Exposure to polycyclic aromatic hydrocarbons (PAHs) from domestic heating and cooking combustion of different fuel types for elders in rural China.

Solid fuel combustion emitted abundant pollutants, especially polycyclic aromatic hydrocarbons (PAHs) which had significant minus impact on human health in rural China. PAHs in PM2.5 emitted from different fuels combustion and hydroxylated metabolites of PAHs (OH-PAHs) in urine samples of different fuel users were detected in this study. The indoor PAHs were higher than that in outdoors for solid fuel use households, and the concentration of PAHs in the indoor of liquefied petroleum gas (LPG) use household was not much lower than solid fuel use households. Biogas-use household produced the lowest PAHs, which significantly reduced 64-82% compared with those emitted by solid fuel combustion. The different combustion conditions influenced the gaseous PAHs in indoors between two sampling sites. The gas/particle partition indicated that PAHs tended to occur in the particle phase with increased molecular weight, and the absorption was the main mechanism. The relative higher contribution of high molecular weight PAHs (HMW-PAHs) in solid fuel use households than in clean fuel use households, induced more health risks of PAHs. The concentration of Σ10OH-PAHs in the urine samples for elders of different fuel-use households displayed the trend of coal (83.27 ng/mL) > wood (79.32 ng/mL) > LPG (51.61 ng/mL) > biogas (28.96 ng/mL), and OH-NaPs was the predominant metabolites, which accounted for more than 90% of the total concentration. The carcinogenic risk of PAHs based on internal exposure was greater than or close to 10-4, with serious carcinogenic risks. This was different with the incremental lifetime cancer risk based on the atmospheric concentrations. The exposure of PAHs from solid fuel combustion for human being especially for the elders in this region should be concerned, and more data should be done for the internal exposure of PAHs.

Occurrence characteristics and potential risk of microplastics under different land conditions.

Microplastics (MPs) pollution has caused widespread concern, more researchers have focused on MPs in farmland soil. However, the distribution of MPs in different land use types, land restoration years and crop types remained largely unexplored. Therefore, the study investigated the distribution characteristics and evaluated ecological risk of MPs in soil of northern Shaanxi Province, China. The abundance, particle size, morphology and polymer types of MPs in soil were analyzed by sample collection, Raman spectroscopy and laser direct infrared spectroscopy (LDIR). The ecological risk index (H) and pollution load index (PLI) were employed to assess the risks posed by MPs in the soil. It was shown that the concentration of MPs in farmland soil was the highest (4483 items·kg-1) among the different land use types. The average abundance of microplastics in farmland soil was 1.98 times than that in industrial park soil. An increase in restoration years corresponded with a decrease in MPs abundance and an increase in smaller-sized MPs. In addition, the content of MPs in the soil of perennial crops was more stable, with fluctuations less than 25%, and the size of MPs was smaller than that of the annual crops. The main types of MPs in the soil of the study area were PP (28.5%) and PET (24.1%), MPs with size between 20 and 40 µm were dominated. Based on the pollution load index (PLI), 51.9% of the sampling sites were categorized as moderately polluted, and the MPs pollution risk of farmland soil was the highest. Mild and moderate pollution caused fewer adverse impact, while extremely strong pollution was detrimental to ecosystems and human health. In general, the study would provide a foundational understanding of MPs pollution levels and environment risk associated with different land use types, land restoration years and crop types.

Characteristics of PM2.5 bounded carbonaceous aerosols, carbon dioxide and its stable carbon isotopes (δ13C) in rural households in northwest China: Effect of different fuel combustion.

In order to fully understand the carbon emission from different fuels in rural villages of China, especially in the typical atmospheric pollution areas. The characteristics of carbonaceous aerosols and carbon dioxide (CO2) with its stable carbon isotope (δ13C) were investigated in six households, which two households used coal, two households used wood as well as two households used biogas and liquefied petroleum gas (LPG), from two rural villages in Fenwei Plain from March to April 2021. It showed that the fine particulate matter (PM2.5) emitted from biogas and LPG couldn't be as lower as expected in this area. However, the clean fuels could relatively reduce the emissions of organic carbon (OC) and element carbon (EC) in PM2.5 compare to the solid fuels. The pyrolyzed carbon (OP) accounted more total carbon (TC) in coal than the other fuels use households, indicating that more water-soluble OC existed, and it still had the highest secondary organic carbon (SOC) than the other fuels. Meantime, the coal combustions in the two villages had the highest CO2 concentration of 527.6 ppm and 1120.6 ppm, respectively, while the clean fuels could effectively reduce it. The average δ13C values (-26.9‰) was much lighter than almost all the outdoor monitoring and similar to the δ13C values for coal combustion and vehicle emission, showing that they might be the main contributors of the regional atmospheric aerosol in this area. During the sandstorm, the indoor PM2.5 mass and CO2 were increasing obviously. The indoor cancer risk of PAHs for adults and children were greater than 1 × 10-6, exert a potential carcinogenic risk to human of solid fuels combustion in rural northern China. It is important to continue concern the solid fuel combustion and its health impact in rural areas.

Tire plastic and road-wear particles on Yujing Expressway in the restoration area of Mu Us Sandy Land: Occurrence characteristics and ecological risk screening.

Tire plastic and road-wear particles (TPR-WP) are a current research priority as one of the main environmental sources of microplastics. We selected a unique land use type - desert restoration area, collected soil and dust samples from the Yujing Expressway and its service areas, and analyzed TPR-WP abundance, type, size and morphology by laser direct infrared (LDIR). The abundance of TPR-WP in expressway dust (14,446.87 ± 10,234.24 n/kg) was higher than that in soil (7500 ± 3253.64 n/kg). Random forest model showed that the source of TPR-WP was highly correlated with economic factors and natural climate. Overall, the proportion of small and medium-sized TPR-WP in dust was higher than soil, more than half of the TPR-WP in dust were in 20 - 50 µm range. The proportion of small particle size TPR-WP increased with the rise of elevation. The pollution load index suggested that the survey region was generally at level I risk zone, while the ecological risk index indicated that the pollution level of expressway was III and IV, and the service area was IV. In general, the study was of great significance for clarifying the distribution and risk of TPR-WP in soil and dust of expressways and service areas.

Antibiotics and microplastics in manure and surrounding soil of farms in the Loess Plateau: Occurrence and correlation.

The wide use of animal manure in farmland operations is a source of soil nutrients. However, the return of manure affected antibiotics and microplastics in the soil, thus the potential ecological risks cannot be overlooked. This study investigated the distribution of different antibiotics and microplastics and their correlation. It was found that multiple classes of veterinary antibiotics and microplastics could be detected simultaneously in most manure and soil. In manure, the average concentration of tetracycline antibiotics was higher than fluoroquinolones and sulfonamides. A much lower concentration of antibiotics was found in the soil samples relative to manure. The abundance of microplastics ranged from 21,333 to 88,333 n/kg in manure, and the average abundance was 50,583 ± 24,318 n/kg. The average abundance was 3056 ± 1746 n/kg in the soil. It confirmed that applying organic fertilizer to agricultural soil and the application of plastic mulch in farmlands introduced microplastics. Moreover, microplastics were found to be significantly correlated with antibiotics (r = 0.698, p < 0.001). The correlation between microplastics and antibiotics in soil was significantly weaker than that in manure. Farms could be the hotspot for the co-spread of microplastics and antibiotics. These findings highlighted the co-occurrence of antibiotics and microplastics in agricultural environments.

Characteristics and health risk assessment of indoor and outdoor PM2.5 in a rural village, in Northeast of China: impact of coal and biomass burning.

Fine particulate matter (PM2.5) has health effects that may depend on its sources and chemical composition. In this study, characteristics of PM2.5 chemical composition and health risk assessment from Songyuan, China, were investigated during day and night in indoor and outdoor from February 4 to 19, 2021. Relative high concentrations of PM2.5 were obtained in indoor environment than outdoor, with 503.95 ± 209.62 µg/m3 during the day and 357.52 ± 232.81 µg/m3 at night for the indoor environment. Relatively high total carbon, organic carbons, elemental carbons, polycyclic aromatic hydrocarbons (PAHs), and oxygenated polycyclic aromatic hydrocarbons (OPAHs) were obtained in indoor environment. However, the average concentrations of PAHs were higher during night (73.57 ± 43.09 ng/m3) in indoor and OPAHs during day (6.027 ± 2.960 ng/m3) in outdoor. They had different I/O distributions of these compounds during day and night. Indeno(1,2,3-cd) pyrene was the dominant PAHs, and benzanthrone was the dominant OPAHs; this is different with the previous studies. The high indoor/outdoor ratios showed the indoor coal and biomass burning greatly affect the indoor pollutants. Average ILCR health risk assessment for PAHs was all higher than 10-6 for different age gender, suggesting there has potential cancer risk existed for populations living in the rural coal and biomass burning area Songyuan, China.

Contribution of microbial necromass to soil organic carbon formation during litter decomposition under incubation conditions.

We conducted a 512-day incubation experiment to study the dynamics of microbial necromass and soil carbon fraction in the 'litter-soil' transformation interface soil layer (TIS) during litter decomposition, using a perennial C3 herb, Stipa bungeana, in the loess hills. The results showed that soil microbial necromass was dominated by fungi in the early and middle stages, and by bacteria in the late stage. The contribution of fungal necromass C to mineral-associated organic C (MAOC) was significantly higher (38.7%-75.8%) than that of bacteria (9.2%-22.5%) and 2-3 times more than the contribution rate of bacterial necromass. Soil organic C (SOC) content was decreasing during litter decomposition. The input of plant C resources stimulated microbial utilization of soil C fractions. The continuous decrease in particulate organic C during the early and late stages of decomposition was directly responsible for the decrease in SOC content. In contrast, the fluctuating changes in microbial necromass C and MAOC played an indirect role in the reduction of SOC. The increase in soil microbial necromass C caused by a single exogenous addition of litter did not directly contribute to SOC accumulation.

A Holocene lacustrine record of variations in chemical weathering intensity in the Mu Us Desert, China.

The Mu Us Desert is an ideal location to study environmental changes during the Late Quaternary, because of its unique characteristics. The Abaoyan (ABY) profile, a typical aeolian-lacustrine profile located at the eastern edge of the desert, was investigated in this study. A basic chronological framework was established based on a combination of radiocarbon dating by accelerator mass spectrometry and in situ sedimentary phase identification. Furthermore, changes in regional chemical weathering intensity since the Holocene were evaluated through comprehensive analysis of the collected samples in terms of grain size, loss on ignition (LOI), chromaticity, geochemical element contents, and soil micromorphology. The results showed that the ABY profile was under the influence of primary and moderate chemical weathering. Regional paleoclimatic environmental changes could be divided into four stages. During Stage I (before 12.6 ka BP; pre-Holocene), the ABY profile was dominated by aeolian sand, showing a coarse average grain size, low LOI, and high chromaticity values, which may have indicated a dry and cold period. During Stage II (12.6-10.3 ka BP; early Holocene), the ABY profile was dominated by lacustrine sediments, indicating a shallow lake water environment with strong chemical weathering and a warm and humid climate. During Stage III (10.3-4.2 ka BP), the profile was dominated by sandy peat deposits with a relatively large proportion of clay particles suggesting that the intensity of chemical weathering was relatively strong in the region during this period and the climate was mainly warm and humid. During Stage IV (after 4.2 ka BP), the sediment was dominated by aeolian sand and secondary loess, the chromaticity increased, the LOI reduced, and the regional chemical weathering intensity was weaker. The change in chemical weathering intensity in this region was inferred to be a positive response to the Holocene East Asian monsoon circulation.

Unintended consequences of combating desertification in China.

Since the early 2000s, China has carried out extensive "grain-for-green" and grazing exclusion practices to combat desertification in the desertification-prone region (DPR). However, the environmental and socioeconomic impacts of these practices remain unclear. We quantify and compare the changes in fractional vegetation cover (FVC) with economic and population data in the DPR before and after the implementation of these environmental programmes. Here we show that climatic change and CO2 fertilization are relatively strong drivers of vegetation rehabilitation from 2001-2020 in the DPR, and the declines in the direct incomes of farmers and herders caused by ecological practices exceed the subsidies provided by governments. To minimize economic hardship, enhance food security, and improve the returns on policy investments in the DPR, China needs to adapt its environmental programmes to address the potential impacts of future climate change and create positive synergies to combat desertification and improve the economy in this region.

New insights into adsorption mechanism of pristine and weathered polyamide microplastics towards hydrophilic organic compounds.

The widespread coexistence of hydrophilic organic compounds and microplastics (MPs) in the environment has greatly increased their associated environmental problems. To evaluate the potential carrier effect of oxygen-containing MPs on coexisting pollutants, adsorption behaviors of four hydrophilic organic compounds (benzoic acid, sulfamethoxazole, sulfamerazine and ciprofloxacin) on MPs (pristine and weathered polyamide (PA)) were studied in the aquatic environment. The results showed that the surface morphology, size, oxygen content, molecular structure, surface charge and crystallinity of PA were changed after weathering, and the weathering degree of PA treated with heat-activated potassium persulfate was the highest. The main adsorption mechanisms included hydrogen bonding, hydrophobic interaction, charge-assisted hydrogen bonding, and electrostatic interaction. Hydrogen bonding and hydrophobic interaction contributed to the adsorption, while electrostatic interaction weakened the adsorption under the specific pH conditions. The formation of charge-assisted hydrogen bonding (CAHB) was also verified through pH influence experiments, and this force can overcome the electrostatic repulsion. The high adsorption of KPA (PA weathered by K2S2O8) under alkaline conditions was well explained by the formation of homonuclear CAHB due to the increase of oxygen-containing functional groups compared to the other three PA. Additionally, weathering did not always enhance the adsorption of hydrophilic organic compounds on PA, which was related to the changes in surface charge, crystallinity and hydrophilicity of PA. Overall, the physical and chemical properties (e.g., specific surface area, oxygen content, molecular structure) of PA after weathering and its trend of adsorption were different from other oxygen-free MPs in this study. This work can provide basic data for environmental risk of MPs and contribute to clarify and understand the processes of oxygenated MPs in the aquatic environment.

Trace elements in outdoor and indoor PM2.5 in urban schools in Xi'an, Western China: characteristics, sources identification and health risk assessment.

The PM2.5-bounded elements were measured in outdoor and indoor from two urban middle schools in Xi'an. The PM2.5 mass was from 42.4 to 283.7 µg/m3 with bounded element from 3.4 to 41.7 µg/m3. Both the particle mass and the bounded elements displayed higher levels compared with previous studies in school environments. The most abundant elements were Ca, K, Fe, S, Zn and Cl both indoor and outdoor in two schools, which accounted for about 90% of the total elements. Strong correlations between indoor and outdoor were obtained along with relative effect from students' and teachers' activities on the indoor distributions between workdays and weekends. There had different indoor/outdoor (I/O) distributions for the two schools. It revealed the main outdoor sources for elements in JT and predominance of indoor sources in HT. The principal component analysis investigated main sources of elements in this study were coal combustion, geogenic dust and industrial emission, even though there displayed differences in the two school classrooms. The health risk assessment showed that the cancer risk for Ni and Pb was below the safe value while As and Cr might pose acceptable potential threat to both students' and teachers' health. The total non-cancer risks of accumulative multi-metals in JT exhibited to be higher than 1, indicating that there existed the potential non-carcinogenic health risks of exposure metals.

Assessment of the inhalation exposure and incremental lifetime cancer risk of PM2.5 bounded polycyclic aromatic hydrocarbons (PAHs) by different toxic equivalent factors and occupancy probability, in the case of Xi'an.

Polycyclic aromatic hydrocarbons (PAHs) are widespread toxic pollutants in the atmosphere and have attracted much attention for decades. In this study, we compared the health risks of PAHs based on different toxic equivalent factors (TEFs) in a heavily polluted area during heating and non-heating periods. We also pay attention to occupancy probability (OP) in different polluted areas. The results showed that there were big differences for calculations by different TEFs, and also by OP or not. Age groups except adults were all lower calculated by OP than not. The sensitivity analysis results on the incremental lifetime cancer risks (ILCR) for population groups by Monte Carlo simulation identified that the cancer slope factor extremely affected the health risk assessment in heating periods, followed by daily inhalation exposure levels. However, daily inhalation exposure levels have dominated the effect on the inhalation ILCR and then followed by the cancer slope factor in non-heating periods. The big differences by different calculations investigated that it is important to set up the correlations between the pollution level and health risks, especially for the longtime health assessment.

The seasonal variation, characteristics and secondary generation of PM2.5 in Xi'an, China, especially during pollution events.

As an important central city in western China, Xi'an has the worst atmospheric pollution record in China and many measures have been taken to improve the air quality in the past few years. In this study, PM2.5 samples were collected across four seasons from 2017 to 2018 in Xi'an. Organic carbon and elemental carbon, water soluble ions, and elements were monitored to assess the air quality. The average annual PM2.5 concentration was (134.9 ± 48.1 µg/m3), with the highest concentration in winter (188.8 ± 93.2 µg/m3), and lowest concentration in summer (71.2 ± 12.1 µg/m3). The secondary generation of sulfate (SO42-) and nitrate (NO3-) was strong in spring, and secondary organic carbon (SOC) was formed in all seasons. The compositions of PM2.5 changed greatly during a sandstorm occurred and the Spring Festival. The sandstorm played a positive role in removing local pollutant NO3-, but also increased the concentration of SO42-, however both the concentration of SO42- and NO3- greatly increased by secondary generation during Spring Festival. Potential source analysis showed that during the sandstorm, pollutants were transported over a long distance from the northwest of China, whereas it was mainly from the local and surrounded emissions during the Spring Festival. Except Ca2+ and geological dust (GM), the other components in PM2.5 increased significantly on the day of the Spring Festival. During sampling time in Xi'an, the positive matrix factorization (PMF) model analysis showed that PM2.5 mainly came from vehicle emission, coal combustion, and biomass burning.

Research progress of heavy metals in desert-visual analysis based on CiteSpace.

In this paper, Web of Science (a database) is used to retrieve related literature in the field of heavy metal pollution in desert. CiteSpace is used to make a quantitative and qualitative evaluation on the literature in the field on the basis of a brief analysis on the research status, research focus, and evolution process in the field. Through CiteSpace visual analysis, a comparative analysis is given on related literature in terms of annual number of published papers, author groups, and their countries and regions, journals, publishing institutions, highly cited papers, research focuses, and burst terms, so as to explore the research status and future development trend of the field on a global scale. The results are shown as follows: (1) The literature in the field was originally published in 2000; the number of published papers increased steadily. The literature was mostly published on high-quality journals, the USA topped in terms of the number of published papers, and the research results achieved by developed countries had a greater influence. Chinese Acad Sci topped with the highest centrality and most published papers, which have made outstanding contributions to the field and occupy a leading position in the field. However, the fact is that there lacks communication and cooperation among research institutions. The most influential journal is Science of the Total Environment. (2) The hot research words in the field are as follows: heavy metal, soil, pollution, lead, desert, cadmium, and microelement. (3) In the field, burst terms have transformed from atmospheric deposition, biomonitoring, and phytoremediation to trace element, stream sediment, street dust, and water quality, and finally transformed to river and sediment. New words keep emerging in the research, and more and more attention is paid to the issue of heavy metal pollution in river sediment, which will be a future research hotspot in the field.

Direct validation of dune instability theory.

Modern dune fields are valuable sources of information for the large-scale analysis of terrestrial and planetary environments and atmospheres, but their study relies on understanding the small-scale dynamics that constantly generate new dunes and reshape older ones. Here, we designed a landscape-scale experiment at the edge of the Gobi desert, China, to quantify the development of incipient dunes under the natural action of winds. High-resolution topographic data documenting 42 mo of bedform dynamics are examined to provide a spectral analysis of dune pattern formation. We identified two successive phases in the process of dune growth, from the initial flat sand bed to a meter-high periodic pattern. We focus on the initial phase, when the linear regime of dune instability applies, and measure the growth rate of dunes of different wavelengths. We identify the existence of a maximum growth rate, which readily explains the mechanism by which dunes select their size, leading to the prevalence of a 15-m wavelength pattern. We quantitatively compare our experimental results with the prediction of the dune instability theory using transport and flow parameters independently measured in the field. The remarkable agreement between theory and observations demonstrates that the linear regime of dune growth is permanently expressed on low-amplitude bed topography, before larger regular patterns and slip faces eventually emerge. Our experiment underpins existing theoretical models for the early development of eolian dunes, which can now be used to provide reliable insights into atmospheric and surface processes on Earth and other planetary bodies.

Metagenomics Reveal Correlations Between Microbial Organisms in Soils and the Health of Populus euphratica.

Biological diversity plays an important role in the stability of ecosystems. The Mu Us Desert (MUD), located in Northern China, is an aeolian desert. Although it has been governed by a series of ecological restoration programs, the MUD still has limited biological diversity. Populus euphratica (P. euphratica), a xerophytic plant, has great potential to improve the biological diversity of the MUD. However, the survival rate of P. euphratica in the MUD has been very low. The current study tried to explore the mechanism of the high death rate of P. euphratica in the microbiome perspective. The correlation study between soil community composition and soil properties showed that water-filled pore space (WFPS), pH, EC, AP, NO3 -, and NH4 + possess higher potential to change the bacterial community (18%) than the fungal community (9%). Principal coordinate analysis indicated that the composition of both bacteria (Proteobacteria and Bacteroidetes) and fungi (Ascomycota) in the root soil can be increased by P. euphratica. By systematically comparing between the fungal diversity in the root soil around P. euphratica and the pathogenic fungus extract from the pathogenic site of P. euphratica, we found that the high death rate of P. euphratica was associated with specific pathogenic fungus Alternaria alternate and Didymella glomerata. In addition, the microbiome composition analysis indicated that P. euphratica planting could also influence the portions of bacteria community, which also has great potential to lead to future infection. However, as the extraction and separation of bacteria from plants is challenging, the correlation between pathogenic bacteria and the high death rate of P. euphratica was not studied here and could be explored in future work.

Effect of vegetation patchiness on the subsurface water distribution in abandoned farmland of the Loess Plateau, China.

Patchiness of grassland results in important effects on ecohydrological processes in arid and semiarid areas; however, the influences on subsurface water flow and soil water distribution remain poorly understood, particularly during vegetation succession on slopes. This study examined these effects by comparing the water flow behaviors and preferential infiltration between vegetation patches (VP) and interspace patches (IP) in three sites at different states of vegetation succession (grass, subshrub and shrub) in abandoned farmland of the Loess Plateau, China. Dye tracer infiltration showed that patchiness of vegetation increased spatial variations of soil water and preferential infiltration by increasing the densities of fine root length and fine root volume in the soil profile. Moreover, the more abundant and intricate roots following a lateral direction beneath VP likely contributed to lateral flow and infiltration variability. However, differences between VP and IP were not significant because considerable living fine roots and decayed roots of IP also provided preferential flow pathways. Our finding indicated that IP could compete with VP for access to soil water resources, which potentially increased hillslope-scale infiltration and reduced surface runoff and erosion risk. Under the different states of vegetation succession, subshrub patches showed significantly greater preferential infiltration volume (28.53 mm) and contribution of preferential infiltration to total infiltration (60.58%) than grass and shrub patches. Vegetation patch size made positive effects on improving preferential flow and water movement. Greater preferential flow in subshrub patches played a positive role in soil water storage and replenishment. Therefore, natural restoration of a slope area with small heterogeneity in preferential flow can be successfully applied in the Loess Plateau, particularly during the subshrub succession state.

The effectiveness of a multi-row Tamarix windbreak in reducing aeolian erosion and sediment flux, Niatak area, Iran.

Windbreaks are barriers that are widely used to reduce wind speed and aeolian erosion. Most windbreak studies have been done in wind tunnels and generally used rigid objects rather than live plants and most of these studies report on the modification of the flow field and not on the effectiveness at reducing sediment transport. A series of experiments were conducted to monitor the effectiveness of a fourteen-rows Tamarix windbreak in the field and in particular to measure the reduction in sediment erosion and transport. Over the course of six dust storm events, with mean wind speed ranging from 9.4 to 18.2 ms-1, sediment flux and wind speed were measured at seven heights (z/h = 0.05, 0.1, 0.2, 0.4, 0.8, 1.4 and 1.8 where h is the mean height of the windbreak) at five locations upwind (x=-100 m), within (x = 100 and 256 m) and downwind (x = 448 and 560 m) of the windbreak. Largest reduction of sediment flux (a reduction of 50%) was observed at the end of the windbreak (x = 256 m). The decrease in silt and clay component is quite uniform but the relative concentration of sand (>100 µ) generally decreases within the windbreak and remained lower downwind of the windbreak compared to the upwind value in two of the three events for which sediment size data are available. The windbreak is effective in aeolian erosion control under a variety of dusty conditions and, in general, the potential of the windbreak is optimum due to its optimal porosity (39%) and structure (multiple-row design). Because Tamarix withstand harsh conditions, it is optimal to use it as a windbreak for wind and blown-sediment control in arid regions.

Vegetation morphologic and aerodynamic characteristics reduce aeolian erosion.

ABSRACT: Vegetation cover is crucial to controlling aeolian erosion but highly efficient vegetation is critical. How this efficiency is influenced by vegetation response to airflow is not clear. Here we evaluate the responses of Cosmos bipinnatus and Ligustrum lucidum Ait to a range of wind speeds in a wind tunnel. For both species, we calculate shelter effect and sand flux. We show that plant effectiveness in reducing wind speed and sediment transport is linked to their aerodynamic response to airflow which results from their morphology. We demonstrate that in low-density cover the flow-response and resistance of individuals is most critical in the optimal effectiveness of a canopy. Our wind tunnel experiment suggests that vegetation morphology and structure must be priority parameters in facilitating aeolian erosion control.