Effects Of Land Use Types Research Articles

Ecology, behavior and bionomics: functional response of Heterotermes tenuis Hagen (Insecta: Blattaria: Isoptera: Rhinotermitidae) in forests of the Colombian Orinoquía

BackgroundLand use intensification may affect diversity, abundance, and functional morphological traits (FMT) related to dispersal, food acquisition, digestion, and nesting in some insects, possibly impacting their ecological role. Most studies of termites on the effects of afforestation focus on diversity and abundance, but changes in FMT have yet to be studied.AimTo better understand the response mechanisms to land use intensification, we compared the FMT of the worker and soldier caste of Heterotermes tenuis among Pinus caribaea plantations of four different ages and gallery forests of the Colombian Orinoquía.MethodologyWe measured thirty-eight FMTs in the worker and soldier castes of H. tenuis from gallery forests and pine plantations. Then, we used a Community-Weighted Mean (CWM), a PERMANOVA, and a nonmetric multidimensional scaling (NMDS) to estimate the possible effect of land use type on the FMT of both castes. We selected the FMTs with the lowest intraspecific coefficient of variation (CV) from each caste to compare their size among the land use types and pine plantation ages.ResultsLand use type had a more significant impact on the FMT size of pine plantation workers than the age of the afforestation. FMT of the worker caste tends to be larger in gallery forests than in pine plantations, while the results were inconclusive for soldiers.ConclusionThe results suggested a homogenization mainly of the feeding FMT of the worker caste of H. tenuis in pine plantations associated with the increase in the softwood food resource of P. caribaea.

Identification of Ecological Risk “Source-Sink” Landscape Functions of Resource-Based Region: A Case Study in Liaoning Province, China

Ecological risk assessment plays an important role in ecosystem management and conservation. Conventional landscape-level assessment can only estimate the ecological risk level. It does not define ecological risk types, resulting in a lack of targeted regulation methods. This study establishes a model for identifying ecological risk-related “source-sink” landscape functions according to (1) “source-sink” landscape theory, (2) the responses of landscape types to ecological risks, and (3) the key influences on ecological risk. Four ecological risk “source-sink” landscape functions were mapped as a grid to understand their distribution. Natural and human activity factors were analyzed to determine their effects. After comprehensively considering the ecological risk levels, types of ecological risk, “source-sink” landscape functions, and their influencing factors, six principles and twenty-four targeted regulation strategies were proposed. Take the Liaoning province, China, as an example. The results prove that more than 80% of the grids were affected by the ecological risk “sink” landscape function for different and multiple ecological risks in the study area. Landscapes with the “source” function were mainly located in central cities and coastal areas. About 65% of the grids with “sink” landscape functions had medium, moderate-high, and high ecological risks. More than 75% of the grids with “source” landscape functions had medium, moderate-low, and low ecological risks. Local terrain features, vegetation, and climate were closely related to the “source” or “sink” landscape function of a grid. The land use type converted to artificial surface had the highest driving effects (q value) on multiple ecological risk “source-sink” landscape functions, and had a significant difference between other factors. The driving effects of land use type converted to artificial surface and road network density gradually increased with the risk level. The influences of GDP and population density gradually weakened with the level. The influence of interaction between any two factors was stronger than the influence of a single factor on ecological risk. The proposed assessment model can help to identify specific ecological risk at the grid level, and combined with the regulation strategy, the scientific basis can be provided for the regulation and management of different ecological risks.

Electrical conductivity as a reliable indicator for assessing land use effects on stream N2O concentration

While it is widely acknowledged that different categories of terrestrial land use significantly affect N2O emissions from streams and rivers, a suitable indicator to comprehensively reflect such influences is still lacking. This study examined the effectiveness of stream environmental and microbial factors in reflecting the influence of land use types on stream N2O concentrations, taking into account both endogenous N2O production and exogenous N2O inputs. Our results showed that human-disturbed (urban and agricultural) streams had nearly four times higher excess N2O concentrations (ΔN2O) than forest streams (5.01 versus 1.32 nmol/L N2O). By combining our observations with previous studies, we identify electrical conductivity as a significant and even the strongest predictor of (excess) N2O concentration and flux in streams across different land uses, surpassing the predictive power of nitrogen content. Elevated ΔN2O was observed at higher conductivities (r = 0.69, p < 0.01), which coincided with higher carbon and nutrient levels across different types of land use. Also, conductivity was positively correlated with the abundance of N2O-producing microbes (p < 0.05), including both nitrifying and denitrifying microbes. Denitrifiers adapted to human disturbance and the genetic potential for net N2O production, as evidenced by the positive correlation between conductivity and nir:nosZ ratio, were enhanced under high-conductivity conditions (p < 0.05). Furthermore, electrical conductivity had great potential to qualitatively indicate the magnitude of exogenous N2O input across different land uses. Overall, our results highlight the value of electrical conductivity as a reliable indicator for assessing the effect of land use types on stream N2O concentrations. This opens opportunities for the development of simple field-based assessments of riverine N2O emissions across regional landscapes.

Woody species diversity and the carbon stock potentials of different land use types in agroecosystem of Jimma Ganati District, Western Ethiopia

We investigated the impact of land use types and topographical variables on the diversity of wood species and their carbon stocks in the studied agroecosystems. A generic allometric equation developed for woody plants in agricultural landscapes was used to estimate the carbon stock. We used a mixed-effects linear model using the lmer function in the lme4 package to test the effects of land use types and topographic variables on wood species diversity (Shannon diversity) and stem carbon stock potential. Our study result showed that there is significantly higher woody diversity (P < 0.05) in forests, home gardens and riverine than in grazing lands and croplands. Conversely, woody DBH (cm) and height (m) are relatively higher for croplands followed by grazing land, but lower for home garden and forest land use. There is a statistically significant difference between land use types in their carbon stock (χ² (4) = 18.164, p=0.0011), with forest having the highest total carbon stock, followed by home gardens, but grazing land having the relatively lower total carbon stock of woody species. The study finds that species diversity has a positive and significant (P<0.05) effect on both aboveground and belowground carbon stocks. However, its effect is modulated by land use types, where it is stronger in forest patches, but weaker in more disturbed land use types (e.g., grazing lands and cropland). The study also finds that topographical variables (elevation, slope, and aspects) have no significant (P>0.05) effect on aboveground and belowground carbon stock. The tree species' structural attributes such as height, DBH size, and basal area (BA) have a positive and statistically significant (P < 0.05) effect on carbon stock. The study also found that only a few high DBH class (old growth) tree individuals that are deliberately spared in cropland and grazing land matrix have a high carbon stock contribution. For example, seven species, Podocarpus falcatus, Ficus vasta, Prunus africana, Schefflera abyssinica, Ficus sur, Ekebergia capensis, and Apodytes dimidiate, contribute an estimated 70% of the estimated total carbon stock in the landscapes. These results indicate the need to protect such scattered old-trees in agricultural landscapes both for biodiversity conservation and carbon sequestration thereby integrating climate change adaptation and mitigation strategies into subsistence farming systems.

Impact of land use type and slope position on the erodibility of karst hillslopes in Southwest China

Land use type and slope position have a considerable impact on soil properties and thus likely influence soil erodibility. Soil erosion on karst hillslopes in South China is still serious due to the high intensity of human activities and fragile ecological environment. Nevertheless, the potential effects of land use type and slope position on soil erodibility indicators in karst areas are still unclear. This study was conducted to investigate the spatial variations in soil erodibility indicators, namely, the saturated hydraulic conductivity (KS), mean weight diameter (MWD), soil structural stability (SSI), soil erodibility K factor, soil organic carbon content (SOC), and a comprehensive soil erodibility index (CSEI) for three typical land uses and three slope positions on a karst hillslope. The results showed that KS, MWD, SSI, K factor, SOC and CSEI varied significantly with land use type and slope position. The measured KS, MWD, SSI, K factor and SOC at the nine tested sites displayed a similar trend with soil depth. SOC, MWD and SSI contributed more to the CSEI, with contributions of 27.9%, 25.9% and 25.9%, respectively. KS and K factor contributed less to the CSEI, with contributions of 17.7% and 2.5%, respectively. Woodland is most susceptible to erosion on upper, cropland on middle and grassland on lower slope positions according to the values of CSEI. There were significant positive correlations among sand content, bulk density and CSEI, and there were significant negative correlations among clay content, silt content, root mass density, SOC and CSEI. The changes in soil properties and soil erodibility indicators with land use type and slope position led to the differences in the CSEI. The results provide valuable information for policymakers to select appropriate land use types to mitigate soil erosion and thus improve the healthy development of the ecological environment on karst slopes. Moreover, the results have crucial implications for understanding the mechanism of the spatial variation in soil erosion of karst hillslopes in Southwest China.

Evaluating the Impact of Long-Term Land Use Change and Age since Disturbance on Soil Faunal Diversity

Soil organisms are the biological drivers of processes and functions that maintain soil properties and ecosystem services. Soil fauna contribute to nutrient turnover, decomposition and other important biogeochemical processes. This investigation assessed the diversity and abundance of soil arthropods (0.1–4 mm) along a chronosequence of land use types covering a relatively small geographical distance but with the same underlying soil type and climatic conditions. The compared habitats and the approximate ages since anthropogenic disturbance were ancient woodland (&gt;200 y), old woodland (&lt;200 y), unimproved semi-natural grassland (&gt;50 y), willow/poplar coppice (&gt;30 y), unimproved permanent pasture (&lt;20 y), improved permanent pasture (&lt;10 y), and recently grazed and reseeded grassland (&gt;2 y), and the soil types of all habitats were the same within a 5 km radius. Land use type and age since anthropogenic disturbance significantly (p &lt; 0.05) influenced the community composition of soil fauna, with richer arthropod communities found in woodlands compared with recently managed grassland. This study has confirmed a significant effect of land use type and age since disturbance on soil faunal diversity and community structure.

Urban wild bees benefit from flower-rich anthropogenic land use depending on bee trait and scale

ContextWild bees are important pollinators for wild and cultivated plants. Besides other causes, their decline has been linked to land-use change such as urbanisation. In contrast, urban habitats are discussed as potential wild bee refuges.ObjectivesTo expand our understanding of cities as wild bee habitats, bee responses to urban land-use types with varying foraging and nesting resources were analysed.MethodsWild bees were sampled with pan traps at 49 study sites in a Central European city. Effects of land-use types on wild bees were examined at 12 scales ranging from 50 to 1500 m from sampling points. For analyses, bees were grouped according to their traits (e.g., size, nesting and pollen-collecting behaviour) to account for species-specific requirements.ResultsLand-use types significantly affected wild bees covering all investigated scales. Anthropogenically managed flower-rich habitats, i.e., long-term allotments and cemeteries, were beneficial for most wild bee groups within varying scales between 200 and 600 m. Impervious surface affected only some of the investigated wild bee groups, mostly in a unimodal manner within a 100 m scale.ConclusionsThis study shows that it is recommended for future investigations to take different scales and different bee traits into account when assessing urban habitat quality for bees. In particular, the non-linear response to impervious surface indicates positive edge effects between urban core and rural areas. Conservation measures and implementation management to support wild bees in urban areas should consider the results on scale and land use to meet species-specific demands effectively.

SPATIO-TEMPORAL ANALYSIS OF THE EFFECTS OF URBAN GROWTH ON URBAN HEAT ISLAND: CASE OF KONYA, TURKIYE

Abstract. The increase in impermeable surfaces within the urban areas contributes to local and regional-scale climate changes. This phenomenon, called "Urban Heat Island," is observed as the temperature in urban areas is higher than rural areas and natural landscape areas on the urban fringe. In recent years, advances in remote sensing and geographic information system technologies have enabled the urban heat island effect to be determined more quickly, economically, and accurately. In this study, the rapidly increasing urbanization in Konya, Türkiye and the resulting urban heat island effect have been analyzed. The study consists of four steps. In the first step, land surface temperatures for 1990 and 2022 of Konya city center were determined using the thermal band of Landsat-5 TM and Landsat-8 OLI satellite images. Then, satellite images were classified using the maximum likelihood method to determine land use and land cover in Konya. The effects of land use types and urban growth on urban heat island were examined. The Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-Up Index (NDBI) analyses were examined the statistical relationships between land surface temperature. The last step, the urban heat island effects of different types of regions in the city center of Konya were determined based on their urban form, texture, structure, landscape, and planning strategy. As a result of the study, measures that can be taken especially in spatial planning and design policies have been identified to reduce and prevent the urban heat island in Konya.

Identifying the spatio-temporal pattern of drought characteristics and its constraint factors in the Yellow River Basin

The Yellow River Basin (YRB) constitutes an important grain-producing area, as well as an economic core area in China. However, drought and water shortage have always been important factors restricting the agricultural sustainable development of this region. The intensity of agricultural drought in the YRB and the factors affecting it need to be urgently clarified. Based on this, this study attempts to assess the spatio-temporal characteristics of agricultural drought in the YRB using the improved traditional temperature vegetation dryness index (ITVDI) and to identify the type and intensity of constraint effects of human activities (population, GDP, land use type), climate change (temperature, precipitation) and topography (elevation, slope) on drought in the YRB with the constraint line method. Results appeared that from 2001 to 2015, the drought intensity in the YRB exhibited fluctuating changes, while it decreased after 2015. Spatially, the drought characteristics of the YRB existed large heterogeneous, with drought showing a significant increase in the northwestern and downstream areas and a significant decrease in the central part of the basin. There were eight types of constraining effects of human activities, climate change, and topographic factors on drought intensity in the YRB, including U-shaped curve, positive linear, negative linear, logarithmic, negative convex, positive convex, exponential, and hump-shaped. Precipitation and temperature were the most direct factors affecting drought intensity and would exert a binding effect on both the upper and lower boundaries of drought intensity. The constraint effect of precipitation on drought varied in space. In the upstream and midstream, precipitation constrained the upper and lower boundaries of ITVDI, and the constraint effect increased with the increase of precipitation. In the downstream, the constraint effect of precipitation did not change significantly, and the maximum value of ITVDI was always less than 0.8. Temperature had upper and lower boundary constraint effects at three scales. The constraining effects of elevation, slope, GDP, and population were stable across scales. It should be noted that the constraint effect of land use type on drought exhibited U-shaped, and the threshold point of minimum values appeared in the areas covered by grassland and water. The constraint line method can improve the drought monitoring ability of ITVDI, as well as help to clarify the constraint factors and mechanism of drought intensity in the YRB and provide scientific decision-making support to mitigate regional drought and promote regional sustainable development.

Interacting Effects of Land Use Type, Soil Attributes, and Environmental Factors on Aggregate Stability

Soil erosion and surface pollution near reservoirs can adversely affect water quality and safety. Soil aggregate stability is an important predictor of soil water loss and erosion resistance that is strongly influenced by land use. This study therefore aimed to identify factors affecting soil aggregate stability near reservoirs to provide empirical and theoretical insights that could guide the development of management measures to increase land quality, optimize land use, and maximize sustainability. This study focuses on the land around the Shitoukoumen Reservoir in China and examines the effects of six land use types, eleven soil physicochemical properties, and five environmental factors. Ninety-four sets of soil samples were collected in 2021 for analysis of soil aggregates and properties. Particle size classification of soil aggregates was carried out using the wet sieve method and four indicators were calculated to evaluate the effects of land use, soil physicochemical properties, and environmental factors on soil aggregate stability: water stable aggregates (WSA), mean weight diameter (MWD), geometric mean diameter (GMD), and fractal dimension (D). Descriptive statistics and geostatistics were used to explore the spatial distributions of soil aggregate stability around the reservoir and the influence of soil properties was studied using correlation analysis and path analysis. The conclusion indicates that land use type significantly affects aggregate stability. The most stable aggregates were found in paddy fields (WSA = 0.77, MWD = 0.76, GMD = 0.57) and forests (WSA = 0.75, MWD = 0.76, GMD = 0.55), followed by an orchard, irrigated land, and grassland. Aggregate stability was worst in upland sites (WSA = 0.61, D = 2.28), where soil aggregates were highly fragmented. There were clear spatial correlations between all four stability indicators. The environmental factors and soil physicochemical characteristics with the strongest influence on aggregate stability were soil organic matter, pH, soil clay content, total nitrogen, and temperature changes. Path analysis revealed that some soil properties affect aggregate stability indirectly, with particularly complex relationships between clay, soil organic matter, and pH. In conclusion, land use type, soil organic matter, pH, soil clay content, total nitrogen, these soil physicochemical properties, and environmental factors, especially temperature, significantly affect soil aggregate stability around reservoirs. In the future, it is necessary to appropriately change upland into paddy land, increase forest land, and appropriately add organic fertilizer to improve soil quality.

Investigate the effects of urban land use on PM2.5 concentration: An application of deep learning simulation

As the fine particulate matter (PM2.5) polluting seriously threat people's health, exploring its mitigation strategies has become an urgent issue to be studied. Urban land use, the carrier of urban functions and human activities, has been widely recognized as an important contributor of PM2.5 pollution. Taking Wuhan metropolitan area as an example, this study employs a deep learning simulation method to explore the effects of land use types and density on the spatial distribution of PM2.5 pollutants. The PM2.5 concentration data, raster-based land use data and meteorological conditions data are analyzed to identify their dynamic spatiotemporal characteristics. The meteorological conditions, including temperature and wind speed, are incorporated into the simulation platform, which improves the precision significantly. The simulation results show that PM2.5 concentration caused by construction land such as industrial, residential, transportation, logistics and warehousing, commercial, utilities, and public service sequentially decreases. The impact of FAR on PM2.5 concentration is spatially different. With the increase of FAR, some north construction pixels present PM2.5 mitigation effects while a few grids in the south appear heavier pollution. By analyzing the results of different simulation scenarios, specific spatial-based PM2.5 mitigation strategies and control measures are provided to promote healthy and sustainable urban development. This method can be transferred and applied to other metropolitans, so as to provide as a reference for policymakers and urban planners to promote effective air pollution mitigation strategies from the view of spatial planning.

Effects of land use types on the depth distribution of selected soil properties in two contrasting agro-climatic zones

The depth distribution of soil properties are governed by several interacting factors including land use types (LUT) and agro-climate (AgC) factors. Yet, there is little information on the effects of LUT, AgC and their combination on soil properties along depth, which this study aimed to investigate. We collected a total of 36 composite soil samples using the manual percussion of a steel core tube layer by layer vertically up to 30 cm in sites representing both highland and lowlands, and analyzed for selected soil properties. A significant main effects of LUT on the depth distribution of bulk density (BD), Ca, Na, K and Cu, and AgC on soil texture, pH, EC, Ca, Na, K, P, Mn, Fe and Cu were noted. The two-way ANOVA analysis also revealed the significant effects of both LUT and AgC on the depth distribution of BD, Na, K, Cu and EC, reflecting their influences on the paths associated to bio-geo-recycling processes. Compared to crop and forestlands, the average SOC and Fe were lower while EC, CEC, Ca, Na, K, P, Mn and Zn were higher in homegarden located in highland than lowland, possibly the acid nature of the highland soil may make the extractable cations available. SOC was not significantly influenced by AgC, LUT and their interaction effect. Based on the Elemental Enrichment Ratio (EER), the SOC was concentrated in the upper surface soil in forest and cropland located both in highland (1.79, 1.33) and lowland (1.80, 1.57), respectively. The reverse propagation pattern SOC depth distribution in soils under homegarden with EER of 0.7 (highland) ad 0.8 (lowland) showed that implementing such system can accelerate carbon sinking and safely store it in subsoil. Also, diversified species composition associated with respective root architectures in the homegarden system, make it an efficient soil nutrient management, which should be widely promoted.

Effects of land-use type on soil organic carbon and carbon pool management index through arbuscular mycorrhizal fungi pathways

Effects of land-use type on soil organic carbon and carbon pool management index through arbuscular mycorrhizal fungi pathways

Evaluating the relationship between groundwater quality and land use in an urbanized watershed.

Understanding the impact of urbanization on groundwater quality is critical. Effective water management requires understanding the relationship between land use and water quality. The study's goals were to compare the effects of land use, identify the types of land that impact hydrochemistry, and define how different land use affects water quality. For this purpose, the comparative relationship between groundwater quality, land use classes and landscape metrics were established for the years 2016 and 2021. Water samples were collected from 42 wells, and different hydro-chemical variables were considered to calculate the water quality index (WQI). The WQI value in 2016 ranged from 26.49 to 151.03 and 29.65 to 155.62 in 2021. The results indicate that the water quality in most parts of the study area is moderate for drinking and domestic purpose use. The google earth engine platform wasused and radiometrically corrected and orthorectified Sentinel-2 satellite images were processedto classify land use classes for selected years. Five buffer zones were established within a 2-km watershed along each well site, and the effects of land use types and landscape metrics on water quality in the buffer zones were analyzed. Results revealed that the effects of land use types on water quality were mainly reflected in buffer 1 (B1), buffer 4 (B4), buffer 5 (B5) in 2016 and B1, buffer 3 (B3), and B5 in 2021. The impacts of landscape-level metrics on water quality are mainly reflected in buffer 2 (B2) and B3 in 2021, while at the class-level, they are mainly reflected in B1 and B4 in 2021. The redundancy analysis revealed that different hydro-chemical variables behaved differently with the land use classes and landscape metrics in the various buffer zones.

The effect of land use type on selected soil physicochemical properties in Shihatig watershed, Dabat district, Northwest Ethiopia

Different land use practices have a substantial influence on soil quality. An inappropriate land use system in Ethiopia leads to extensive deforestation which aggravates the loss of soil fertility. Even though there are various studies conducted on the effect of land use type on soil physicochemical properties, it is inadequate in the northern highlands of Ethiopia, in particular in the Dabat district. Thus, this study aimed to assess the effect of land use type and soil depth on selected soil physicochemical properties in the Shihatig watershed, Northwest Ethiopia. A total of 24 undisturbed core and disturbed composite soil samples were collected from the four land use types (natural forest, grazing, cultivated, and Eucalyptus lands) and two depths (0–20 cm and 20–40 cm) with three replications. The physicochemical properties of the soil were determined using standard operating procedures. The two-way analysis of variances was conducted using SAS software, Version 9.4. The result showed that the texture and soil organic carbon were affected by land use type, soil depth, and the interaction of the two factors; while bulk density, soil moisture content, total nitrogen, available phosphorus, cation exchange capacity, and level of Mg2+ were significantly affected by both land use and soil depth, whereas pH and electrical conductivity were affected by only the land use type. The highest clay, pH, electrical conductivity, total nitrogen, cation exchange capacity, and exchangeable cations (Ca2+ and Mg2+) were recorded in the natural forest land, while the lowest values of the same parameters were found under cultivated land. The mean values of most of the soil properties were low in the cultivated and Eucalyptus lands. Therefore, adopting sustainable cropping systems such as crop rotation and the addition of organic manure, and minimizing planting the Eucalyptus tree is vital to improve the existing soil quality and enhance crop productivity.

Effects of Land-Use Types on Topsoil Physicochemical Properties in a Tropical Coastal Ecologically Fragile Zone of South China

Understanding the effects of land use on soil structure and nutrients is important for soil and water conservation in an ecologically fragile zone. This study was carried out to examine the variability of physicochemical properties in three different land use types: abandoned land (AL), eucalyptus plantation (EP), and road lawn (RL) sites at soil depths of 0–10 and 10–20 cm in the Leizhou Peninsula, a tropical coastal ecologically fragile zone of South China. Soil physicochemical property patterns exhibited extremely significant differences among the three land uses (p &lt; 0.001) at both soil depths. Soil nutrients, natural water content, and total porosity, from high to low, in the different land use types were RL, AL, and EP, while the bulk density, from high to low, was EP, AL, and RL. Soil total nitrogen, total phosphorus, total potassium, available potassium, exchangeable calcium, exchangeable magnesium, and natural water content exhibited significant differences (p &lt; 0.05) among the three land use types at soil depths of 0–10 and 10–20 cm, while no significant changes were detected regarding soil organic carbon, available phosphorus, and total porosity. The correlation between physical and chemical properties at the 10–20 cm depth (R = 0.97, p &lt; 0.001) was closer and more significant than that at the 0–10 cm depth (R = 0.95, p &lt; 0.01). Overuse of land (EP) without a rest in the ecologically fragile zone leads to soil erosion and compaction. Compared with natural restoration (abandoned land), artificial restoration (road lawn) can improve soil nutrient and water status more quickly, but cannot modify the soil organic carbon and porosity in the short term.

Effects of Main Land-Use Types on Plant and Microbial Diversity and Ecosystem Multifunctionality in Degraded Alpine Grasslands

Grassland resources occupy an important place in the national economy. However, grasslands in alpine regions of China are severely degraded, and the effects of land-use types on species composition, soil nutrients, and ecosystem multifunctionality of degraded alpine grasslands are less certain. To ascertain the effects of main land-use types (no-tillage reseeding and fertilization) on species diversity and ecosystem multifunctionality in alpine grasslands, we investigated the changes in these factors by subjecting specified areas. Using a standardized field survey, we measured the cover, richness, and evenness of plants. At each site, we measured microbial diversity and twelve soil variables critical for maintaining ecosystem multifunctionality in alpine grasslands. The results showed that: (1) the Margalef, Shannon–Wiener, and Simpson indices of plant community, and fungal diversity indices increased significantly in no-tillage reseeding and fertilization; (2) at the phyla level, the relative abundances of Basidiomycota, Olpidiomycota, and Proteobacteria increased significantly in no-tillage reseeding and fertilization, as well as, at the genus level, those of Coniochaeta, Solirubrobacter, Pseudonocardia, and Microvirga; (3) the soil physicochemical properties (except the C:N of soil) increased significantly in no-tillage reseeding and fertilization; (4) correlation analysis showed that species diversity was mainly correlated with soil nutrients in control check, while it was mainly correlated with soil physical properties in no-tillage reseeding and fertilization; (5) linear regression analysis showed significant positive relationships between Margalef, Shannon–Wiener, and Simpson indices of plant community and ecosystem multifunctionality. In addition, ecosystem multifunctionality was positively related to Pielou, Shannon–Wiener, and Simpson indices of the fungal community and it was positively related to Pielou and Shannon–Wiener indices of bacterial community. These observations indicated that no-tillage reseeding and fertilization of degraded alpine grasslands had the potential to improve ecosystem functions in many ways.

Effects of land use on the distribution of soil microplastics in the Lihe River watershed, China

Soil contamination by microplastics (MPs) has gained widespread attention, whose fate may be influenced by land use types. The effects of land use types and the intensity of human activities on the distribution and sources of soil MPs at the watershed scale are unclear. In this study, 62 surface soil sites in representing five land use types (urban, tea garden, dryland, paddy field and woodland) and 8 freshwater sediment sites were investigated in the Lihe River watershed. MPs were detected in all samples, and the average abundance of soil and sediments was 401.85 ± 214.02 and 222.13 ± 54.66 items/kg, respectively. The soil MPs abundance followed the sequence: urban > paddy field > dryland > tea garden > woodland. Soil MP distribution and MP communities were significant different (p < 0.05) among land use types. The similarity of MP community highly correlated with geographic distance, and woodlands and freshwater sediments may be a potential fate for MPs in the Lihe River watershed. Soil clay, pH, and bulk density significantly correlated with MP abundance and fragment shape (p < 0.05). The positive correlation between population density, Total- Point of Interest (POI) and MP diversity indicates the importance of intensity of human activities in exacerbating soil MP pollution (p < 0.001). Plastic waste sources accounted for 65.12%, 58.60%, 48.15% and 25.35% of MPs in urban, tea garden, dryland and paddy field soils, respectively. Differences in the intensity of agricultural activities and cropping patterns were associated with different percentages of mulching film sources in the three types of agricultural soils. This study provides new ideas for the quantitative analysis of soil MP sources in different land use types.

Effects of land use types on soil quality dynamics in a tropical sub-humid ecosystem, western Ethiopia

Soil quality degrades when natural forests are converted to human-managed ecosystems. Limited empirical evidence of such soil quality changes has been observed in tropical sub-humid ecosystems. This study aimed to analyze the impact of land use change on soil quality dynamics in a tropical sub-humid ecosystem in western Ethiopia. To analyze some impacts, 80 composite soil samples (0–20 cm depth) and 45 undisturbed soil samples (0–7 cm depth) were collected from different land use patterns, including natural forests, grasslands, recently developed commercial lands, old commercial farmlands, and smallholder cultivated farmlands. A one-way analysis of variance (ANOVA) was performed to determine the effect of different land uses on soil quality indicators. The soil quality index (SQI) was used to evaluate the impact of land use on selected soil quality indicators, using the weighted additive SQI method derived from Principal Component Analysis (PCA). Our results showed that certain soil quality indicators, such as soil organic matter, total nitrogen, bulk density, porosity, cation exchange capacity, exchangeable calcium, and magnesium, were significantly degraded when compared to forest soils as a benchmark (at significance levels of P < 0.05, 0.01, and 0.001). Our study concluded that soil organic matter content, pH, field capacity, exchangeable calcium and potassium, available phosphorus, and bulk density could be used as key SQI assessment attributes in tropical sub-humid ecosystems and similar environments. Sustainable land management practices are crucial in enhancing soil quality indicators across different land use systems in tropical sub-humid ecosystems.

Effects of Land Use Type on Water Quality and Organisms in a Small River of the Shizukuishi River Basin, Iwate Prefecture, Japan

Effects of Land Use Type on Water Quality and Organisms in a Small River of the Shizukuishi River Basin, Iwate Prefecture, Japan