[Objective] An ecological security pattern with regional characteristics was constructed in order to provide a scientific reference for the protection of the ecological environment and the construction and zoning management of ecological security patterns at the county level. [Methods] Referring to the Guide for Delimitation of Ecological Protection Red Lines, we selected four indicators for quantitative evaluation of ecology at Yongchun County in Fujian Province: soil and water conservation, water conservation, biodiversity protection, and forestry protection. The minimum cumulative resistance (MCR) model and the gravity model were used to build the wildlife corridor, evaluate the importance of the corridor by grades, extract ecological nodes, and construct the ecological security pattern of Yongchun County. [Results] A total of 11 ecological source areas were identified in Yongchun County, with a total area of 64.8 km2, accounting for 4.45% of the total area. Fifty-five ecological corridors and 27 ecological nodes were constructed, including 25 important corridors and 30 secondary corridors that were concentrated in the central and eastern regions with a reticular distribution. [Conclusion] According to the results of ecological source identification and corridor division, an ecological security pattern framework for Yongchun County was constructed, with source as the core, corridor as the network, and ecological nodes as the focus. The interaction intensities between ecological source areas were obviously different. The distribution densities of source areas and the stability of the wildlife corridor in the central region were greater than in the western region, and should be regarded as key protection areas.
[Objective] The value change and radiation effect of the regional aquatic ecosystem service function were analyzed in order to provide a scientific basis for sustainable development of regional water resources and ecological compensation of a river basin. [Methods] ArcGIS software was used to extract land use data for Luoyang City, Henan Province from 2000 to 2020 in order to obtain the area of water type. The emergy method was used to quantify and analyze the changes of aquatic ecosystem service functions, and the functional radiation was analyzed by the break point model. [Results] From 2000 to 2020 (in five-year time steps), the total emergy values of aquatic ecosystem services at Luoyang City were 8.01×1021 sej， 1.29×1022 sej， 1.27×1022 sej， 1.29×1022 sej， and 1.31×1022 sej, respectively, with a general increasing trend. Among these emergy values, the focus of service composition had shifted from supply function to cultural function. In this system, biodiversity protection, aquatic product production, water resource supply, water resource regulation, and leisure and entertainment functions were dominant. Leisure and entertainment functions have become core functions. In addition, the main transfer areas of the aquatic ecosystem service function in Luoyang City were Songxian County and Luoning County, with total outward transfer values of 3.10×1020 sej and 3.21×1020 sej, respectively. The main transfer areas were Luanchuan County, Yiyang County, Yichuan County, and Ruyang County. [Conclusion] Greater attention will need to be given to ecological protection of water, increasing support and guidance for regional tourism, and reasonably carrying out ecological compensation in areas similar to Luoyang City to promote the coordinated development of the economy, society, and ecology in various regions.
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI′) was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI′ was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI′ at the city scale, with relatively small LCI′ in Nanping, Sanming, and Longyan (<0) and large LCI′ in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (>0). The LCI′ of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI′ combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
[Objective]The construction and mechanical model of soil-concrete composite slope protection technology were analyzed in order to provide scientific reference for the implementation of slope modification engineering in soil-rock mountain area.[Methods]Using a slope damage mechanism based on the basic principles of geotechnics,we proposed the slope stability design concept of "retaining soil with soil".We used this basic design concept,combined with construction experiments to establish a stability calculation mechanics model of "soil-concrete composite",and also provided design suggestions for medium-high slopes.[Results]After nearly six years of construction experiments and operation,the rationality of the slope stability design concept of "retaining soil with soil"was verified.The two scientific models of "soil-concrete composite"(i.e.,critical equilibrium state and ultimate equilibrium state)and their supporting formulas were also verified.Compared with traditional stone slopes,the "soil-concrete composite"slope protection technology could save more than 80％ of the materials used in construction,and could accelerate construction speed by more than five times,with the initial construction cost being no higher than the cost of the stone slope.[Conclusion]Soil-concrete composite slope protection can replace the traditional stone bank slope protection,thereby effectively alleviating the conflict between slow construction speed and schedule requirements,as well as the conflict between the large amount of stone material needed for construction and the environmental protection aspects of quarrying.The soil-concrete composite slope protection technology has broad application prospects in the future.
[Objective]Population structure characteristics and survival status of natural Platycladus orientalis in the loess hilly region were determined in order to provide a scientific basis for high-quality and sustainable development of forest grassland in this area.[Methods]Characteristics were quantitatively analyzed by using a dynamic change index based on a static life table combined with spectral analysis on the time scale and time series simulation prediction to carry out a comprehensive survival analysis of this cypress species.[Results]① The height,crown width,and diameter structure of the P.orientalis population indicated that young trees were abundant.② The survival curve of the P.orientalis population was close to Deevey-Ⅱ type,and the population was sensitive to external interference.③ Population dynamics were characterized by strong viability in the early stage,stable growth in the middle stage,and decline in viability in the later stage.Time series simulation and prediction analysis showed that the population of P.orientalis showed different degrees of increasing trend and strong growth recovery ability.[Conclusion]The natural population structure of P.orientalis in the loess hilly region was stable and growing,and the survival curve was close to that of Deevey-Ⅱ type.
[Objective]The change characteristics and influencing factors of vegetation coverage and its spatial distribution in the Binchang mining area were analyzed,and the ecological status of the mining area was evaluated in order to provide a scientific reference and theoretical basis for reclamation and ecological restoration of the mining area.[Methods]Landsat Surface Reflectance Tier 1 data(30 m resolution)from 1986 to 2021 were obtained from the Google Earth Engine cloud platform.Based on a pixel binary model,the trend analysis method and F-test were used to quantitatively analyze the temporal and spatial variation of vegetation coverage in the Binchang mining area over many years.Geodetector was used to analyze the spatial heterogeneity of vegetation coverage.[Results]① Vegetation coverage in the Binchang mining area increased from 1986 to 2021,and the overall growth trend was good(average growth rate of 0.64％/a).The average multi-year vegetation coverage in the study area was relatively high,with the area of medium coverage and greater accounting for 87.14％ of the total area.The spatial distribution was characterized as "higher in the southeast and lower in the northwest".② In terms of the change trend of vegetation coverage,the study area was dominated by significantly improved areas,accounting for 56.65％ of the total area.However,there were still some areas with significant vegetation degradation,mainly concentrated in the area near urban river roads.③ The factors influencing vegetation coverage followed the order of slope＞elevation＞annual precipitation＞GDP＞population density＞annual average temperature＞vegetation type＞soil type.The interaction between slope and annual precipitation had the strongest influence on the spatial heterogeneity of vegetation coverage.[Conclusion]From 1986 to 2021,the vegetation coverage in the Binchang mining area was good,showing a significant growth trend as a whole,and the vegetation improvement was obvious.The dominant factor affecting the spatial heterogeneity of vegetation coverage in the study area was slope.
[Objective]The coordinated state of socio-economic level(SEL)and ecological resilience(ER)in the Fuzhou metropolitan area(FMA)and its development trend were analyzed in order to provide regulatory suggestions and theoretical references for high-quality and sustainable development of this metropolitan area.[Methods]Data were obtained for 27 county cities in FMA,and a three-dimensional ecological resilience evaluation model based on the "resistance-recovery-adaptability"characteristics of resilience was constructed.A universal social and economic level evaluation index system was also constructed.The entropy weight method,coupling coordination degree model,kernel density model,scissors difference method,and gravity center migration model were used to determine the temporal and spatial evolution trends of SEL,ER,and coupling and coordination level of FMA.The main factors affecting the coordinated development were determined by Pearson correlation analysis.[Results]① The mean value of SEL for FMA increased from 0.181 2 to 0.320 8.The spatially high SEL areas were distributed as "one core and three centers"with FMA as the core.② The mean value of ecological environmental resistance(ER)decreased from 0.429 4 to 0.349 4,and the high ER areas were mainly concentrated in the inland mountainous areas such as "Yanping-Gutian",while the low ER areas were located in the coastal area of "Mawei-Meizhou Island",and formed a resilience "depression"in and around FMA.ER and its subsystems exhibited strong positive autocorrelation in space.③ The mean value of coupling coordination degree steadily increased from 0.51 to 0.56.The speed of development in terms of the SEL and ER of counties tended to be balanced,and the scissor angle difference generally decreased.The center of gravity of coordinated development moved to the central part of FMA,and the number of counties entering a type of coordinated development increased significantly.The main factors hindering the coupled coordination were the risk resistance index,per capita GDP,and the number of hospital beds per thousand people.[Conclusion]The SEL and ER of FMA showed a trend of"misaligned"development in space-time,and the coupling and coordination level of both still has much room for improvement.
[Objective]The ecological security pattern of Anhui Province was constructed and the key areas of ecological restoration were identified in order to build an ecological basis for urban development,and to provide a scientific basis for the territorial ecological restoration of Anhui Province.[Methods]The InVEST model and the MCR model were used to evaluate and identify ecological source areas from the supply side and the internal response side of the ecosystem.The resistance surface was modified by nighttime light data.The ecological security pattern for Anhui Province was constructed based on the circuit theory.The ecological pinch points and ecological barrier points were identified,and differentiated restoration and maintenance measures were proposed according to spatial differentiation and terrain characteristics.[Results]① There were 53 ecological source areas in Anhui Province,with a total area of 4.22 × 104 km2,accounting for 30.5％ of the total area of Anhui Province.The southern source areas were concentrated and had high ecological value,while the northern source areas was scattered and had low ecological value.② Ninety-five ecological corridors were constructed.Based on landscape connectivity analysis,68 key corridors,26 important corridors,and one general corridor were selected.③ There were 119 ecological pinch points with an area of 412.45 km2,and 46 ecological barrier points with an area of 423.20 km2.④ Ecological pinch points and scattered ecological barrier points were maintained by nature,and artificial restoration and natural restoration of large ecological obstacles were implemented simultaneously.[Conclusion]The ecological security pattern constructed with the help of ecological assessment and circuit theory was more in line with the actual process of species movement,and can effectively identify the key areas of ecological restoration and their distribution characteristics.
[Objective]Through the treatment of hydrophilic and hydrophobic by the conditioner,the influence of different interface characteristics of the conditioner on the soil water and salt transport law was explored,and the improvement mechanism of fly ash-based soil conditioner on saline-alkali land was revealed in order to provide scientific reference for the improvement of different types of saline-alkali land in irrigation area of the Yellow River.[Methods]Taking sodic sline soil in Ningxi Hui Autonomous Region as a case study,the spatial transport patterns of different salt ions in the soil before and after modification with the soil conditioners were investigated by soil column experiments.[Results]After the addition of unmodified conditioner,hydrophilic-modified conditioner,and hydrophobic-modified conditioner,the surface desalination rates were 79.72％,59.91％,and 84.79％,respectively,for a sodic saline soil far greater than the values obtained without conditioner added(12.64％).Compared with the unmodified conditioner treatment group,the water content of the hydrophilic treatment group was 6.59％ greater,and the total salt amount was 47.13％ greater.The water content of the hydrophobic treatment group was 0.67％ less,and the total salt amount was 25.22％ less.The pH values were reduced from 10.5 to 8.08 and 8.71,respectively.The surface Na+contents were reduced by 10.39％ and 30.46％,and the K+contents were reduced by 10.22％ and 45.93％,respectively.[Conclusion]The interface properties of soil conditioners significantly affected water and salt transport in the soil.The hydrophobic conditioner treatment was more effective in improving saline land,and increasing the infiltration of salts with soil water is more important for saline land improvement.
[Objective]The effects of desulfurized gypsum and polyglutamic acid(γ-PGA)improves saline soil were studied in order to provide a theoretical and technical basis for improving saline soil in Northwest China.[Methods]Simulated leaching tests in soil columns and simulated growth tests in pots were used to determine the effect of combining desulfurized gypsum with y-PGA on saline soils from the perspectives of promoting salt leaching,reducing soil salinity,lowering soil pH value,improving soil nutrient status,and promoting crop growth.[Results]The leaching tests showed that combining desulfurized gypsum with γ-PGA could further reduce soil pH value after leaching and increase Na+leaching;reduce HCO3- and Cl-contents after leaching,but increase SO42-,Ca2+,and Mg2+ contents;and effectively reduce the sodium adsorption ratio(SAR)value of the soil.Desulfurized gypsum combined with y-PGA significantly increased maize height,leaf area,and dry weight,with maximum dry weight at 30 days of growth increasing by 54.40％compared with the control treatment,and by 40.27％and 29.47％compared with desulfurized gypsum and y-PGA treatments alone,respectively.In addition,soil pH value was lower and soil N,P,and K nutrient contents and soil enzyme activities were higher after the plants were harvested from the combined desulfurized gypsum and y-PGA treatment.[Conclusion]The application of desulfurized gypsum and y-PGA can produce complementary and synergistic effects,thereby further promoting soil ion exchange,lowering pH value,increasing soil nutrient content,and promoting crop growth.
[Objective]The current status and hot trends of slope greening research were studied in order to provide theoretical support and references for subsequent research.[Methods]Professional bibliometric tools CiteSpace and VOSviewer were used to visualize and analyze slope greening research literature indexed by the China National Knowledge Infrastructure(CNKI)database.The main indicators included publication volume,high-frequency keywords,keyword co-occurrence clusters,and burst keywords.The research hotspots and changes in research trends were discussed from three aspects:mechanisms of slope root fixation of soil,selection and configuration of slope plants,and application of engineering greening technology.[Results]There has been a good trend of publishing scientific research results in the field of slope greening in China.Research institutions were mostly higher education institutions(colleges and universities)with programs in the fields of agriculture,forestry,science,and engineering.As a multidisciplinary and comprehensive application technology,slope greening has a very necessary role to play in industry associations.[Conclusion]At present,the variation pattern of slope stability is an important research direction.Numerical simulation technology is expected to play a greater role in the study of slope stability.Plant screening research has focused on the ecological adaptability of plants,which can strengthen future investigations and breeding efforts related to plants adapted to slope protection in the region.Determining the factors influencing plant diversity changes can contribute to the sustainability of plant configuration.Spraying was found to be the most widely used greening technology.The topics of erosion resistance and stability of substrate materials were research hotspots.In the future,it will be necessary to start with the standardization of terminology,construction methods,equipment,and materials so as to gradually establish a standard system for spraying and greening technology applicable to conditions found in China.
[Objective]A factor importance analysis of vegetation changes in East Africa based on different machine learning algorithms was conducted to measure the accuracy and applicability of the different algorithms in order to provide a scientific basis for protecting,restoring,and promoting sustainable forest management and comprehensive prevention and control of soil erosion.[Methods]Changes in normalized difference vegetation index(NDVI)for nine countries in East Africa from 2001 to 2020 were determined.The independent treatment variables were two climatic factors and five human activity factors affecting vegetation changes in East Africa.Six machine learning algorithms were used to establish NDVI prediction models:random forest(RF),BP neural networks(BP),support vector machines(SVM),genetic algorithm(GA),radial basis function(RBF),and convolutional neural networks(CNN).Coefficient of determination(R2),mean absolute error(MAE),and mean relative error(MRE)were used as error indicators to evaluate the potential of the six machine learning algorithms for predicting NDVI changes.Based on the optimal model(RF),the importance of the selected seven factors was determined.[Results]The accuracy verification results showed that the regression accuracy of the CNN algorithm was the worst for the full factor case in the study area.After deleting an algorithm with poor comprehensive performance in each round of testing,the model established by the RF algorithm had the highest regression accuracy for NDVI change analysis in East Africa.The importance of different factor variables to NDVI change based on RF showed that annual precipitation,N2O emission,CH4 emission,and livestock number had the greatest influence on the results of the NDVI change regression.[Conclusion]RF had a comparative advantage for NDVI simulation in East Africa.Precipitation was the most important climatic factor affecting vegetation changes.At the same time,greenhouse gas emissions also had an important impact on vegetation changes in East Africa.East African countries should raise awareness and understanding of the interdependence of vegetation changes on climate,environment,socio-economic conditions,and political systems,and develop appropriate policies to promote sustainable forest management and to combat desertification.
[Objective]The effects of soil moisture content and root area ratio on the soil consolidation effect of Medicago sativa and Euphorbia hypericifolia root systems and the interaction mechanism of root-soil were studied in order to provide scientific basis for selecting plant species and controlling soil moisture content in ecological restoration of mines.[Methods]Wild M.sativa and E.hypericifolia were observed on a Haizhou open pit mine slope in Burin City,Liaoning Pvocince.Tests were conducted to determine the tensile properties of the root systems.The root-soil complex shear test was used to determine the optimum moisture content of the root systems of the two plants.The root-soil composite shear optimization test was conducted based on the optimal moisture content to determine the optimal root area ratio for soil consolidation efficiency.[Results]① The tensile resistance of the root systems of the two species increased as a power function of root diameter.The tensile strength of the root systems decreased as a power function of root diameter.② The cohesive force of the vegetative soil and the two root-soil complexes tended to increase and then decrease with increasing moisture content,and the angle of internal friction tended to decrease with increasing moisture content.③ The M.sativa and E.hypericifolia root systems had the greatest soil consolidation effect when the moisture content was 25％ and 21％,respectively.④ At the optimal moisture content,the greatest soil consolidation efficiency was achieved when the root area ratios of the M.sativa and E.hypericifolia root systems were 0.04％ and 0.08％,respectively.[Conclusion]The morphological and mechanical effects of the E.hypericifolia root system made it the superior species because of its greater soil consolidation than the M.sativa root system.
[Objective]The relationship between farming and herding households'livelihood capital and livelihood strategies was studied,and the spatial differences of farming and herding households'livelihood capital and the transformation between livelihood strategies were analyzed in order to provide a theoretical basis for reducing farming and herding households'livelihood vulnerability and ultimately achieving sustainable development.[Methods]Starting from the theoretical framework of sustainable livelihood analysis,a household questionnaire survey was used to analyze the key factors of livelihood capital and livelihood strategy transformation for farming and herding households in the national sandy land enclosed reserves in Maqu,Minqin,Shandan County,and Liangzhou District in Gansu Province,which were approved to be established in 2017,by combining a Logistic regression model and one-way analysis of variance(ANOVA).[Results]Financial capital was the most abundant form of livelihood capital,while natural capital was the least abundant form of livelihood capital for the farmers and herdsmen in the enclosed reserves of desertified land.There were significant differences in the distribution of livelihood capital among farmers and herdsmen with different livelihood strategies,and the livelihood capital of non-agricultural farmers and herdsmen was better than that of purely farming households.Cultivated(or grassland)area,cultivated(or grassland)quality,and production tools had significant positive effects on the choice of purely farming households.The size of the family labor force,the education level and the total household income had a significant negative impact on the choice of purely farming livelihood strategy.[Conclusion]The following countermesures should be promoted in the future.Those are increasing the publicity of ecological environmental protection in enclosed protected areas,strengthening the awareness of ecological protection among farmers and herdsmen,accelerating the development of agricultural mechanization,and encouraging the transformation of the remaining labor force to non-agricultural industries,thereby achieving diversification of livelihoods.
[Objective]The biological characteristics of different attached algae were determined and the relation between water quality indicators and algae biological characteristics were analyzed in order to provide scientific support for screening scientifically reasonable attached substrates and enriching the growth of attached algae.[Methods]The biological characteristics of algae attached to three different building material substrates(granite,polyethylene mesh,wood)were analyzed using simulation experiments.The types of attached substrates having good effects and easy resource utilization were selected.[Results]The periphytic algae communities attached to granite and wood substrates were more stable,and had better biological characteristics and more functional algae species,and thereby were more conducive to providing an ecological effect of periphytic algae in the water environment.[Conclusion]The granite substrate was considered to be the most suitable substrate among the three tested substrates because of its ready availability and ease of use.
[Objective]The spatial-temporal variation characteristics of water yield services in Harbin City,Heilongjiang Province from 2000 to 2020 were determined,and the driving mechanism of the spatial-temporal differentiation characteristics of Harbin City's water yield was analyzed in order to provide a scientific basis for the management and sustainable development of water resources in Harbin City.[Methods]The study was conducted in Harbin City,a typical cold land city.The spatial-temporal variation characteristics of water yield in 2000,2010,and 2020 were analyzed based on the InVEST model's water yield module,and the spatial and temporal evolution of water yield services in Harbin City was determined by using a parameter optimal geographic detector.[Results]① The water output of Harbin City from 2000 to 2020 increased from 9.68 × 109 m3 in 2000 to 2.23 × 1010 m3 in 2020.The spatial distribution pattern of water yield in different years was basically similar.The overall spatial distribution of water yield was characterized as "higher in the east and lower in the west".② There was a strong positive spatial correlation in the distribution of water yield in the study area,with the main types being low-low aggregation and high-high aggregation.The proportions of the two areas relative to the city's total area showed a downward trend from 2000 to 2020.③ The influence of each driving factor on water yield exhibited obvious spatial heterogeneity.Actual evapotranspiration and land use type were the main driving factors of the economic quality development zones.In the nature-dominated ecological barrier area,the comprehensive driving forces of actual evapotranspiration and land use type were far less than in the economic quality development area.[Conclusion]Water yield assessment was closely related to ecosystem services and ecological product value,and serves as the basis of water conservation research.The temporal and spatial changes of water production in Harbin City from 2000 to 2020 were significant,and meteorological and land use factors were the main driving factors.
[Objective]This study was conducted to determine a rill erosion technology having high efficiency,high accuracy and strong adaptability,and overcome deficiencies associated with traditional measurement methods(low efficiency,high cost,poor applicability,etc.)in order to provide new ideas and technical means for the evolution of slope rill erosion and quantitative research.[Methods]UAV technology was used to acquire high-resolution images and models of rill development on slopes under six consecutive simulated rainfall events by use of nap-of-the-object photogrammetry.The feasibility of slope rill erosion and morphological evolution was quantitatively evaluated by positioning accuracy,model accuracy,and erosion simulation.[Results]① The root mean square error(RMSE)of geographic registration of the 3D real scene model was 1.5 cm.The image control point plane RMSE was 0.42 cm.The elevation RMSE was 0.88 cm.The model details and texture were clear,with millimeter-level resolution.② The multi-phase model clearly described five stages of rill development:raindrop splash erosion,sheet erosion,small waterdrop erosion,intermittent rill erosion,and continuous rill erosion.The average width,depth,and density of rills on the slope surface developed from the initial values of 1.25 cm,0.82 cm,and 0.05 to the final values of 3.27 cm,4.75 cm and 0.23,respectively.The maximum trench length was 236 cm and the maximum trench depth was 14.23 cm.③ As rainfall duration increased,the simulated values of soil erosion in rills were close to the real values and tended to become stable,with an average error of less than 10％.[Conclusion]UAV nap-of-the-object photogrammetry can better reflect rill development and evolution,and has significant advantages over traditional measurement methods in efficiency and convenience.
[Objective]Research was conducted on understory litter and soil hydrological function for artificial forests in the forest protection station in the eastern section of the Kubuqi Desert.The comprehensive weight value of various indicators of the artificial forests in this area were scientifically calculated,and the hydrological effect and water conservation function of artificial forest litter and soil were determined in order to provide theoretical guidance for the directional tending of returning sand to forest in this area and related sandy areas.[Methods]Five common types of artificial shelterbelts were used in the Ordos afforestation station in the Kubuqi Desert.The water-holding capacity of litter and soil were determined using field measurements and the indoor immersion method,and the water conservation function of each forest was assessed using a combination of the analytic hierarchy process(AHP)and the entropy-weight method(EWM).[Results]① The litter thickness in each stand ranged from 6.56 to 22.20 mm,and the litter accumulation ranged from 1.44 to 13.62 t/hm2.Interception capacity for the different forest stands followed the order of Salix matsudana-Populus × euramericana mixed forest＞Populus × euramericana forest＞Pinus sylvestris forest＞3-year S.matsudana forest＞8-year S.matsudana forest.② The maximum water-holding depth of litter was linearly related to the dry mass,and the maximum storage was about 1.36～2.04 L of precipitation in each stand.These results showed that the maximum water-holding capacity of the litter depended mainly on the dry weight of the litter,while related factors such as tree species,age,and meteorology indirectly affected the water-holding capacity by influencing the dry weight of the litter.③ Logarithmic and power functions provided good representations of the dynamic water-holding capacity and dynamic water uptake of litter,respectively.④ The saturated water-holding rate,capillary water-holding rate,and total porosity basically showed decreasing trends as soil depth increased,and soil bulk density showed an increasing trend.⑤ The S.matsudana-Populus × euramericana mixed forest exhibited a higher water conservation function than the other forests,the Populus × euramericana and Pinus sylvestris forests had similar water conservation functions,and the S.matsudana forests had the lowest water conservation functions.[Conclusion]Construction of future artificial shelterbelts in desert regions should prioritize the cultivation of mixed forests,and a more scientific plan for the return of sand to forests should be developed by considering differences in the water conservation function between tree species.
[Objective]The spatio-temporal coupling coordination relationship between high-quality development and water resource conservation and utilization in the urban agglomerations of the middle reaches of the Yellow River in order to provide decision support and a scientific basis for the sustainable use of water resources and effective protection of water ecology in the region.[Methods]Based on the panel data of high-quality development and water resources protection and utilization in 19 cities in the middle reaches of the Yellow River from 2011 to 2021,the coupling coordination degree of high-quality development and water resources protection and utilization and its spatio-temporal characteristics were analyzed by means of combination weighting,coupling coordination degree model and a geographic detector model.[Results]The level of high-quality development and water resource conservation and utilization in the urban agglomeration of the middle reaches of the Yellow River had improved continuously,and regional disparity has gradually narrowed.The coupling coordination degree of the two systems increased over time,with some areas transitioning from the brink of imbalance to the initial stage of coordination.Furthermore,the coupling coordination degree exhibited positive spatial autocorrelation,radiating outward from the two central cities of Xi'an and Zhengzhou City.The degree of dependence on foreign trade and the proportion of tertiary industry output had significant impacts on the coordination of the two systems,with nonlinear enhancement or mutual strengthening relationships among interactive factors.[Conclusion]To enhance the spatial dependence of high-quality development and water resource conservation and utilization in urban agglomerations of the middle reaches of the Yellow River,it will be necessary to strengthen regional cooperation,optimize water resource utilization structures,improve water resource management capabilities,increase investment in science and technology,enhance regional innovation capacity,and actively promote coordinated regional development.
[Objective]The spatial-temporal evolution pattern and influencing factors of the dominant marginalization of cultivated land in Guizhou Province from 2010 to 2020 were analyzed in order to provide policy guidance for the intensive use of cultivated land in mountainous areas.[Methods]A land use transfer matrix,spatial autocorrelation model,and geographic detector were comprehensively used to systematically determine the overall situation,spatial agglomeration effect,and related influencing factors of the dominant marginalization of cultivated land in Guizhou Province.[Results]① The dominant marginalization rate of cultivated land in Guizhou Province during 2010-2020 was 10.20％.In general,natural marginalization was the main factor,but economic marginalization developed rapidly.With economic and social development,the dominant marginalization rate of cultivated land continued to accelerate.② The dominant marginalization level of cultivated land in Guizhou Province during 2010-2020 generally showed a pattern characterized as "higher in the south,lower in the north,and gradually expanding to the west and southeast".During 2010-2015,the pattern was characterized as "higher in the south and lower in the north".Duging 2015-2020,the pattern was "higher in the middle surrounded by lower".③ Per capita cultivated land area,urbanization rate,vegetation coverage,and other factors were the main influencing factors of the spatial difference in the marginalization of cultivated land in Guizhou Province.[Conclusion]The temporal and spatial evolution of the dominant marginalization of cultivated land in Guizhou Province exhibited significant differences.Natural conditions such as elevation,slope,and vegetation coverage were the basic characteristics of the temporal and spatial differences in the dominant marginalization of cultivated land.Socio-economic factors,such as per capita cultivated land area,urbanization rate,GDP density,etc.were the main driving force behind the rapid development rate of the dominant marginalization of cultivated land.
