[Scaling laws of altitudinal pattern of soil fauna diversity in Dongling Mountain, Beijing, China]. / åŒ—äº¬ä¸œçµå±±åœŸå£¤åŠ¨ç‰©å¤šæ ·æ€§æµ·æ‹”æ ¼å±€çš„å°ºåº¦æŽ¨ç»Žè§„å¾‹.

Identifying the complexity of diversity pattern of various taxa within a community is a challenge for ecologist. Scaling law is one of the suitable ways to detecting the complex ecological structure. In this study, we explored the scaling laws of soil fauna diversity pattern along an altitudinal gradient by multifractal analysis, and compared the difference of multifractal spectra between the litter and the soil layers. Consistent with results from plant communities in previous studies, there was power law scaling law for soil fauna diversity, i.e., richness, the exponential of Shannon's Diversity Index, and the inverse Simpson's Diversity Index. Moreover, power law scaling law also existed for the richness changes of different relative abundance species in both litter and soil layers. Although multifractal characteristics existed for both litter layer and soil layer of soil fauna diversity, the fractal structure of the diversity in the litter layer was more even than that in the soil layer, and the scaling properties of dominant and rare species showed different patterns in multifractal spectra between litter layer and soil layer. In conclusion, there were power law scaling laws for soil fauna diversity which had high richness and abundance along the altitudinal gradient, which would help us uncovering the spatial distribution mechanism of belowground biodiversity.

[Research progress on the effects of urban road green space on dispersion of local air pollutant]. / åŸŽå¸‚é“è·¯ç»¿åœ°å¯¹å±€åœ°ç©ºæ°”æ±¡æŸ“æ‰©æ•£çš„å½±å“ç ”ç©¶è¿›å±•.

In recent years, the research on the effects of urban road green space on local pollutant dispersion has been quite active, with mounting empirical results. Due to the lack of summary and arrangement, however, it is difficult to effectively guide the practice of urban green space construction. In this review, the road and green belt research objects were classified. Based on two common methods of field measurement and numerical simulation, the pollutant concentration index, vegetation characters and other influencing factors involved in relevant research were systematically reviewed. The effects of road green space on dispersion of local pollution were summarized. Future research should be strengthened in the aspects of expanding research objects, comprehensively considering multiple ecological processes, integrating two basic methods, and improving the accuracy and richness of data.

[A review of air pollutant diffusion models for urban street]. / 城市街道空气污染物扩散模型综述.

Street is an important place for urban residents, and the air quality in streets is closely related to residents' health. Air pollutant diffusion model is an often used measure to simulate and evaluate air quality in street canyon in recent years, but the problems existing in model application need to be clarified. This review selected four air pollutant diffusion models, i.e., ENVI-met, FLUENT, MISKAM and OSPM, which were most popular in street canyon studies. Through comparisons on the model mechanisms, the operational processes, the temporal-spatial resolutions and so on, their differences in model scopes and modeling capabilities in street canyon air quality simulation were discriminated, the model deficiencies were pointed out according to temporal scale, modeling, weather handling, turbulent simulation and photochemical pollution, and several model optimization measures were suggested in terms of street canyon study. Moreover, through reviewing the case stu-dies of the four models, the shortcomings in model application were concluded, and some new techniques were highlighted for future application studies such as laser radar to improve input data accuracy, and the importance of considering urban heat island and urban pollutant island simultaneously was emphasized in evaluating street environment quality.

[Content trends of pollutants in street dust of Beijing along the urban-rural gradient and road density gradient].

In the article, pollutant content of 220 road dust samples within the sixth ring road of Beijing have been investigated by using grid stationing sampling method. The changing characteristics of road nude number per unit area, road network density and pollutant content within buffering areas along urban to rural gradient were also studied. Three following variation trends are presented as each index varies widely within the research areas. Firstly, road nude number per unit area, road network density and Cu, Cr, Pb content decrease along urban to rural gradient, and they decrease sharply in the beginning. Secondly, Mn, Cd content change a little along urban to rural gradient, and mean value remains stable. Thirdly, the content of Ni, TOC, TN decreases along with the distance fluctuations in the beginning and their mean values are then rising slowly in the suburbs. The turning point of pollutant content are found in places 15-20 km away from city center. The article shows that the road index and Cd content are irrelevant, and weak correlations are found between road index, TS, Mn and pH. And other relevance ranking are described as follows: Cu > TN > TOC > Pb > Ni > Cr. In contrast with road network density, higher correlations between road nude number per unit area and each element are fond, and element pollution of Cu, TN, TOC, Pb, Ni and Cr could be indicated by these indicators.

[Effects of altitude on soil microbial community in Quercus liaotungensis forest].

Taking the Quercus liaotungensis forest soil in Dongling Mountain of Beijing as the object, and by using chloroform fumigation-extraction and phospholipid fatty acid (PLFA) analysis methods, this paper studied the variation characteristics of soil microbial community along an altitudinal gradient in the tree growth season. With increasing altitude, the soil microbial biomass carbon and nitrogen and the quantities of various soil microbial groups in the forest had definite differences but not significant. The ratio of soil bacteria to fungi increased, but the ratio of G(+)- to G- bacteria decreased. The soil microbial biomass carbon and nitrogen and the quantities of soil bacteria, fungi, and G(+)- and G- bacteria had significant positive correlations with the contents of soil moisture, organic carbon, and total nitrogen, and the quantity of soil fungi was positively correlated with soil carbon/nitrogen ratio. The variations of the soil microbial community structure (bacteria/fungi and G(+)-/G- bacteria) were mainly affected by soil temperature and moisture content, which meant that the soil microbial community structure was sensitive to the environmental conditions. Along with the global warming, the proportions of soil fungi and G+ bacteria in the Q. liaotungensis forests in warm temperate zone would have an increase.

[Influence of soil moisture, nitrogen and phosphorus contents on Bauhinia faberi seedlings growth characteristics in arid valley of Minjiang River].

To study the influence of resources thresholds on plant growth is a major theme in restoration ecology. Based on the simulation of the natural thresholds of soil moisture, nitrogen (N), and phosphorus (P) under drought condition in the arid valley of Mingjiang River, a full factorial experiment was designed to study the dynamics of Bauhinia faberi seedlings survival rate, growth, biomass production, and resources use efficiency across one growth season. High soil moisture (40% field water capacity), high soil P (24 mg P x kg(-1)), and low N (100 mg N x kg(-1)) increased the seedlings survival rate, and promoted the seedlings growth, biomass production, and water use efficiency. There was a significant coupling effect between soil N and P, but the interactions between soil moisture and soil N and P were not obvious. High N (240 mg N x kg(-1)) restrained the seedlings growth markedly, while high P mitigated the negative effects of high N via increasing root area, root length, and root mass to promote the seedlings N and P uptake. The N and P use efficiency across one growth season kept steady, and had significant positive correlation with root/shoot mass ratio. The combination of high soil moisture, low N, and high P promoted the seedlings growth effectively, while that of low soil moisture, low P, and high N inhibited the seedlings growth markedly.

[Spatio-temporal dynamics of nitrogen in agricultural ditch systems in Sanjiang Plain].

Agricultural drainage water sampling was conducted along ditch systems from 1st order to 5th order in Nongjiang River and Bielahonghe River during June to September, 2005. The spatio-temporal dynamics of nitrogen concentrations in agricultural ditch systems were analyzed. Results showed that there were higher concentrations of nitrogen in Bielahonghe ditch system. Peak values of TN, NH4(+) -N and NO3(-) -N moved from 1" order to 3rd and 5th order in Nongjiang and Bielahonghe ditch systems respectively. The retention of nitrogen in Bielahonghe ditch system was more than Nongjiang ditch system. The temporal dynamics of TN and NH4(+) -N were parallel in the two ditch systems, which decreased from June to September. But the temporal dynamics of NO3(-) -N had no obvious trend. The relationships between TN and NH4(+) -N and NO3(-) -N were positively correlated in both Nongjiang and Bielahonghe ditch systems, fitting for Power model and Cubic model respectively. The relationships between TN and NH4(+) -N and NO3(-) -N can be described by multi-variance linear regression, which explained 78% of TN concentration in Bielahonghe ditch system.

[Zoning planning in non-point source pollution control in Hanyang district].

It is most important for managing urban non-point source (NPS) pollution, actualizing the urban sustainable development as well, that zoning planning of urban NPS pollution control is studied. A case study on principles and methods of zoning planning in urban NPS pollution is carried out. Principles of urban sustainable development, priority of urban NPS pollution sensitivity, similarity of urban NPS control direction and region conjugate are put forward. Besides, it is for the first time that a more quantitive method is presented, in the case of Hanyang district, Wuhan city, which is based on L-THIA model and spatial analysis technique in GIS. Assessment of NPS pollution status quo, as well as analysis of NPS sensitivity, is the kernel component of the quantitive method. Hanyang might be divided into four NPS pollution control zones. It is helpful for decision-making of regional NPS pollution control.

[Main sources of urban non-point source pollution and control measures for classified catchments].

The change of land use and management practices is one of the most important factors that affecting water quality, proper land use management practices can improve water quality in a watershed. A stepwise regression model was used for finding the relationship between lake water quality and urban land use types, and rural residential, urban residential, commercial land and bottomland were determined as the main sources of non-point source pollution (NPS). The 17 catchments in the study area were clustered into 3 groups through land use types, representing rural residential, urban residential, commercial land and bottomland separately. According to the different characters of landscape structures in each group, appropriate countermeasures designed for effective NPS control simplified the practices and improved the maneuverability of urban NPS control.

[Research on the relationship between water and eco-environment construction in Loess Hilly and Gully regions].

Water is an important factor for eco-environmental construction. Eco-environmental construction has a great impact on water. There is a circular correlation between eco-environmental construction and water. Water resource is lack and loss of soil and water is serious in the loess hilly and gully regions. The regions are the main regions of eco-environmental construction, especially of vegetation restoration and rehabilitation. It is important studying the relationship between water and eco-environmental construction in the regions. According to the data in Yanhe River watershed, some conclusion are demonstrated: 1. More water resource was demanded when population was increasing rapidly and economy was developing fleetly. Water for eco-environmental construction was threatened directly. 2. Eco-environmental construction, especially the built vegetation decreased the runoff. The dried soil layers have appeared in some places. 3. Shortage of water resource limited the farther tree and grass planting and brought on some negative impacts. Small aged trees have appeared in some places. The eco-environmental benefits of the built vegetation have been influenced. On the basis of relationship between water and eco-environmental construction, some advice for sustainable use of water resource, sustainable construction of eco-environment and sustainable development of society and economy was given.

[Impacts of the urbanization on waters non-point source pollution].

Non-point source (NPS) pollution is the prominent source of water pollution in many countries, included America and China, of the world. Urban NPS pollution was attached little importance for long, compared with agriculture NPS pollution. While urbanization is the dominant form of land-use change in terms of impacts on water quality, the hydrology, other physical properties of watersheds as well as their NPS pollution potential at present. The formation of urban NPS pollution of water could be described by "source-process-sink". Urbanization has changed the source, process and sink of urban NPS pollution. A review was conducted on the international researches of urbanization impacts on NPS pollution in urban water environment from the point of view of "describe-predict and evaluation-application". The studies of urbanization impacts on urban NPS pollution were focused on modeling the process of urban NPS pollution by hydrologic model, predicting the pollutants load of NPS pollution. It is a fresh methodology that the relationship between urbanization and urban NPS pollution of water was analyzed by the method of landscape change and ecological process. The research on temporal-spatial comprehensive impacts of landscape pattern changes, led by urbanization, on the urban NPS pollution will be one of the hotspots.

Characterising biocomplexity and soil microbial dynamics along a smelter-damaged landscape gradient.

Soil micro-organisms are an integral but often underestimated part of plant and soil ecosystems. Long-term industrial air pollution in the Sudbury, Ontario region has altered vegetation and soil, and therefore, possibly, soil microbial function. This study focuses on the historical pollution gradient resulting from a decommissioned smelter near Sudbury, and aims to determine the effect of contaminant concentrations (such as soil heavy metals) and environmental variables (such as soil moisture and vegetation cover) on soil microbial populations and diversity. Results suggest that increasing distance from the pollution source did not correlate well with increasing micro-organism population or diversity. Metal concentrations also did not correlate with microbial dynamics. Only soil nutrient abundance showed a significant relationship, and revealed that phosphorous may be the rate-limiting influence. Secondary affects of pollution such as soil erosion and removal of plant litter are suggested to be important causes. The study reinforces the complex nature of landscape scale recovery and shows that recovery pathways are not linear or dependent upon single variables.

Comparing the soil quality changes of different land uses determined by two quantitative methods.

Soil quality is one of the most important environmental factors in sustaining the global biosphere and developing sustainable agricultural practices. A study was initiated in Wolong Nature Reserve, Sichuan Province, China to elucidate the soil quality changes of natural secondary succession, forest planting and agricultural practices after deforestation in the humid mountainous region. The soil qualities of six land use types (natural forestland, grassland, shrub land, secondary forestland, cultivated land and reforested land) were compared using two quantitative methods: the integrated soil quality index (QI) and soil deterioration index (DI). The QI values of natural forestland, grassland, shrub land, secondary forestland, cultivated land, reforested land were 0.8039, 0.3277, 0.9127, 0.6881, 0.0285 and 0.3183, respectively. The DI values were 0%, -14%, 12%, 1%, -26% and -18% respectively. Both indexes suggested that shrub land can restore soil properties. To compare the two methods more directly, a deduced index QI' based on QI value was developed. The results showed that DI and QI' had a very high linear correlation coefficient (r = 0.9775) despite the values were different. Both methods were efficient in evaluating the soil quality levels and DI was a more simple way in soil quality assessment, while QI could show more ecological meanings.