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City is a kind of social-economic-natural complex ecological systems.Urban ecological land is an important component of urban ecosystem,which plays a key role to guarantee urban social-economy sustainable development,provide urban ecosystem services and improve residents′ quality.The rapid spread of urban area and intensive human activities have significantly changed the urban land use structure and ecological land quantity,thus seriously impacted the urban ecological service and human living environment.However,little information was available on the influence of urban land structure on ecosystem services in resource-exhausted cities.Through the remote sensing,GIS technology and evaluation method of ecological service value,the variations of land use structure and ecological service value were assessed in a typical resource-exhausted city—huaibei during 1987 to 2007 in this study.The results showed that from1987 to 2007,the total area and structure of ecological land in this city were drastically changed,with the proportion of ecological land area decreased from 91.45% to 71.86%.From 1987 to 2000,the area of farmland substantially reduced,but the areas of forest,water and built-up lands increased.While from 2000 to 2007,the area of farmland increased but the area of forest and water significantly reduced.Although there were no obvious changes of total areas of the built-up land in this period,the aggregation level of the built-up land increased significantly.However,the comprehensive land use dynamic degree of huaibei city has a decreasing tendency from 1987 to 2007,which reflecting the gentle land circulation during this period.Moreover,in these 20 years,urban ecological service value increased between 1987 and 2000 then decreased since 2000.The maximum value of ecological service appeared in 2000,which was 31.32×108 yuan.During 2000 to 2007,the ecosystem services of waste treatment and water conservation function mainly provided by water and forest have the greatest contribution.The variation of ecological service value during 1987—2000 was mainly due to the impacts of coal mining,which occupied large area of cultivated land and made the surface area sinking into desolated beaches or depression,thus caused the significantly reduction of food production services.Meanwhile,the increasing of wetlands from sink area and woodland by ecological constructions such as returning farmland to forest and artificial afforestation made other ecosystem services obviously improved.From 2000 to 2007,the increasing urban expansion and population growth convert a large sum of ecological land to built-up area,resulting the decreasing of the ecosystem services values.In addition,the distribution of urban ecological land significantly influenced the spatial variability ecological service value.The higher service value areas were mainly distributed on the south part of huaibei city where farmland and forestland is relatively concentrated,while lower service value areas were mainly concentrated in the built-up area.Thus it can be seen that urban land use structure change greatly influenced ecological services,and the results can provide certain scientific basis to the optimization of the landscape pattern and reasonable control of urban land in the huaibei city.

The concept of urban green space,which comprises gardens and parks,urban forestry,urban agriculture,greenways,waterfront greenbelt,and roof greening,is different from traditional garden greenland,and forms functional eco-networks.On the other hand,the ecological and environmental impacts of urbanization extend over large areas even though the areal percentage of urban land in regional land-cover maps is typically quite small.Urban land use changes altered the green space patterns dramatically,and sequentially influenced urban landscape structure and ecosystem services.With the concern of high speed of urbanization and serious urban environmental problems,a common consensus has been achieved that the spatio-temporal dynamics of urban green space patterns are important factors to social,economic and ecological functions of urban ecosystems.Many countries have formulated urban landscaping as an essential part of the strategy of sustainable development.Nevertheless,under most circumstances,the green spaces were built more arbitrarily than based upon scientific analyses.Therefore,study on the quantitative methods of urban green space patterns revealed broad applications in protecting and planning green space structure and functions,which could further promote urban human settlements. Among various quantitative methods of urban green space patterns,detecting methods of green space changes under urbanization was a hotspot.Urban development and suburbanization had shrunk the size of green spaces and got the green patches fragmented.In terms of measuring green space fragmentation,it was of prime importance to select appropriate fragmentation metrics and improve the method of weighting to aggregate to get an unique fragmentation score.Contrary to landscape fragmentation,improvement in green space connectivity rehabilitated and optimized network structure,which could further enhance ecosystem services supply.Recently,assessment of green space connectivity had been transited from metric-based approaches to the coupling of both landscape metrics and models,and an increasing number of researches focused on the network scenario analysis of urban green spaces had gradually formed an united methodological framework for reconstruction of urban eco-networks.Meanwhile,accessibility analysis of urban green spaces was an important researching topic to assess the spatial interactions between residential land use and urban green spaces,and could help to identify the truly underserved areas lacking opportunities of accessing green spaces which was critical for effective urban planning and development.Moreover,spatial-temporal gradient analysis,combined with quantified landscape metrics,was judged to be the most appropriate way of relating the spatial pattern of urban green spaces to urbanization and underlying human processes,and of determining their influence on ecological attributes of the environment.Three sampling methods were commonly used for detecting the gradient changes of green space patterns: buffer gradient analysis,directional transects and moving window method.For comparative studies on the spatial variations of green space patterns along urban-rural gradients,multiple approaches of mapping peri-urban areas should be addressed in a scientific way. In the final section,suggestions for future researches were put forward,which highlighted the importance of quantifying green space patterns spatially explicit at multiple scales.In order to achieve these goals,the so-called local analysis,combined with quantified landscape metrics and accessibility measurements,which was often conducted at grid level,patch level and local areas according to the research objectives respectively,was widely used.Considering the scale effects involved in the spatial analysis associated with urbanization,multi-scale methods of quantifying green space patterns need to be carried out both at diverse spatial grains and extents to facilitate comparisons among different cities and periods of time.In addition,the quantification of green space patterns should also be integrated with planning or policy issues,as well as be applied to evaluating ecosystem services.In other words,quantifying green space patterns could not only serve as guidelines in terms of decision making,but help evaluating the impacts of regional development policies on future ecological benefits and ecosystem services.

Laccases catalyze the oxidation of various aromatics,particularly phenolic and amine substrates,making them valuable in industrial applications.Laccases also play an important role in soil organic matter(SOM) turnover processes and the global carbon cycle due to their involvement in the synthesis and degradation of lignin as well as transformation of lignified substrates and humic substances.Laccases belong to the protein family of multicopper oxidases characterized by copper atoms in the active center.Laccases or laccase-like multicopper oxidases(LMCO) have been extensively studied especially in fungi.Recently,increasing evidence points to a wide occurrence of LMCO in bacteria.As bacterial communities are known to decompose pollutants and municipal wastes involving large quantities of phenolic substances and organic matter,it can be deduced that bacterial LMCO might also participate in lignin degradation and SOM cycling.Copper atoms not only constitute the catalytic center of laccases but can also confer copper resistance to bacteria.Consequently,copper ions have a well known use in isolating LMCO-producing bacteria.To gain deeper insights into the ecological role of bacteria with LMCO activity in soil,we used traditional plating methods and PCR-DGGE(denaturing gradient gel electrophoresis) technology to examine the community structure of LMCO-producing bacteria in forest soil of Liangshui nature reserve,Heilongjiang Province. Soil samples were collected in three patterns of forests: Pinus koraiensis,Betula platyphylla and Picea dietrich.Soil samples were enriched in M9 basal medium and then screened in LB medium with gradient Cu2+.Ten bacteria strains were isolated and identified based on traditional plating methods of bacteria separation.The results showed that they all belonged to Bacillus sp.,falling into four different species: Bacillus pumilus,Bacillus subtilis,Bacillus fusiformis and Bacillus amyloliquefaciens,among which no laccase-relative results have been reported on Bacillus fusiformis.To investigate the structural variation of LMCO-producing bacteria,16S-rDNA-V3-fragment-based DGGE and clone sequence BLAST technologies were applied.The data based on DGGE plot indicated there was no distinct variation of LMCO-producing bacteria structure among soil samples of different forest patterns in the research district.The diversity of LMCO-producing bacteria in Pinus koraiensis forests was more abundant than that in Betula platyphylla and Picea dietrich.The results derived from BLAST revealed that Ralstonia sp.,Enterobacter sp.and other uncultured species existed in soil samples in addition to Bacillus sp..Band 3 was present in all soil samples and had a 100% homology to Ralstonia mannitolilytica.Ralstonia sp.had highly physical and biochemical similarities as well as sequence homology with Cupriavidus sp.which was a copper-philic bacteria community.Bands 2,7 and 11 were commonly present except lane 8 and had a highly homology with Enterobacter ludwigii which had recently attracted interest in environment ecological research.Bands 5 and 9 had a highly homology with Bacillus circulans and Bacillus thuringiensis,respectively.Furthermore,Bands 1,4,6,8 and 10 had highly homology with an uncultured bacterial clone which needed further investigation.

City is a kind of social-economic-natural complex ecosystem dominated by human activities. With the accelerating of urbanization,the land use is being transformed from natural landscape to impervious surface in urban areas, such as buildings,roads,roof,squares and so on. Urban imperious surface changes the environment factors,hinders energy exchange between air and soil,and influences urban plant growth. In this research we studied the effects of urban imperious surface on habitat of Ginkgo biloba and its ecophysiology response to the imperious surface. We designed two different types of imperious surface in urban areas. One is totally impervious cover ( TIC) which is a marble square,and the coefficient of permeability is zero. The other is partially impervious cover ( PIC) which is covered by bricks,and the coefficient of permeability is 33% . A turf cover ( NC) was chosen as the contrast,and the coefficient of permeability is 88% . The Ginkgo bilobas growing on the three kinds of land covers were planted in the same time and received the same maintenance. Soil temperature ( Ts ) and water content of soil ( WCS ) were measured by ECH2O. Gas exchange characteristics such as photosynthesis ( Pn ) ,transpiration ( Tr ) ,stomata conductance ( Gs ) ,saturation vapor pressure deficit of leaf ( VPDL ) were measured by Portable photosynthesis measuring system Li-6400. chlorophyll fluorescence