Soil microbiota are significantly influenced by their microenvironments. Therefore, to understand the impacts of various land use patterns on the diversity and composition of soil bacterial communities, this study focused on three typical land use types-NF (natural forest), AF (artificial forests), and FL (farmland)-in the Heilongjiang Central Station Black-billed Capercaillie National Nature Reserve, located in the southwestern part of Heihe City, Heilongjiang Province, China. Using high-throughput sequencing of the 16S rRNA gene, we examined the soil bacterial community structures in these different land use types and explored their correlation with soil environmental factors. The following were our main observations: (1) Significant variations in soil chemical properties among different land use patterns were observed. In artificial forests, total nitrogen (TN), alkali hydrolyzed nitrogen (AN), total phosphorus (TP), and available phosphorus (AP) were higher compared to farmland and significantly higher than those in natural forests. Furthermore, the organic carbon content (SOC) in natural forests was higher than in artificial forests and significantly higher than in farmland. (2) Comparative analysis using the Shannon and Simpson indices revealed that bacterial community diversity was higher in artificial forests than in natural forests, which was significantly higher than in farmland. (3) The effect of different land use types on soil bacterial community structure was not significant. The three land types were dominated by Proteobacteria, Acidobacteria, and Actinobacteria. Proteobacteria exhibited a higher relative abundance in farmland and artificial forests compared to natural forests, whereas Actinobacteria exhibited the lowest relative abundance in natural forests. (4) Redundancy analysis (RDA) revealed that SOC, TN, AN, and AP were key environmental factors influencing the microbial communities of soil. Collectively, our findings demonstrated that land use practices can significantly alter soil nutrient levels, thereby influencing the structure of bacterial communities.

New construction has resulted in impervious surfaces increasingly replacing natural landscapes, altering surface radiation, thermal properties, and humidity in urban areas. Based on Landsat-8 data, the temporal and spatial impacts of the construction of Dalian Jinzhouwan Airport and Beijing Daxing Airport on the thermal environment were studied. The local thermal gradient (LTG) of the airport before and after construction is compared. The results showed that after the completion of the airport, the LTG value of Daxing Airport increased by 0.033 and that of Jinzhou Bay Airport increased by 0.009. After the airport operation, LTG values increase again. Daxing Airport added another 0.053, and Jinzhou Bay Airport added another 0.127. Two land classification models (land use type, LUT; local climate zone, LCZ) were used to explore the relationship between land use type and LTG. The results show that the increase of alloy buildings after the completion of the airport has a great influence on the thermal environment of the two study areas. The operation of airports will further enhance this effect. Our study can provide a reference for the influence of large-scale traffic construction on the urban thermal environment.

Evidence on land use/land cover (LULC) change and its effect on soil properties are important for sustainable land management interventions. Hence, this study was conducted to analyze LULC change over a period of 31 years and to evaluate the effects of land use on soil properties in the Ganzer watershed, northwest Ethiopia. Landsat satellite images (1988, 2002 and 2019) were used as a source of information image analysis and LULC classification were done using ERDAS imagine 2010 software. About 24 composite soil samples were collected from four land use types (natural forest, plantation forest, cultivated and grazing lands) at two soil depths (0-20 and 20-40 cm) to determine soil properties. Standard soil analytical methods were used in carrying out soil analysis. The result revealed that the study site has undergone extensive land use changes where cultivated and grazing lands declined by 5.4% and 22.6%, respectively. However, the settlement and forest lands increased by 7.9% and 20%, respectively (1988-2019). The soil physicochemical properties differed significantly (p < 0.05) across the land use types and with soil depth. Higher contents of clay, pH, organic carbon (OC), total nitrogen (TN), available phosphorus (AP), exchangeable bases (Ca, Mg, K, Na) and CEC were recorded in the natural forest than in the other land use types. Similarly, pH, clay, BD and exchangeable bases increased with an increase in soil depth across all land use types. Generally, LULC change in the study area showed a significant increase in settlement and forest lands due to population pressure and expansion of eucalyptus plantation forests. These inappropriate land use changes have a negative effect on soil properties. Therefore, an appropriate and effective intervention in the land use systems should be implemented to amend soil properties.

Land use change obviously changes the plant community composition and soil properties of grasslands and thus affects multiple functions and services of grassland ecosystems. However, the response mechanisms of soil microorganisms, key drivers of the nutrient cycle and other soil functions during changes in grassland use type and associated vegetation are not well understood. In this study, Illumina high-throughput sequencing was used to analyze the changes in the soil microbial community structure of four grassland use types: exclosure (EL), mowed land (ML), grazed land (GL), and farmland (FL) in the Songnen Plain of Northeast China. The results showed that the FL and EL had significantly higher soil total nitrogen (TN) and lower soil electrical conductivity (EC) and pH than GL and ML. In contrast, the GL and ML had higher soil bulk density (BD) and organic matter, respectively, than the other land use types. In addition, the values of the Shannon diversity and Pielou\'s evenness indexes were highest in the EL of all the land use types. Based on the high-throughput sequencing results, we observed high levels of α diversity in the FL for both bacteria and fungi. A structural equation model (SEM) revealed that pH and EC had a direct and positive effect on the bacterial community structure and composition. In addition, plant taxonomic diversity (according to the Shannon diversity and Pielou\'s evenness indexes) indirectly affected the bacterial community composition via soil pH and EC. Notably, fungal composition was directly and positively correlated with soil nutrients and the value of Pielou\'s evenness index changed with land use type. In conclusion, soil properties and/or plant diversity might drive the changes in the soil microbial community structure and composition in different grassland use types.

Soil is a naturally occurring non-renewable resource, and good soil quality is a prerequisite for the survival of plants, animals and humans. Soil quality depends on the content and distribution of trace elements. Gold mining in the Witwatersrand Basin in South Africa left behind enormous unrehabilitated mining waste tailings near the City of Johannesburg that are contaminated by trace elements. Heavy metals change the physical and chemical properties of the soil derived from the mining waste material, consequently disturbing the normal functions of the soil and posing a potential health risk to plants, animals, and humans. To assess soil quality from abandoned historical gold mine residues, three conglomerate samples were petrologically examined using hand specimen, polished thin sections viewed under a reflected light microscope, and X-ray diffraction, to determine the mineralogical composition. The minerals include quartz, mica, chlorite, calcite and sulphides. Geochemical data of major elements measured by weight percent (wt%) were generated using X-ray fluorescence (XRF) technique and are NiO < Cr2O3 < V2O5 < ZrO2 < MnO < P2O5 < TiO2 < Al2O3 < CaO < MgO < Na2O < K2O < Fe2O3 < SiO2. The geochemistry of trace elements, pH, and electrical conductivity (EC), were determined from 21 soil samples. The samples were collected from 30 to 150 cm depths from nine sites and investigated using inductively coupled plasma optical emission spectroscopy (ICP-EOS) and XRF. ICP-EOS data (mg/kg): Fe > S > Cu > Mn > Cr > Zn > Ni > Co > Mo > P, and XRF data (mg/kg): S > F > Cl > V > Cr > Zn > Co > Cu > Ni > Mo. The trace elements data are variable in the tailing soil than in the crustal background soil. According to ICP-EOS data, the surveyed sites show increased Cu content, pH values of 1.9-5.3 and EC values of 43-679 mS/m, indicating soil contamination.

Rivers act as a natural source of greenhouse gases (GHGs). However, anthropogenic activities can largely alter the chemical composition and microbial communities of rivers, consequently affecting their GHG production. To investigate these impacts, we assessed the accumulation of CO2, CH4, and N2O in an urban river system (Cuenca, Ecuador). High variation of dissolved GHG concentrations was found among river tributaries that mainly depended on water quality and land use. By using Prati and Oregon water quality indices, we observed a clear pattern between water quality and the dissolved GHG concentration: the more polluted the sites were, the higher were their dissolved GHG concentrations. When river water quality deteriorated from acceptable to very heavily polluted, the mean value of pCO2 and dissolved CH4 increased by up to ten times while N2O concentrations boosted by 15 times. Furthermore, surrounding land-use types, i.e., urban, roads, and agriculture, could considerably affect the GHG production in the rivers. Particularly, the average pCO2 and dissolved N2O of the sites close to urban areas were almost four times higher than those of the natural sites while this ratio was 25 times in case of CH4, reflecting the finding that urban areas had the worst water quality with almost 70% of their sites being polluted while this proportion of nature areas was only 12.5%. Lastly, we identified dissolved oxygen, ammonium, and flow characteristics as the main important factors to the GHG production by applying statistical analysis and random forests. These results highlighted the impacts of land-use types on the production of GHGs in rivers contaminated by sewage discharges and surface runoff.

Influence of land use type and urbanization level on the distribution of pharmaceuticals and personal care products (PPCPs) from the developed regions of Beijing-Tianjin-Hebei in the northern China was evaluated. The seasonal and spatial variations of the 22 target PPCPs were analyzed in the 63 sampling sites along the whole Beiyun River Basin. Results showed that the total PPCPs concentration had a wide variation range, from 132 ng L-1 to 25474 ng L-1. Spatial interpolation analysis showed that agricultural land presented higher PPCPs contamination level than build-up land (p < 0.05) and the concentration was negatively correlated with urbanization level. Source apportionment showed the untreated sewage source contributed to 34%-53% of the PPCPs burden in the Beiyun River. Risk assessment indicated that diethyltoluamide, carbamazepine, octocrylene, gemfibrozil and triclocarban had high risks (RQ > 1), and small tributaries had the highest mixed risk (MRQ = 34). Species sensitivity distribution combined with the safety threshold method showed that PPCPs would have potential risk on aquatic organisms even at very low concentrations and triclocarban posed the highest risk in the Beiyun River.

UNASSIGNED: Management of malaria transmission relies heavily on vector control. Implementation and sustenance of effective control measures require regular monitoring of malaria vector occurrences, species abundance and distribution. The study assessed mosquito larval species composition, distribution and productivity in Kakamega County, western Kenya.
UNASSIGNED: A cross-sectional survey of Anopheline larvae was conducted in various aquatic habitats and land use types in Kakamega County, highlands of western Kenya between the month of March and June 2019.
UNASSIGNED: One thousand, five hundred and seventy six aquatic habitats were sampled in various land use types. The mean densities of An. gambiae s.l (46.2), An. funestus (5.3), An. coustani (1.7), An. implexus (0.13) and An. squamosus (2.0) were observed in fish ponds, burrow pits, drainage ditches, and tire tracks, respectively. High mean densities of An. gambiae s.l was reported in farmland (20.4) while high mean abundance of An. funestus s.l (8.2) and An. coustani s.l (4.0) were observed in artificial forests.
UNASSIGNED: The study revealed that the productivity of anopheles larvae varied across various habitat types and land use types. Therefore, treatment of potential breeding sites should be considered as an additional strategy for malaria vector control in Kakamega County, western Kenya.

In order to determine the ecological risk and health risk of Arsenic (As) and Cadmium (Cd) in soils from a typical mining city in Huainan, a total of 99 soil samples were collected and analyzed. The results showed that the concentrations of As and Cd ranged from 3.2 to 39.50 and 0.01 to 0.19 mg/kg, respectively, which exceeded the soil background values by 6.06 and 14.14%, respectively. The soil pH and content of organic carbon demonstrated no significant (P > 0.05) correlation with the As and Cd concentrations, while the land use types significantly (P < 0.05) affected the As and Cd distribution. According to the Nemero synthesis pollution index, three spot areas were identified as moderately to strongly polluted. The potential ecological risk index ranged from 4.34 to 108.64, which represented that the potential ecological risk was low. In addition, children faced more carcinogenic risk of As. Consequently, mining has increased the concentrations of As and Cd in soils, and the carcinogenic risk of As to children should be paid more attention.

Land use types with different disturbance gradients show many variations in soil properties, but the effects of different land use types on soil nitrifying communities and their ecological implications remain poorly understood. Using 13CO2-DNA-based stable isotope probing (DNA-SIP), we examined the relative importance and active community composition of ammonia-oxidizing archaea (AOA) and bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in soils under three land use types, forest, cropland, and greenhouse vegetable soil, representing three interference gradients. Soil net nitrification rate was in the order forest soil > cropland soil > greenhouse vegetable soil. DNA-SIP showed that active AOA outcompeted AOB in the forest soil, whereas AOB outperformed AOA in the cropland and greenhouse vegetable soils. Cropland soil was richer in NOB than in AOA and AOB. Phylogenetic analysis revealed that ammonia oxidation in the forest soil was predominantly catalyzed by the AOA Nitrosocosmicus franklandus cluster within the group 1.1b lineage. The 13C-labeled AOB were overwhelmingly dominated by Nitrosospira cluster 3 in the cropland soil. The active AOB Nitrosococcus watsonii lineage was observed in the greenhouse vegetable soil, and it played an important role in nitrification. Active NOB communities were closely affiliated with Nitrospira in the forest and cropland soils, and with Nitrolancea and Nitrococcus in the greenhouse vegetable soil. Canonical correlation analysis showed that soil pH and organic matter content significantly affected the active nitrifier community composition. These results suggest that land use types with different disturbance gradients alter the distribution of active nitrifier communities by affecting soil physicochemical properties. IMPORTANCE Nitrification plays an important role in the soil N cycle, and land use management has a profound effect on soil nitrifiers. It is unclear how different gradients of land use affect active ammonia-oxidizing archaea and bacteria and nitrite-oxidizing bacteria. Our research is significant because we determined the response of nitrifiers to human disturbance, which will greatly improve our understanding of the niche of nitrifiers and the differences in their physiology.