The impact of grazing intensity on soil characteristics of Stipa grandis and Stipa bungeana steppe in northern China (autonomous region of Ningxia)

Abstract. Large areas of grassland in the agro-pastoral region of northern China were converted into cropland for grain production, and the remaining grasslands are being overgrazed and seriously degraded. The objective of this study was to evaluate how reductions in grazing intensity affect the soil and vegetation characteristics in grasslands of northern China. Soil heterogeneity and vegetation characteristics were evaluated for ungrazed (UG), moderate grazing (MG), and heavy grazing (HG) sites. Grazing increased diversity, but heavy grazing decreased aboveground biomass and increased the non-grass component. Vegetation biomass was greatest at the UG site (220 g m−2) followed by the MG (99 g m−2) and HG (27 g m−2) sites (P < 0.05). The non-grass proportion of total biomass increased with grazing intensity, which was 8, 16, and 48 % for UG, MG, and HG sites, respectively. Species richness at the MG and HG sites was significantly higher than at the UG site (P < 0.05) with 3.6, 5.5, and 5.7 for UG, MG, and HG sites, respectively. Over grazing homogenized soil characteristics at a 10 m scale. The ranges of spatial autocorrelation for soil organic C (SOC) and total N were both > 120 m at the HG site, which was considerably larger than that at the MG and UG sites with corresponding distances of 17.3 and 20.8 m for the MG site and 25.8 and 15.0 m for the UG site, respectively. Therefore, MG was recommended as the preferred management alternative for grasslands in northern China because of increased plant diversity without negative consequences related to decreased forage quality and forage quantity, and soil heterogeneity in northern China's grasslands.

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The impact of grazing intensity on the allelopathic effect of Artemisia frigida in a temperate grassland in northern China

Flora ◽

10.1016/j.flora.2022.152005 ◽

2022 ◽

pp. 152005

Author(s):

Qing Wang ◽

Haidong Zhang ◽

Qian Yang ◽

Tiemei Wang ◽

Ziwei Zhang ◽

...

Keyword(s):

Grazing Intensity ◽

Northern China ◽

Temperate Grassland ◽

Allelopathic Effect ◽

Artemisia Frigida ◽

The Impact

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Grazing effects on soil characteristics and vegetation of grassland in northern China

Solid Earth ◽

10.5194/se-7-55-2016 ◽

2016 ◽

Vol 7 (1) ◽

pp. 55-65 ◽

Cited By ~ 9

Author(s):

Z. Wang ◽

D. A. Johnson ◽

Y. Rong ◽

K. Wang

Keyword(s):

Soil Properties ◽

Grazing Intensity ◽

Northern China ◽

Soil Heterogeneity ◽

Soil Characteristics ◽

Negative Consequences ◽

Total N ◽

Organic C ◽

Heavy Grazing ◽

Vegetation Characteristics

Abstract. Large areas of grassland in the agro-pastoral region of northern China were converted into cropland for grain production, and the remaining grasslands are being overgrazed and seriously degraded. The objective of this study was to evaluate how reductions in grazing intensity affect the soil and vegetation characteristics in grasslands of northern China. Soil heterogeneity and vegetation characteristics were evaluated for ungrazed (UG), moderate grazing (MG), and heavy grazing (HG) sites. Grazing increased diversity, but heavy grazing decreased aboveground biomass and increased the non-grass component. The non-grass proportion of total biomass increased with grazing intensity, which was 8, 16 and 48 % for UG, MG and HG sites, respectively. Species richness at the MG and HG sites was significantly higher than at the UG site (P< 0.05) with 3.6, 5.5 and 5.7 for UG, MG and HG sites, respectively. Strong spatial dependence of the examined soil properties at 10 m scale for all grazed sites was revealed by the ratio of nugget to total variation (0–23 %). Overgrazing homogenized soil characteristics at a 10 m scale. The ranges of spatial autocorrelation for soil organic C (SOC) and total N were both > 120 m at the HG site, which was considerably larger than that at the MG and UG sites with corresponding distances of 17.3 and 20.8 m for the MG site and 8.6 and 15.0 m for the UG site, respectively. The sampling density and sampling space for the HG site could be decreased under this scale sampling interval (10 m). Therefore, MG was recommended as the preferred management alternative for grasslands in northern China because of increased plant diversity without negative consequences related to decreased forage quality, forage quantity and soil heterogeneity for the investigated soil properties in northern China's grasslands.

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Effect of the Assimilation Frequency of Radar Reflectivity on Rain Storm Prediction by Using WRF-3DVAR

Remote Sensing ◽

10.3390/rs13112103 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2103

Author(s):

Yuchen Liu ◽

Jia Liu ◽

Chuanzhe Li ◽

Fuliang Yu ◽

Wei Wang

Keyword(s):

Data Assimilation ◽

Northern China ◽

Horizontal Resolution ◽

Radar Reflectivity ◽

Small Scale ◽

Time Interval ◽

Outer Domain ◽

Storm Prediction ◽

The Impact ◽

Assimilation Time

An attempt was made to evaluate the impact of assimilating Doppler Weather Radar (DWR) reflectivity together with Global Telecommunication System (GTS) data in the three-dimensional variational data assimilation (3DVAR) system of the Weather Research Forecast (WRF) model on rain storm prediction in Daqinghe basin of northern China. The aim of this study was to explore the potential effects of data assimilation frequency and to evaluate the outputs from different domain resolutions in improving the meso-scale NWP rainfall products. In this study, four numerical experiments (no assimilation, 1 and 6 h assimilation time interval with DWR and GTS at 1 km horizontal resolution, 6 h assimilation time interval with radar reflectivity, and GTS data at 3 km horizontal resolution) are carried out to evaluate the impact of data assimilation on prediction of convective rain storms. The results show that the assimilation of radar reflectivity and GTS data collectively enhanced the performance of the WRF-3DVAR system over the Beijing-Tianjin-Hebei region of northern China. It is indicated by the experimental results that the rapid update assimilation has a positive impact on the prediction of the location, tendency, and development of rain storms associated with the study area. In order to explore the influence of data assimilation in the outer domain on the output of the inner domain, the rainfall outputs of 3 and 1 km resolution are compared. The results show that the data assimilation in the outer domain has a positive effect on the output of the inner domain. Since the 3DVAR system is able to analyze certain small-scale and convective-scale features through the incorporation of radar observations, hourly assimilation time interval does not always significantly improve precipitation forecasts because of the inaccurate radar reflectivity observations. Therefore, before data assimilation, the validity of assimilation data should be judged as far as possible in advance, which can not only improve the prediction accuracy, but also improve the assimilation efficiency.

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Characterization of pasture biophysical properties and the impact of grazing intensity using remotely sensed data

Remote Sensing of Environment ◽

10.1016/j.rse.2007.01.013 ◽

2007 ◽

Vol 109 (3) ◽

pp. 314-327 ◽

Cited By ~ 82

Author(s):

Izaya Numata ◽

Dar A. Roberts ◽

Oliver A. Chadwick ◽

Josh Schimel ◽

Fernando R. Sampaio ◽

...

Keyword(s):

Grazing Intensity ◽

Remotely Sensed ◽

Biophysical Properties ◽

Remotely Sensed Data ◽

The Impact

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The Influence of Altitude on Erythropoietin Resistance Index in Maintenance Hemodialysis Patients: Data from Tibetan Plateau

Blood Purification ◽

10.1159/000510997 ◽

2020 ◽

pp. 1-6

Author(s):

Yan Wang ◽

Zong-hui Dang ◽

Liang-ying Gan ◽

Ciren Luobu ◽

Lei Zhang ◽

...

Keyword(s):

High Altitude ◽

Sea Level ◽

Resistance Index ◽

Hemoglobin Concentration ◽

Maintenance Hemodialysis ◽

Autonomous Region ◽

Tibet Autonomous Region ◽

Dialysis Vintage ◽

Peking University ◽

The Impact

Background: It is known that hypoxia influences many of the biologic processes involved in erythropoiesis; therefore, the high-altitude hypoxia may affect erythropoietin (EPO) responsiveness in maintenance hemodialysis (MHD) patients. This study aimed to evaluate the impact of altitude on EPO responsiveness in MHD patients. Methods: In this retrospective study, MHD patients from Tibet Autonomous Region People’s Hospital (3,650 m above sea level) and Peking University People’s Hospital (43.5 m above sea level) were recruited between May 2016 and December 2018. Patients were divided into 2 groups according to altitude. Variables including age, sex, dialysis vintage, dialysis modality, duration of EPO use, EPO doses, and laboratory tests were collected and analyzed. EPO responsiveness was measured in terms of the EPO resistance index (ERI). ERI was defined as the weekly weight-adjusted dose of EPO (IU/kg/week) divided by hemoglobin concentration (g/dL). The association between ERI and altitude was estimated using a multivariable linear regression model. Results: Sixty-two patients from Tibet Autonomous Region People’s Hospital (high-altitude [HA] group) and 102 patients from Peking University People’s Hospital (low-altitude [LA] group) were recruited. The ERI for HA group and LA group was 6.9 ± 5.1 IU w−1 kg−1 (g/dL)−1 and 11.5 ± 6.4 IU w−1 kg−1 (g/dL)−1, respectively. After adjusting for covariates by multivariable regression, altitude was independently associated with ERI (R2 = 0.245, p < 0.001). Conclusion: Altitude had an independent negative correlation with ERI. This result supported the hypothesis that altitude-associated hypoxia improved EPO responsiveness in MHD patients.

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Soil Type Modifies the Impacts of Warming and Snow Exclusion on Carbon and Nutrient Losses

10.21203/rs.3.rs-1139295/v1 ◽

2021 ◽

Author(s):

Stephanie M. Juice ◽

Paul G. Schaberg ◽

Alexandra M. Kosiba ◽

Carl E. Waite ◽

Gary J. Hawley ◽

...

Keyword(s):

Climate Change ◽

Nutrient Cycling ◽

Soil Type ◽

Soil Characteristics ◽

Nutrient Loss ◽

Climate Projections ◽

Nutrient Losses ◽

N Losses ◽

Total N ◽

The Impact

Abstract The varied and wide-reaching impacts of climate change are occurring across heterogeneous landscapes. Despite the known importance of soils in mediating biogeochemical nutrient cycling, there is little experimental evidence of how soil characteristics may shape ecosystem response to climate change. Our objective was to clarify how soil characteristics modify the impact of climate changes on carbon and nutrient leaching losses in temperate forests. We therefore conducted a field-based mesocosm experiment with replicated warming and snow exclusion treatments on two soils in large (2.4 m diameter), in-field forest sapling mesocosms. We found that nutrient loss responses to warming and snow exclusion treatments frequently varied substantially by soil type. Indeed, in some cases, soil type nullified the impact of a climate treatment. For example, warming and snow exclusion increased nitrogen (N) losses on fine soils by up to four times versus controls, but these treatments had no impact on coarse soils. Generally, the coarse textured soil, with its lower soil-water holding capacity, had higher nutrient losses (e.g., 12-17 times more total N loss from coarse than fine soils), except in the case of phosphate, which had consistently higher losses (23-58%) from the finer textured soil. Furthermore, the mitigation of nutrient loss by increasing tree biomass varied by soil type and nutrient. Our results suggest that potentially large biogeochemical responses to climate change are strongly mediated by soil characteristics, providing further evidence of the need to consider soil properties in Earth system models for improving nutrient cycling and climate projections.

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The Impact of Environmental Pollution on Ethnic Unrest in Xinjiang: A Uyghur Perspective

Modern China ◽

10.1177/0097700418819090 ◽

2018 ◽

Vol 45 (5) ◽

pp. 504-536 ◽

Cited By ~ 1

Author(s):

Nimrod Baranovitch

Keyword(s):

Environmental Degradation ◽

Large Body ◽

Han Chinese ◽

Ethnic Violence ◽

Chinese Government ◽

Autonomous Region ◽

Mass Migration ◽

Ethnic Tension ◽

Xinjiang Uyghur Autonomous Region ◽

The Impact

Since the early 1990s, the Xinjiang Uyghur Autonomous Region has been one of the most restive areas in China, and in recent years, following the July 2009 Urumchi riots, it has experienced frequent incidents of severe ethnic violence. A large body of scholarship has attempted to explain the sources of Uyghur discontent and pointed to various factors, including cultural and religious repression, unemployment, discrimination, and the mass migration of Han Chinese settlers into the region. This article proposes that environmental degradation, a factor that so far has received little attention in the research that focuses on ethnic tension in Xinjiang, is another important contributing factor. Focusing on air and water pollution in Xinjiang, but also addressing other types of environmental degradation, the article examines the attitudes of Uyghurs toward the phenomenon and shows how their perceptions have affected and been affected by their tense relationship with the Chinese government and the Han Chinese settlers in the region.

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Impact of grazing intensity on seasonal variations in soil organic carbon and soil CO 2 efflux in two semiarid grasslands in southern Botswana

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2012.0102 ◽

2012 ◽

Vol 367 (1606) ◽

pp. 3076-3086 ◽

Cited By ~ 53

Author(s):

Andrew D. Thomas

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Seasonal Variations ◽

Field Experiments ◽

Grazing Intensity ◽

C Sequestration ◽

Ecosystem Functions ◽

Semiarid Environments ◽

The Impact ◽

And Storage

Biological soil crusts (BSCs) are an important source of organic carbon, and affect a range of ecosystem functions in arid and semiarid environments. Yet the impact of grazing disturbance on crust properties and soil CO 2 efflux remain poorly studied, particularly in African ecosystems. The effects of burial under wind-blown sand, disaggregation and removal of BSCs on seasonal variations in soil CO 2 efflux, soil organic carbon, chlorophyll a and scytonemin were investigated at two sites in the Kalahari of southern Botswana. Field experiments were employed to isolate CO 2 efflux originating from BSCs in order to estimate the C exchange within the crust. Organic carbon was not evenly distributed through the soil profile but concentrated in the BSC. Soil CO 2 efflux was higher in Kalahari Sand than in calcrete soils, but rates varied significantly with seasonal changes in moisture and temperature. BSCs at both sites were a small net sink of C to the soil. Soil CO 2 efflux was significantly higher in sand soils where the BSC was removed, and on calcrete where the BSC was buried under sand. The BSC removal and burial under sand also significantly reduced chlorophyll a , organic carbon and scytonemin . Disaggregation of the soil crust, however, led to increases in chlorophyll a and organic carbon. The data confirm the importance of BSCs for C cycling in drylands and indicate intensive grazing, which destroys BSCs through trampling and burial, will adversely affect C sequestration and storage. Managed grazing, where soil surfaces are only lightly disturbed, would help maintain a positive carbon balance in African drylands.

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The Impact of Air Pollution (PM2.5) on Atherogenesis in Modernizing Southern versus Northern China

Atmosphere ◽

10.3390/atmos12121552 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1552

Author(s):

Kamsang Woo ◽

Changqing Lin ◽

Yuehui Yin ◽

Dongshuang Guo ◽

Ping Chook ◽

...

Keyword(s):

Risk Factors ◽

Air Pollution ◽

Northern China ◽

Age And Gender ◽

Carotid Imt ◽

Southern Chinese ◽

Northern Chinese ◽

Traditional Risk Factors ◽

And Gender ◽

The Impact

To evaluate the impact of PM2.5 air pollution on atherogenic processes in modernizing Southern versus Northern China, we studied 1323 asymptomatic Chinese in Southern and Northern China in 1996–2007. PM2.5 exposure and metabolic syndrome (MS) were noted. Brachial flow-mediated dilation (endothelial function FMD) and carotid intima-media thickness (IMT) were measured by ultrasound. Although age and gender were similar, PM2.5 was higher in Northern China than in Southern China. The Northern Chinese were characterized by lower lipids, folate and vitamin B12, but higher age, blood pressures, MS and homocysteine (HC) (p = 0.0015). Brachial FMD was significantly lower and carotid IMT was significantly greater (0.68±0.13) in Northern Chinese, compared with FMD and IMT (0.57 ± 0.13, p < 0.0001) in Southern Chinese. On multivariate regression, for the overall cohort, carotid IMT was significantly related to PM2.5, independent of location and traditional risk factors (Model R2 = 0.352, F = 27.1, p < 0.0001), while FMD was inversely related to gender, age, and northern location, but not to PM2.5. In Southern Chinese, brachial FMD was inversely correlated to PM2.5, independent of age, whereas carotid IMT was significantly related to PM2.5, independent of age and gender. In Northern Chinese, brachial FMD was inversely related to gender only, but not to PM2.5, while carotid IMT was related to traditional risk factors. Despite a higher PM2.5 pollution in Northern China, PM2.5 pollution was more significantly associated with atherogenic surrogates in Southern compared to Northern Chinese. This has potential implications for atherosclerosis prevention.

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