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Soil pore water salinity is widely accepted to be the primary influencing factor determining coastal vegetation succession. This study investigated an ecological wetland restoration process on the Nanhui coast, Shanghai, during which seasonal changes in vegetation density, soil salinity, and coastal elevation were recorded in detail. These variables interacted with each other and showed coincident distributions. The whole restoration process was categorized into four periods according to vegetation community dynamics. Regression analysis revealed that elevation, not soil pore water salinity, was the most critical factor influencing the spatial pattern of vegetation survival, expansion, and extinction on the Nanhui coast. From a long-term perspective, the local vegetation extinction pattern may have an irreparable influence on salt marsh succession, especially in environments with intricate hydrological and sedimentary conditions such as the Nanhui coastline. Without intact vegetation communities, deficiencies in coastal ecosystem resilience may cause vegetation extinction under the influence of a strong hydrological environment. The area between vegetation communities and bare tidal flats, the “vulnerable zone”, was a critical area determining the ultimate success of coastal vegetation restoration.

Watershed and catchment area-based water quality management are important methods for comprehensive management of rivers and lakes. The impacts of land use/land cover (LULC) on river water quality vary with spatial scales, such as watersheds, catchments, and riparian zones. Achieving an effective spatial scale relationship between LULC and water quality, determining priority management areas, and reaching sustainable development of large estuarine deltas remain problematic. In this study, buffering analysis on the water quality data of the Yangtze River Estuary from 2009 to 2018 was conducted based on LULC, and the priority management areas of the basin were identified. Also, we infer that future river restoration or management efforts should focus on priority management area construction of a 1500 m riparian zone and a 150 km reach zone. Conclusively, establishing a priority management area within the effective buffer zone is key to watershed water quality management.

At present, field grinding measurement devices are mainly adopted for DC synthetic electric field measurement. The sensor unit of the device is of a rotating blade structure, and the surface wind generated by rotation causes ion flow distortion, making it difficult to ensure the accuracy of measurement data. In order to optimize the sensing structure of measuring equipment, the vibration-type synthetic field sensing mode was obtained through selection analysis, the horizontal vibration sensor structure and data acquisition hardware circuit structure were proposed, and a vibration-type synthetic field measuring prototype was developed. Through the simulation comparison of the influence of vibration type and field grinding type on the electric field, it can be known that the internal field intensity of the upper and lower 1 mm planes of the equipment shell is basically uniform, and the field intensity of the square and the corner position of the equipment shell are distorted. The electric field distortion of the upper surface of the field grinding device and vibration device is 2.36-8.55 and 1.9-6.84, respectively. The higher the device is, the greater the distortion of the field intensity near the shell, and the distortion of the field grinding type is larger than that of the vibration type. Vibration equipment has less influence on the background field intensity when measuring the ground composite field intensity.

This study proposed an in situ soil experimental system to quantify concentration and accumulation rates of polychlorinated biphenyl (PCB) congeners in the soil in a rural-urban fringe and correlated them with multiple variables in the area. Variables, including road density, normalized difference vegetation index (NDVI), distance to the nearest highway and industrial area from the soil experimental sites, land-use impact index, population density, population change index (PCI), total population, and percentage of water area, were used to explain the concentration of different PCB congeners in soil during the experimental period. A proportion of 40.1%, 22.6%, 56.9%, and 34.3% accumulation rates of PCB8, PCB18, PCB28, and PCB118, respectively was explained by industrial developments, using stepwise linear regression analysis. NDVI was used to explain 33.6%, 61.5%, 49.1%, and 53.2% accumulation rates of PCB44, PCB101, PCB187, and PCB180, respectively. Filtering and transferring of airborne organic pollutants from atmosphere to soil by forests or tree stands and farmlands were all NDVI-related factors that affected the concentrations and accumulation rates of PCB congeners in soil. The traffic-related particle deposition might be the reason why the concentrations and accumulation rates of PCB congeners in soil were affected by road density. The findings can help quantitatively understand urbanization and the associated environmental effects. Graphic abstract.

The purpose of this paper is to understand the sources of potentially toxic elements (PTE) and provide some suggestions to control PTE pollution. For this purpose, data from 30 monitoring stations for 2009-2018 were used to assess the PTE concentrations of Hg, Cu, Pb, Cd, Zn, and As in the Yangtze River Estuary. The PTE concentrations varied significantly (P < 0.05) by one-way ANOVA in the ranges of 0.002-0.224 (Hg, 0.043 ± 0.032), 0-9.700 (Cu, 1.600 ± 1.000), 0-3.900 (Pb, 1.000 ± 0.700), 0.002-0.370 (Cd, 0.050 ± 1.000), 0.100-85.000 (Zn, 14.000 ± 13.000), and 0.998-3.290 μg/L (As, 1.857 ± 0.455). Generally, the PTE concentrations decreased from year to year and were consistently satisfied the "grade-one seawater" quality standard after 2014. The concentrations of Cu, Cd, Zn, and As decreased as far from inshore, while increased closer to land in the estuary. Concentrations of Pb and Hg showed differences because of local industrial and aquacultural activities. This study identified three clusters and two PTE sources and provided some constructive suggestions for pollution control in PTE.

Theory of self-organization, i.e., scale-dependent feedback (SDF), has been widely used to explain mechanisms of spatial patterns in different ecosystems. Studies have demonstrated that self-organization is one of the mechanisms through which ecosystem resilience is maintained. However, the application of SDF in real ecological restoration practices is a challenge due to the lack of a controlled experimental validation. In the present study, multiple scales of vegetation patches were constructed along an elevation gradient in the saltmarsh ecosystem on Nanhui coasts and were investigated to verify if there was an effect of SDF. Results of the density-variation curves analyses revealed that most constructed self-organized patches could survive and an optimal curve was found of which the density-dependent feedback was proven through fitting with the asymptotic regression model. The large vegetation patches exhibited considerable increases in density when compared to the small vegetation patches, which occurred in challenging environments, i.e., on the verges of elevation thresholds, and with a tendency to shrink. Analyses using one-way ANOVA revealed that there was an optimal patch scale and elevation in the study area, i.e., 1 m × 1 m scale and 3.2 m, respectively. Optimal scale and elevation provide a comprehensively explanations of SDF, although with the positive effects gradually decreased along the distance away from the optimal condition. The present study provides novel insights on applying the theory of SDF in facilitating the restoration process of coastal saltmarshes.

We studied various soil characteristics associated with Scirpus mariqueter growth and spatial heterogeneity in the Shanghai Nanhui Dongtan wetlands. In September and October 2015, 12 soil characteristics (soil organic carbon, total phosphorus, total nitrogen, nitrate, nitrite, ammonia, orthophosphate, pH, moisture content, particle size, salinity, and tidal elevation) were analyzed from 101 soil samples. The key factors affecting S. mariqueter spatial distribution were determined using canonical correspondence analysis and curve-fitting analysis. Results showed that vegetation indices of height, cover, density, and biomass were positively correlated (P

Exploring how suitable habitat and population size of Red-crowned crane Grus japonensis respond to long-term coastal reclamation plays an important role in species conservation and in related coastal management. Here, we combined field data for suitable habitats and wintering population size of G. japonensis with GIS-based information to elucidate the influence of long-term coastal reclamation on this species and related conservation efforts. During 1975–2013, the intensity and spatial extent of coastal reclamation exhibited a temporal change, increasing dramatically in 1975–2000 and lessening considerably in 2000–2013. Under the pressure of long-term coastal reclamation, the decline of suitable habitat of G. japonensis was affected by increasing levels of human disturbance and decreasing availability of natural habitat. Moreover, the wintering population size of G. japonensis exhibited a decreasing trend during 1975–2013 as a result of the decreasing availability of fish ponds, bare tidal flats, and increasing spatial extent of residential areas and P. australis habitat, which were indirectly affected by long-term reclamation. Our results highlight the importance of considering the long-term effects of coastal reclamation on both populations and suitable habitat of G. japonensis, which should be considered in future plans for coastal management and conservation.

The question of where and how to carry out reclamation work in coastal areas is still not well addressed in coastal research. To answer the question, it is essential to quantify the impact of reclamation and the associated ecological and/or environmental responses. In this study, ordinary least square (OLS) analysis and geographical weighted regression (GWR) analysis were performed to identify the reclamation variables that affect soil and vegetation characteristics. Reclamation related variables, including residential population (RP), years of reclamation (YR), income per capita (IP), and land use-based human impact index (HII), were used to explain nitrate, ammonium, total phosphorous, and heavy metals in soil, and the height, density, and above-ground biomass of native hydrophytic vegetation. It was found that variables IP, RP, and HII could be used to explain the height of Scirpus and Phragmites australis as well as above-ground biomass with a R 2 value of no > 0.55, and almost all the variables could explain the hydrophytic vegetation characteristics with a higher R 2 value. In comparison to OLS, GWR more reliably reflected the reclamation effects on soil and vegetation characteristics. By GWR analysis, total soil phosphorous, and nitrate and ammonium nitrogen could be explained by RP, YR, and HII, with the highest Ad-R 2 value of 0.496, 0.631 and 0.632, respectively. Both of the GWR and OLS analysis revealed that HII and RP were the better variables for explaining the soil and vegetation characteristics. This work demonstrated that coastal reclamation was highly spatial dependent, which sheds a light on the future development of spatial explicit and process-based models to guide coastal reclamation around the world.

We examined how various soil characteristics are associated with Scirpus mariqueter growth and spatial heterogeneity in Shanghai Nanhui Dongtan wetlands and addressed a major knowledge gap regarding the effects of reclamation on microbial communities in the soil. Biolog was used to examine soil carbon resources, diversity, abundance, and community structure of S. mariqueter soil microbes after a 72-h culture. Tidal elevation influenced soil microbes, which used carbon resources at higher rates, exhibited more community diversity and had greater species richness in areas with dense S. mariqueter cover than in bare tidal flats (P

An in situ soil experimental system was designed to determine how urbanization impacts soil nitrogen and phosphorus dynamics. Variables including the road density, normalized difference vegetation index, distance to the nearest highway and industrial area from the soil experimental site, land use impact index, population density, population change index, total population, and percentage of water area were used to quantitatively explain the soil nitrogen and phosphorous contents. The results showed that the total phosphorous in the soil increased slowly after September 2013, indicating a phosphorous accumulation phenomenon in the soil in urban areas. The nitrate nitrogen in the soil had a higher value in September 2013, while the soil ammonium nitrogen content was higher during the winter. Moreover, the soil ammonium nitrogen content was higher than the nitrate nitrogen content during most of the experimental period. The distance from the urban centre, road density, proportion of built-up land, and population density can explain the soil nutrient dynamics quantitatively, showing that 45.4% of the soil nitrate nitrogen content, 84.1% of the soil ammonium nitrogen content, 44.6% of the ratio of NO3/NH4, 58.1% of the ratio of total inorganic nitrogen (TIN)/total phosphorous (TP), and 81.6% of the TIN could be explained by one of these variables at most. The potential factors affecting the changes in soil N contents include changes in human dietary habits as more people migrate to cities and industrial wastewater discharge. This study is helpful in quantitatively understanding the urbanization process and associated environmental impacts.

Little is known about consequences of Spartina alterniflora invasion on soil sulfate-reducing bacteria (SRB). This study compared the abundance, diversity, and community structure of SRB in S. alterniflora and in native plant communities along a successional gradient (bare mudflat, young/mature S. alterniflora, Suaeda salsa, and Phragmites australis) in coastal salt marshes of Eastern China. Quantitative polymerase chain reaction of dissimilatory sulfite reductase (dsrB) gene was applied to assess SRB abundance, and the diversity and composition of SRB was analyzed by 454 pyrosequencing of partial dsrB gene. We found that S. alterniflora had a significantly higher abundance and diversity of SRB than native plant species. For all plant covers, Desulfobacteraceae was the largest soil SRB group, with a relative abundance of 33.6%, followed by Desulfobulbaceae (29.2%). S. alterniflora showed a higher relative abundance of Desulfobacteraceae (42.5%) than native species (29.5%) did. Notably, S. alterniflora invasion decreased the relative abundance of a SRB branch clustering with the thermophilic Thermodesulfovibrio yellowstonii. In conclusion, S. alterniflora invasion of the eastern coast of China has greatly increased the abundance and diversity of SRB communities and altered their structure. This might further influence carbon mineralization and inhibit the production of methane in China’s coastal marshes.

Although seed dispersal is a key process determining the regeneration and spread of invasive plant populations, few studies have explicitly addressed the link between dispersal vector behavior and seedling recruitment to gain insight into the invasion process within an urban garden context. We evaluated the role of bird vectors in the dispersal of pokeweed (Phytolacca americana), a North American herb that is invasive in urban gardens in China. Fruiting P. americana attracted both generalist and specialist bird species that fed on and dispersed its seeds. The generalist species Pycnonotus sinensis and Urocissa erythrorhyncha were the most frequent dispersers. Seedling numbers of P. americana were strongly associated with the perching behavior of frugivorous birds. If newly recruited bird species use seedling-safe perching sites, the P. americana will regenerate faster, which would enhance its invasive potential. Based on our observations, we conclude that the 2 main bird vectors, P. sinensis and U. erythrorhyncha, provide potential effective dispersal agents for P. americana. Our results highlight the role of native birds in seed dispersal of invasive plants in urban gardens.

This study aimed to develop a practical approach to identify the priority areas with ecological significance along highly human disturbed coastal areas. Field surveys were used to assess and complement to the results of the remote sensing (RS)-based analysis. The RS-based biodiversity hotspot (BH) identification process was accomplished in three steps. The lands with native vegetation cover, including the national natural reserve lands, were first selected as the baseline BHs (BBHs). Then, after assigning resistance coefficients to each land use, the least accumulative cost (LAC) of the BBHs was calculated by distance analysis, while the normalized differential vegetation index (NDVI) from the Landsat Thematic Mapper was reclassified into 20 grades based on the Euclidean distance to the main anthropogenic sources. Finally, the RS-based BH identification was realized through the logistic calculation of LAC less than a series of thresholds and NDVI more than 10. While the field survey-based BH identification was through the logistic calculation between HM potential ecological risks of low to moderate and BHs acquired by NDVI-based integrated assessments. The results proved that RS-based analysis could be an important surrogate for necessary field surveys to manage BHs along coasts.

According to the data in May, September and October 1993, the variation range of Cd content in the water body of Jiaozhou Bay was 0.07-0.23μg/L, which conforms to the national water quality standard of Class I. It indicated that in May, September and October, the water in the entire water area of Jiaozhou Bay was not contaminated by Cd content. In May, the variation range of Cd content in the waters of Jiaozhou Bay was 0.09-0.18μg/L. In the coastal waters of the north of Jiaozhou Bay, the Cd content reached a relatively high value, which was 0.18μg/L. In September, the variation range of Cd content in the waters of Jiaozhou Bay was 0.07-0.23μg/L. In the coastal waters of the east of Jiaozhou Bay, the Cd content reached the highest value, 0.23μg/L. In October, the variation range of Cd content in the waters of Jiaozhou Bay was 0.08-0.18μg/L. In the coastal waters of the east of Jiaozhou Bay, the Cd content reached a relative high value, 0.18μg/L. In terms of Cd content, the water quality of Jiaozhou Bay had reached high quality. The water was clean, and it was not polluted by Cd content at all. The Cd content in the waters of Jiaozhou Bay mainly came from two sources, the transport of surface runoff and the transport of atmospheric deposition. The Cd content from surface runoff transportation was 0.18μg/L, and the Cd content from atmospheric deposition transportation was 0.18-0.23μg/L. The Cd content transported by atmospheric deposition was very close to the Cd content transported by surface runoff, and was very low, ranging from 0.18 to 0.23μg/L, far less than 1.00 μg/L. This revealed that the humans had realized the importance of environmental protection, and the emissions to the environment were very low. The atmosphere, land and sea were not polluted by Cd content. The Cd content transported by atmospheric deposition 0.18-0.23μg/L ≥ the Cd content transported by surface runoff 0.18μg/L, which indicated that the Cd content was mainly discharged into the atmosphere by humans and then deposited on the land.

Terrestrial ecosystems carbon (C) and nitrogen (N) cycles, affected by plant invasion, are not fully understood. In this study, the impact of 10 years Spartina alterniflora invasion on soil organic matter (SOM), labile, and recalcitrant pools was examined comparing with bare flat and native Suaeda salsa and Phragmites australis communities in tidal salt marshes of the Eastern Chinese coast. Short-term S. alterniflora invasion significantly raised C and N concentrations in SOM, labile and recalcitrant pools compared to bare flat, S. salsa and P. australis soils. Spartina alterniflora soil had higher recalcitrant index for C relative to bare flat. The proportion of S. alterniflora-derived C and the decomposition rate of old C in the labile pool were significantly higher than those in the recalcitrant pool. However, the S. alterniflora-derived C stock of the recalcitrant pool was much greater than that of the labile pool. The SOM and recalcitrant pools in S. alterniflora soil had significantly higher δ15N levels compared with bare flat, indicating an increased N loss following S. alterniflora invasion. The results suggested that short-term S. alterniflora invasion significantly enlarged soil organic C and N pools via altering SOM input and decomposition.

This study initiated an in-situ soil experimental system to quantify the annual dynamics of polychlorinated biphenyl (PCB) congener's concentrations and accumulation rates in soil from atmosphere deposition in a rural-urban fringe, and correlated them by landscape physical and demographic variables in the area. The results showed that the concentrations of all PCB congeners significantly increased with the sampling time (p 0.05); nearly all the PCB congener concentrations decreased while moving outwards from the urban center. The moderate average concentrations along the gradient for PCB 8, 18, and 28 were 31.003, 18.825, and 19.505 ng g-1, respectively. Tetra-CBs including PCB 44, 52, 66, and 77 were 10.243, 31.214, 8.330 and 9.530 ng g-1, respectively. Penta-CBs including PCB 101, 105, 118, and 126 were 9.465, 7.896, 17.703, and 6.363 ng g-1, respectively. Hexa-CBs including PCB 128, 138, 153, 170, 180, and 187 were 6.798, 11.522, 4.969, 6.722, 6.317, and 8.243 ng g-1 respectively. PCB 195, 206, and 209 were 8.259, 9.506, and 14.169 ng g-1, respectively. Most of the PCB congeners had a higher accumulation rate approximately 28 km from the urban center. The computed variables were found to affect the soil PCB concentrations with a threshold effect (p 0.05). Regression analysis showed that the thresholds were 10-20 km, 1 km/km

An approach of identifying priority spatial patterns in response to different ecological risk levels associated with heavy metals (HM) is proposed. First, ecological hotspots (EH) are delineated by integrating NDVI-based assessment with the impact assessment of anthropogenic impact sources. Second, the HM potential ecological risks index (PERI) is calculated and spatially interpolated. Finally, the EH with different PERI values are identified through logic calculation. Study results show that 45.2% of the study region has low HM risks, 53.2% with moderate HM risks, and only 1.6% with high HM risks. In addition, the percentage of EH with low HM risks is 6.5%; the percentage with moderate HM risks is 5.4%; and the percentage with high HM risks is 0.4%. The EH with low and moderate HM ecological risks are proposed to be the regions in priority for management. This approach is potentially useful to HM ecological risk assessment and HM contamination management around the world.

IntroductionChina feeds 22 % of the world’s population, yet commandsonly 9 % of the arable land, necessitating an intensive ap-proach to agricultural production. Food production more thandoubled in China from 239.96 million tons in 1970 to 530.82million tons in 2009. Among other factors, application ofnitrogenfertilizershascontributedtothisremarkableincrease.There is pervasive nitrogen fertilizer over-application inChina.Forexample,theaveragenitrogenfertilizerapplicationrate for rice production is 180 kg per hectare, about 75 %higher than the world average (Peng et al. 2009). Nitrogenfertilizerthatisnotabsorbedbycropscontributessignificantlyto nutrient enrichment in waters, causing negative impacts onenvironmental quality, ecosystem services, and biodiversity(Glibert et al. 2006; Howarth 2008). These problems in theLakeTairegionareamongthemostintenseintheworld.LakeTai is increasingly eutrophied and has suffered from episodesofcyanobacterialblooms.In2007,aseverealgaebloominthelake left 4.43 million people without safe drinking water innearby Wuxi City (Yang et al. 2008).Much research has been conducted to mitigate the seriouswater pollution problems associated with inappropriate fer-tilizer application (Hite et al. 2002; Ladha et al. 2005; Cui etal. 2010). Nevertheless, most of the existing research hasbeen devoted to the measures for reducing environmentaldegradation, and little has focused on understanding farm-ers’ perceptions towards these measures (Adrian et al. 2005;Han and Zhao 2009). Across China, there is a paucity ofreliable information on how farmers make decisions on theamount and timing of fertilizer application, their perceptionstowards the potential adverse environmental impacts offertilizers, and their attitudes towards best managementpractices (BMPs) (Cui et al. 2010).In order to facilitate the development offeasible and cost-effective programs to mitigate the serious situation of Nfertilizer over-application, face-to-face surveys were con-ducted in 15 villages within 5 km west of Lake Tai. Thesurvey results provide insight into the local farmers’ currentfertilizing practices as well as their perceptions towardsfertilizer use and implementation of BMPs.Study Area and MethodsWhile accounting for 0.4 % of its land area and 2.9 % of itspopulation, the Lake Tai basin generates more than 14 % ofChina’s Gross Domestic Product (GDP) (Zhang et al. 2007).Rapid economic development in the basin has led to the lossof cropland to urbanization, although agriculture is still thelargest land use category (Zhang and Liu 2011). Overall, theLake Tai basin is a region of intense economic developmentand industrial modernization. Yet, the agricultural sectormaintains elements of traditionalism that intersect withmodernization in unique and sometimes unfortunate ways.The 5 km riparian region west of Lake Tai has been offi-ciallydesignatedasthecategoryIcriticalzone.Fifteenvillageswith large acreage of cropland were randomly selected in thecritical zone. A random sample of farmers in the villages wereinterviewed with a pre-constructed questionnaire designed togain insights into the farmers’ fertilizer application behaviors,their decision-making process, and their perceptions of theenvironmental impacts of fertilizer use (Fig. 1).

This paper analyzed the content, distribution, and sedimentation mechanism of Cd in Jiaozhou Bay based on investigation data in April, July and October 1985. Results showed that the Cd contents in surface waters ranged from 0.04-0.32 μg L -1 , and were meeting Grade I for Cd (1.00 μg L -1 ) in Chinese Sea Water Quality Standard, indicated that Jiaozhou Bay and the open sea had not been polluted by Cd in 1985. High Cd sedimentation locations were occurring in different regions due to Cd contents were different in surface waters. In April and October, high Cd sedimentation location was in the open sea in where marine current was the major source; while in July, high Cd sedimentation location was in the bay mouth in where stream flow was the major source. In generally, the spatial-temporal of sedimentation features of Cd were determined by pollution sources and the vertical water's effect.

Based on investigation data on Pb in surface waters in Jiaozhou Bay during 1979 to 1983, this paper analyzed the annual change of both contents and pollution levels of Pb. Results showed that Pb contents in surface waters in Jiaozhou Bay in 1979, 1980, 1981, 1982 and 1983 were 0.25-1.52 μg L -1 , 0.07-2.71 μg L -1 , 0.00-3.34 μg L -1 , 0.30-3.35 μg L -1 and 0.58-2.34 μg L -1 , respectively, indicated that his bay had been slightly of moderated polluted by Pb in 1979 to 1983, and the pollution level of Pb in Jiaozhou Bay was increasing since the reform and opening-up. The promotion of waste treatment and environmental protection was essential. The investigation data of this study would be basic information to the relevant scientific research on this bay.

Natural wetlands, occupying 3.8% of China's land and providing 54.9% of ecosystem services, are unevenly distributed among eight wetland regions. Natural wetlands in China suffered great loss and degradation (e.g., 23.0% freshwater swamps, 51.2% costal wetlands) because of the wetland reclamation during China's long history of civilization, and the population pressure and the misguided policies over the last 50 years. Recently, with an improved understanding that healthy wetland ecosystems play a vital role in her sustainable economic development, China started major efforts in wetland conservation, as signified by the policy to return reclaimed croplands to wetlands, the funding of billions of dollars to restore degraded wetlands, and the national plan to place 90% of natural wetlands under protection by 2030. This paper describes the current status of the natural wetlands in China, reviews past problems, and discusses current efforts and future challenges in protecting China's natural wetlands.

This paper describes a study of how the demographic and physical variables affected the heavy metal (HM) contamination along the urban-rural gradient in PuDong New District, Shanghai. The road density (RDi) and the percentage of built-up areas (BAi) were calculated for various widths of buffers around the soil sampling sites. Through distance allocation, the demographic values of the population change index (PCI) were assigned, with the value being associated with the nearest town. We initiated the use of the population migration rate from 2000 to 2010, i.e., PCI, to represent the urbanization rate. Regression analysis between the soil HM concentrations and the PCI, the RD, and the BA was estimated. The results indicated that the PCI significantly affected the Cd and Cu distribution (p < 0.05), while the RD of the 3-km buffer affected the Pb concentrations. The BA of 2-km buffers affected the spatial distribution of Cd, Cu, and Zn. Zn was also affected by the RD within the 4-km buffer. Using the median values of the PCI and the BA of the 2-km buffer, and the RD of the 3-km buffer, logistic analysis was performed to identify the priority areas for managing HM hazards. The two identified priority areas were the towns of Kangqiao and Zhuqiao, both of which were rapidly urbanized areas with higher PCI values. Our research demonstrated that understanding the rate of urbanization may be as important as the degree of urbanization when examining associated HM contamination patterns.

The contribution of forest generalists and specialists to the dispersal pattern of tree species is not well understood. Specialists are considered low-quality dispersers because their dispersal distance is often short. However, disregard for seed deposition site may result in underestimation of the dispersal quality of specialists. The present study estimated the contribution of generalist and specialist species to the dispersal patterns of the endangered Chinese yew (Taxus chinensis) in a subtropical patchy forest in Southeast China. A relatively diverse assemblage of frugivorous birds visited T. chinensis source trees and specialist Hypsipetes leucocephalus and generalist Urocissa erythrorhyncha were by far the highest-quantity dispersers. Considering dispersal effectiveness, the quantity aspect of effectiveness differed between the specialist assemblage and generalist assemblage; the contribution of specialists to the quantity part of effectiveness was significantly higher than that of generalists despite the relatively low diversity of specialists. After foraging, both specialist H. leucocephalus and generalist U. erythrorhyncha significantly contributed to the number of seedlings and their contributions to seedling recruitment did not differ with regard to quality. Our results highlight the ability of T. chinensis to recruit an effective disperser assemblage in patchy habitats, thus increasing its persistence in this disturbed habitat.

Urban growth can present distinct geometric forms, the patterns and determinants of which remain little understood. The aim of this study is to explore the spatial patterns of different urb...

Face-to-face interviews (n = 553) were conducted in five counties in East-Central China to study farmers’ fertilizer application behaviors, decision-making processes, attitudes towards adopting better fertilizer application technologies, and environmental consciousness. The survey results revealed widespread fertilizer misapplication and highly variable application behaviors in the study regions. The lack of scientific knowledge on fertilizers and the absence of guidance from agricultural extension services have forced the farmers to rely on personal judgment and advice from fertilizer dealers and friends to make decisions in fertilizer application. Overall, farmers have been idiosyncratic in fertilizer application with limited adoption of better fertilizer application technologies. There are great potentials for reducing pollutant load from agricultural runoff through promoting scientific fertilizer application in the regions. However, farmers’ diverse preferences over agricultural extension programs necessitate an integrated approach emphasizing farmer involvement throughout the development of such programs for promoting better fertilizer application practices.

An understanding of trace metal pollution due to reclamation activities around Yancheng National Nature Reserve is important for the utilisation and management of the reserve and surrounding coastal and marine areas. In the present study, we evaluated the current state of Cu, Cd, Pb and Zn pollution (total concentrations and ecological risk), their potential hazard (availability index and desorption rate) and soil properties (cation exchange capacity, iron and manganese oxide content, soil organic matter, salinity and pH) in different land use types around this nature reserve. Although the current state of trace metal pollution was not severe, the potential hazards of these trace metals should not be ignored, especially for Cd because of its significantly higher availability index values in farmlands and aquaculture ponds than in natural habitats (by 33 and 32% of the total amount of Cd respectively). Thus, strict monitoring and environmentally responsible land reclamation management practices should be considered for these coastal areas.

Mid-scale regional ecosecurity, which takes practical ecosecurity issues as its priority, should be viewed as the core of the multi-scale concept of ecosecurity. For urban area, a special region taking ecological infrastructure as its core mission, the construction of regional ecosecurity pattern may provide a good chance to realize its sustainable development. Based on land use analysis, a qualitative and quantitative research on the landscape pattern, ecovalue evaluation, and driving force analysis of social economy could provide an effective approach to construct the ecosecurity pattern in urban area. This study showed that in Lanzhou, the ecosecurity pattern consisted of three parts, i.e., eco-safeguarding system, eco-buffering system and eco-percolating system, among which, eco-buffering system was the decisive part determining ecosecurity pattern construction. The quantitative analysis of urban spatial expansion pattern was taken as the decisive function to determine the security level of the ecosecurity pattern, which was divided into low, middle and high levels.