200m profile on the Loess Plateau.

Nitrogen (N) stored in deep profiles is important in assessing regional and/or global N stocks and nitrate leaching risk to groundwater. The Chinese Loess Plateau, which is characterized by significantly thick loess deposits, potentially stores immense stocks of mineral N, posing future threats to groundwater quality. In order to determine the vertical distributions of nitrate and ammonium content in the region, as well as to characterize the potential accumulation of nitrate in the deep loess profile, we study loess samples collected at five sites (Yangling, Changwu, Fuxian, An'sai and Shenmu) through a 50 to 200m loess profile.

Sap flow of black locust in response to short-term drought in southern Loess Plateau of China.

Soil water shortage is a major factor influencing the ecology and hydrology of vegetation in China's semihumid Loess Plateau. However, few studies have experimentally assessed how expected changes in precipitation will affect sap flow in semihumid forest ecosystems. In this study, we measured the sap flow of black locust (Robinia pseudoacacia Linn.

Phases and rates of iron and magnetism changes during paddy soil development on calcareous marine sediment and acid Quaternary red-clay.

Dynamic changes in Fe oxides and magnetic properties during natural pedogenesis are well documented, but variations and controls of Fe and magnetism changes during anthropedogenesis of paddy soils strongly affected by human activities remain poorly understood. We investigated temporal changes in different Fe pools and magnetic parameters in soil profiles from two contrasting paddy soil chronosequences developed on calcareous marine sediment and acid Quaternary red clay in Southern China to understand the directions, phases and rates of Fe and magnetism evolution in Anthrosols. Results showed that paddy soil evolution under the influence of artificial submergence and drainage caused changes in soil moisture regimes and redox conditions with both time and depth that controlled Fe transport and redistribution, leading to increasing profile differentiation of Fe oxides, rapid decrease of magnetic parameters, and formation of diagnostic horizons and features, irrespective of the different parent materials.