Dynamic changes and driving factors of land surface phenology under the background of urbanization.

Rapid urbanization would have significant impacts on vegetation phenology. However, the factors influencing the spatiotemporal changes in urban vegetation phenology are still unclear. We used five fitting methods to construct normalized difference vegetation index (NDVI) curves in the Beijing-Tianjin-Hebei urban agglomeration, and obtained the phenology characteristics of urban vegetation in this area from 2001 to 2019 by the threshold method. We compared the spring and autumn phenology in urban built-up areas and hilly areas, and analyzed the effects of precipitation, air temperature, and land surface temperature (LST) on vegetation phenology. The results showed that from 2001 to 2019, the start of the growing season (SOS) in urban built-up areas in the Beijing-Tianjin-Hebei agglomeration was on average 16.88 days earlier than that in hilly areas, and that the end of the growing season (EOS) in urban built-up areas was 12.22 days later than that in hilly areas. During the study period, the SOS of vegetation in urban built-up areas of the Beijing-Tianjin-Hebei region had been gradually delayed, while that in hilly areas was gradually advanced, and the rate of change of phenology in the urban built-up areas was faster than that in the hilly areas. The difference between the SOS of the two areas decreased significantly over time (-0.58 d·a-1). As for the EOS, the urban built-up areas and hilly areas both showed a trend of delayed, but the differences between them was not significant with time (-0.10 d·a-1). The contribution of LST in the urban built-up areas to SOS was close to that of air temperature, while the contribution of LST in hilly areas to SOS was only 1/2 of that of air temperature, indicating that the heat island effect and air temperature within the city jointly influenced urban vegetation phenology, and their contributions were almost equal. The results could help understand the role of urbanization in the variations of vegetation phenology and provide a reference for further assessment of carbon sink potential of urban vegetation.

Connotation of urban ecological quality and the construction of its core index system.

Urban ecological quality is a necessary attribute for a healthy urban ecological state. In the period of urban development from large-scale incremental construction to stock improvement and quality transformation and incremental structural adjustment, there are many gaps between urban ecological quality construction and the requirements of the new stage. There is an urgent need to understand and integrate multiple needs, and construct an indicator system to promote the balance between supply and demand of ecological resources and efficient use to enhance urban ecological quality. We used the analysis methods of CiteSpace literature analysis, relevant policy collation and questionnaire survey to systematically sort out the key points of concern and differences in understanding among the three perspectives of science, government, and the public. The results showed that all the three perspectives, i.e., science, government, and public, were more concerned with indicators related to urban green space, gray infrastructure, and policy control. The concerns of science and public addressed indicators related to urban green space the most, while government being most concerned with indicators related to gray infrastructure. Based on those findings, we developed a core urban ecological quality index system with a total of 25 indicators, covering 10 major types of urban green space, environmental quality, gray infrastructure, and so on.

[Effects of sawdust dosage on the diversity and community structure of bacteria associated with the hyphae of Pleurotus eryngii]. / æœ¨å±‘æ·»åŠ å¯¹åˆºèŠ¹ä¾§è€³èŒä¸å ±ç”Ÿç»†èŒå¤šæ ·æ€§å’Œç¾¤è½ç»“æž„çš„å½±å“.

Some fungi engage symbiosis with bacteria, which can effectively promote the metabolism and growth of fungi. The diversity and community structure of bacteria can reflect the growth and substrate utilization of fungi. In this study, we analyzed the effects of different sawdust dosages on the community structure and diversity of bacteria associated with the hyphae of Pleurotus eryngii using high-throughput sequencing technology (HST) based on PCR-amplified 16S rRNA V3-V4 fragments. The results showed that the high-quality sequences from five groups of mycelia samples were clustered into 25 phyla, 52 classes, 114 orders, 199 families, and 406 genera. Proteobacteria (35.0%-85.9%) and Firmicutes (6.5%-38.4%) were the most abundant bacterial phyla, while Acinetobacter (14.8%-71.6%) and Pseudomonas (1.7%-22.3%) were the dominant symbiotic genera. Compared with the mycelia grown on the complete culture medium, sawdust addition could increase the diversity of bacteria coexisting with P. eryngii mycelia, and change the community structure of 10 dominant phyla and 9 dominant genera. P. eryngii cultivated in substrate containing 5 g sawdust had the fastest mycelium growth rate, thick mycelia, and neatly edges. Furthermore, judging from the abundance and diversity, Pseudomonas and Lactobacillus became the dominant genera, which were positively correlated with the mycelia growth vigour. Sawdust, as an important carbon source, could affect the growth and development of P. eryngii and the community structure and diversity of bacteria coexisting with mycelia. This study would lay a theoretical foundation for exploring the molecular mechanism of sawdust and mycelium symbiosis affecting the growth and development of P. eryngii.

[Relationship Between Source-Sink Landscape Pattern and Antibiotics in Surface Water in Peri-urban Watershed].

Quantitively identifying the effect of land use patterns on antibiotics in surface water has significance in maintaining water quality and protecting residents' health in urban and rural regions. In this study, a typical peri-urban watershed, located in the Yangtze River Delta, was selected as the study area. Based on surface water sampling, laboratory analysis, and source-sink landscape model (SSLM) analysis, the component and distribution characteristics of antibiotics in surface water in different sub-watersheds were analyzed. The effects of source and sink landscape patterns on antibiotic concentrations in surface water were identified. The results of this study showed substantial differences in types and concentrations of antibiotics in surface water in different sub-watersheds. The total concentrations of antibiotics in surface water ranged from 1.12 ng·L-1 to 53.74 ng·L-1. From upstream to downstream, the area of "source" landscape increased, and the area of "sink" landscape decreased based on landscape pattern analysis. The results of non-metric multidimensional scaling (NMDS) showed that sub-watersheds with similar "source-sink" landscape patterns were detected as having similar antibiotics types and concentrations in surface water. Land use composition, distance, elevation, and slope degree had substantial impacts on antibiotic concentrations in surface water. The results of this study also found that location-weighted landscape index (LWLI) was positive correlated with antibiotics concentrations in surface water based on correlation analysis and redundancy analysis. The sub-watersheds with high LWLI values usually had relatively higher antibiotic concentrations in surface water. This study indicated that optimization of "source" and "sink" landscapes at the watershed scale can decrease antibiotic contamination in surface water. Furthermore, SSLM is an effective tool in landscape optimization at the watershed scale.

Effect of Dry Needling Stimulation of Myofascial Trigger Point on Sample Entropy of Electromyography of Gastrocnemius Injured Site in Rats / 针刺研究

OBJECTIVE: To attempt to establish an objective quantitative indicator to characterize the trigger point activity, so as to evaluate the effect of dry needling on myofascial trigger point activity. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into blank control group, dry needling (needling) group, stretching exercise (stretching) group and needling plus stretching group (n＝6 per group). The chronic myofascial pain (trigger point) model was established by freedom vertical fall of a wooden striking device onto the mid-point of gastrocnemius belly of the left hind-limb to induce contusion, followed by forcing the rat to make a continuous downgrade running exercise at a speed of 16 m/min for 90 min on the next day which was conducted once a week for 8 weeks. Electromyography (EMG) of the regional myofascial injured point was monitored and recorded using an EMG recorder via electrodes. It was considered success of the model if spontaneous electrical activities appeared in the injured site. After a 4 weeks' recovery, rats of the needling group were treated by filiform needle stimulation (lifting-thrusting-rotating) of the central part of the injured gastrocnemius belly (about 10 mm deep) for 6 min, and those of the stretching group treated by holding the rat's limb to make the hip and knee joints to an angle of about 180°, and the ankle-joint about 90° for 1 min every time, 3 times altogether (with an interval of 1 min between every 2 times). The activity of the trigger point was estimated by the sample entropy of the EMG signal sequence in reference to Richman's and Moorman's methods to estimate the curative effect of both needling and exercise. RESULTS: After the modeling cycle, the mean sample entropies of EMG signals was significantly decreased in the model groups (needling group [0.034±0.010], stretching group [0.045±0.023], needling plus stretching group [0.047±0.034]) relevant to the blank control group (0.985±0.196, P0.05), suggesting a better efficacy of dry needling in easing trigger point activity. CONCLUSION: Dry needling is able to relieve myofascial trigger point activity in rats, which is better than that of simple passive stretching therapy.

[Composition and Distribution of Antibiotics in Soils with Different Land Use Types in a Typical Peri-urban Area of the Yangtze River Delta].

Antibiotics have been widely used for agriculture, aquaculture, and livestock, as well as for human disease treatment, in recent decades. However, antibiotics cannot be completely absorbed, and most of them are excreted through urine and feces. A substantial part of the antibiotics enter soils through fertilization and irrigation. Antibiotics persist in the soil environment and threaten human and ecological security. Identifying the composition, distribution, and factors affecting antibiotics in soils with different land use types can help in understanding the spatial distribution and migration processes of antibiotics. In this study, a typical peri-urban catchment located in the Yangtze River delta was selected as the study area, and 82 sampling sites were selected based on land use and topographical features. Soil samples were collected at depths of 0-40 cm at each sampling site. The types and quantity of antibiotics in each soil sample were identified and analyzed by using HPLC-MS/MS in the laboratory. The composition and concentration of antibiotics in different soil layers and the land use types were compared, and the factors affecting the spatial distribution of soil antibiotics were analyzed. Results from this study showed that the total concentration of antibiotic compounds (total) ranged from 0.05 µg·kg-1 to 395.55 µg·kg-1 in the study area, and a significant spatial distribution of antibiotics was found between different land use types. The total in cropland ranged from 0.35 µg·kg-1 to 395.55 µg·kg-1, and tetracyclines (TCs) were the dominant antibiotics (81.45%). The total in forestland ranged from 0.07 µg·kg-1 to 3.65 µg·kg-1, with values significantly lower than those in cropland (P<0.05). The total in orchard soil were significantly lower than in cropland (P<0.05), and no significant differences in antibiotics were found between orchards and forestland (P>0.05). The analysis of the composition and quantity of antibiotics in the soils showed that tetracyclines (TCs) and quinolones (QNs) were the dominant antibiotic types in orchards (TCs:67.63%, QNs:29.55%) and forestland (TCs:13.25%, QNs:70.04%). The indices, including distance to town, distance to road, elevation, and C/N value in soils, were selected to explore the influence of human activity on soil antibiotic concentration. Results of the correlation analysis showed that the concentration of soil antibiotics decreased with increasing values of the four indices. This indicated that the concentrations of soil antibiotics in peri-urban areas were dominantly affected by land use and its spatial distribution, and the concentrations increased with the intensity of human activities. Results of this study can provide scientific guidance for soil management and soil security.

[Characteristics of Carbon Transportation Under Rainfall Events and Associated Carbon Loss Evaluation in Loess Plateau, China: A Case Study of Yangjuangou Dam Watershed].

In this study, by monitoring carbon transportation and its rainfall-runoff process during the rainy season in Loess Plateau's Yangjuangou dam watershed, we analyzed changes in carbon transportation driven by rainfall and further evaluated the C loss flux for the dam watershed. Results showed that the monthly C wet deposition flux for the wet and dry seasons were 3.33 kg·hm-2and 2.18 kg·hm-2, respectively, which were only small contributions to C transportation for the watershed. C transportation under the rainfall-runoff process in this watershed can reach 944.89 kg·km-2 and 300.29 kg·km-2 in August and September, respectively. Different intensities of rainfall runoff lead to different C loss processes, wherein dissolved inorganic carbon (DIC) is the main C form. Under small rainfall events, the output of dissolved total carbon (DTC) in this watershed was 156.98 kg·km-2; and the output of moderate rainfall events was 284.60 kg·km-2. Finally, we determined that the C loss modulus of the Yangjuangou watershed was 1.89 kg·(km2·mon)-1 in the rainy season, thus the C loss modulus for the study area could reach 2.70 kg·(km2·a)-1.

[Characteristics of Nitrogen Transport and Its Source Trace in Loess Plateau's Dam Watershed in Alternating Wet and Dry Seasons:A Case Study of Yangjuangou Watershed].

In this study,we wanted to explore the impacts of N wet deposition on N export and trace the N source by isotopic method through monitoring N wet deposition in Loess Plateau's Dam Watershed in alternating wet and dry seasons,through measuring N wet deposition,rainfall-runoff and base flow process and analyzing concentration change of different forms of N.The results showed that there were 11 rainfall events in the 2015 wet season,in which N wet deposition load reached 814.18 kg and N deposition flux was about 4.26 kg·hm-2,while there were three rainfall events in the 2015 dry season,in which N wet deposition load reached 155.58 kg and N deposition flux was 0.83 kg·hm-2,so it presented a great seasonal variability.By collecting the dynamic process of four rainfall events,we found that,different rainfall intensity had different influence on N export process.The contribution of N wet deposition of four rainfall events to N export in watershed was 16.94 kg.The ratio that N output load of rainfall and river in watershed N output load was 14.45%-64.84%,which showed that the contribution of rainfall to watershed N transport was big.The variation range of δ15 N in Loess Plateau's Dam Watershed was big,which was -0.844‰-12.791‰,and the δ18 O was within the range of 8.166 ‰-15.115 ‰ in the dam watershed.

[Comparison of Soil Hydraulic Characteristics Under the Conditions of Long-term Land Preparation and Natural Slope in Longtan Catchment of the Loess Hilly Region].

Soil moisture plays a crucial role in maintaining the health and sustainability of dryland ecosystems. Terracing and other similar land preparations can reshape the natural slope and change underlying surface into different micro-landforms, which are significant for rainwater harvesting, erosion control, and vegetation promotion in arid regions. In this study, the Longtan Watershed in Dingxi region was selected as the study area. Based on in situ experiments, soil sampling analysis, and modeling simulation, the effects of land preparation and artificial vegetation (Fish-scale pit/Adverse grade tableland-Platycladus orientalis) on soil moisture characteristics curves and soil moisture constants were quantitatively analyzed. ①The land preparations could effectively improve the soil moisture content in the study catchment of Loess Plateau. Compared with natural slope, soil water content of land preparations increased by 1.883%(volume fraction) on average and fish-scale pit method and adverse grade tableland method enhanced the soil moisture by 29.69% and 15.55%, respectively. ② Compared with the natural slope, fish-scale pit and adverse grade tableland could significantly improve the soil hydraulic properties. After carrying out the land preparations, saturated soil water content and soil properties such as field capacity increased by 4.24%-11.40%, suggesting that land preparations can improve soil moisture and water supply ability. ③ Surface soil moisture characteristics were better than those of the underlying soil layers after land preparations. Compared with the natural slope, fish-scale pit and adverse grade tableland's shallow soil layer (0-20 cm) increased the moisture by 38.75% and 23.84%, respectively, whereas in the deep layer (60-80 cm) the increment of moisture were only 3.34% and 3.85%, respectively. This research provides scientific basis for vegetation restoration and land improvement in fragile semi-arid ecosystems.

[History and distribution of terraced landscapes and typical international cases analysis.] / æ¢¯ç”°æ™¯è§‚çš„åŽ†å²åˆ†å¸ƒåŠå ¸åž‹å›½é™ æ¡ˆä¾‹åˆ†æž.

Terracing, developed in those large mountainous areas with high pressure of dense population, is believed as one of the most effective land use approaches. Based on the geographical and climatic differences, the various types of terraces are widely distributed and highly evaluated in terms of ecological and cultural values around the world. Since ancient times, humans have used terracing practices for intensive agricultural production. The main objective of terracing is for mitigating water erosion, stabilizing hill slopes, improving site conditions and crop productivity. During the last decades, agricultural land use in the world has changed considerably. Terraces in many regions were abandoned and had resulted in increasing soil erosion, slope collapse and land degradation along with the socioeconomic development. In this study, through summarizing the origin, history and distribution of terraces in different geographical regions and environmental conditions around the world, we discussed how the different historical and environmental contexts such as climate change, public policy, demographic migration and economic change affected the cycles of terracing construction, usage and abandonment. Aiming at maintaining the sustainable use and mana-gement of terraced fields, further studies regarding water management and terrace maintenance needed to be enhanced.

[Spatial distribution characteristics of carbon, nitrogen and phosphorous and pollution status evaluation of sediments in the Haihe River Basin, China.] / 海河流域水体沉积物碳、氮、磷分布与污染评价.

Studying the distribution of carbon, nitrogen and phosphorus of sediments on a whole-watershed scale is important to the research and management of water resources in the Haihe River Basin (HRB). In this study, total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) of 163 samples were investigated in the HRB. Based on these data, the pollution le-vels of sediments were assessed by using different quantitative indices. The results showed that the concentrations of TOC, TN, and TP in the HRB were heterogeneous at different locations. A decreasing trend of concentrations was found from downstream plains (e.g., the Beisihe River and the Heilonggang River) to mountain areas (e.g., the Yongdinghe River, the Beisanhe River, and the Luanhe River). In addition, the concentration of TOC in river sediments was higher than that of reservoir sediments. The statistical analyses showed that TN was significantly (P<0.01) correlated to TOC and TP, with a correlation coefficient of 0.704 and 0.250, respectively. The pollution level based on organic indices was classified as the clean level in the HRB. However, the areas with a relatively high pollution level were still found in some spots, such as the Beisihe River, and the Heilonggang River. Sediments of rivers and reservoirs were similar in the pollution intensity. The average C/N value of sediments in the HRB was 12.71, indicating that the TOC was derived from algae, phytoplankton flora and fauna, followed by higher plants. The C/N value of reservoir sediments was higher than that of river sediments, indicating that the contribution of terrigenous material inputs to TOC was larger in reservoirs than in rivers.

[Review on studies of anthropogenic heat emission.] / äººä¸ºçƒ­è®¡ç®—æ–¹æ³•çš„ç ”ç©¶ç»¼è¿°.

With the rapid development of metropolises worldwide, the urban heat island (UHI) effect is becoming a serious environmental problem in recent years. The rapidly increasing anthropogenic heat (AH) from human activities has more significant impacts on urban microclimate which aggravates the UHI effect. The characteristics of AH emissions at different scales may vary according to different natural backgrounds. Therefore, the calculation of AH is complicated and uncertain due to the temporal and spatial variation. This review presented different methods of AH calculation according to specific case studies at home and abroad. We summarized the scales of different methods and required data set as well as the certainty of error sources. Last we discussed the advantages, limitations, and potential improvements for different approaches. By the review, we suggested that the AH research should first choose a reasonable calculation method based on spatial and temporal scales to guarantee the accuracy. The calculation of AH could provide useful information to better understand the AH emissions of specific areas, which bring more potentials to improve the living environment through rational urban planning.

[Comparison on the methods for spatial interpolation of the annual average precipitation in the Loess Plateau region].

Based on 57 years (1957-2013) daily precipitation datasets of the 85 meteorological stations in the Loess Plateau region, different spatial interpolation methods, including ordinary kriging (OK), inverse distance weighting (IDW) and radial-based function (RBF), were conducted to analyze the spatial variation of annual average precipitation regionally. Meanwhile, the mean absolute error (MAE), the root mean square error (RMSE), the accuracy (AC) and the Pearson correlation coefficient (R) were compared among the interpolation results in order to quantify the effects of different interpolation methods on spatial variation of the annual average precipitation. The results showed that the Moran's I index was 0.67 for the 57 years annual average precipitation in the Loess Plateau region. Meteorological stations exhibited strong spatial correlation. The validation results of the 63 training stations and 22 test stations indicated that there were significant correlations between the training and test values among different interpolation methods. However, the RMSE (IDW = 51.49, RBF = 43.79) and MAE (IDW = 38.98, RBF = 34.61) of the IDW and the RBF showed higher values than the OK. In addition, the comparison of the four semi-variagram models (Circular, Spherical, Exponential and Gaussian) for the OK indicated that the circular model had the lowest MAE (32.34) and the highest accuracy (0.976), while the MAE of the exponential model was the highest (33.24). In conclusion, comparing the validation between the training data and test results of the different spatial interpolation methods, the circular model of the OK method was the best one for obtaining accurate spatial interpolation of annual average precipitation in the Loess Plateau region.

[Analysis of sap flow characteristics of the Chinese pine in typical Loess Plateau Region of China].

Transpiration is one of the major processes of water consumption. It is significant for nutrients transportation, plant development, drought stress alleviation and micro-climate amelioration. In this study, the artificially planted Chinese pine (Pinus tabuliformis) was selected as an example to explore its transpiration characteristics, water-use strategies and the adaptability of the living environment in a typical loess hilly area of China. The results showed that: the sap flow rates of Chinese pine varied obviously in different seasons. The minimum sap flow rate occurred in April, followed by October, September and August, which was 0.024, 0.057, 0.062 and 0.071 mL x (cm2 x min)(-1), respectively. The rule of the diurnal variation of sap flow rate was regular, higher in daytime than at night. The flow rate was low during nighttime, but not zero. In rainfall events, the proportion of sap flow during nighttime was significantly increased, which was 3.9 times of that on sunny days, with 31.8% decrease in daytime. Chinese pine had great adaptability to unexpected climates. The variation trend of flow rate in the clod was similar to that on rainy days. The sap flow velocity was in great relevance with meteorological factors, with a declining order of solar radiation, vapor pressure deficit, relative humidity, and atmospheric temperature.

Potential effects of large linear pipeline construction on soil and vegetation in ecologically fragile regions.

Long-distance pipeline construction results in marked human disturbance of the regional ecosystem and brings into question the safety of pipeline construction with respect to the environment. Thus, the direct environmental impact and proper handling of such large projects have received much attention. The potential environmental effects, however, have not been fully addressed, particularly for large linear pipeline projects, and the threshold of such effects is unclear. In this study, two typical eco-fragile areas in western China, where large linear construction projects have been conducted, were chosen as the case study areas. Soil quality indices (SQI) and vegetation indices (VI), representing the most important potential effects, were used to analyze the scope of the effect of large pipeline construction on the surrounding environment. These two indices in different buffer zones along the pipeline were compared against the background values. The analysis resulted in three main findings. First, pipeline construction continues to influence the nearby eco-environment even after a 4-year recovery period. During this period, the effect on vegetation due to pipeline construction reaches 300 m beyond the working area, and is much larger in distance than the effect on soil, which is mainly confined to within 30 m either side of the pipeline, indicating that vegetation is more sensitive than soil to this type of human disturbance. However, the effect may not reach beyond 500 m from the pipeline. Second, the scope of the effect in terms of distance on vegetation may also be determined by the frequency of disturbance and the intensity of the pipeline construction. The greater the number of pipelines in an area, the higher the construction intensity and the more frequent the disturbance. Frequent disturbance may expand the effect on vegetation on both sides of the pipeline, but not on soil quality. Third, the construction may eliminate the stable, resident plant community. During the recovery period, the plant community in the work area of the pipeline is replaced by some species that are rare or uncommon in the resident plant community because of human disturbance, thereby increasing the plant diversity in the work area. In terms of plant succession, the duration of the recovery period has a direct effect on the composition and structure of the plant community. The findings provide a theoretical basis and scientific foundation for improving the environmental impact assessment (EIA) of oil and gas pipeline construction as it pertains to the desert steppe ecosystem, and provide a reference point for recovery and management of the eco-environment during the pipeline construction period.

The effects of pipeline construction disturbance on soil properties and restoration cycle.

Disturbance to the physical-chemical properties of soil caused by pipeline installation was evaluated using two soil quality indices to identify the scale of disturbance and the restoration cycle. The integrated soil quality index (SQI) was used to evaluate soil property changes in different pipeline zones (0, 10, 20, and 50 m from the pipeline) at sites 1 and 2. The soil restoration index (SRI) was used to estimate soil recovery from three pipelines with different recovery periods (2, 6, and 8 years) at site 3. The results showed that the adverse effects of pipeline construction on soil properties mainly occurred in the right-of-way (ROW) areas and the impaired zones were in the order trench > piling and working areas > 20 and 50 m. The soil restoration cycle may be complete within 6 years of construction. At site 3, the SRI in the ROW area of a pipeline after 6 years of restoration was close to 100 %, showing full soil recovery. However, the SRI in the disturbed areas of a pipeline after 2 years of restoration was much lower than that after 6 years of restoration, indicating that the soil was still recovering from the disturbance. The topography may change the intensity of disturbance in different areas due to the movement patterns of heavy machinery and traffic routes. There were local variations in the SQI within the pipeline zones, with flat areas suffering greater disturbance than hilly areas, indicating that topography should be considered in a pipeline's environmental impact assessment.

[Health assessment of river ecosystem in Haihe River Basin, China].

With the development of economy, the health of river ecosystem is severely threatened because of the increasing effects of human activities on river ecosystem. In this paper, the authors assessed the river ecosystem health in aspects of chemical integrity and biological integrity, using the criterion in water quality, nutrient, and benthic macroinvertebrates of 73 samples in Haihe River Basin. The research showed that the health condition of river ecosystem in Haihe River Basin was bad overall since the health situation of 72. 6% of the samples was "extremely bad". At the same time, the health situation in Haihe River Basin exhibited obvious regional gathering effect. We also found that the river water quality was closely related to human activities, and the eutrophication trend of water body was evident in Haihe River Basin. The biodiversity of the benthic animal was low and lack of clean species in the basin. The indicators such as ammonia nitrogen, total nitrogen and total phosphorus were the key factors that affected the river ecosystem health in Haihe River Basin, so the government should start to curb the deterioration of river ecosystem health by controlling these nutrients indicators. For river ecosystem health assessment, the multi-factors comprehensive evaluation method was superior to single-factor method.

[Regionalization of the freshwater eco-regions in the Haihe River Basin of China].

There is a growing concern about the ecological conditions in the Haihe River which have been profoundly impacted by the growing human population and intensifying development over the past several decades. By identifying the spatial characteristics of terrestrial and fluvial landscapes, we propose the guidelines and criterions for regionalizing the freshwater ecosystems in the Haihe River basin. The first-level and second-level zones reflect the spatial patterns of the natural backgrounds which could impact the surface water quantity and quality. The 6 first-level zones are regionalized according to topographic characteristics, runoff depth, annual precipitation and evaporation. They represent the spatial pattern of water resource quantity. The 16 second-level zones are regionalized according to the vegetation and soil types overlaid by the first-level zones. They represent the spatial patterns of eco-hydrological processes and water purifying functions of terrestrial landscapes. Finally, the eco-regions are evaluated by the field survey data including water quality, aquatic vegetation and zoobenthos communities. This study could potentially be used to guide the decision-making process for the management of water resources and local ecological projects in the Haihe River basin. The methods formulated in this research can possibly provide important references for other watersheds in China.

[Response of sloping water erosion to rainfall and micro-earth pattern in the loess hilly area].

Severe water erosion in the key loess hilly area is affected by the coupling role of rainfall and earth surface features. In this study, rainfall simulation techniques at the micro-plot scale (1.2 m x 1.2 m; 2 m x 1.2 m) was used as the basic measures, the relations between rainfall depth, intensity and runoff-erosion under different plant morphology features as well as micro-landscape positions were quantified and analyzed. Several key findings were captured. Firstly, rainfall depth and intensity both affected water erosion significantly, while the role of the rainfall intensity was more important than that of the depth. Secondly, a strong negative correlation was found between the antecedent soil moisture content and the generation timing of surface runoff, while water erosion had a positive relation with the antecedent soil moisture. Thirdly, different plant morphology and micro-landscape positions of shrub plant (seabuckthorn) played different roles leading to different rates of surface runoff and soil erosion. Dominated by a rainfall intensity ranging from 50 to 60 mm x h(-1), runoff coefficient in those micro-plots covered by seabuckthorn was about 5%-8%, and changed into 25%, 45% and 63% in grassland-plots, bared plots covered by biological-crust and bared plots without any coverage, respectively. Fourthly, the specific landscape position of seabuckthorn in the plots was also found to play a key role in affecting water erosion processes, and seabuckthorn at the lower landscape position, rather than the upper and middle position, played a better buffering role in reducing runoff and soil loss.

[Applicability of traditional landscape metrics in evaluating urban heat island effect].

By using 24 landscape metrics, this paper evaluated the urban heat island effect in parts of Beijing downtown area. QuickBird (QB) images were used to extract the landscape type information, and the thermal bands from Landsat Enhanced Thematic Mapper Plus (ETM+) images were used to extract the land surface temperature (LST) in four seasons of the same year. The 24 landscape pattern metrics were calculated at landscape and class levels in a fixed window with 120 mx 120 m in size, with the applicability of these traditional landscape metrics in evaluating the urban heat island effect examined. Among the 24 landscape metrics, only the percentage composition of landscape (PLAND), patch density (PD), largest patch index (LPI), coefficient of Euclidean nearest-neighbor distance variance (ENN_CV), and landscape division index (DIVISION) at landscape level were significantly correlated with the LST in March, May, and November, and the PLAND, LPI, DIVISION, percentage of like adjacencies, and interspersion and juxtaposition index at class level showed significant correlations with the LST in March, May, July, and December, especially in July. Some metrics such as PD, edge density, clumpiness index, patch cohesion index, effective mesh size, splitting index, aggregation index, and normalized landscape shape index showed varying correlations with the LST at different class levels. The traditional landscape metrics could not be appropriate in evaluating the effects of river on LST, while some of the metrics could be useful in characterizing urban LST and analyzing the urban heat island effect, but screening and examining should be made on the metrics.