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Volume 32 Issue 5
25 September 2016
Theories, Ideas and Methods for Diagnosis of Ecological Degradation in Important Ecological Function Areas
TIAN Mei-rong, GAO Ji-xi, ZOU Chang-xin, QIAO Qing
2016, 32(5):  691-696.  doi:10.11934/j.issn.1673-4831.2016.05.001
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Precise diagnosis of degradation of a regional ecological system by degree with its driving factors specified is the precondition and basis for efficient implementation of ecological restoration. Based on the prevailing theories for diagnosis of ecological degradation, it has been pointed out that ecological degradation is a relative concept and that determination of a reference system and an index system is an essential step for the diagnosis. The determination of a reference system for the diagnosis shows that for diagnosis of degradation of a regional ecosystem should not focus on just one specific historical status, but rather pay more attention to temporal dynamics and spatial variability of the degradation, so as, to ensure objectivity of the diagnosis. On such a basis, to highlight the close relationship between ecological degradation and ecological functions as well as the comprehensiveness of ecosystem degeneration in important ecological function areas, a train of thought and a flowchart for diagnosis of ecological degradation from the perspective of ecological maintaining ability, ecological self-restoration ability and ecological pressure have been brought forth, and an index system for the diagnosis has been set up. In order to embody the comprehensiveness and hierarchy of ecological degradation diagnosis, single factor analyses, including ecological function maintain index (EMI), ecological resilience index (ERI) and ecological pressure index (EPI), is combined with comprehensive analysis, and an integrated index for determining ecological degradation is set up for comprehensively diagnosis degree, which may provide some theoretical guidance and technical support for higher precision of the diagnosis of ecological degradation.

Human Well-Being and Its Applications and Prospects in Ecology
WANG Bo-jie, TANG Hai-ping
2016, 32(5):  697-702.  doi:10.11934/j.issn.1673-4831.2016.05.002
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Maintaining and improving human well-being and promoting sustainable development has become an important topic and a new direction in the research of ecology. However so far only limited information relevant to human well-being in ecology is available in literature. A brief introduction to the concept, and development of human well-being, a review of human well-being evaluation index systems, and a summary that currently the concept of human well-being is embodied are presented in the following 3 aspects in the study of ecology: (1) relationships between human well-being and ecosystem services; (2) characteristics of the spatio-temporal distribution of human well-being; and (3) effects of driving forces behind the variation of the ecosystem on human well-being. The directions and challenges of the research in future are prospected. Building up a comprehensive human well-being evaluation index system, quantifying the relationships between human well-being and ecosystem services, and enhancing the study on the local and regional scale are the frontiers of the study on human well-being in ecology. Working on these scientific issues will promote application of the concept of human well-being to decision-making management at various governmental levels.

Variation of Ecology in the Key Ecological Function Zones in China
WU Dan, ZOU Chang-xin, GAO Ji-xi
2016, 32(5):  703-707.  doi:10.11934/j.issn.1673-4831.2016.05.003
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Key ecological function zones are essential to guarantee of national and regional ecological safety. Changes in ecology of the key ecological function zones of China during the years of 2000-2010 were analyzed, using ecological function index, ecological structure index and ecological stress index as indicators. Results show that among the eight key ecological function zones of the water source conserving type, the Greater and Lesser Khingan forest ecological function zone, the Altai mountain forest steppe ecological function zone and the Nanling mountain forest and biodiversity ecological function zone tended to deteriorate in ecological status, while the other five did reversely. The key ecological function zones of the water and soil conservation type all turned better, especially the Loess Plateau hill and gully soil-water conservation ecological function zone. Among the six key ecological function zones of the sand-shifting control type, the Hulunbuir prairie meadow ecological function zone and the Arkin steppe desertification control ecological function zone went towards better in ecology, while the other four did towards worse. And all the key ecological function zone of the biodiversity protection type were getting somewhat better.

Variation of Spatial Estimation and Distribution of Vegetation Biomass in Yangtze River Delta During 2000-2010
LI Guang-yu, CHEN Shuang, ZHANG Hui, ZHANG Tong
2016, 32(5):  708-715.  doi:10.11934/j.issn.1673-4831.2016.05.004
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Vegetation biomass is an important indicator of the service function of terrestrial ecosystems. It is of great significance to the formulation of rational vegetation protection policies to ascertain spatial distribution rules and temporal variation of vegetation biomass. Though a lot of works have been done on estimating vegetation biomass at regional and global scales, little is available in the literature about spatial estimation of biomass of an ecosystem as a whole and, what is more, spatial resolution of the estimation is too low to reflect changes in land use/cover. Based on multi-sourced data including remote sensing, meteorology, land use/cover, forest inventory, and grain yield, spatial distribution of vegetation biomass at 250 m resolution was studied with the aid of remote-sensing models, spatial downscaling technique, GIS spatial operation and mathematical statistical analysis. Results show that the spatial estimation of vegetation biomass not only inherits the accuracy of statistical data, but also reflects spatial distribution of vegetation biomass. The vegetation biomass in the Yangtze River Delta (YRD) displays a general distribution trend of rising from north to south and being relatively low alongside the Yangtze River and around the Tai Lake Basin. The total vegetation biomass increased significantly during the years from 2000 to 2010. It increased significantly or by 47.74 Tg in parts of Zhejiang, and remained stable with a slight rise (0.94 Tg) in parts of Jiangsu and (0.33 Tg) in Shanghai. Vegetation biomass is closely related to land use/cover (LUCC). The growth of biomass is mainly attributed to the maintenance of forest lands and farmlands in land use. In highly developed plain areas, conversion of forest lands and farmlands has led to significant decline in biomass, however, greening of construction lands helps offset the declining trend of biomass triggered by destruction of vegetation.

Assessment of Ecological Effect of the Natural Forest Protection Project in Southwest China
TAO Yun-zhi, LV Yi-he, LI Feng-quan, HU Jian, ZHANG Kun, LI Ting, REN Yan-jiao
2016, 32(5):  716-723.  doi:10.11934/j.issn.1673-4831.2016.05.005
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With the development and continuous deepening of large-scale ecological protection and restoration projects, project effectiveness has become a hot issue arousing more and more attention. Assessment of the effectiveness of the large-scale ecological protection and restoration projects is of great scientific significance to correspondent macroscopic policy decision-making and management. The assessment of the effectiveness of the natural forest protection projects was conducted in four provinces, Southwest China, based on annual mean vegetation coverage, landscape index and the human threat factor assessment index system. Results show that the four projects, as a whole, are improving remarkably in effectiveness, with landscape patches distributed more reasonably and regularly to have better connectivity and less human disturbance. Especially the forest regions in the bordering areas between the four provinces or cities, like those between Chongqing and Hubei, between Sichuan and Shanxi, between Sichuan and Sanjiangyuan, have witnessed remarkable improvement in ecological effect. In the same time, the forest regions around Wenchuan, some in the Hengduanshan Mountains and the Wenshan forest region in Yunnan are not so lucky. Therefore in further implementation of the natural forest protection projects, it is necessary to adopt the strategy, designed on the basis of the feature of spatial variability of protection effectiveness, of emphasizing both protection and restoration simultaneously, so as to integrate the factors, such as vegetation, landscape pattern, habitat quality and disturbance and pressure of human activities, in promoting sustainable effective management of large-scale protection and restoration.

Holiday Effect of Spring Festival on PM2.5 Pollution in Chang-Zhu-Tan Metropolitan Area
CHANG Jing-liang, YU Hong, LUO Wei-wei, WANG Lei
2016, 32(5):  724-728.  doi:10.11934/j.issn.1673-4831.2016.05.006
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PM2.5 has been a major concern of the public due to its obvious effect of reducing visibility and endangering human health. Based on the hourly PM2.5 monitoring data gathered around the clock at 24 monitoring sites in the Chang-Zhu-Tan metropolitan area, analysis was performed of variation of PM2.5 pollution throughout 7 days before spring festival, 7 days of spring festival and 7 days after the festival in 2013, 2014 and 2015 to explore impacts of holiday activities, including tourism, on air quality. After excluding the effect of meteorological factors (e.g. daily precipitation >4 mm), holiday impacts were analyzed from the following three aspects, namely, difference in PM2.5 pollution level, difference in daily variation of PM2.5 concentrations, and spatial variation of the holiday effect. Results show that PM2.5 concentration was 12 μg·m-3 higher during the holiday period than during the days before and after the holiday, as a whole in the metropolitan area, and 41.5% lower during the 7 days after the holiday than during the holiday period, revealing an obvious "post-holiday effect". Strongly affected by holiday activities, like setting off fire-cracks and fireworks, PM2.5 concentration soared dramatically during the early hours from 00:00 to 02:00 each day of the holiday period, peaking at 02:00 and being 47.6% higher than that during the non-holiday periods. The holiday effect varied spatially across the study area. In Changsha, being the destination of tourists during the holiday period, PM2.5 concentration was 33.5% higher during the Spring Festival than during the non-holiday periods, demonstrating apparent impacts of travelling and tourism activities on air quality.

Residue Level, Spatial Distribution and Source of Organochlorine Pesticides in Atmospheric PM25 in Jiangyin City
ZHANG Xiao-yu, ZHOU Xiao-jing, ZHAO Xin, JI Gui-xiang, SHAN Yan-hong, LIN Yu-suo, LV Wei-ming, YAN Hui, LI Xia, LIU Li, ZHU Hai-liang
2016, 32(5):  729-734.  doi:10.11934/j.issn.1673-4831.2016.05.007
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Atmospheric PM2.5 samples were collected in different functional areas of Jiangyin, Jiangsu Province with high volume sampler in the autumn of 2013, for analysis of concentrations of 19 kinds of organochlorine pesticides (OCPs) with GC-MS in an attempt to determine residue level, spatial distribution and source of the pollutants. Results show that the mean total concentration of ∑OCPs in PM2.5 was 2.84 ng·m-3. Among the 19 kinds of OCPs, HCHs, DDTs, chlordanes and methoxychlor were the dominant ones in the PM2.5, accounting for 48.2%, 19.7%, 12.3% and 12.5%, respectively. Compared with the atmospheres in other regions either domestic or abroad, the one in Jiangyin was moderate by the upper side in OCPs pollution level. The OCPs spatial distribution tendency map shows that the pollution level is the highest in the Environmental Monitoring Center, and the lowest in the Shengang Park. Source analysis reveals that DDTs and chlordane in the PM2.5 came from historical residue pollution, while HCHs did from both historical residue of industrial HCHs and recent input of large volumes of lindane.

Influence of Natural Endowment of Scaled Rice Farms in Resource on Their Environment-Friendly Technology Adoption Behavior: Based on Analysis of Micro Data of South Jiangsu
ZHU Meng, QI Zhen-hong, WU Lan-ya, WANG Xin-hua, WANG Pu-qing, HE Hui-qin
2016, 32(5):  735-742.  doi:10.11934/j.issn.1673-4831.2016.05.008
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To encourage scaled rice farms to adopt environment-friendly technology,influences of natural endowment in resources of scaled rice farms on their environment-friendly technology adoption behavior were empirically analyzed using the bivariate Probit model on the basis of the field investigation of 395 scaled rice farms in South Jiangsu. Results show that the endowment did influence the farms' behavior in adopting environment-friendly technology. Among the variables reflecting human and capital resource, age of a farmer was a factor that negatively affected his/her behavior. Among the variables reflecting social and economic resource, whether or not having joined in a farmers' professional cooperative, total agricultural income of a household, annual household income and proportion of non-agricultural income were all factors that might influence the behavior of a household. The influences of the first three factors were often positive, while that of the last was negative. And among the variables reflecting information resources, acquisition channel and type of technical information is a positive factor. Based on all these findings, it is recommended to set young farmers as target for extrapolation of environment-friendly technology, encourage them to take an active part in farmers' professional cooperatives, increase their agricultural income and broadening and enriching their access to information of agricultural technology.

Spatial Optimization of Wetland Landscape Pattern in Jiangsu Yancheng Nature Reserve
CAO Ming-chang, GONG Xi, SUN Xiao-ping, LE Zhi-fang, WU Yi, XU Hai-gen
2016, 32(5):  743-749.  doi:10.11934/j.issn.1673-4831.2016.05.009
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The Jiangsu Yancheng Nature Reserve (YNR) is the largest coastal reserve in China, deeming red-crowned cranes (Grus japonensis) and tidal wetland ecosystems as its main protection targets. It is an urgent task to effectively manage and control resource utilization activities and protect the wetland habitat of red-crowned cranes in the YNR. Three target-driven scenarios of harmonized ecological protection and economic development in YNR were designed, and a land use pattern optimization (LUPO) model was used to simulate spatially optimized wetland landscape patterns in YNR once the scenarios were realized. The simulation reveals as follows: (1) Under Scenario A, the reserve has turned large areas of mudflats and smooth cordgrass tidal flats into seepweed tidal flats, thus achieving the ecological target of expanding over 80% suitable habitat for red-crowned crane in the reserve, but has to face a drastic fall of regional annual economic benefit. (2) Under Scenario B, the reserve has large tracts of mudflats, farmlands, and smooth cordgrass tidal flats converted into fishponds, thus realizing the economic goal of raising its regional annual economic benefit by over 40%, but at the cost of decrease of suitable habitat for red-crowned cranes; (3) Under Scenario C, the reserve has converted smooth cordgrass and reed tidal flats in seepweed tidal flats and mudflats and farmlands into fish ponds, thus achieving the ecological target of expanding the area of suitable habitat for red-crowned crane over 40% as well as the economic goal of increasing its regional annual economic benefit by over 20%. Obviously Scenario C is an optimal win-win option.

Scale Effects on Species Diversity of Subtropical Evergreen Broad-Leaved Forest on Wuyi Mountains
CHEN Ting-ting, XU Hui, MA Fang-zhou, CHEN Shui-fei, XU Hai-gen, FANG Yan-ming, YANG Qing, XU Xian-jun, DING Hui
2016, 32(5):  750-756.  doi:10.11934/j.issn.1673-4831.2016.05.010
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Scale effect is of fundamental ecological significance to exploration of structural variation and dynamics of plant communities. As the Wuyishan preserves certain patches of natural primary forest ecosystems typical of the central subtropics, exploration was carried out in that region of mechanisms of the formation and maintenance of the species diversity, and spatial distribution of the species diversity index in the region and its scale effects. Based on trees ≥1 cm in DBH within the forest dynamics monitoring zone, 9.6 hm2 in area on the Wuyishan, Fujian Province, Simpson index, Shannon-Wiener index and Pielou's evenness index were calculated using seven sampling scales (5 m×3 m, 10 m×6 m, 20 m×12 m, 40 m×24 m, 80 m×48 m, 133.3 m×80 m, 200 m×120 m). Variance and coefficient of variation was used to describe spatial variability, as well as relationships between these indices and sampling scale. Results show that all the indices are related with scale, and feature significantly regional distribution. In addition, species diversity is not only related to spatial scale, and its distribution also follows the rule of scale deduction. Therefore, in analyzing species diversity of plant communities in future, attention should be paid to the rule of scale deduction and spatial variability brought about by sampling scale and areas.

Spatio-Temporal Variation of Vegetation Cover in Shule River Valley During 2000-2014
QI Jing-hui, NIU Shu-wen, MA Li-bang, HE Hong
2016, 32(5):  757-766.  doi:10.11934/j.issn.1673-4831.2016.05.011
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Based on relevant MODIS NDVI data, spatio-temporal variation of the vegetation cover in the Shule River Valley during 2000-2014 was analyzed using the linear trend analysis, M-K test and Hurst index methods, with the aid of ArcGIS and Matlab software. Results show that in the past 15 years, vegetation cover has been increasing rapidly and steadily in the middle and lower reaches of the Shule River Valley, while fluctuating with a mild rising trend in the upper reaches. However, as a whole, it has been improving remarkably in the river valley. The areas with vegetation cover significantly or extra-significantly improved now account for 30.86% of the valley, and are mainly distributed in the irrigated agricultural regions in the middle and lower reaches and mountainous areas with slope less than 20 degree in the upper reaches; while the areas with vegetation cover significantly or extra-significantly degraded do less than 1%, and are concentrated in the regions with natural vegetation cover in the middle and lower reaches of the valley. Since 2004, the valley has been under a relatively warm and humid climate. The total precipitation and mean temperature of the period from June to August affects growth of the vegetation the most significantly in the upper reaches of the valley, showing a significant positive relationship, and that the effect of precipitation is much higher than that of temperature. The vegetation in the middle and lower reaches is not so sensitive to meteorological factors as that in the upper reaches. The areas with vegetation to be improved in future, mostly to be continuously improved, account for 18.63%, and are mainly distributed around the new settlements and in nature reserves in the middle and lower reaches of the Shule River Valley and the west section of the northern piedmont of the Qilian-Altun Mountains, whereas the areas with vegetation degraded amount to 14.25%, and are mostly transformed from areas with vegetation improved and mainly distributed on slopes less than 20 degree in the mountainous areas of Danghenan Mountain, Yema Mountains and Zhaobi Mountain, in the upper reaches of the valley.

Effects of Reforming Low-Efficient Cypress Forest on Meso- and Micro-Soil Faunal Community
TIE Lie-hua, BAI Wen-yu, FENG Mao-song, WU Tao, LI Wen-bing, HAN Dong-miao, ZHANG Zhong-yu
2016, 32(5):  767-773.  doi:10.11934/j.issn.1673-4831.2016.05.012
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Meso- and micro-soil fauna can be used as an important indicator of habitat quality. It's not only sensitive to changing environment, but also plays an important role in soil ecosystem. So it is used to evaluate ecological effects of measures of reforming low-efficient cypress forests in this study. A field experiment, carried out in a cypress forest, was designed to have 6 treatments, that is, Treatment HT (interplanted with walnut trees free of mulch), Treatment HB (interplanted with walnut trees and mulched with white film), Treatment HH (interplanted with walnut trees and mulched with black film), Treatment HZ (interplanted with walnut trees and mulched with shade net), Treatment HD (interplanted with walnut trees and mulched with litter) and Treatment BM (no interplanting and no mulching). Investigations of meso- and micro-soil faunal diversity were performed during the period from June, 2013 to June, 2014 for comparison. Meso- and micro-soil animals were isolated from the soil, using the dry and wet funnel methods, and a total of 4 893 soil faunal individuals were gathered and sorted into 13 groups, 5 classes and 2 phyla. Results show that composition of that soil fauna, in terms of dominant group, common group, and scarce/rare group, varied sharply with the treatment. Similarity analysis reveals that structure of the soil fauna community also differed greatly between treatments. In Treatments HT, HB, HH and HZ population, individual density, Shannon index, Pielou index and Simpson index of the meso and micro-soil fauna increased significantly(P<0.05), with Treatment HD in particular. Besides, the four treatments affected spatial distribution of the soil fauna remarkably, and improved soil physic-chemical properties. And the improved soil properties and their interactions jointly affected structure of the soil faunal community. Treatment HT did have some marked effects on soil total potassium, readily available potassium, organic matter and spatial distribution of the soil fauna (P<0.05), but not much on population, individual density, Shannon index, Pielou index and Simpson index of the soil fauna. In conclusion, the treatments of interplanting walnut trees and mulching is proven to be able to improve community structure of the meso and micro-soil fauna in the low-efficient cypress forest and the treatment of interplanting walnut trees and mulching with litter (HD) is the most outstanding in this effect.

Effect of Combined Application of Chemical Fertilizer With Organic Manure on Cucumber Yield and Soil Microbial Diversity
LUO Jia, LIU Li-zhu, WANG Tong, YAN Shao-hua, LU Xin, FAN Ru-qin, ZHANG Zhen-hua
2016, 32(5):  774-779.  doi:10.11934/j.issn.1673-4831.2016.05.013
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Combined application of chemical fertilizer with organic manure has obvious advantages over application of chemical fertilizer or organic manure alone in terms of crop yield, but little has been reported about effect of the combination on soil microbial diversity. A greenhouse experiment was conducted to investigate effects of the combined application of chemical fertilizer with organic manure on cucumber yield and soil microbial diversity. The experiment was designed to have 5 treatments, that is, Treatment CK (no fertilization), Treatment CF[Chemical fertilizer w(N):w(P2O5):w(K2O)=15:15:15], Treatment WOF (NPK+water hyacinth), Treatment POF (NPK+pig manure) and Treatment FOF (NPK+fermented bedding). All the treatments, except for Treatment CK, were the same in N input and the combination followed 1:1 ratio. Results show that the treatments of combined application were higher than or equal to Treatment CF in cucumber yield. Treatment FOF in particular was 26.77% higher, and followed by Treatment WOF. The combined fertilization was found to be able to maintain or raise cucumber yield and improve quality of the fruit as well. The cucumbers from the treatments of combined fertilization were about 30% higher than those from Treatment CF in Vitamin C content. The combined fertilization also improved nitrogen use efficiency, but the effect varied sharply from treatment to treatment. PCR-DGGE shows that soil bacteria community structure in the five treatments could be classified into three groups. Treatments CK and CF were quite similar in soil bacterial community structure and Treatments WOF and POF were similar too, while Treatment FOF was unique. The treatments of combined fertilization, regardless of source of organic manure, all increased the Shannon-Wiener index and abundance of soil bacteria by as far as over 5% as compared with Treatment CF, which indicates that application of extraneous organic matter could alter structure of the soil microbial community and improve soil microbial diversity, but the application of chemical fertilizer (CF) has little effect on the soil microbial community structure.

Analysis of Soil Microbial Diversity in Shapotou Area of Tengger Desert
LI Jing-yu, ZHANG Xiu, SUN Min, ZHANG Yan-ling
2016, 32(5):  780-787.  doi:10.11934/j.issn.1673-4831.2016.05.014
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Community composition, abundance and diversity of soil microbe in different vegetation rhizospheres and their responses to desert extreme environments in an artificial sand fixed area and a natural bare sand area in the Shapotou Desert, were studied. In the study, soil total DNA was extracted with the aid of the E.Z.N.A.® Soil DNA Kit, V4-V5 sections of the 16S rDNA of the soil bacterial community analyzed with a MiSeq pyrosequencer for community composition, abundance and diversity of the soil bacteria, and responses of the soil microbial community in structure to changes in environment explained with the NMDS and Venn diagrams. In the soil samples, no matter from which area, Proteobacteria, Actinobacteria, Acidobacteria and Cyanobacteria were dominant groups in the soil microbial community on the phylum level, while the soil samples from the two different areas differed sharply in dormancy of groups on the genus level. The 11 soil samples were divided into two groups along the vertical axis of the NMDS in accordance with the artificial sand fixed area and the natural bare sand area, indicating that the microbial community responded to changes in the environment, i.e. sand fixation. The Venn diagram analysis indicates that although some differences are found between different soil samples,groups of microbes common in the two groups of soil samples exist and are thought to play a core role in the Shapotou Desert ecosystem. Cyanobacteria and Rhizobia are the two species of soil microbes that play an important role in biogeochemical cycling, like providing nutrients to psammophytes in sand-fixing process.

Effects of Organic Management Measures for Tea Plantations on Control of Soil Erosion in a Typical Hilly Region in Yunnan Province
LIU Shi-liang, DONG Yu-hong, YIN Yi-jie, CHENG Fang-yan, DONG Shi-kui
2016, 32(5):  788-793.  doi:10.11934/j.issn.1673-4831.2016.05.015
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A study was carried out in a typical hilly region in Yunnan Province in order to investigate effects of organic farming measures for management of tea plantations on soil erosion. A water erosion prediction project(WEPP) model specific for mechanism of soil erosion on slopes was used to simulate effects of higher vegetation coverage and/or higher straw mulching rate on soil erosion on slopes. Results show that rainfall intensity is the major factor, rather than slope length, significantly affecting soil loss and sediment output in either conventional or organic tea plantation on slope. Straw mulching significantly increases soil nutrient contents in the surface soil layer, and at the same time reduces soil erosion rate remarkably, and the soil conservation effect is more obvious, especially in the cases of heavy rain shower and rainstorm. Soil erosion rate drops significantly when straw mulching rate reaches 1.0 kg·m-2. The simulation shows that soil erosion rate reduces with increasing vegetation coverage. The simulation of combined effect of vegetation coverage and straw mulching indicates that the combination of different management measures can significantly reduce soil erosion and sediment yield, especially in tea plantations with low vegetation coverage, where the effect of straw mulching is more obvious.

Spatio-Temporal Variation of Water Quality in Lake Luoma, Jiangsu Province, China
HU Ting-ting, LIU Jin-song, DAI Xiao-ling, CAI Yong-jiu, XU Hao, GONG Zhi-jun
2016, 32(5):  794-801.  doi:10.11934/j.issn.1673-4831.2016.05.016
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Water physicochemical parameters were monitored at 10 sites in Lake Luoma from January to December 2014, for assessment of quality and trophic status of the lake water and for analysis of spatio-temporal variation of the water quality with multi statistical analysis methods, including cluster analysis. One-way ANOVA shows that secchi depth, conductivity and concentrations of dissolved oxygen, nitrogen, phosphorus and Chl-a differed significantly from month to month, while spatial differentiation analysis reveals that only water depth varied remarkably between sites, indicating that water quality little varied spatially in the lake. The monthly mean value of TN, TP, CODMn and Chl-a varied in the range of 0.71-2.08 mg·L-1, 23.82-71.78 μg·L-1, 1.87-5.09 mg·L-1 and 4.49-10.83 μg·L-1, respectively, indicating that Lake Luoma fell into the categories of Ⅲ-Ⅴ in water quality in 2014 according to the standard for surface water quality (GB 3838-2002), with TN being the principal pollutant. The comprehensive trophic level index (TLI) indicates that the lake reached the mesotrophic to light eutrophic level. Cluster analysis divided the 12 months of a year into two clusters (winter-spring group and summer-autumn group). The former was apparently higher than the latter in secchi depth, DO, TN and NO3--N, but lower in Chl-a and TP. Cluster analysis also divided the ten sampling sites into two groups, the north and the south groups. The former was significantly higher than the latter in TN, NO3--N and conductivity, which were the main factors responsible for differentiation of water quality in the lake.

Identification of Sources of Nitrate in the Yongan River With Isotopic Technology
WU Wen-huan, HE Xiao-juan, WU Hai-lu, WANG Xin-ze, SHEN Jian
2016, 32(5):  802-807.  doi:10.11934/j.issn.1673-4831.2016.05.017
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A case study of the Yongan River, a major inflow of the Erhai Lake, was conducted to identify sources of nitrate-N in the river water with the δ15N-NO3-and δ18O-NO3- double isotope technique. Along the river, 9 monitoring sites were set up, responsible for characterizing nitrate pollution of the water, and measuring nitrate δ15N-NO3- and δ18O-NO3- in the water samples after treatment with ion exchange resin. Results show that the nitrate sources along the Yongan River are responsible for about 50% of the total nitrogen pollution load in the water. Nitrate concentration in the water samples at the monitoring sites varied in the range of 0.07-5.22 mg·L-1, with mean being in the range of 1.00-2.39 mg·L-1. The isotope test reveals that the mean δ15N-NO3- of the water samples at the monitoring sites ranged from 6.12‰ to 13.88‰, and the mean δ18O-NO3- did from 8.24‰ to 11.72‰. The findings demonstrate that the nitrate pollutant in the river comes mainly from chemical fertilization, livestock manure, domestic sewage, and nitrification of organic nitrogen in the soil in the valley. Quantification of contributions of the four sources with the IsoSource mixing model tells that 37.3% was attributed to chemical fertilization, 34.6% to disposal of livestock manure, 18.2% to discharge of rural domestic sewage and 9.9% to nitrification of organic nitrogen in the soil. The experiment shows that the use of the IsoSource mixed model to quantify sources of nitrate pollutant in the river may provide future studies with a new train of thought and that ratio of the contributions of the sources to the total nitrate pollutant in the river is related to location of the villages the river runs through and type of land use therein.

Effects of Interior Electrolytic Substrates Fe-Cu Ratio and Hydraulic Retention Time on Pollutant Removal Efficiency of Constructed Wetlands
CAO Chen-liang, ZHANG Yu-yuan, REN Li-jun, AN Shu-qing, LENG Xin
2016, 32(5):  808-812.  doi:10.11934/j.issn.1673-4831.2016.05.018
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To investigate effects of interior electrolytic substrates Fe-Cu ratio and hydraulic retention time (HRT) on pollutant removal efficiencies of constructed wetlands, an experiment was carried out using surface flow constructed wetland beds different in interior electrolytic substrates Fe-Cu mass ratios (1∶0, 1∶0.05, 1∶0.1 and 1∶0.2) and in hydraulic retention time (1, 2, 3, 4 and 5 h). Data of the experiment were analyzed using two-way analysis of variance (ANOVA) with Fe-Cu interior electrolytic and HRT as two factors. Results show that TP removal efficiency of the bed varied sharply with Fe-Cu ratio, but CODCr and TN removal efficiencies did not. Pollutant removal efficiencies varied with hydraulic retention time, too, and the longer the HRT, the higher the pollutant removal efficiency. However, no significant effect of interactions between Fe-Cu interior electrolytic and hydraulic retention time was observed.

Effect of Animal Disturbance on Organic Carbon and Form of Nitrogen in Wetland Plant Root Zone
WANG Qi-fei, GU Jia-ru, XU De-fu, LI Xin, LI Ying-xue, ZHANG Yu
2016, 32(5):  813-817.  doi:10.11934/j.issn.1673-4831.2016.05.019
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A complex vertical-flow wetland consisting of an upstream flow cell and a downstream flow cell was constructed in an experiment for exploration of effects of addition of earthworms and loaches into the two cells on organic carbon and nitrogen in form and content in the plant root zone of the constructed wetland. Results show that the addition of loaches increased the average content of total organic carbon (TOC), easily oxidized organic carbon (EOOC), microbial biomass carbon (MBC), dissolved organic carbon (DOC) and nitrate nitrogen by 16.7%, 10.8%, 19.1%, 33.8% and 68.4%, respectively, and decreased the average content of ammonia nitrogen by 14%, while the addition of earthworms increased the content of TOC, EOOC, MBC, DOC and nitrate nitrogen by 74.6%, 39.7%, 40.4%, 45.1% and 91.8%, respectively, and decreased the content of ammonia nitrogen by 42.8%. Obviously the effects of the addition of earthworms were higher than those of loaches on organic matter, nitrate nitrogen and ammonia nitrogen. Correlation analysis shows that the content of TOC, EOOC and MBC was significantly related to the content of nitrate nitrogen (P<0.01). All the findings indicate that introduction of animals into wetlands increases organic carbon content in the plant root zone of the constructed wetland, and stimulates nitrification process in the wetland, thus increased the content of nitrate nitrogen in the soil.

Preparation of Floriform BiOBr and Its Photocatalytic Characteristics in Degrading Wastewater Substrate
YANG Jia-tian, WEI Qing-min, XIE Qiu-ji, YAN Quan, LI Zhong-liang, CHEN Yuan
2016, 32(5):  818-825.  doi:10.11934/j.issn.1673-4831.2016.05.020
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With Bi(NO3)3·5H2O as bismuth source and KBr as bromine source, floriform photocatalyst of BiOBr was synthesized using the hydrothermal method to adjust pH of precursor solutions and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectrometer(FTIR) and UV-vis diffuse reflectance spectroscopy (UV-vis). Meanwhile, the floriform photocatalyst was tested in photodegrading sugarcane molasses alcohol wastewater for effects of dosage of BiOBr, pH of the wastewater, aeration rate, dosage of KBrO3 and intensity of illumination on decoloration rate of the wastewater. Results show that the hydrothermal products were all BiOBrs of the tetragonal crystal system with a band gap energy being 2.57-2.65 eV. The floriform BiOBr is capable of degrading effectively organic pollutants in sugarcane molasses alcohol wastewater, with a high decoloration rate. To treat 1∶30-diluted sugarcane molasses alcohol wastewater, the optimum running conditions were set as pH 0.11, BiOBr 3.0 g·L-1, KBrO3 3.0 g·L-1, aeration rate 120 L·h-1(medium in rate), 180 min illumination under a 400 W metal halide lamp, 9 cm above the surface of the solution. In this case, the decoloration rate of the wastewater was 98.5% and the CODCr removal rate reached 51.8%. The photocatalysis process fits the first-order kinetic reaction.

Impact of Combined Cyhalothrin-Cd Pollution on Soil Microbes and Bioavailability of Cd
LI Jie, ZHANG Si-fan, XIAO Lin
2016, 32(5):  826-831.  doi:10.11934/j.issn.1673-4831.2016.05.021
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To assess the joint impact of cyhalothrin and cadmium on soil microbial activity and bioavailability of Cd, soil samples were collected from a polluted field for analysis of changes in microbial biomass, respiration, enzymatic activity, pollution induced community tolerance (PICT), as well as bioavailability of Cd. For determining the latter two indices, the isotope-labeling and DGT (diffusive gradients in thin-films) technologies were used. Results show that soil respiration rate increased when 2 mg·kg-1 Cd was amended into the soil, but decreased when 10 mg·kg-1 Cd was. The amendment of both cyhalothrin and a low level of Cd stimulated soil biomass and respiration. Soil catalase, urease and alkaline phosphatase responded differently in activity to Cd and cyhalothrin. Urease was inhibited by Cd and revived to some extend when cyhalothrin was added, whilst alkaline phosphatase was inhibited in the initial 30 days and revived till the 60th day. The pollution of cyhalothrin alone did not show any PICT effect, however, the combined pollution elevated PICT to Cd, as well as bioavailability of Cd represented by DGT concentration. All the findings suggest that Cd in the combined pollution plays an essential role in affecting the studied indices, but the stimulating effects on soil microbial activity are synergistic ones when pyrethroidis coupled with a low level of Cd. CHT could increase PICT to Cd as well as bioavailability of Cd, which should be considered in the issue of food safety.

Deposition and Degradation of Myclobutanil in Cowpea and Open Field
LIU Ya-nan, LI Wen-zhuo, WEI Peng, CAO Meng-chao, ZHAO Ying, WANG Meng-cen, ZHU Guo-nian
2016, 32(5):  832-836.  doi:10.11934/j.issn.1673-4831.2016.05.022
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An analytical method using QuEChERS extraction and GC-MS/MS (gas chromatography coupled with tandem mass spectrometry)was established for analysis of myclobutanil residues in cowpea and soil of the field, and initial deposition and degradation dynamics of myclobutanil in cowpea and soil of the field was also investigated in a field experiment. Results show that response value of the instrument was in linear relationship with concentration of myclobutanil in the range of 0.001-2 mg·kg-1, and LOD of the instrument was 8×10-12 g. Myclobutanilin cowpea and soil samples were extracted with acetonitrile, purified with SPE Bond Elut-Fl columns and determined with GC-MS/MS. When myclobutanil content in the cowpea and soil samples was in the range between 0.05-2 mg·kg-1, the mean recovery rate reached 86.6%-105.4% with relative standard deviation being 3.0%-7.0%, which means the method satisfies the requirements for detection of myclobutanil residue in cowpea and soil in accuracy, precision and sensitivity. The field experiment shows that the deposition of myclobutanil in cowpea in the initial phase was not significant and differed slightly from that in the soil. The half-life of the substance in cowpea and soil ranged of 3.1-4.3 and 10.5-12.1 d and the growth-dilution effect of cowpea and precipitation are two dominant factors leading to variation of degradation rate of the substance in different regions.

Degradation of 1,2,4-Triazole Fungicides in the Environment
WU Wen-zhu, GUO Min, KONG De-yang, XU Jing, SHAN Zheng-jun
2016, 32(5):  837-841.  doi:10.11934/j.issn.1673-4831.2016.05.023
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The knowledge of behaviors and fates of 1,2,4-triazole-typed fungicides in the environment is critical to assessing their environmental risks. An in-laboratory experiment was performed to examine influences of temperature, pH and light on degradation of three kinds of 1,2,4-triazole fungicides(epoxiconazole, tebuconazole, and flutriafol)in water and soil. Results show that the photolysis half-life of epoxiconazole, tebuconazole, and flutriafol was 0.68, 2.35 and 9.30 h, respectively. Epoxiconazole and tebuconazole were readily photolyzed pesticides, while flutriafol was medium in readiness. In water with pH being 4.0, 7.0 and 9.0 under 25 ℃,the hydrolysis half-life was 120, 131 and 151 d, respectively, for epoxiconazole,and 257, 198 and 187 d for tebuconazole and 204, 182 and 182 d for flutriafol. Hydrolysis of the three types of fungicides was closely related to water pH and their chemical structure. The half-lives of epoxiconazole, tebuconazole, and flutriafol were 58.2 to 72.9 days in the red soil of Jiangxi, 182 to 365 days in the paddy soil of Taihu Region and 102 to 161 days in the black soil of Northeast China. The findings of the experiment indicate that epoxiconazole, tebuconazole, and flutriafol all have a long residual period in water and soil, which calls for more attention to their pollution of the environment and monitoring of their application and residues in the environment.

Emission of Harmful Gases From High-Temperature Combustion of Bio-Materials
JIAN Shou-wei, SUN Meng-qi, HE Gui-hai, ZHI Zhen-zhen, MA Bao-guo, XIAO Hui
2016, 32(5):  842-846.  doi:10.11934/j.issn.1673-4831.2016.05.024
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Emissions of PM2.5 from burning of wheat straw, corn stalks and rice straw were quantified with the aid of FACTSAGE and effects of oxygen supply and temperature during the combustion process on emissions of HF, HCl, SOx and NO with smoke were explored in an attempt to define proper conditions for burning of bio-materials. Results show that as crop straw contains much F and Cl, burning of the material generates a large amount of HF and HCl. In order to control the generation of F/Cl compounds from burning of bio-materials, temperature of the combustion should be controlled at 1 000-1 100 ℃, and oxygen supply should be from natural air. When oxygen supply is too low, more ammonia and hydroxides will be generated and emitted with the tail gas, while it is too high, more sulfur oxides and nitrogen oxides will, causing formation of secondary aerosol,PM2.5 and then environment pollution.

Pyrolytic Features of Enteromorpha compressa and Zea mays and Comparison Between Their Biochar Products in Property
ZHANG Xing-yuan, SHAN Rui-feng, SUN Xiao-yin, LIU Fei, WANG Ping, ZHANG Zi-tong, ZHANG Zhen-bei
2016, 32(5):  847-851.  doi:10.11934/j.issn.1673-4831.2016.05.025
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In order to explore potential of the algae to be used as resource, researches were done to determine pyrolytic feature of algae(Enteromorpha compressa) and cornstalk(Zea mays) with the technology of differential scanning calorimetry & thermo-gravimetric analysis (TG-DSC)and compare their pyrolysis products of biochar under different temperatures (350, 500 and 650 ℃) in property. Results show that the two materials differed sharply in pyrolytic feature. The algae are quite low in thermo-stability and pyrolytic reaction temperature, so they do not need so much heat as cornstalk does to get pyrolyzed into biochars at the same set temperature. Analysis of properties of the biochars prepared out of the algae and cornstalk shows that the biochar of algae was 33.47%-37.86% in carbon content, equaling to 49.07%-65.41% of the carbon content in the biochar of cornstalk, and also lower in specific surface area and aromatization degree than the biochar of cornstalk. However, the former was far too much higher than the latter in ash content and nitrogen content or 3.83-4.53 and 3.38-30.33 times as high as the latter.

Methods for Comprehensive Quality Assessment of Rural Environment and Empirical Research
RUI Han-yi, ZHU Lin, ZHAO Ke-qiang, SUN Qin-fang, ZHU Hong-biao, ZHANG Wei-dong, ZHU Qin-yuan
2016, 32(5):  852-856.  doi:10.11934/j.issn.1673-4831.2016.05.026
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Comprehensive quality assessment of rural environment means great significance to guiding management of rural environment. The main methods currently available for quality assessment of rural environment were compared in terms of advantages and disadvantages. In the light of characteristics of the rural environment and present requirements for monitoring and management of rural environment, a comprehensive index method was suggested for adoption in comprehensive quality assessment of rural environment. Based on the assessment index system, methods for calculation of rural environmental quality indices and criteria for grading of the indices were brought forth and applied to demonstration in Yixing. Results show that this method is practicable and can be used as technical support to the government in managing the rural environment.

Problems With Supervision of Rural Environment in China
JU Chang-hua, ZHU Lin, ZHU Hong-biao, ZHANG Wei-dong, RUI Han-yi, SUN Qin-fang
2016, 32(5):  857-862.  doi:10.11934/j.issn.1673-4831.2016.05.027
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At present, supervision of rural environment is still in its infancy, which is mainly reflected in insufficient supervision of environmental quality, pollution sources and rural environment management. In supervising rural environment, existing problems, like shortage of basis, absence of supervisory institutions and entities to be supervised and inadequate supervision means, which affect progresses and effects of the supervision of rural environment. Countermeasures and suggestions are put forward for the supervision from the aspects of building up a rural environmental supervision institutional system, consummating technical criterion for the rural environmental supervision, and setting up a supervision technical system.