Forests play an important role in mitigating climate change by absorbing carbon from atmosphere. The global forests sequestrated 2.4±0.4 Pg C y^-1 from 1990 to 2007, while the quantitative assessment on the carbon sequestration potential (CSP) of global forests has much uncertainty. We collected and compiled a database of site above-ground biomass (AGB) of global mature forests, and obtained AGB carbon carrying capacity (CCC) of global forests by interpolating global mature forest site data. The results show that: (i) at a global scale, the AGB of mature forests decline mainly from tropical forests to boreal forests, and the maximum AGB occurs in middle latitude regions; (ii) temperature and precipitation are main factors influencing the AGB of mature forests; and (iii) the above-ground biomass CCC of global forests is about 586.2±49.3 Pg C, and with CSP of 313.4 Pg C. Therefore, achieving CCC of the existing forests by reducing human disturbance is an option for mitigating greenhouse gas emission.

West China provides important ecological services to the rest of the country, and has attracted great attention because of its serious ecological degradation and frequent natural disasters, and its strong connection with the industrial and economic development in East China. In order to strengthen ecological restoration and promote sustainable economic development in West China, the Chinese government adopted the Western Development Policy, which offered financial aid to and initiated a large number of projects in the region. Although many previous studies have emphasized the positive effects of ecological restoration in West China on ecological security and sustainable development of China, relatively less attention has been paid to analyzing multiple conflicts related to sustainable development in the region. This paper examines the main development goals and interests that have caused these conflicts. The authors suggest that integrated conflict management should be carried out for the sustainable development in West China.

The potential impact of climate change on water eutrophication and ecosystems is of great international and domestic concern. This study aims to analyze the impact of climate change on algal bloom problems in large river systems by utilizing a parametric river eutrophication model that is established using indicators of climate change, hydrological regimes, water quality and nutrient loads. Specifically, the developed parametric modeling method is based on statistical and simulation methods including: Multiple Linear Regressions (MLR), Multiple Non-linear Regressions (MNR), Artificial Neural Network (ANN) based on Back-propagation (BP) algorithms, as well as an integrated river eutrophication model. The developed model was applied to Han River, which is one of the major sources of fresh water in Wuhan City, China. The impacts of climate change and human activities on the occurrence mechanisms of algal blooms in the Han River were identified by scenarios analysis. The individual assessment result indicates that the waste nutrient P load has the most significant impact (14.82%), followed by the flow rate (5.56%) and then by temperature (3.7%). For the integrated climate change assessment, it has been found that there is a significant impact (20.37%) when waste load increases and flow rate decreases at the same time. This is followed by increase of both waste load and temperature (15.82%). If temperature increases but flow rate decreases, the impact is predicted to be 11.11%. The final results point to human activities as a significant influence on water quality and the Han River ecosystem, temperature is also one of the main factors which directly contribute to algal blooms in Han River. The results in present study are expected to give theoretical supports for further relevant research on water eutrophication.

Temperature changes are known to have significant impacts on human health. Accurate estimates of population—weighted average monthly air temperature for US counties are needed to evaluate temperature's association with health behaviours and disease, which are sampled or reported at the county level and measured on a monthly—or 30-day—basis. Most reported temperature estimates were calculated using ArcGIS, relatively few used SAS. We compared the performance of geostatistical models to estimate population—weighted average temperature in each month for counties in 48 states using ArcGIS v9.3 and SAS v 9.2 on a CITGO platform. Monthly average temperature for Jan–Dec 2007 and elevation from 5435 weather stations were used to estimate the temperature at county population centroids. County estimates were produced with elevation as a covariate. Performance of models was assessed by comparing adjusted R2, mean squared error, root mean squared error, and processing time. Prediction accuracy for split validation was above 90% for 11 months in ArcGIS and all 12 months in SAS. Cokriging in SAS achieved higher prediction accuracy and lower estimation bias as compared to cokriging in ArcGIS. County—level estimates produced by both packages were positively correlated (adjusted R² range=0.95 to 0.99); accuracy and precision improved with elevation as a covariate. Both methods from ArcGIS and SAS are reliable for U.S. county—level temperature estimates; However, ArcGIS's merits in spatial data pre—processing and processing time may be important considerations for software selection, especially for multi—year or multi—state projects.

Ecosystem management is an ecological approach to the sustainable development of the nature rubber industry. Hainan is selected as an example to present a basic model of natural rubber industry ecosystem management. Based on the systematic analysis of structure and function of natural rubber industry ecosystem, we discuss the basic principles, management steps and management approaches of natural rubber industry ecosystem management. The goal of this paper is to provide the theoretical basis and practical guidance for healthy and sustainable development of the natural rubber industry ecosystem.

Species richness and diversity indices (Shannon-Wiener index, Simpson dominance index and Pielou evenness index) in alpine grassland ecosystems (alpine meadow, alpine steppe and desert steppe) under grazing—excluded and freely grazed sites were investigated along the Northern Tibetan Plateau Alpine Grassland Transect during summer 2009 and 2010. We found that species richness and diversity have not been significantly altered by short—term grazing exclusion since 2006 at vegetation and regional scales. Species richness and diversity were mainly driven by growing season precipitation (GSP), which accounted for over 87 % of the total variation observed. Species richness and diversity at grazingexcluded and freely grazed sites appear to respond to growing season precipitation in parallel. Species richness exponentially increased with GSP while diversity indices showed positively linear relationships with GSP. This indicates that GSP on the Northern Tibetan Plateau is crucial in regulating species richness and diversity and should be taken into account in future studies on alpine grassland conservation.

A number of empirical studies in Euro—American region consistently demonstrate that, parks and open space have a positive impact on property values. However, this effect has not been investigated in Beijing, China. And the public and city managers often ignore or underestimate the role of urban green spaces. This paper surveyed the relationship between the average house prices of 76 residential areas and 14 parks in Beijing, and measured the total benefits of 18 070 ha public green spaces on residential property value, by using the inventory data of urban green spaces (2009) and GIS techniques. Results showed that the residential property values located 850–1604 meters away from parks achieved a 0.5% to 14.1% increase in sales price. The overall benefit of Beijing's public green spaces on residential property was 2.86 billion CNY (1 USD=6.83 CNY), and the average benefit of per hectare public green space was 0.16 million CNY, corresponding to 1.8–3.9 times of the maintenance cost of green space in Beijing. Therefore, there is chance for local governments to increase property tax revenues due to the creation and maintenance of urban green spaces.

Land resources not only provide support for urban development, but play a feedback and restricting role in unregulated urban growth. Taking Beijing City as an example, this paper analyzes supply and demand relationships and upper limits for the growth of land resources during the process of urban development. By analyzing dominant factors and trends in the demand for land resources, this paper gives preliminary estimates on the minimum size of the land demand in Beijing in view of constructing a World City. According to the basic characteristics of supply and demand relationships for land, current land use in Beijing is confronting a grim situation of conflict between supply and demand. We also point out maximum growth and three types of constraints on land resources. Last, we propose solutions to resource and environmental bottlenecks, and urban disease amid urban development.

Henan is a large agricultural province and one of China's major grain-producing areas. Agricultural land transfer and large-scale operations will have a profound impact on regional economic development and food security. This is a case study taken in Xiwan village in Qinyang city, Henan. This paper builds a transferring pricing model using land use rights assessment and characteristic correction of land contract and management rights. Results show that the transferring price of land contract and management rights should include the economic price, social price and corrected price. The use of a price model should focus on the distinction of theory and practical application. If there is no change in agricultural project, the actual transferring price should be the sum of the economic price and social security price. If there is a change in agricultural projects, such as cropland into cash crops, the actual transferring price should be the sum of the economic price, social price and corrected price. Because of the complexity of income distribution following the transfer, transferring gains should follow a rational distribution in the outflow side, inflow side, managers and land owner. The government should establish reasonable and orderly contracted management of land circulation transferring and use this to build a land transferring price system.

The recent global food security crisis is garnering increasing attention and calls for innovative solutions to mitigate its negative impacts on people, especially the most economically vulnerable. In urban regions, this issue is aggravated by the fact that, on one hand, rapid urbanization and greater levels and diversity of food consumption associated with the growing affluence of urban inhabitants has led to rising urban food demand, while on the other hand, the rapid loss of farmland due to urban expansion or irrational sprawl and increasing extreme weather events for agricultural producers due to the impact of global climate change is sharply reducing the urban food production and local supply capacity. Therefore how to realize the urban food supply potential and optimize the utilization of the urban farmlands to enhance the local food supply rate and improve urban food security more generally is becoming a key issue. In this paper, we use the case of Beijing to examine the opportunities to enhance the supply of local, affordably priced food under existing land resource constraints, by restructuring farmland utilization. In this paper, we firstly calculate the changes in the food footprint needed by Beijing and its food self-sufficiency rate over the thirty year period from 1981 to 2011. We show that although Beijing's food footprint has grown from 11 800 to 29 400 km² over this 30—year period, its food self-sufficiency rate has dropped from 59.3%, 35.8%, 37.3% and 13.1% to about 39.0%, 27.0%, 6.7% and 2.2% for vegetable, fruit, grain and edible oil, respectively. Following this analysis, we calculate Beijing's potential food production under different agricultural production allocation scenarios. We conclude that with a proper shift of farmland use, full utilization of temporary idle land, and the development of rooftop farming, Beijing could increase its vegetable self—sufficiency rate to 60% without significantly reducing the production of other types of local food. Given the sensitivity of fresh vegetables to long-distance transport, and the potential to reduce transport—related carbon emissions, this is a worthwhile adjustment that will benefit the city both by meeting the growing need of its residents for fresh food, and by improving the overall regional eco—environment.

The relationships between invasive plant species and environmental and anthropogenic factors were analyzed in five nature reserves in northern China. The distribution of invasive plants was analyzed using a Canonical Correspondence Analysis. Stepwise backward multiple regression was then done to identify the most important environmental and anthropogenic factors determining the richness and distribution of alien plants in the reserves. Total invasive plant richness varied was 25 species, 12 species, 13 species, five species and five species across the nature reserves. Invasive species richness decreased in response to environmental factors such as maximum temperature and minimum precipitation and increased in line with human activities, the total area of farmland and volume of freight. Tropical plant species declined from 31% to zero while the species originally from North America gradually increased. In respect of family composition of invasive species, most species belonged to the composites, whose proportion increased from 15%–40% from north to south across the five nature reserves while species from other families varied greatly along this gradient. Life-forms of invasive plant species varied between the reserves, but annual and perennial herbs were generally dominant. Pathways of such species were highly related to human activities and utilizations.