The axial skeleton of Tiktaalik roseae.

The axial columns of the earliest limbed vertebrates show distinct patterns of regionalization as compared to early tetrapodomorphs. Included among their novel features are sacral ribs, which provide linkage between the vertebral column and pelvis, contributing to body support and propulsion by the hindlimb. Data on the axial skeletons of the closest relatives of limbed vertebrates are sparce, with key features of specimens potentially covered by matrix. Therefore, it is unclear in what sequence and under what functional context specializations in the axial skeletons of tetrapods arose. Here, we describe the axial skeleton of the elpistostegalian Tiktaalik roseae and show that transformations to the axial column for head mobility, body support, and pelvic fin buttressing evolved in finned vertebrates prior to the origin of limbs. No atlas-axis complex is observed; however, an independent basioccipital-exoccipital complex suggests increased mobility at the occipital vertebral junction. While the construction of vertebrae in Tiktaalik is similar to early tetrapodomorphs, its ribs possess a specialized sacral domain. Sacral ribs are expanded and ventrally curved, indicating likely attachment to the expanded iliac blade of the pelvis by ligamentous connection. Thus, the origin of novel rib types preceded major alterations to trunk vertebrae, and linkage between pelvic fins and axial column preceded the origin of limbs. These data reveal an unexpected combination of post-cranial skeletal characters, informing hypotheses of body posture and movement in the closest relatives of limbed vertebrates.

Does settlement land expansion necessarily induce the decrease of cultivated land? Differences in national scale and local counties of China.

With the extensive industrialization and urbanization taking place in China during the recent decades, land use throughout the country has experienced profound changes influenced not only by the demand for population growth and living standard improvement but also by the constraints of series of land use policies. However, whether the conflict between the expansion of settlement land (SL) and the loss of cultivated land (CL) have been resolved at the national scale or transferred between the local regions remains unclear. Based on yearly ESA CCI land use and land cover products from 1992 to 2020, the long-term trends of quantity and spatial pattern of SL expansion and CL change in China from national and local views were investigated using trend statistic methods, and finally a comprehensive zoning framework was proposed to recognize the trade-off and synergies relationships between SL expansion and CL change. There are a continuous expansion of SL with global linear trends showing three breakpoints in 2000, 2005, and 2012, and a fluctuation decline of CL presented with four breakpoints in 1997, 2002, 2006, and 2013. Aggregation and dispersion tendencies with linear characteristics of SL expansion and CL change were found with breakpoints in 2001, 2008, 2012, and 2016 and breakpoints in 2001 and 2010, respectively. A spotty spatial pattern of SL was shown spatially coincident with urban agglomerations in China while the planar continuous characteristic was found for CL. Local counties were classified into five tradeoff and synergies zones (TSZs), where general synergies (G-S) and decoupling (D) of SL expansion and CL change were rare cases and the different change in quantity and trend of SL expansion and CL change in local counties was concealed by the national trend. A few scattered counties were belonging to G-S and D TSZs, while most of the counties in the central-east and western China were in General-Tradeoff (G-T) and Superior-Tradeoff (S-T) TSZs. Counties in south and north China with higher percentages of CL were more prevalent in Superior-Synergy (S-S) TSZ. Our findings explicated the complex relationships between SL expansion and CL change of China at the national scale and in local counties, which pointed out the differences of unified land use management activities across scales and could provide insights for future policy-making and management measures of land use to both ensure the national food security and promote regional sustainable development more synchronously.

Characterizing landscape fragmentation of Koitobos river sub-basin, Trans-Nzoia, Kenya.

The changes in landscape structure and functioning due to unprecedented human interference are hastening across the globe and it is thus a compelling necessity to preserve and restore our ecosystems. This study aimed to characterize levels of landscape fragmentation, habitat structure, driving forces, and perceptions of the residents on the most preferred reconfiguration approaches. The land use/land cover [LULC] change was first determined by interpreting the 1973, 1986, 1995, 2002, 2014, and 2022 Landsat images using the QGIS 3.26 while the selected landscape fragmentation metrics were analyzed using FRAGSTATS 4.2. Forests, shrubs, and grasslands showed a declining trend, except for agriculture, water, and built-up areas, which depicted high increases for the study periods [1973 to 2022]. The landscape of the study area is characterized as progressively fragmenting as signified by high escalated values of patch number [374 %], edge density [7828 %] between 1986 and 2002, contagion [10.3%], and a declined value of Shannon Diversity Index [SHDI] [-17.42%], Shannon evenness index [SHEI] [-25.8 %] and connectedness [-43.3%]. Considering these results, high losses of forests and grasslands coupled with expansive farmlands and built-up areas have led to unprecedented landscape fragmentation From field surveys and oral interviews, this has not only left streams vulnerable to massive sediment loads but has also triggered annual floods which occur during wet months even though change in onset of rainfall seasons was also reported. The findings call for restoration and integrated and sustainable restoration efforts, especially for the forests, grasslands, and riparian corridors along with sustainable urban planning and community-based sensitization on watershed management.

Evaluating tramway infrastructure on biodiversity and ecosystem services.

Tramways in urban areas for mass transit has been suggested to have a lower environmental footprint than roads. However, studies on the impact of tramways and the surrounding infrastructure on biodiversity is extremely rare despite the potential ecological effects associated with this anthropogenic feature. Surprisingly, we found fewer than 10 papers published on tramway-wildlife interactions, which is significantly lower (vs dozens of thousands) than that of other transportation methods. As tramways and stations may be managed sustainably by planting short vegetation on the track and roofs of tramway stations, they may be good examples of land-sharing policies in green urban planning, improving both biodiversity and people's well-being. The potential environmental benefits of green practices for commercially available tramways should be strictly tested and applied, especially in the context of the growing popularity of tramway systems worldwide.

Spatial and temporal changes in shorebird habitats under different land use scenarios along the Yellow and Bohai Sea coasts in China.

The effect of coastal wetland loss on shorebird habitat in recent years has been widely reported in previous studies. Various coastal wetland conservation and restoration measures have been implemented or will soon be implemented in China. The extent to which these measures will affect the area and structure of coastal wetland habitat in the future remains unclear. Here, we predicted changes in habitat area and structure for 39 common shorebird species along the coasts of the Yellow and Bohai Seas using a cellular automata-Markov (CA-Markov) land use scenario model and a maximum entropy species distribution model, along with terrain factors (slope, aspect, and digital evaluation model) and climate factors (temperature and precipitation) from the Data Centre for Resources and Environmental Sciences at the Chinese Academy of Sciences, land cover maps interpreted using the human-computer interactive method, and citizen science data of shorebird occurrences derived from eBird, Global Biodiversity Information Facility, and Bird Report. We found that shorebird habitat was most abundant along the coasts of Bohai Bay, Laizhou Bay, and Yancheng. The area of habitat decreased and became increasingly fragmented between 2000 and 2020 for more than half of the 39 species. Under the future business-as-usual scenario, the area of shorebird habitat decreased from 2020 to 2050, and the remaining habitat became increasingly fragmented. Under the ecological protection (EP) scenario, habitat loss was mitigated, and habitat connectivity was improved. The area of habitat was lower in 2050 under the EP scenario than in 2000 for most species, especially threatened species, suggesting that the area of habitat will not return to year-2000 levels under the EP scenario. These results emphasize the need to protect remaining shorebird habitats and implement ecological conservation measures to ensure the long-term preservation of coastal wetlands.

Correlated Decision Fusion Accompanied with Quality Information on a Multi-Band Pixel Basis for Land Cover Classification.

Decision fusion plays a crucial role in achieving a cohesive and unified outcome by merging diverse perspectives. Within the realm of remote sensing classification, these methodologies become indispensable when synthesizing data from multiple sensors to arrive at conclusive decisions. In our study, we leverage fully Polarimetric Synthetic Aperture Radar (PolSAR) and thermal infrared data to establish distinct decisions for each pixel pertaining to its land cover classification. To enhance the classification process, we employ Pauli's decomposition components and land surface temperature as features. This approach facilitates the extraction of local decisions for each pixel, which are subsequently integrated through majority voting to form a comprehensive global decision for each land cover type. Furthermore, we investigate the correlation between corresponding pixels in the data from each sensor, aiming to achieve pixel-level correlated decision fusion at the fusion center. Our methodology entails a thorough exploration of the employed classifiers, coupled with the mathematical foundations necessary for the fusion of correlated decisions. Quality information is integrated into the decision fusion process, ensuring a comprehensive and robust classification outcome. The novelty of the method is its simplicity in the number of features used as well as the simple way of fusing decisions.

Planned expansion of transportation infrastructure in Brazil has implications for the pattern of agricultural production and carbon emissions.

High transportation costs have been a barrier to the expansion of agriculture in the interior of Brazil. To reduce transportation costs, Brazil launched the National Logistics Plan, aiming to expand its railway network by up to 91 % by 2035. Such a large-scale infrastructure investment raises concerns about its economic and environmental consequences. By combining geospatial estimation of transportation cost with a grid-resolving, multi-scale economic model that bridges fine-scale crop production with its trade and demand from national and global perspectives, we explore impacts of transportation infrastructure expansion on agricultural production, land use changes, and carbon emissions both locally and nationally in Brazil. We find that globally, the impacts on output and land use changes are small. However, within Brazil, the plan's primary impacts are impressive. PNL2035 results in the reduction of transportation costs by 8-23 % across states (depending on expansion's extent) in the interior Cerrado biome. This results in cropland expansion and increases in terrestrial carbon emissions in the Cerrado region. However, the increase in terrestrial carbon emissions in the Cerrado is offset by spillover effects elsewhere in Brazil, as crop production shifts away from the Southeast-South regions and accompanying change in the mix of transportation mode for farm products from roadway to more emission-efficient railway. Furthermore, we argue that the transportation infrastructure's impact on the enhanced mobility of labor and other agricultural inputs would further accentuate the regional shift in agricultural production and contribute to carbon emission mitigation. Upon its completion, PNL2035 is expected to result in the reduction of net national emissions by 1.8-30.7 million metric ton of CO2-equivalent, depending on the impacts on labor and purchased input mobility. We conclude that the omission of spillover effects due to infrastructure expansion can lead to misleading assessments of transport policies.

Integrating meteorological and geospatial data for forest fire risk assessment.

Understanding the factors that cause fire is crucial for minimizing the fire risk. In this research, a comprehensive approach was adopted to recognize factors influencing forest fires. Golestan National Park (GNP) was considered as a representative area with a humid climate in this study. Initially, using the Multi-Criteria Evaluation Method, a fire risk map was created by analyzing natural and human factors, and vulnerable areas were identified. Then, the relationship between key elements such as meteorological conditions, Land Surface Temperature (LST), and precipitation, with the occurrence of fire in different years was investigated. CHIRPS and Landsat data were utilized to assess LST changes and precipitation. 23-year changes in fire occurrence areas in GNP were acquired using MODIS products. The results of the data analysis showed that the highest number of fires occurred in forest areas, and in the fire risk prediction map, the extremely high-risk class is completely consistent with the ground truth data. The assigned weights, derived from expert opinions, highlight the substantial significance of elevation, and distance from roads and settlements. Additionally, the effectiveness of the model in providing reliable forecasts for fire risks in GNP is highlighted by the ROC curve with an AUC value of 0.83. Forest fires within GNP exhibit a distinct seasonality, predominantly occurring from July to December. During the warmer months, by coinciding with summer excursions, human activities may contribute to the ignition of fires. In 2013 and 2014, rising fire incidents correlated with elevated temperatures, hinting at a potential connection. GNP fires showed an upward trend with higher monthly LST and a downward trend with increased annual precipitation. The results showed that there is a relationship between LST, precipitation, and the occurrence of fire in GNP. Approximately 176.15 ha of GNP's forest areas have been destroyed by fires over the last two decades. This research demonstrated that there is a dynamic interaction between environmental conditions and fire incidents. By considering these factors, managers and environmental planners can develop effective strategies for managing and preventing forest fire risks.

Does commercial indoxacarb pose ecotoxicological consequences? Employing a multi-marker approach in the model species Theba pisana.

Indoxacarb is one of the most extensively used oxadiazine insecticides worldwide, but it may exert detrimental effects on ecosystems, population dynamics, and health. Due to the lack of knowledge on the ecotoxicity of indoxacarb, it is still challenging to assess whether this insecticide poses an ecotoxicological impact on terrestrial environments. Therefore, our study aims to provide novel data on the toxic effects of 28-day dietary exposure to commercial grade indoxacarb at two environmentally relevant concentrations, 0.02 µg/mL and tenfold (0.2 µg/mL) on the model species, Theba pisana. Their effects were studied using a multiple biomarker approach by evaluating physiological, biochemical, and histopathological responses. After 28 days of treatment, indoxacarb at both concentrations significantly reduced the food intake and growth of the treated snails. Also, it caused decreases in lipid peroxidation (LPO)  levels after 7 and 14 days of exposure, whereas an opposite effect occurred after 21 and 28 days. All treated snails were found to exhibit a lower content of glutathione (GSH) after all times of exposure. Moreover, catalase (CAT), glutathione-S-transferase (GST), and glutathione peroxidase (GPx) activities, as well as protein content (PC), were elevated in the treated snails after all time intervals. Post exposure to both realistic indoxacarb concentrations, changes in acetylcholinesterase (AChE) activity between a decrease and an increase were observed. Furthermore, indoxacarb caused histo-architectural changes in the hepatopancreas of T. pisana. Our results demonstrate that, at environmentally relevant concentrations, indoxacarb poses negative consequences for T. pisana, indicating its ecotoxicological impacts.

Impacts of climate and land use change on terrestrial carbon storage: A multi-scenario case study in the Yellow River basin (1992-2050).

Currently, socioeconomic development and climate change pose new challenges to the assessment and management of terrestrial carbon storage (CS). Accurate prediction of future changes in land use and CS under different climate scenarios is of great significance for regional land use decision-making and carbon management. Taking the Yellow River Basin (YRB) in China as the study area, this study proposed a framework integrating the land use harmonization2 (LUH2) dataset, the patch-generating land use simulation (PLUS) model, and the integrated valuation of ecosystem services and trade-offs (InVEST) model. Under this framework, we systematically analyzed the spatiotemporal evolution characteristics of land use and their impact on CS in the YRB from 1992 to 2050. The results showed that (1) CS was highest in forestland and lowest in construction land, with a spatial distribution of high in the south and low in the north. From 1992 to 2020, construction land, forestland, and grassland increased while cropland decreased, reducing the total CS by 74.04 Tg. (2) From 2020 to 2050, under SSP1-2.6 scenario, forestland increased by 158.87 %; under SSP2-4.5 scenario, unused land decreased by 65.55 %; and under SSP5-8.5 scenario, construction land increased by 13.88 %. By 2050, SSP1-2.6 scenario exhibited the highest CS (8105.25 Tg), followed by SSP2-4.5 scenario (7363.61 Tg), and SSP5-8.5 scenario was the lowest (7315.86 Tg). (3) Forestland and construction land were the most critical factors affecting the CS. Shaanxi and Shanxi had the largest CS in all scenarios, and Qinghai had a huge carbon sink potential under SSP1-2.6 scenario. Scenario modeling demonstrated that future climate and land-use changes would have significant impacts on terrestrial CS in the YRB, and green development pathways could strongly contribute to meeting the dual­carbon target. Overall, this study provides a scientific basis for promoting low-carbon development, land-use optimization, and ecological civilization construction in YRB, China.

Influencing factors and risk assessment of phthalate ester pollution in the agricultural soil on a tropical island.

Phthalate esters (PAEs) are widely prevalent in agricultural soil and pose potential risks to crop growth and food safety. However, the current understanding of factors influencing the behavior and fate of PAEs is limited. This study conducted a large-scale investigation (106 sites in 18 counties with 44 crop types) of 16 types of PAEs on a tropical island. Special attention was given to the impacts of land use type, soil environmental conditions, agricultural activity intensity, and urbanization level. The health risks to adults and children from soil PAEs via multiple routes of exposure were also evaluated. The results showed that the mean concentration of PAEs was 451.87 ± 284.08 µg kg-1 in the agricultural soil. Elevated agricultural and urbanization activities contributed to more pronounced contamination by PAEs in the northern and southern regions. Land use type strongly affected the concentration and composition of PAEs in agricultural soils, and the soil PAE concentration decreased in the order of vegetable fields, orchards, paddy fields, and woodlands. In paddy fields, di-isobutyl phthalate and di-n-butyl phthalate made more substantial contributions to the process through which the overlying water inhibited volatilization. Soil microplastic abundance, pesticide usage, crop yield, gross domestic product, and distance to the nearest city were calculated to be the major factors influencing the concentration and distribution of PAEs. Soil pH, organic matter content, microplastic abundance and the fertilizer application rate can affect the adsorption of PAEs by changing the soil environment. A greater risk was detected in the northern region and paddy fields due to the higher soil PAE concentrations and the dietary structure of the population. This study reveals important pathways influencing the sources and fate of PAE pollution in agricultural soils, providing fundamental data for controlling PAE contamination.

Evaluation of land resources carrying capacity based on entropy weight and cloud similarity.

Land is the foundation of human life and development, which is also the most important part of a country. The study of land carrying capacity is one of the important contents of land management, wherein the evaluation of land resource carrying capacity (LRCC) is an important reference for land resource planning. Aiming at the information fuzziness and uncertainty in the evaluation of LRCC, firstly, a comprehensive evaluation model based on entropy weight and normal cloud similarity was proposed, which is based on cloud model theory and combined with normal cloud similarity measurement method and entropy weight method. Secondly, taking the asphalt pavement experiment as an example for empirical analysis, the experimental results are consistent with the actual situation, which proves the feasibility and effectiveness of the proposed model. Finally, taking China's Chongqing city as the research area, the proposed evaluation model is used to study LRCC. The research results indicate that the comprehensive carrying capacity and average carrying capacity of various systems in China's Chongqing have been improved in the past decade. Among them, the comprehensive carrying capacity rose from the second level during the "12th Five-Year Plan" period to the third level during the "13th Five-Year Plan" period. In the future, it is necessary to focus on the improvement of soil and water resources system and economic and technological system. This conclusion reflects LRCC of Chongqing in China objectively and has a reference value for Chongqing's land planning.

Which Strength Manifestation Is More Related to Regional Swimmers' Performance and In-Water Forces? Maximal Neuromuscular Capacities Versus Maximal Mechanical Maintenance Capacity.

PURPOSE: To explore the association of the load-velocity (L-V) relationship variables and ability to maintain maximal mechanical performance during the prone bench-pull exercise with sprint swimming performance and in-water forces. METHODS: Eleven competitive adult male swimmers (50-m front crawl World Aquatics points: 488 [66], performance level 4) performed 1 experimental session. The L-V relationship variables (L0 [ie,  maximal theoretical load at 0 velocity]; v0 [ie, maximal theoretical velocity at 0 load], and Aline [ie, area under the L-V relationship]) and maximal mechanical maintenance capacity were assessed at the beginning of the session. Afterward, sprint swimming performance and in-water force production were tested through a 50-m front-crawl all-out trial and 15-s fully-tethered swimming, respectively. RESULTS: Only v0 presented high positive associations with 50-m time and swimming kinematics (r > .532; P < .046). The L0, v0, and Aline showed very high positive associations with the in-water forces during tethered swimming (r > .523; P < .049). However, the ability to maintain maximal mechanical performance, assessed by the mean velocity decline during the prone bench pull, was only significantly correlated with stroke rate (r = -.647; P = .016) and stroke index (r = .614; P = .022). CONCLUSIONS: These findings indicate that maximal neuromuscular capacities, especially v0, have a stronger correlation with swimming performance and in-water force production than the ability to maintain maximal mechanical performance in level 4 swimmers.

[Scale Effects of Landscape Pattern on Impacts of River Water Quality： A Meta-analysis].

The landscape pattern determines water pollution source and sink processes and plays an important role in regulating river water quality. Due to scale effects, studies on the relationship between landscape pattern and river water quality showed variance at different scales. However, there is still a lack of integrated study on the scale effect of landscape pattern and river water quality dynamics. This study collected 4 041 data from results of previous publications to address the characteristics of landscape pattern and river water quality dynamics at different scales and to identify the key temporal and spatial scales as well as landscape pattern indices for regulating river water quality. The results indicated that, compared to precipitation events, base flow periods, and interannual scales, the high-flow period was the key temporal scale for linking landscape pattern on river water quality. Compared to the watershed scale, the landscape pattern of buffer zones had a greater impact on river water quality. The high-flow period-buffer zone scale was the key spatiotemporal coupling scale for linking landscape pattern and river water quality. Compared to croplands, water bodies, grasslands, and the overall landscape of the watershed, the landscape pattern of forests and urban areas had a greater impact on river water quality. Fragmentation degree was the most important landscape pattern factor regulating river water quality. In river water quality management, it is important to focus on the landscape configuration of buffer zones, increase forest area, reduce patch density of forests and water bodies, and decrease the aggregation degree of urban areas.

[Land Change Simulation and Grassland Carbon Storage in the Loess Plateau Based on SSP-RCP Scenarios].

Exploring the spatial distribution of land use/coverage (LUCC) and ecosystem carbon reserves in the future of climate change can provide a scientific basis for optimizing the distribution of land resources and formulating social economic sustainable development policies. In this study, we integrated the plaques generating land use simulation (PLUS) model and ecosystem services and weighing comprehensive evaluation (InVEST) model. Based on the CMIP6-based sharing socio-economic path and representative concentration path (SSP-RCP), we evaluated the Loess Plateau for time and space dynamic changes in LUCC and ecosystem carbon reserves, analyzed the impact of driving factors on different regions, and explored the correlation between carbon reserves in various regions. The results showed:① In the future, the three scenarios were similar to the LUCC changes. The area of cultivated land, grassland, and unused land would be reduced to varying degrees, and the construction land had expanded sharply. The increase in the three scenarios was 29.23%-53.56% (SSP126), 34.59%-63.28% (SSP245), and 42.80%-73.27% (SSP585). ② Compared with that in 2020, the carbon reserves of SSP126 sites in 2040 increased by 1.813 8×106 t, and in the remaining scenarios it would continue to decline. By 2060, the grassland carbon reserves in the three scenarios decreased by 13.391×106, 33.548×106, and 85.871×106 t, respectively. ③ From the perspective of space correlation, the carbon reserves of the Loess Plateau were correlated between cities. The difference in future scenarios was not significant. The hotspots were distributed in the middle and north of the research area. There was no obvious cold spot area. ④ The changes in land use were predicted to increase or lose carbon reserves. Forestry, cultivated land, and grassland had more carbon reserves those in than other land types. Increasing their area and restrictions on the conversion of other land types should increase the ecosystem carbon reserves.

[Effects of Land Use Change on Soil Aggregate Stability and Soil Aggregate Organic Carbon in Karst Area of Southwest China].

Investigating the relationship of soil aggregate stability with the organic carbon in the aggregate and its response to land use change is conducive to the estimation of soil carbon sink potential, improvement of rocky desertification, and rational land use in karst areas of Southwest China. In order to explore the effects of land use change on the composition and stability of soil aggregate stability as well as the content of aggregate organic carbon, the soil (0-30 cm) of five land use types (secondary forest, pomelo forest, paddy field, pepper forest, and dry land) was selected as the research object. The characteristics and correlation of soil aggregate components and organic carbon under different land use patterns were obtained, and the contribution of soil aggregates to the change in organic carbon after land use change was calculated. The results showed that the macroaggregates in the surface soil (0-15 cm) of the secondary forest, pomelo forest, and paddy field were 63.32%, 52.38%, and 47.77%, respectively, which were significantly higher than that of dry land (23.70%), as was also seen in the lower layer (15-30 cm). The geometric mean diameter (GMD) and mean weight diameter (MWD) of soil aggregates in the secondary forest, pomelo forest, and paddy field were significantly higher than those in dry land. In the surface soil, the organic carbon of the secondary forest and paddy field was significantly higher than that of other land use patterns. By contrast, in the lower soil layer, only the organic carbon of the paddy field was significantly higher than that of the others. Under different land use patterns, the organic carbon content of aggregates followed the same order of macroaggregates > microaggregates > silt and clay, indicating that macroaggregates allowed soil organic carbon to accumulate, whereas silt and clay did the opposite. According to correlation analysis, the content of soil macroaggregates was significantly positively correlated with GMD, MWD, and soil aggregate organic carbon, suggesting that the increase in soil macroaggregates could improve the stability of soil aggregates and store more soil organic carbon. Further, as land use change may have significantly affected the soil aggregate, moderate development of forestry and paddy cultivation is suggested to improve the soil carbon sequestration potential in the karst area of Southwest China.

[Multi-scenario Simulation of Construction Land Expansion and Its Impact on Ecosystem Carbon Storage in Beijing-Tianjin-Hebei Urban Agglomeration].

It is of great practical significance for regional sustainable development and ecological construction to quantitatively analyze the impact of construction land expansion on terrestrial ecosystem carbon storage and to explore the optimization scheme of simulating construction land expansion to improve future ecosystem carbon storage. Based on the land use and cover change (LUCC) and other geospatial data of the Beijing-Tianjin-Hebei Urban Agglomeration from 2000 to 2020, this study utilized the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and the patch-generating land-use simulation (PLUS) model to assess and analyze the changes in ecosystem carbon stocks and spatial patterns regionally. In this study, we performed linear regression analysis to investigate the relationship between urban land expansion and changes in ecosystem carbon stocks for varying urban land proportion levels during two distinct time intervals, 2000-2010 and 2010-2020, which was conducted at a spatial resolution of 2 km. Three distinct urban land expansion scenarios were subjected to simulation to forecast the prospective land use pattern by 2030. Subsequently, we quantified the ramifications of these scenarios on ecosystem carbon stocks during the period from 2020 to 2030. The results were as follows:① In the Beijing-Tianjin-Hebei Urban Agglomeration, the ecosystem carbon stocks exhibited notable variations over the study period, with values of 2 088.02, 2 106.78, and 2 121.25 Tg recorded for the years 2000, 2010, and 2020, respectively, resulting in a cumulative carbon sequestration of 33.23 Tg C during the study duration. It is noteworthy that forest carbon storage emerged as the dominant contributor, with an increase from 1 010.17 Tg in 2000 to 1 136.53 Tg in 2020. Throughout the study period, the spatial distribution of carbon stocks displayed relative stability. Regions characterized by lower carbon content were concentrated in the vicinity of the Bohai Rim region and in proximity to cities such as Beijing, Tianjin, and Shijiazhuang, as well as rural settlements. In contrast, grid units with moderate and high carbon stocks were predominantly situated in the western Taihang Mountain and the northern Yanshan Mountain. Additionally, there was a tendency of increasing carbon stocks in the Taihang Mountain and Yanshan Mountain region, whereas those surrounding major urban centers such as Beijing, Tianjin, Shijiazhuang, and Tangshan experienced a notable decline in carbon stocks. Such reductions were most pronounced in regions undergoing urban land expansion during the study period. ② In grid units with an urban land proportion exceeding 10% at each level, a strong correlation was observed between urban land expansion and changes in carbon stocks during both the 2000-2010 and 2010-2020 periods. The changes in urban land proportion adequately explained the variations in carbon stocks. However, the explanatory power of urban land on carbon stocks decreased during the 2010-2020 period, indicating that other factors played a more substantial role in influencing carbon stocks during this time. The regression coefficients for both periods exhibited a fluctuating upward trend. In comparison to that during the 2000-2010 period, the impact of urban land expansion on carbon stocks was relatively smaller during 2010-2020, indicating a weakening influence. ③ In light of three distinct development scenarios, namely natural development (Scenario Ⅰ), a 15% reduction in the rate of urban land expansion (Scenario Ⅱ), and a 30% reduction in the rate of urban land expansion (Scenario Ⅲ), the projected ecosystem carbon stocks for the Beijing-Tianjin-Hebei Urban Agglomeration in the year 2030 were estimated to be 2 129.12, 2 133.55, and 2 139.10 Tg, respectively. These projections indicated an increase of 7.88, 12.30, and 17.85 Tg in comparison to the current carbon stocks. All scenarios demonstrated that the terrestrial ecosystem would play a role of carbon sink, particularly with the greatest carbon sink observed in the scenario with a 30% reduction in urban land expansion. The fit performance between urban land expansion and carbon stock changes during the 2020-2030 period was significantly better than that during the 2000-2010 and 2010-2020 periods, and the regression coefficients showed a fluctuating increase with an increase in urban land proportion. Across grid units with different urban land proportion levels, the regression coefficients exhibited the order of Scenario Ⅰ < Scenario Ⅱ < Scenario Ⅲ. In pursuit of the carbon peaking and carbon neutrality goals, the Beijing-Tianjin-Hebei Urban Agglomeration should prioritize scenarios with reduced rates of urban land expansion, especially in regions with higher urban land proportions.

[Integrated Analysis of Soil Organic Matter Molecular Composition Changes Under Different Land Uses].

The application of biomarkers to study the molecular composition of soil organic matter (SOM) can be used to analyze the source and degradation of SOM and reveal the stability mechanism of soil organic carbon (SOC) at the molecular level. In order to further clarify the effects of different land use patterns (farmland, grassland, and forest) on the molecular composition of SOM, the changes in molecular composition of organic matter (free lipids, cutin, suberin, and lignin) on a global scale were studied using a meta-analysis method. The results showed that there were significant differences in the molecular composition of organic matter under different land use patterns. The contents of free lipids (n-alkanes, n-alkanols, n-alkanoic acids, and cyclic lipids), cutin, and lignin phenols in forest soil were significantly higher than those in grassland and farmland. There was no significant difference in the content of suberin between grassland and forest soil. The ratio of suberin to cutin in grassland was the highest, with an average of 2.96, and the averages of farmland and forest were 1.68 and 2.21, respectively. The ratio of syringic acid to syringaldehyde (Ad/Al)S and the ratio of vanillic acid to vanillin (Ad/Al)V of farmland soil were the largest, which were 1.25 and 1.58, respectively, and were significantly higher than those in grassland (0.46 and 0.69) and forest (0.78 and 0.7). The results of correlation analysis showed that in farmland soil, suberin was significantly correlated with mean annual precipitation (MAP) and clay; cutin was significantly correlated with clay; and lignin was significantly correlated with mean annual temperature (MAT), MAP, sand, and bulk density. In grassland soil, total free lipids were significantly correlated with MAP and bulk density; suberin and cutin were significantly correlated with MAT and MAP; and lignin was significantly correlated with MAP, pH, sand, and bulk density. However, only lignin was significantly correlated with MAP and sand in forest soils. Overall, the contents of SOC and molecular components in forest soil were higher under the three land use practices, and the contribution of plant roots to SOM in grassland soil was greater. In farmland soil, the degradation of lignin was accelerated due to human farming activities. Future research should focus on the regulation of soil physicochemical properties and climatic conditions on the molecular composition of SOM.

[Effects of Land Use Patterns on Soil Microplastic Pollution in the Luoshijiang Sub-watershed of Erhai Lake Basin].

Microplastic pollution in the soil environment has received extensive attention, but the effects of different land use patterns on the sub-watershed scale on soil microplastic pollution are poorly understood. The Luoshijiang sub-watershed in the north of Erhai Lake was selected as the research object, and the characteristics of microplastic pollution in farmland, riparian zone, grassland, and woodland soils were analyzed. The pollution risks of microplastics in the four types of soil were assessed using the polymer risk index method, and the effects of land use patterns on the distribution and risk of microplastic pollution were further explored. The results showed that:① The abundance of microplastics in the soil of the Luoshijiang sub-watershed ranged from 220 to 1 900 n·kg-1, and the average abundance was (711 ± 55) n·kg-1. The main polymer types were polyester (PES, 32.52%) and polyethylene terephthalate (PET, 21.95%). The particle size of microplastics was concentrated in the range of 0.5-2 mm (61.89%). Fiber was the main shape of microplastics (>75%), and the dominant color was transparent (58.50%). ② Land use patterns determined the abundance and pollution characteristics of soil microplastics in the Luoshijiang sub-watershed. A significantly higher abundance of microplastics was found in the soil of farmland[(885 ± 95) n·kg-1] and riparian zone[(837 ± 155) n·kg-1], which had stronger intensities of human activity, than that in woodland soil[(491 ± 53) n·kg-1] (P<0.05). Film and fragment microplastics mainly occurred in farmland soil, which also had the largest number of polymer types and the most abundant colors. ③ The risk index level of microplastics (Level Ⅲ) in the soil of farmland was higher than that of the other three land use patterns (Level Ⅰ). This research indicated that the higher the intensity of human activities of a sub-watershed was, the more complex the occurrence characteristics of soil microplastics, the richer the types of polymers, and the higher the potential pollution risks would be. Therefore, it is necessary to strengthen the control of soil microplastic pollution in farmland.

Appling fluorescence spectroscopy with absolute principal component coefficient to explore dynamic migration of DOM fractions from an urbanized river during torrential rainfall.

This research delves into the dynamic interplay between urbanization and the characteristics of Dissolved Organic Matter (DOM) in the Anyang River, particularly under the stress of torrential rain. The motivation stems from a critical need to decipher how urban landscapes influence water quality, focusing on the intricate transformations and movements of DOM. Employing advanced fluorescence spectroscopy techniques like Excitation-Emission Matrices (EEM) and Parallel Factor Analysis (PARAFAC), the study meticulously differentiates DOM compositions in urban and agricultural settings. It unveils a pronounced distinction, with urban streams showing elevated proteinaceous DOM from wastewater, contrasting with the humic substances prevalent in agricultural runoff. The analysis also captures how intense rainfall events catalyze significant shifts in DOM profiles, thereby emphasizing the need for tailored water quality management strategies in urbanized catchments. This comprehensive approach not only bridges gaps in understanding the urban impact on riverine ecosystems but also sets a foundation for future research and policy development in the face of escalating environmental changes.