Landscape patterns, dynamics, and processes are at the core of landscape ecology. The scientific analysis of dynamic changes in coastal landscape patterns plays an important role in regional development planning. This paper used land-use data from remote sensing products for the Guangxi Gulf of Tonkin Economic Zone (GGTEZ) from 2000, 2010, and 2020 as data sources. Then landscape pattern index and coefficient of variation were used to quantify the grain size effect of the landscape index at 30-1 000 m at the landscape level and class level. Information entropy models were elaborated to determine the optimal granularity. Further, the landscape index and the transfer matrix were used to analyze the dynamic changes in landscape structure in the GGTEZ between 2000, 2010, and 2020. The results show that:(1) At the landscape level and class level, landscape indices exhibited variable degrees of sensitivity to different grain sizes. The grain size effect of different landscape types was slightly different, and the optimum grain size for landscape pattern analysis was 60 m. (2) Forest was the main landscape type in the study area, and construction land was the fastest growing landscape type. Forest, agricultural land, and construction land areas changed dramatically due to human activities. (3) In the GGTEZ, the patch density increased, the landscape became fragmented and more complex, and the spatial heterogeneity increased. In the context of rapid social, economic, and tourist industry development, the landscape patterns of the GGTEZ changed at an accelerated pace. Therefore, when planning territorial space it is necessary to analyze the landscape structure from a regional perspective to adjust landscape structure, to strengthen the protection of natural resources, so as to achieve sustainable economic and ecological development.

The Yangtze River Delta (YRD) is a region in China with an active economy, a high level of openness, and a dense population. Given the prominence of this region, it is important to explore the spatial-temporal evolution of the region's ecosystem service value (ESV) and its driving factors. This is needed to support the joint protection and management of the ecological environment in the YRD, to enhance regional sustainable development capabilities, and to advance the integrated development of the YRD. Using four-stage land use data from the YRD for 1990 to 2018, this study included a quantitative analysis of the trends in ESV changes in the YRD, and the trade-off and synergies between multiple services. This included a spatial correlation analysis, hot spot analysis, and geodector models to explore the spatio-temporal differentiation characteristics and driving factors of ESV in the YRD. The results show that:(1) Both ESV and ecosystem service function in the YRD showed a downward trend, and this trend slowed down after 2010. Before 2010, the trade-offs between regional ecosystem services decreased, and the synergies increased. After 2010, the synergies were dominant; (2) The spatial differentiation of the ESV in the YRD showed a pattern of high values in the south and low values in the north, with a significant positive spatial autocorrelation relationship. The cold spot peaked in 2010, and then began to decrease. The hot spots decreased after 2000, but the rate of the decrease declined gradually; (3) Elevation, sunshine duration, and annual precipitation were the main factors leading to the spatial differentiation of ESV in the YRD. The interaction between the proportion of primary industry and elevation was the strongest, with a q value of 0.883. The interaction between natural geographical factors and socio-economic factors are the main driving forces to the spatial differentiation of the ESV in the YRD during the study period.

The study on the explicit gradient change in urban ecological space helps a deeper understanding of the landscape pattern-process relationship, and could provide the support for the urban landscape pattern optimization and management. Meanwhile, rapid urbanization caused a series of ecological problems associated with the changes of urban ecological space in Changsha. In this study, remote sensing (RS), geographic information system (GIS) technology, landscape pattern index, and Fragstats 4.2 moving window method were adopted to explore the gradient and directional differentiation of landscape pattern characteristics of urban ecological space in Changsha metropolitan area at optimal spatial scale based on remote sensing images in 2013, 2017 and 2020. The results prove that:(1) The most suitable grain size is 60 m, and 1 000 m moving window is the most suitable size for analysis. (2) The increase of the construction land area came from the reduction of part of the cultivated land, and the dominant position of cultivated land was gradually weakened. The largest patch area and aggregation degree of urban green space and forest showed an overall upward trend, while the fragmentation level was weakened. Urban ecological space presented the trend of discrete development from 2013 to 2017 and agglomeration from 2017 to 2020. (3) The construction land is the dominant landscape component of the urban center, and the landscape homogeneity is strong. The construction level develops rapidly, and the urban ecological space has a high degree of fragmentation and diversity in the sub center of the city. Moreover, the urban-rural transition area has the largest landscape diversity, high degree of fragmentation and strong landscape heterogeneity, which makes it a typical area of urban expansion. The cultivated land and forest constituted the ecological barrier of ecological conservation area in Changsha metropolitan area. (4) From 2013 to 2020, the ecological space of the metropolitan area, as a whole, had a north-east and south-east shift trend, while the spatial center of gravity showed an east-west shift trend, and the construction land spread from the city center to all directions, especially in the north-south, east-west and north-east directions. The landscape of cultivated land has been seriously impacted. The largest patch area of forest increased and the degree of fragmentation decreased in the north, north-east, south-east and south. The ecological function of the east and west sides of the central Xiangjiang River has been significantly enhanced.

Coordination is an important part of the new development philosophy. Promoting the coordinated development is the main goal of deepening the reform and development in state-owned forest region. Aiming to provide scientific basis and theoretical supports for promoting the continuous deepening of reform of state-owned forest region and realizing comprehensive and high-quality coordinated development, the key state-owned forest region in Daxing'anling, Heilongjiang Province was chosen as the research object. A compound system covering ecological conservation, industrial development, enterprise management, well-being of the people and support capability was constructed. The coupling coordination model was used to quantitatively evaluate the coupling coordination status of the compound system from 2000 to 2020. The Grey Markov model was used to predict the trend of coupling coordination development in this compound system from 2021 to 2022. Results show that, after 21-year of transformation and development, the development index of each subsystem of state-owned forest region in Daxing'anling, Heilongjiang Province has been changed, however, the process were different among subsystems. The growth rates of the subsystems of well-being of the people and resource conservation have been high, while the subsystems of enterprise management and the support capability have been lagged dramatically behind. The development stage of coupling coordination of the compound system has changed from misalignment to coordination, nevertheless, the coordinated development level was regressive in recent years due to certain factors such as policy, COVID-19, etc. It is predicted that by 2022, the development stage of coupling coordination of compound system will be recovered to the benign coordinated development type, however, there is still a big gap before it reaches the high-quality coordinated development type. It is suggested that the existing support policies and inputs should be kept stable, moreover, the enterprise management and support capability should be strengthened, in order to promote the stable and high-quality coupling coordinated development in the key state-owned forest regions in Daxing'anling, Heilongjiang Province.

Water retention and biodiversity conservation zone of Great Xing'an Mountains is an important ecological barrier in North China. Quantitative analysis of dynamics and internal relationship among the ecosystem service functions is of great scientific significance for reasonable utilization of natural resources and sustainable development in this region. Based on multi-source data and the models for ecosystem service function evaluation, dynamics of service functions in the ecological functional zone of Great Xing'an Mountains during 2000-2015 was analyzed, including water supply, carbon storage and habitat quality function. Furthermore, this study discussed the balance and coordination among the ecosystem service functions through the combination of correlation analysis and trade-off and synergic relation model. The results were concluded as follows:(1) woodland was the dominant ecosystem in this region, accounting for 67.80% of the total area, followed by wetland and grassland. The three ecosystem types accounted for 92.35% of the total area. During 2000-2015, woodland increased by 2 080 km², while grassland and wetland decreased by 1 365 and 1 265 km², respectively. The area of other ecosystems changed insignificantly. (2) From 2000 to 2015, the function of water supply was obviously weakened, carbon storage was enhanced slightly, and the habitat quality was significantly improved. Wherein, water supply decreased by 1.51 billion cubic meters, the quantity of carbon storage increased by 16.79 Tg, and the area with good or higher habitat quality increased by 5 746 km², accounting for over 85.41% of the total ecological functional area. The habitat quality of biological inhabitation and activity zone was significantly improved. (3) At the regional and municipal scale, water supply and carbon storage showed a trade-off relation whereas carbon storage and habitat quality presented a synergic relation. A trade-off relation was revealed between water supply and habitat quality functions at the regional scale. At the municipal scale, there was a trade-off relation between Chifeng City and Heihe City, but a synergic relation between Great Xing'an Mountains Prefecture and Tongliao City. The results provide important data support and decision basis for regional natural resources management, ecological planning and improvement of overall benefit of ecological system.

The well-being of the human race is closely related to the ecological environment. In the past few decades, indicators retrieved from remote sensing data have been increasingly more widely applied to ecological environment evaluation for their advantages of spatial visualization, and remote sensing technology offers important reference to regional ecological environment governance, improvement, and development planning by quickly assessing regional ecological environment quality. Based on Landsat 5/8 images from 1987, 2000, 2007, 2017 and 2020, vegetation coverage (FVC) and remote sensing ecological index (RSEI) were selected to explore the spatial-temporal changes of ecological environment in Helan Mountains, Ningxia, and to analyze the vegetation status and ecological restoration effect before and after the implementation of ecological protection action in Helan Mountains in 2017. The results show that:(1) In general, the vegetation coverage and ecological environment of Helan Mountains in Ningxia had been continuously improved during 1987-2020. The annual average FVC had increased from 31.03% (1987) before the ecological battle to 43.35% (2020) recently, and the RSEI had increased from 32.71% to 50.45%, indicating a significant effect of ecological restoration. (2) The FVC and RSEI were still at low level, and the overall ecological quality in the research area was in ordinary status. The FVC and RSEI of the higher altitude areas in the west and the tourist-intensive areas in the central and southern regions had been obviously degraded, with degradation rates of 12.11% and 8.30%, respectively. (3) The spatial distribution and variation trend of FVC was highly consistent with those of RSEI, and the correlation coefficients are all greater than 0.80. Greenness index has the highest weight in principal component analysis, indicating that the increase of FVC has a positive impact on the ecological environment of Helan Mountains in Ningxia. The results in the present study have important reference significance for the restoration and management of the ecological environment in the area of ecologically fragile area such as Helan Mountains and other similar protected areas.

Evaluating ecosystem services and quantifying the trade-offs and synergies between those services on the bases of the coupled social-ecological system, have theoretical and practical significance for ecosystem services research and national park planning and management. Taking China's Pudacuo National Park as the research site, this article employs the SolVES and InVEST models to construct the coupling coordination degree model between perceived biodiversity value and habitat quality and comprehensively evaluates biodiversity value using Getis Ord G _i^* to obtain social-ecological hotspots. The results show that:(1) The hotspots of perceived biodiversity value exhibit a "multi-core and multi-strip" spatial pattern, with a significant negative correlation with distance to roads and water bodies, a significant positive correlation with altitude, and its value index reaches its maximum in forest land. (2) The habitat quality index is high in the central, southern, and northeastern regions, low in the western and eastern regions; the high-value areas of habitat quality are found in forest land and grassland in the mountainous areas, while the low-value areas are found in the valley and plain areas. (3) The coupling degree between perceived biodiversity value and habitat quality is at the high-level stage. Their coupling ordination degree is at the middle-level stage of good coordination. The coupling coordination category belongs to the social lag ecotype. (4) Social-ecological hotspots are concentrated in the park's southwest part and forming a "single strip" distribution pattern, and some of the hotspots are distributed in the northeast. In contrast, the social-ecological coldspots are relatively concentrated and mainly located in the lower reaches of Niru River in the east of the park. This study provides a scientific basis for reconstructing the theoretical framework of biodiversity assessment and biodiversity protection, regulation, and management.

In the context of global biodiversity decline, biodiversity is becoming one of the hottest research topics in the field of contemporary ecology. Amphibians have unique habits and life histories, so that, they can be used as indicators to judge environmental quality. To understand the current status and spatio-temporal pattern of amphibian diversity in Yinggeling National Nature Reserve, Hainan Province, 11 sampling transects representing three habitats (stream, river, and cropland) were established. Field investigations were conducted in April, June, and August of 2018. A total of 535 individuals belonging to one order, five families, seven genera and nine species were recorded. Limnonectes fragilis is a vulnerable species endemic to Hainan, and Fejervarya multistriata is the dominant species. Species diversity indexes did not differ significantly among the three months, whereas significantly more amphibians were observed in April and June than in August. Species diversity indexes varied significantly among the three habitat types, with all three indexes (Shannon-Wiener index, Pielou's evenness index, and Simpson index) being comparatively lower in farmland habitats. This investigation has shown the current situation and distribution pattern of amphibians in Yinggeling Nature Reserve, and the way of how to combine with natural and anthropogenic factors in making relevant suggestions on protection of local amphibian diversity and environments.

The influences of salinity on bacterial communities in a coastal area of Yuniao River in the Muping District of Yantai City, China, were analyzed by high-throughput sequencing of in situ and simulation experiments. Proteobacteria, Bacteroidetes, and Cyanobacteria were shown to have a high relative abundance in the community compositions of bacterioplankton and attached bacteria in situ. Proteobacteria occupied the highest relative abundance among all samples, while Cyanobacteria with the second highest relative abundance was inversely proportional to salinity levels in Yuniao River. Among the bacterioplankton community, ammonia-oxidizing bacteriaNitrosomonas and halophile Candidatus Nitrotoga, that have important roles in the nitrogen cycle, were with high abundance. Among the attached bacteria community, salt-tolerant bacteria Porphyrobacter had a high relative abundance that changed according to the abundance of cyanobacteria. Similar results for dominant bacterial communities in different salinities were observed in the simulation experiment. Bacteroidetes and Cyanobacteria had high relative abundance in the simulation experiment, and salinity influenced the diversity and richness of the bacterial community. This was verified by correlation analysis and principal component plot analysis. These findings could provide information and data support for the understanding of the effects of salinity on bacterial communities in coastal areas and the application of salt-tolerant bacteria.

Based on the hourly observation data of "dry" aerosol scattering coefficient and absorption coefficient, as well as the simultaneous monitoring data including visibility (V), relative humidity (RH), and nitrogen dioxide (NO₂) during October to December 2017 in Chengdu, aerosol scattering hygroscopic growth factor (f) was calculated by optical synthesis method, and then the complex response-relationship of f to synergistic action between RH and aerosol components was further investigated. Firstly, there were strong multicollinearity among different indicators including RH, ρ_BC, ρ_BC/ρ_PM1, ρ_BC/ρ_PM2.5, ρ_BC/ρ_PM10, ρ_PM1/ρ_PM2.5, ρ_PM1/ρ_PM10, and ρ_PM2.5/ρ_PM10 by using the method of correlation analysis combined with variance inflation factor (ρ_BC, ρ_PM1, ρ_PM2.5 and ρ_PM10 represent mass concentrations of BC, PM₁, PM_2.5, and PM₁₀, respectively). Subsequently, the explanatory variable set of f which included RH, ρ_BC, ρ_BC/PM_2.5, ρ_PM1/ρ_PM2.5, and ρ_PM2.5/ρ_PM10 were obtained. Secondly, the diagnostic results of f single-variable by adopting generalized additive model (GAM) validated that although RH was the decisive influencing factor of f, f also had significant nonlinear relationship with other explanatory variables (all passed the significance test of α=0.01), especially ρ_BC. Finally, the model of the multivariable influence factors of f were constructed based on GAM and the corresponding independent variables including RH, ρ_BC, ρ_BC/ρ_PM2.5, ρ_PM1/ρ_PM2.5 and ρ_PM2.5/ρ_PM10, respectively. The corresponding adjustment determination coefficient (R²) and the determination coefficient of reduced major axis regression were 0.787 and 0.797, respectively, which significantly improved the simulation effect of aerosol scattering hygroscopic growth factor.

To evaluate the safety of Panax notoginsengas medicinal materials and provide theoretical basis for the control of soil heavy metal pollution, the contents of eight heavy metals in tillage layer soil (0-20 cm), subsoil layer (>20-40 cm) and P. notoginseng in the main planting fields of Yunnan Province were analyzed. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the contents of heavy metals. Soil heavy metal pollution was assessed by single pollution index (P_i), Nemerow integrated pollution index (NIPI) and potential ecological risk index (PERI). Estimated daily intake (EDI), target hazard quotient (THQ) and hazard index (HI) were used to estimate the risk of intake of parts of plants on human. Bioconcentration factor (BCF) and transport factor (TF) were used to evaluate the enrichment and transport capacity of heavy metals in plants. The results show that the pollution degree of heavy metals in P. notoginseng planting soil is in the order of Cd>Cu>Cr>Ni>Pb>As>Hg>Zn; The planting soil of P. notoginsengis moderately contaminated by heavy metals and has moderate ecological risk; The contents of heavy metals exceeded the standard for all five parts of P. notoginseng,including taproots, fibrous roots, rhizomes, stems and leaves. Especially Hg in the shoots excessively exceeds the standard. However, none of them pose any human health risk; The enrichment coefficients of heavy metals in all parts of plants are less than 1. Specifically, the enrichment capability of Cd is the strongest and Pb is the weakest in taproots, fibrous roots, rhizomes and stems. The enrichment capability of Hg is the strongest and Cr is the weakest in leaves; The transport capacity of heavy metals in plants is in the order of Hg>Cu>As>Zn>Pb>Cd>Ni>Cr.

Pot experiments using a cadmium (Cd)-contaminated agricultural soil (total Cd 0.79 mg·kg^-1, pH 6.71) were carried out to study the influence of three alkaline conditioners, namely mercapto-modified sepiolite (SGP, pH 9.31, application rate 0.5 g·kg^-1), amino-modified attapulgite (ISS-1, pH 9.78, application rate 0.5 g·kg^-1) and humus-sepiolite complex (ISS-2, pH 9.94, application rate 1.3 g·kg^-1) on soil total and 0.1 mol·L^-1 calcium chloride (CaCl₂)-extractable Cd, rice biomass and brown rice Cd content. Soil solution Cd concentrations declined rapidly during the first three weeks after application of SGP, ISS-1 and ISS-2 conditioners by 47.2%, 50.1% and 48.6% at the tillering, jointing and maturity growth stages, respectively. ISS-1 application decreased only soil CaCl₂-extractable Cd at jointing (25.4%). ISS-2 application decreased soil CaCl₂-extractable Cd concentrations at tillering (20.2%) and jointing (25.3%). SGP and ISS-2 applications also decreased the Cd contents in brown rice by 35.2% and 34.7%, respectively, but treatment with ISS-1 had no significant effect. All three conditioners showed no significant effect on rice plant height or yield, ratio of productive tillers, 1 000-grain weight, or soil pH. The decrease observed in soil Cd bioavailability may be related to adsorption and complexation by the conditioners. Controlled application rates of the modified and compounded clay mineral conditioners (SGP and ISS-2) to slightly Cd-contaminated neutral agricultural soil may effectively reduce soil Cd bioavailability and brown rice Cd content without any significant change in soil pH.

Northeast China is an important national grain production base with a cultivation rate of 38.58%, and the ratio of paddy fields to dry land is about 1:4.75. In recent years, the amount of chemical fertilizer input per unit area has kept rising, and the threat of non-point source pollution caused by agricultural activities has become more and more serious. In this study, a nitrogen loss risk assessment system was constructed for the three northeastern provinces by considering the difference in annual rainfall pattern and various ways of nitrogen loss from farmland to water. The distribution characteristics of nitrogen loss risk in this region and the main influencing factors are analyzed, and the influence of crop type and precipitation type on the distribution of nitrogen loss are discussed. The results show that the areas of "extremely high risk" and "high risk" concentrate in central Jilin Province, central and southern Liaoning Province, and central and eastern Heilongjiang Province. More than 80% of paddy fields are extremely high or high risk areas, whereas 35% of dry land are at high risk. It shows that paddy fields have a higher risk potential for nitrogen loss. Dry land accounts for the largest proportion among the medium and higher risk areas, and contribute dominant nitrogen loss risk, especially for corn as it accounts for the largest planting area. There are significant differences in the distribution of nitrogen loss risk at county level under different precipitation types. Compared with normal and dry years, wet years have more obvious impact on the distribution of nitrogen loss risk. The cities in the study area were divided into 4 groups. Among them, the group that need priority control includes Changchun, Panjin, Liaoyuan, Shenyang, Siping and Jinzhou. This study identifies the key areas and their characteristics of nitrogen loss in northeast China, and provides reference for agriculture management and non-point source pollution prevention.

Selecting Tongsheng Lake in Changsha City as the research object and using parallel fixed-point actual measurement method combined with computational fluid dynamics (CFD) scenario simulation, the changing law of "wet island effect" in suburban lakes and the influence of architectural factors on "wet island effect" in summer are studied. The results show that:(1) The suburban lakes have a humidifying effect on their surrounding environment in summer, with the increasing of average daily humidifying intensity of 0.99 percentage point and the maximum increasing of humidifying intensity as 2.02 percentage point; (2) The humidifying effect of the lake water body is significantly and positively correlated with the distance from the lake shore, with its maximum at a distance of 0 m, and their humidifying effect on downwind area is far higher than on upwind and vertical areas; (3) Architectural factors (height, retreat distance, spacing, etc.) are the major factors affecting the size of "wet island effect" of lakes, resulting in the difference in the distribution characteristics and changing law of "wet island effect". For every 100 and 200 m far away from lake shore, the relative humidity in the northwestern area of the lakes increases by 0.27-1.40 percentage point, and humidifying scope is enlarged by 100-300 m. For an increase of height by 10 and 20 m, the relative humidity above the water bodies of the lakes decreases by 0.60-0.87 percentage point, with their humidifying scope in the northwestern area being reduced by 50-100 m. The relative humidity in the southeastern region decreases by 0.59-0.81 percentage point when the distance between buildings increases by 2 times, and water bodies of the lakes can affect the northwestern area 500-600 m far away.