This paper presents spatial and temporal dynamics of fraction of vegetation in Xinjiang Uygur Autonomous Region of China. Fractional vegetation cover (FVC) was estimated by using MODIS-NDVI data from 2005 to 2015. The study area was divided into 11 ecological and climate regions according to the altitude and land cover. Slope, variability and linear regression model were used to analyze the present situation and future tendency for FVC in Xinjiang and its sub-regions. The BP-ANN neural network analysis was used to predict FVC from 2016 to 2020, and the FVC trend over the entire study area during 2005-2020 was discussed. The results showed that: From 2005 to 2015, FVC increased in general over time, and spatially, decreased from northwest to southeast; In mountain areas, FVC increased in general; desert system showed no significant change, and multi-average FVC was about 0.10. The dynamic change of FVC was mainly caused by precipitation. We observed an improvement of vegetation cover over oasis and desert ecotone. FVC showed a significant increase over oasis. The year 2009 was the turning point with a historical low value. The variation near areas covered by ice and snow, river and lakes was remarkable, showing a change rate of 150%-316%. This change was probably responded by glacial depletion and fluctuation changes of lakes due to global climate change. The ecosystem in northern Xinjiang is obviously better than that in southern and eastern Xinjiang. In terms of oasis, the northern part is improved remarkably (P = 0.001). There was an obvious FVC fluctuation in Yili region compared to other regions. The mountain area showed an obvious degeneration tendency. The local minima point of FVC was observed in Yili in 2008, while it was in the other three regions in 2009. The lag of local minima occurring in the northern and southern parts of the study areas may have been caused by precipitation and temperature variation across the study area. Predicted average FVC from 2016-2020 demonstrated trends and patterns identical to 2005-2015 with some local differences. For example, FVC increases (P = 0.002) during 2005-2020 in general. In desert areas, the trend is from non-significant decrease during 2005-2015 to non-significant increase for 2005-2020. In oasis region, predicted FVC showed a slightly rising trend compared to the obviously rising trend in 2005-2015. The multi-average FVC is above 0.62 and it showed improvement during 2005-2020. For sub-regions and ecosystems, the trend differs significantly between 2005-2015 and 2005-2020. In northern part, the trend in 2005-2020 was almost the same with that of 2005-2015, while in 2016-2020 the tendency was opposite to 2005-2015, with oasis and mountain FVC showing a decreasing trend. In Yili, the general trend in 2005-2020 was almost the same with that of 2005-2015, but the amplitude of variation became smaller in 2016-2020 when compared to early stage and the mountain area showing a remarkably decreasing trend. Our results demonstrated that BP-ANN model can predict FVC in Xinjiang with statistical significance, the coefficient of determination (R²) of 0.95, root-mean-square error of 0.05, suggesting that this method gained a statisifactory result.

Accurate estimation of the carbon sequestration potential of afforestation helps us better understand the carbon cycle in China and provides the guide for national forest policies. Forest data from China Forestry Statistical Yearbook were used to estimate carbon stocks and explore the carbon sequestration potential in China's forests in the next 100 years. In this study, we estimate the forest biomass carbon storage and carbon sequestration potential of new afforestation in China over the next 100 years based on new afforestation area from China Forestry Statistical Yearbook during 2005-2013 and forest type map in 2010 derived from remote sensing information. In the consideration of annual forest survival rate, carbon pools of the new afforestation are estimated with the forest growth equations for different forest types. The potential changes in China's forest biomass carbon storage between 2005 and 2100 were estimated with reconstructed forest areas. The results show that the total new afforestation area of China are 4394×10⁴ hm² from 2005 to 2013. With the assumption of continuous natural forest growth, the volume of new afforestation during 2005-2013 will increase to 16.8 billion m³. The biomass and carbon pool will increase to 1.6 Pg and 0.76 Pg C by 2020, respectively. The new afforestation biomass carbon storage will increase by 2.11 Pg C during 2005-2100. The carbon storage of new afforestation over the next 100 years are about 25% of current biomass carbon stocks in forests and are about 1.5 times of total forest carbon sink of the past 20 years. Furthermore, the biomass carbon density of China's afforestation will reach 48.1 Mg C/hm² by 2100. In China, the new afforestation has played an important role in the increase of forest carbon storage and has a great potential for carbon sequestration. Therefore, forest management in China is of importance to mitigate increases in greenhouse gas emissions.

The global karst area is about 2.2×10⁷ km², wherein China reaches up to 3.44×10⁶ km², occupying more than one third of the global karst area. The previous studies have showed that carbon (C) sequestration rate by chemical weathering in Chinese karst zone range from 5 Tg C yr^-1 to 18 Tg C yr^-1, which are considered as one of important "residual land sink" in global change research. In order to accurately estimate the C sequestration rate in karst area, we put forward the concept of Earth Critical Zone (CZ) for karst ecological system. In this study, we comprehensively understand the C cycle in karst CZ, introduce the estimation of the methods on karst CZ, and then re-evaluate the C sequestration rate in the karst CZ. At last, we systematically discuss the uncertainty of the C sinks in karst CZ. The results show that the rock-weathering-related C sink rate in Chinese karst CZ is about 4.74 Tg C yr^-1. In addition, we elaborate the significance of C sequestration to ecological system service in karst CZ, strive to to strengthen the C monitor at rock-soil-water-biological-atmosphere continuum level in the future, and then use different methods to estimate and evaluate C cycle at multi-scale in karst CZ.

Based on the cross-section data of pollutant discharge and socio-economic development in 2012, by using the indicators of total discharge of COD and SO₂ and various sources, the spatial differentiation and agglomeration effects of pollutant discharge are measured quantitatively in 339 cities at prefecture level or above in China. Meanwhile, the socio-economic drivers of environmental pollution are estimated through the econometric model, and some suggestions are put forward to reduce and control pollutant discharge. The results show that: (1) The regional differences of the structure of pollutant source are of great significance in China. Specifically, the types of water pollutant sources are mainly included in the region dominated by agricultural source, the region dominated by urban domestic source, and in the region jointly dominated by agricultural and urban domestic source, with the proportions of these regions being 35.40%, 33.92% and 25.66%, respectively. Among them, the discharge intensity of water pollutant is the highest in the region dominated by agricultural source, which are mainly located in North and Northeast China. Meanwhile, the types of air pollutant sources in China are mostly involved in the region absolutely dominated by industrial source, which accounts for 74.63% and is distributed in the vast area of China in addition to the Qinghai-Tibet Plateau. (2) Single and bivariate LISA cluster maps of total discharge and various sources indicate that the agricultural source makes contribution to the spatial agglomeration of high intensity discharge of water pollutants, while the industrial source leads to the concentrated discharge of air pollutants. Especially, in the Bohai Rim region and its economic hinterland, the structure of pollutant sources strengthens the agglomeration effects of pollutant discharge intensity. (3) By means of OLS estimation for nationwide regression model, it is demonstrated that population size, urbanization rate and economic growth are the main driving factors of environmental pollution, and population size is the key factor in China. Moreover, in terms of regression models of regional types, the economic development level makes different contributions to pollutant discharge in various regions, which shows a positive effect on the air pollutant discharge in the region dominated by industrial source, while shows a negative effect on the water pollutant discharge in the region dominated by urban domestic source. In addition, the degree of industrialization has positive influence on the air pollutant discharge in the region absolutely dominated by industrial source.

Human activities during the early stage in Tibetan Plateau are crucial to improve the knowledge about how human beings react and respond to extreme environmental conditions, especially those in the area with elevation > 4000 m asl, which is considered as the key of the migration and diffusion of human from plain to hinterland. Ash layer dated as 11290±69 cal. a BP and stoneworks such as micro-blade and fine flake mainly occurring at ca.11.2 cal ka BP were found in the archaeological site XDW1, which can be considered as the first evidence to show the human activities above 4000 m asl in the Tibetan Plateau. This study indicates that human beings have migrated to hinterland in the early Holocene, and evaluated the spacial and temporary population diffusion patterns in northeastern Tibetan Plateau: (1) human beings dominated the marginal regions with 3000-4000 m asl in northeastern Tibetan Platean, such as Qinghai Lake Basin and Gonghe Basin during the Last Deglaciation. (2) They expanded to the regions above 4000 m asl during the Early Holocene. (3) People diffused toward hinterland with higher elevation during the Holocene Climatic Optimum. The three stages of human migration and diffusion in the Tibetan Plateau are closely related to the improving climate conditions from the Last Deglaciation until the Holocene Climatic Optimum.

Comprehensive assessment of the positive ecosystem services and disservices provided by urban landscape and evaluation of its contribution of different urban landscapes to total value of ecosystem services, are crucial to optimizing and regulating the urban landscape configuration and the eco-environment construction in rapid urbanization. Based on the knowledge of landscape ecology and ecosystem service and the Landsat images (OLI-TIRS) data, we valued the ecosystem services of urban landscape including its disservices and analyzed their spatial pattern of Xi'an urbanized area by building the models and employing software of ERDAS, ArcGIS10.1 in 2013. The results showed that: (1) The disservice value of urban landscape is remarkably higher than the positive ecological service value, and the net value is approximately -12.71×10⁸ yuan in Xi'an city. In the process of rapid urbanization, the positive service value of urban landscape dramatically decreased and the negative service took up a large proportion of total values resulting from the transformation from natural landscape to semi-artificial landscape and artificial landscape, 87.81% of the urbanized area provided for negative net value of ecosystem services, and only 12.19% of the area provided positive net services. The expansion of urban landscape dominated by large built-up area will inevitably lead to the decline in ecosystem service value. (2) The value of positive ecosystem services provided by urban landscape in Xi'an city varied from urban core area to urban fringe obviously, which is lower in central area than in fringe area; And the high value area close to the road and in the parks shows the mixed patterns with plaque and grid. The total value of negative ecosystem services in the inner area is higher than that in the urban fringe, and high value area is more concentrated in space. Natural landscape and semi-artificial landscape are the main providers of the positive ecosystem services in city. (3) The spatial distribution of the urban landscape fundamentally determines the spatial pattern of the comprehensive ecosystem services, and the mosaic of different urban landscape types reflects the spatial pattern of the positive and negative ecosystem services shaped by the patches and the chessboard structure. The nearer to the area of urban fringe, the higher the comprehensive ecosystem services value is. There are the high value areas where the forest, grassland and water were distributed or scattered in the park or along road side in the city.

Based on objective data collected from interviews in typical villages of the Three Gorges Reservoir area, this study presents three livelihood scenarios related to rural transformation development: agriculturally dominant livelihood, multiple-type livelihood and non-agriculturally dominant livelihood. Results indicated the following: (1) The current farmland pattern shows a trend of diversification as self-cultivation, cropland transfer and fallow in the sample region. Dynamic characteristics of cultivated land present a special feature that is more "transfer-into" than "transfer-out". Various scales of planting are represented among various households, according to the following decreasing order: half-labor household > non-labor household > adequate labor household. (2) The highest pollution loading produced by crop farming occurs in half-labor households while the lowest occurs in non-labor households. With the increase of labor, the pollution load per unit area tends to first increase and then decrease within families with enough labor. (3) As the type of livelihood transitions from agriculturally dominant to non-agriculturally dominant, the maximum reduction of total pollution loading produced by the agricultural industry can reach 72.01%. Compared to agriculturally dominant livelihoods, multiple-type livelihoods produce a pollution load reduction yield of 19.61%-29.85%, and non-agriculturally dominant livelihoods reduce the pollution load yield by 35.20%-72.01%. However, the rate of reduction of total nitrogen is not the same as total phosphorus. (4) The non-agricultural characteristics of labor allocation and income promote the transformation from dominant livelihood types to non-agricultural livelihoods, and potential revenue conversion follows a similar trend. In addition, different household types do not display identical conversion rates, according to the following decreasing order: enough labor household > half-labor household > non-labor household. (5) During rapid urbanization and the building of new industrial systems, the livelihood types of rural households have been further transformed to non-agricultural household types in the mountainous region; this process will lead to the further reduction of pollution load generated by planting and agriculture.

Population exposure to high temperature (extremely high temperature) is represented by the multiplication of the population in each grid cell and the projected mean annual number of hot days with daily maximum temperature above 35℃ (40℃) for each corresponding grid cell. Based on daily maximum temperature data from 21 global climate models under the RCP8.5 scenario and population projection data under the A2r socio-economic scenario, population exposures for four future periods (2021-2040, 2041-2060, 2060-2081 and 2081-2100) in China were projected at the grid cell level. The ensemble mean method was used to calculate the annual number of hot days. The relative importance of population and climate as drives of exposures was evaluated at the national level and the meteorological geographical division level. Compared with the population exposure for the 1981-2010 base period, population exposure to high temperature (≥ 35℃) over China for four future periods will increase by 1.3, 2.0, 3.6 and 5.9 times respectively and population exposure to extremely high temperature (≥ 40℃) will increase by 2.0, 8.3, 24.2 and 82.7 times respectively. Population exposure to high temperature will increase significantly in Jianghuai region, Southwest China and Jianghan region, especially in North China, Huanghuai region, South China, Jiangnan region. Population exposure to extremely high temperature will increase significantly in Southwest China and Jianghan region, especially in North China, Huanghuai region, Jiangnan region and Jianghuai region. Climate factors are the most important driver of exposures for Huanghuai region, Jianghuai region, Jianghan region, Jiangnan region, South China and Southwest China, followed by the interact effect of population and climate. At the national level, climate factor is also the most important driver, followed by the interact effect of population and climate. The contribution rate of climate to national-level projected change in exposure will decrease gradually from about 70% to about 60% and the contribution rate of concurrent changes in population and climate will increase gradually from about 20% to about 40% over the four future periods.

Taking the semi-arid area of Yulin City as an example, this study improves the vulnerability assessment methods and techniques on the county scale using VSD (Vulnerability Scoping Diagram) assessment framework, integrates the VSD framework and SERV (Spatially Explicit Resilience-Vulnerability) model, and decomposes the system vulnerability into three dimensions including exposure, sensitivity and adaptive capacity. Firstly, with the full understanding of the background and exposure risk source of the research area, the vulnerability indexes were screened out by the SERV model and the index system was constructed to assess the characteristics of the local eco-environment. Secondly, with the aid of RS and GIS, this study measured the spatial differentiation and evolution of social-ecological systems in Yulin City during the period 2000-2011 and explored intrinsic reasons for spatial-temporal evolution of vulnerability. The results are as follows: (1) The spatial pattern of Yulin City's SESs vulnerability is "high in northwest and southeast and low along the Great Wall", although the degree of system vulnerability reduced significantly during the period 2000-2011 and the system development trend is better, there is a sharp distinction in the spatial distribution between the system vulnerability and exposure risk; (2) The evolution of system vulnerability is influenced by the risk factors of exposure, and the regional vulnerability and the spatial heterogeneity of exposure risk are affected by the social sensitivity, economic adaptive capacity and other factors. Finally, according to the uncertainty of decision makers, the future scenarios of regional vulnerability are simulated under different decision risks by taking advantage of the OWA multi-criteria algorithm, and the vulnerability of regional system under different development directions was predicted based on the decision makers' rational risk interval.

The identifying of land multifunctionality is a basic tool for organization, coordination and configuration of urban land, and is a key criterion for urban land functions forms, composite pattern and dynamic tradeoffs. This topic is of important theoretical and practical significance. An available identification system of urban land multifunctionality, however, had not been built for a long time. This paper develops a function classification system for urban ecological-production-living spaces from an integrated perspective of land function, ecosystem services and landscape function. We integrated a value function group of space function based on ecosystem services valuation. A comparison method of vertical and cross direction is proposed to identify dominant function type of urban land. The empirical results show that in the study area, function classification system of urban ecological-production-living spaces can reflect differentiated function types of different land use classes. The identified result of dominant function for urban space is matched with the functions of different land types. Meanwhile, we also found that there are some problems on urban land use, such as the low adjacency degree with different spaces, and poor complementarity with different space functions. The result indicates that the spatial distribution of urban ecological-production-living spaces is congregated in the study area.

In this study, we selected Hunan province as the study area. The vegetation NPP and its changes from 2000 to 2013 were calculated using improved Carnegie-Ames-Stanford Approach (CASA) model with MODIS-NDVI data at a 250 m×250 m spatial resolution and meteorological data. Furthermore, we quantitatively analyzed the correlation between NPP and climate for various land-cover types so as to provide reliable information for local environment and sustainable development. The results indicate that: (1) The annual amount of NPP decreased from 41.62 Tg C/yr in 2000 to 125.40 Tg/yr in 2013, with an average being about 86.34 Tg C/yr. In general, the total amount of NPP has decreased obviously since 2000, with an annual rate of about 2.70 Tg C/yr. (2) The annual NPP from 2000 to 2013 had significant spatial differences throughout the study area, decreasing from the southwest to the northeast. There were obvious differences over various vegetation divisions. (3) According to the changes rate of NPP from 2000 to 2013, the study area could be divided into five regions, namely, extremely remarkable increase rate (slope > 0, p < 0.01), remarkable increase rate (slope > 0, 0.01 ≤ p < 0.05), unnoticeable rate (p ≥ 0.05), extremely remarkable decrease rate (slope < 0, p < 0.01) and remarkable decrease rate (slope < 0, 0.01 ≤ p < 0.05), which accounted for 5.40%, 2.02%, 61.64%, 16.79% and 14.15%, respectively. In general, NPP decreased from 2000 to 2013 over different land-cover types, among which, the most significant change took place in grassland and forestland, followed by other types of land, construction land and farmland. (4) The spatial distribution of NPP had higher correlation with precipitation than with temperature.

In this paper, field sampling data, remote sensing data, and ground meteorological observation data were used to estimate the net primary productivity (NPP) in the grassland ecosystem in Inner Mongolia from 2001 to 2012 based on a light use efficiency model. The spatiotemporal distribution of the NEP in the Inner Mongolia grassland ecosystem was then analyzed by estimation of the NPP and soil respiration from 2001 to 2012. This paper also investigated the response of the NPP and NEP to main climatic variables on the spatial and temporal scales from 2001 to 2012. Results showed that most of the grassland area in Inner Mongolia has functioned as a carbon sink since 2001 and that the annual carbon sequestration rate amounts to 0.046 Pg C·yr^-1. The total net carbon sink of the Inner Mongolia grassland ecosystem over the 12-year period reached 0.557 Pg C. The carbon sink area accounted for 60.28% of the total grassland area and sequestered 0.692 Pg C, whereas the C source area accounted for 39.72% of the total grassland area and released 0.135 Pg C. The NPP and NEP of the Inner Mongolia grassland ecosystem have more significant correlations with precipitation than with temperature, and the Inner Mongolia grassland ecosystem has great potential for carbon sequestration.

In this paper, we developed a series of assessment indexes based on the evaluation of ecological effects, which consists of the ecosystem structure, qualities, services, and main impacting factors for these changes. Comprehensive monitoring and assessment methods that focused on the planning objectives of ecological conservation and restoration project were developed based on field observation, remote sensing monitoring and quantitative simulation of ecological processes. Then we assessed the ecological effects of the first-stage of ecological conservation and restoration project in Sanjiangyuan region by adopting the trend analysis of dynamics in ecosystem structure and services. The results showed that since the beginning of the project eight years ago, the macro-situation of ecosystem in this region has been getting better but not reached the best situation in the 1970s. The continued degradation trends of grassland have been initially contained, but it is difficult to achieve the expected objective of "the vegetation coverage of grassland increasing by an average of 20%-40%". The wetland and water-body ecosystems have been restored. The water conservation service of ecosystem and water supply capacity of watershed were increased, and the volume of?ecosystem water conservation reached the objective of increasing by 1.32 billion m³. The ecological restoration in the project regions tended to be better than that outside the project regions. In addition to climate change, implementation of the ecological conservation and restoration project had obvious and positive effects on vegetation restoration. However, the degradation situations of grassland were not fundamentally reversed, and the implementation of the project has not been curbing the increasing trend of soil erosion. Therefore, the local and preliminary characteristics of the first-stage of the project highlighted the long-term and arduous ecosystem conservation and protection in the Sanjiangyuan region.

In this study, we extracted nine river profiles from a 5-m DEM of the Mt. Lushan region. Knickpoints of two types, namely the vertical-step knickpoint and the slope-break knickpoint, are recognized, and are compared with the geological settings to determine their origins. At the same time, we calculated the channel steepness index (k_sn) and concavity (θ) of separated parts of these rivers, using the stream-power incision model. The results show that these rivers are almost in a transient state represented by the occurrence of knickpoints. The vertical-step knickpoints are related to inhomogeneous substrates and the slope-break knickpoints are ascribed to the lowering of the base level due to rapid mountain uplift. The parts of the rivers below the slope-break knickpoint have a relatively large k_sn, which probably indicates a shift from low rate at early uplift to a later high rate. The steepness index in the south of the mountain is larger than that in the north, which might be induced by different uplift rates or substrates.

The capacity of soil and water conservation measures, defined as the maximum quantity of suitable soil and water conservation measures contained in a region, were determined for the Loess Plateau based on zones suitable for establishing terraced fields, forestland and grassland with the support of geographic information system (GIS) software. The minimum possible soil erosion modulus and actual soil erosion modulus in 2010 were calculated using the revised universal soil loss equation (RUSLE), and the rate of the minimum possible soil erosion modulus under the soil and water conservation measures to the actual soil erosion modulus was defined as the soil erosion control degree. The control potential of soil erosion and water loss in the Loess Plateau was studied using this concept. Results showed that the actual soil erosion modulus were 3355 t·km^-2·a^-1, the minimum possible soil erosion modulus was 1921 t·km^-2·a^-1, and the soil erosion control degree was 0.57 (medium level) on the Loess Plateau in 2010. In terms of zones, the control degree was relatively high in the valley plain zones, soil and rock mountainous zones, and windy sand zones, but relatively low in the soil and rock hilly forest zones, hilly gully zones and plateau gully zones. In terms of river basins, the soil erosion control degree was relatively high in the Dahei River, Huangfu River, Qingshui River, Kuye River and Pianguan River basins, but relatively low in the Qingjian River, Wuding River, Jialu River, and Yanhe River basins. The rate of erosion zones with a soil erosion modulus of less than 1000 t·km^-2·a^-1 increased from 50.48% to 57.71%, forest and grass coverage rose from 56.74% to 69.15%, ratio of terraced fields increased from 4.36% to 19.03%, and per capita grain yield rose from 418 kg·a^-1 to 459 kg·a^-1 under the soil and water conservation measures compared with actual conditions.

The vegetation dynamic change can be analyzed by applying the discrete wavelet multi-resolution analysis (MRA) to decompose the normalized difference vegetation index (NDVI) time series into subseries at different time scales. In this thesis, the NDVI time series over Dongting Lake Basin was decomposed under different time scales by the wavelet transform. Then the latent seasonal and inter-annual variability of vegetation was mined and assessed. Finally, the possible causes of the changes were analyzed in combination with the land cover change analysis result and the rainfall data. The results show that by using the wavelet multi-resolution analysis, the information related to vegetation dynamics in Dongting Lake Basin can be extracted, which includes the mean of the inter-annual component of NDVI, the minimum level of NDVI, the amplitude of the annual phonological cycle, the timing of the maximum NDVI, the trend in the data series and the magnitude of the land cover change. The information effectively depicts the basin's vegetation dynamics characteristics. Furthermore, with the combination of land cover change analysis result and precipitation data, an obvious correlation was found between the change of vegetation cover and the precipitation change in the basin, that is, the vegetation dynamic changes response to precipitation is the most obvious in the western and northwestern parts of the basin. Although there is no obvious decrease in precipitation in some areas, the vegetation cover has a decreasing trend, which may be related to other factors, such as higher terrain and urbanization.

Human activity intensity is a synthesis index for describing the effect and influence of land surface. This paper presents the concepts of human activity intensity and construction land equivalent, builds an algorithm model for human activity intensity, and establishes a method for converting different land use/land cover types into construction land equivalent as well. An application in China based on the land use data from 1984 to 2008 is also included. The results are shown as follows: (1) Human activity intensity is defined as the degree of land use, transformation and exploitation by human beings. It is an effective way to determine the construction land equivalent coefficient of different land use/land cover types by taking construction land equivalent as a basic unit and identifying the alteration of land surface natural properties caused by human activities. The application in China and correlation analysis with population density indicated that it is feasible to take the ratio of the construction land equivalent area to the total area as an indicator of human activity intensity. (2) We adopted a two-level method of eight attribute labels to construct general standard of converting different land use types into construction land equivalent, and establish a method for calculating the coefficient of construction land equivalent. We also built a coefficient table for constructing land equivalent of 49 land use types based on the latest land use classification system. (3) The human activity intensity in China increased from 7.63% in 1984 to 8.54% in 2008. It could be generally divided into five levels: very high, high, medium, low and very low, according to the human activity intensity at county level in 2008, which is rated by over 27%, 16%-27%, 10%-16%, 6%-10% and below 6%. The human activity intensity in China was spatially split into eastern and western parts by the line of Helan Mountain-Longmen Mountain-Jinghong; the eastern part was characterized by the levels of very high, high and medium, while the western part was featured by the low and very low levels.

As the city social-ecological system was regarded as the risk assessment target, a 3D framework of ecological adaptive cycle was built, which extended the landscape ecological risk assessment indicators to the potential-connectedness-resilience 3D criteria from the former landscape index level. Emphasis was placed on the principle of static spatial pattern with interactive dynamic trend from a geographical spatial analysis view. It was believed that the 3D framework could describe the pattern-process interaction with specific landscape elements much more clearly. Taking Shenzhen city as a study area, this study adopted the 3D framework of ecological adaptive cycle in building a landscape ecological risk assessment index system with the help of GIS spatial analysis method. Different scenarios were established based on the ordered weighted averaging (OWA) algorithm in the risk assessment. The results show that among the three scenarios, the concrete value of landscape ecological risk showed a similar distribution trend that the Dapeng Peninsula had the lowest landscape ecological risk in Shenzhen city; Yangtai Mountain and Bijiashan Park showed relatively low risks in the city area, even though the risks in each scenario were specifically different. This indicated that the choice of the specific threshold in "development" or "protection" largely depended on the city development strategy created by decision makers under current cognition. The emphasis of scenario tradeoff was extracting the risk and uncertainty interval rather than an optimal value. The development or protection methods through each of the specific planning objectives would be the ultimate goal of the ecological risk assessment at a regional scale. The evaluation in this study improved the landscape ecological risk assessment indices and methods based on the adaptive cycle concept, which reflected the spatiotemporal dynamics and exposure disturbed by human interference. Furthermore, the preference transform in OWA method reduced the uncertainty caused by the subjective risk assessment, which could improve the theoretical basis as well as maneuverability in urban planning. This study not only extended the landscape ecological risk assessment to spatial-temporal integration perspective, but also made a significant improvement in ecological risk assessment of landscape indicator system. Therefore, the results of this study could offer a powerful quantitative support for landscape development and protective measures effectively, such as city construction and demarcation of ecological control line.

This paper presented a new conceptual framework by taking account of heat stress, social vulnerability, and population exposure. Meanwhile, an index system combining environmental data, demographics data and socioeconomic data has been built for the quantitative assessment of county-level heat stress risk pattern of China. The counties with the greatest vulnerability scores contain the Tarim Basin in Northwest China, Yudong Plain and Huaibei Plain in North China, Sichuan Basin in Southwest China, Jianghan Plain and Dongting Lake Basin in Central China, and Pearl River Basin in South China. The hot spots of heat stress risk are located in Jianghan Plain and Dongting Lake Basin in Central China, Sichuan Basin in Southwest China, the junction of Jiangsu, Zhejiang and Shanghai in East China, and Pearl River Basin in South China, especially the Pearl River Delta Region. The hot spots of vulnerability are located in counties of high heat stress or high social vulnerability level, while the hot spots of risk mainly consist of metropolitan areas with dense population and advanced economic level. The results of dominant factor partition show that heat stress dominant areas are mainly located in basins or plains which are more prone to high temperature, social vulnerability dominant areas are mainly located in less developed counties, and population exposure dominant areas are mainly located in coastal counties with dense population.

A total of 21 typical coupled large samples were chosen from areas in the nature reserves and their surroundings on the Tibetan Plateau (TP) with large-sample-comparison method (LSCM). To evaluate the protection effectiveness of the nature reserves, we compared the alpine grassland net primary production (NPP) of these coupled samples and analyzed the differences between them before and after their establishment as protected areas. The results show that: (1) In view of alpine grassland NPP, the ecological and environmental conditions of most nature reserves were more fragile than those of their surrounding areas and also lower than the average values for the TP. (2) Of the 11 typical nature reserves selected, the positive trend of NPP in Manzetang is the most significant, while in Taxkorgan, the trend is not obvious. Moreover, with the exception of Selincuo, the annual NPP growth rate in nature reserves covered by meadow and herbaceous wetland is higher than that in nature reserves consisting of steppe and desert grassland. (3) Some notable findings existed in 21 typical coupled samples: (a) After the establishment of nature reserves, the annual NPP increase rate in 76% of samples inside nature reserves and 82% of samples inside national nature reserves are apparently higher than that of corresponding samples outside nature reserves. (b) The ecological protection effectiveness in Central Kunlun, Changshagongma, Zoige Wetland, and Siling Co nature reserves is significant; in most parts of the Three Rivers' Source and Qiangtang nature reserves, the protection effectiveness is relatively significant, while in south-east Manzetang and north Taxkorgan, the protection effectiveness is not obvious. (c) The ecological protection effectiveness is significant in nature reserves consisting of meadow; however, it is weak in nature reserves covered by steppe.