Search

The karst landform is a typical ecologically vulnerable region, and the problem of karst rocky desertification in southtern and western China has led to impoverishment and a degraded local ecological environment, which severely limits local socioeconomic development. An effective and appropriate control of karst rocky desertification in southtern and western China requires knowledge about its characteristics of variation and driving mechanisms. In this study, we chose eight regions in the southtern and western China as research areas and analysed the characteristics of the changes in karst ecosystem patterns and rocky desertification from 2000 to 2015. Based on these characteristics, we present the mechanisms that drive karst rocky desertification in the southtern and western China by utilizing the redundancy analysis (RDA) ordination method. The results show that the total area of rocky desertification in southtern and western China had been continuously decreasing from 2000 to 2015, revealing a positive development trend in rocky desertification. Rocky desertification variations were mainly affected by human activities. The reduction in farmland area improved farmland management and increased regional gross industrial product, which together with continuously rising gross domestic product of the tertiary industry caused a positive rocky desertification development. However, the local karst tourism has a certain effect on inducing slight rocky desertification.

Since the industrial revolution, human activities have both expanded and intensified across the globe resulting in accelerated land use change. Land use change driven by China’s development has put pressure on the limited arable land resources, which has affected grain production. Competing land use interests are a potential threat to food security in China. Therefore, studying arable land use changes is critical for ensuring future food security and maintaining the sustainable development of arable land. Based on data from several major sources, we analyzed the spatio-temporal differences of arable land among different agricultural regions in China from 2000 to 2010 and identified the drivers of arable land expansion and loss. The results revealed that arable land decreased by 5.92 million ha or 3.31%. Arable land increased in the north and decreased in the south of China. Urbanization and ecological restoration programs were the main drivers of arable land loss, while the reclamation of other land cover types (e.g., forest, grassland, and wetland) was the primary source of the increased arable land. The majority of arable land expansion occurred in the Northwest, but the centroid for grain production moved to northeast, which indicated that new arable land was of poor quality and did not significantly contribute to the grain production capacity. When combined with the current ‘Red Line of Arable Land Policy’ (RAL) and ‘Ecological Redline Policy’ (EPR), this study can provide effective information for arable land policymaking and help guide the sustainable development of arable land.

Overwhelming water-deficiency conditions and an unbalanced water supply and demand have been major concerns of both the Chinese government and the general public during recent decades. Studying the spatial-temporal patterns and impact factors that influence water retention in China is important to enhance the management of water resources in China and other similar countries. We employed a revised Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and regression analyses to investigate the water retention service in China. The results showed that the southeastern China generally performed much better than Northwest China in terms of the spatial distribution of water retention. In general, the efficacy of the water retention service in China increased from 2000 to 2014; although some areas still had a downward trend. Water retention service increased significantly (P < 0.05) in aggregate in the Qinghai-Tibet Plateau, and the Da Hinggan Mountains and Xiao Hinggan Mountains. However, the service in southwestern China showed a decreasing trend (P < 0.05), which would have significant negative impact on the downstream population. This study also showed that in China the changes in water retention service were primarily due to climate change (which could explain 83.49% of the total variance), with anthropogenic impact as a secondary influence (likewise the ecological programs and socioeconomic development could explain 9.47% and 1.06%, respectively). Moreover, the identification of water retention importance indicated that important areas conservation and selection based on downstream beneficiaries is vital for optimization protection of ecosystem services, and has practical significance for natural resources and ecosystem management.

Urban plants provide various ecosystem services and biodiversity for human well-being. It is necessary to examine the plant species and functional traits composition and the influencing factors. In this study, a field survey was conducted using the tessellation-randomized plot method to assess the plant species and functional traits variability in greenspaces across eight land use types (LUTs) in the built-up areas of Beijing, China. Results showed that the woody plants in the built-up areas of Beijing comprised 85 non-native species (57%), 21 pollen-allergenic species (14%), and 99 resistant species (67%). Residential areas, community parks and institutional areas had higher woody plant species richness than other LUTs. Native and extralimital native species were more widespread than exotic species. Proportions of species with resistances were low except for cold- and drought-resistance; consequently, a high intensity of management and maintenance is essential for survival of plants in this urban area. Caution should be exerted in selecting plant species with resistance to harsh conditions in different LUTs. Housing prices, distances from the urban center, years since the establishment of LUTs and greening rate were strongly correlated with the plant functional traits and species diversity. Urban forest managers should consider plant functional traits and LUT-specific strategies to maximize both forest and human health.

Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negative impacts. In this study, we propose an assessment concept framework model for indirect-direct-ecosystem service (IN-DI-ESS) driving forces within this context and method for index construction that considers the selection of a robust and parsimonious variable set. Factor analysis was integrated into two-stage data envelopment analysis (TS-DEA) to determine the driving forces and their effects on water conservation services in forest ecosystems at the provincial scale in China. The results showed the following. 1) Ten indicators with factor scores more than 0.8 were selected as the minimum data set. Four indicators comprising population density, per capita gross domestic product, irrigation efficiency, and per capita food consumption were the indirect driving factors, and six indicators comprising precipitation, farmland into forestry or pasture, forest cover, habitat area, water footprint, and wood extraction were the direct driving forces. 2) Spearman’s rank correlation test was performed to compare the overall effectiveness in two periods: stage 1 and stage 2. The calculated coefficients were 0.245, 0.136, and 0.579, respectively, whereas the tabulated value was 0.562. This indicates that the driving forces obviously differed in terms of their contribution to the overall effectiveness and they caused changes in water conservation services in different stages. In terms of the variations in different driving force effects in the years 2000 and 2010, the overall, stage 1, and stage 2 variances were 0.020, 0.065, and 0.079 in 2000, respectively, and 0.018, 0.063, and 0.071 in 2010. This also indicates that heterogeneous driving force effects were obvious in the process during the same period. Identifying the driving forces that affect service changes and evaluating their efficiency have significant policy implications for the management of forest ecosystem services. Advanced effectiveness measures for weak regions could be improved in an appropriate manner. In this study, we showed that factor analysis coupled with TS-DEA based on the IN-DI-ESS framework can increase the parsimony of driving force indicators, as well as interpreting the interactions among indirect and direct driving forces with forest ecosystem water conservation services, and reducing the uncertainty related to the internal consistency during data selection.

The establishment of nature reserves is a key approach for biodiversity conservation worldwide. However, there is a lack of unified methodology to evaluate the effectiveness of nature reserves, particularly in China, the world′s most populous nation supporting some of the most valuable biodiversity hotspots in the world. In this study, we conducted a long-term and large-scale analysis of the effectiveness of 20 of the earliest nature reserves established in Hainan Province, an island home to among the highest concentration of plants and animals in China. Remote sensing imagery from 1988, 1998, and 2008 were analyzed to investigate the temporal and spatial changes of natural forests in these nature reserves and surrounding areas. We also conducted transition matrix analysis and principle component analysis to identify the driving factors that affect the protection effectiveness of nature reserves. The results were as follows: 1) During the 20-year period from 1988 to 2008, natural forests coverage of the 20 studied nature reserves dropped 2.34 percentage points, whereas the natural forests coverage dropped 11.31 percentage points in a 0–5 km outside reserve buffer and 9.36 percentage points in a 5–10 km outside reserve buffer, indicating a significant inhibitory effect of the nature reserves on the loss of natural forests. 2) Natural forests coverage dropped in 60% of the studied nature reserves during the 20-year period, suggesting a poor protection effectiveness of these reserves, while the coverage proportion showed some increase (0%/yr–5%/yr) in other reserves. 3) Expansion of rubber and pulp forests as part of a booming economy were the main factors affecting the effectiveness of the nature reserves for conserving natural forests in Hainan Province. The results of this study provide an important empirical basis for the protection of natural forests in Hainan Province, which can be used as a blueprint for nature reserve evaluation in other places in China.

River water plays a key role in human health, and in social and economic development, and is often affected by both natural factors and human activities. An in-depth understanding of the role of these factors can help in developing an effective catchment management strategy to protect precious water resources. This study analyzed river water quality, patterns of terrestrial and riparian ecosystems, intensity of agricultural activities, industrial structure, and spatial distribution of pollutant emissions in the Haihe River Basin in China for the year of 2010, identifying the variables that have the greatest impact on river water quality. The area percentage of farmland in study area, the percentage of natural vegetation cover in the 1000-m riparian zone, rural population density, industrial Gross Domestic Product (GDP)/km2, and industrial amino nitrogen emissions were all significantly correlated with river water quality (P < 0.05). Farming had the largest impact on river water quality, explaining 43.0% of the water quality variance, followed by the coverage of natural vegetation in the 1000-m riparian zone, which explained 36.2% of the water quality variance. Industrial amino nitrogen emissions intensity and rural population density explained 31.6% and 31.4% of the water quality variance, respectively, while industrial GDP/km2 explained 26.6%. Together, these five indicators explained 67.3% of the total variance in water quality. Consequently, water environmental management of the Haihe River Basin should focus on adjusting agricultural activities, conserving riparian vegetation, and reducing industrial pollutant emissions by optimizing industrial structure. The results demonstrate how human activities drive the spatial pattern changes of river water quality, and they can provide reference for developing land use guidelines and for prioritizing management practices to maintain stream water quality in a large river basin.

Human activities significantly alter ecosystems and their services; however, quantifying the impact of human activities on ecosystems has been a great challenge in ecosystem management. We used the Universal Soil Loss Equation and county-level socioeconomic data to assess the changes in the ecosystem service of soil conservation between 2000 and 2010, and to analyze its spatial characteristics and driving factors in the southwestern China. The results showed that cropland in the southwestern China decreased by 3.74%, while urban land, forest, and grassland areas increased by 46.78%, 0.86%, and 1.12%, respectively. The soil conservation increased by 1.88 × 1011 kg, with deterioration only in some local areas. The improved and the degraded areas accounted for 6.41% and 2.44% of the total land area, respectively. Implementation of the Sloping Land Conversion Program and urbanization explained 57.80% and 23.90% of the variation in the soil conservation change, respectively, and were found to be the main factors enhancing soil conservation. The 2008 Wenchuan earthquake was one of the factors that led to the degradation of soil conservation. Furthermore, industrial adjustment, by increasing shares of Industry and Service and reducing those of Agriculture, has also promoted soil conservation. Our results quantitatively showed and emphasized the contributions to soil conservation improvement made by implementing ecological restoration programs and promoting urbanization. Consequently, these results provide basic information to improve our understanding of the effects of ecological restoration programs, and help guide future sustainable urban development and regional industrial restructuring.

Ecosystem services valuation seeks to increase the social relevance of ecosystem characteristics, the underlying biological mechanisms that support services, by making the contribution of ecosystems to human well-being explicit. Economic valuation can help management by clarifying the full range of benefits and costs of proposed management actions. In the past two decades, economic valuation of wetland ecosystem services has become one of the most significant scientific priorities for wetland protection. In this paper, we provide an overview of ecosystem services, and summarize the main interdisciplinary approaches to measure and value wetland ecosystem services. We identified four main methodological gaps preventing progress on wetland valuation of ecosystem services in China, which are: 1) confusion on terminology like intermediate and final ecosystem services, 2) lack of ecological production functions to link ecosystem characteristics to final ecosystem services, 3) static valuation making it difficult to evaluate the trade-offs and synergies among ecosystem services, and 4) lack of clear guidance on relating ecological compensation programs to conservation targets. Overcoming these gaps is important to inform wetland compensation mechanisms and conservation policies. We propose future research on wetland ecosystem services in China should be focused on: 1) defining final ecosystem services based on beneficiary preferences and underlying biophysical mechanisms, 2) establishing wetland monitoring programs at specific sites to collect data on final ecosystem service indicators and ecosystem characteristic metrics to create ecological production functions for economic valuation and rescaling techniques, and 3) incorporating wetland ecosystem service values into decision-making processes to inform wetland management.

Payments for Ecosystem Services(PES) are thought to be an effective method to solve eco-environmental problems,and it′s widely adopted to promote ecological conservation all around the world.During the application of PES,Establishing the standard of compensation is crucial,because unreasonable standard may not compensate for the losses of stakeholders,which may dampen participants′ enthusiasm and influence the effects of PES. Sanjiangyuan Natural Reserve,which is one of the most important natural reserves of China,plays key role to the ecological security of lower watershed in China and Southeast Asia.Before setting up this reserve,there are large numbers of herdsmen living in this area,and conservation projects in reserve,including "Return Husbandry to Grassland","Return Grain for Green","Ecological Migration" and so on,lead to a series of losses of local residents.So giving these migrations compensation through PES is important to the development of reserve and local social harmony. During this research,we take two migration villages of Sanjiangyuan natural reserve(GuoLuo village and HeYuan village) as example to calculate the standard of compensation.Basing on the practical situation of research area,and considering the common problems of Chinese PES projects,we adopt 3 types of approaches("opportunity cost of livestock","opportunity cost of pasture" and "difference of regional development").Because the preferences of these approaches are different,the established standards of compensation have slight difference. The result of "opportunity cost of livestock" is 13.9 thousand Yuan per household per year.Livestock is the main source of herdsmen′s revenue,and the ecological migration project let them lose this part."Opportunity cost of livestock" takes livestock as proxy when calculating compensation standard,and can compensate for their direct economic losses.So this approach is strongly correlated to the benefits of herdsmen and can maximize the compensation. The result of "opportunity cost of pasture" is 10.3 thousand Yuan per household per year.Herdsmen can rent out their pasture to others to get rent,and the ecological migration project also let them lose this part of income."Opportunity cost of pasture" takes pasture as proxy,and compensate for the losses of rent.This approach considers pasture as commodity and reflects the relationship between supply and demand,and this approach can also simplify the calculating process.But this approach doesn′t consider natural heterogeneity,and all the pastures are calculated equally. The result of "difference of regional development" is 11 thousand Yuan per household per year.There is great regional economic development difference in our research area,and this actuality should not be ignored during the PES project,especially for ecological migration."Difference of regional development" can consider this difference,but the standard is still too low,comparing to the other two approaches.And neither herdsmen′ losses nor ecosystem services are related to this approach. Our results suggests that PES may provide limited benefits for the poverty reduction,but this research can still provide scientific foundation of establishing the compensation standard for Sanjiangyuan natural reserve,and case studying in other area can also borrow idea from our research.

Natural landscape provides us lots of benefits,such as sightseeing,adventuring,relaxing and learning.However,primarily due to unprecedented human activities(e.g.,aggressive land development and discharge of pollutants) and the lack of recognition of the value of nature,there have been extensive losses of precious natural resources and destruction of ecosystems.To partly address these problems,one solution is to conduct economic valuation of the natural landscape and integrate the economic value into the decision making process.To evaluate the economic value of the natural landscape,this study used travel cost method to evaluate use value and contingent valuation method to evaluate non use value.Use value consists of consumer cost and consumer surplus while the non use value is reflected by people′s willingness to pay for a landscape.Wulingyuan Scenic Area is in Zhangjiajie City of Hunan Province,it is famous in the world for the beautiful and unique natural scenery.We conducted the survey in October,2011,interviewing visitors from 28 provinces in China.Our results show that the consumer cost and consumer surplus are 6.755 billion Yuan and 1.175 billion Yuan,respectively,and thus the use value of Wulingyuan is 7.930 billion Yuan.With respect to the nonuse value,the median payment is 46.06 Yuan per year,and the pay rate is 65.73%,and thus the total nonuse value is 971 million Yuan.The nonuse value is made up of existence value,option value and bequest value,which are 496 million Yuan,174 million Yuan and 301 million Yuan,respectively.In sum,the total economic value of the natural landscape of Wulingyuan is 8.90 billion Yuan in 2011.The economic value of the landscape in 2011 is much more than the previously estimated value or the average tourism revenue in recent years,which indicates a remarkable achievement of environmental protection and resources conservation in this area.In addition,the administrative bureau of the scenic area should understand that economic value is only a part of,though often regarded as the most important part of,the intrinsic value of the Wulingyuan scenery.

Ecological compensation institution plays a key role in promoting ecological protection and coordinating regional development.However,how to establishing effective and operational ecological compensation framework is still a great challenge.We summarized the ecological compensation practices in China and analyzed their problem,including lack of systematic institution design,deficient participation of stakeholders,lacking for scientific identification of ecological compensation scope,lower ecological compensation standards and absent supervision mechanism.Finally,the following strategies for ecological compensation institution establishment were put forward: fundamental principle for establishing ecological compensation institution,scientific definition of compensatory scope,identification of the compensatory carrier and object,building scientific method for compensatory standard accounting,and corresponding policy measures.

Soil conservation service,as one of the most important regulating services provided by ecosystems,guarantees the ecological security and sustainable development of a region.We quantified the soil conservation service of ecosystems in Hainan Island using the InVEST(Integrated Valuation of Ecosystem Services and Tradeoffs) tool,so as to have a knowledge of its spatial characteristics and impact factors,which could be used for its preservation and ecosystem management then.Our results showed that,the amount of soil preserved by ecosystems of Hainan Island was approximately 8.16×108 t,and the average capacity per unit area was 247.28 t · hm-2 · a-1 for the entire region.With regard to the spatial pattern,the central part displayed a much higher capacity than surrounding areas in general,which could be confirmed from the comparison of soil conservation capacity between inside and outside of Mountainous Area of Central Hainan National Ecological Function Conservation Area(NEFCA).Consequently,this NEFCA could be considered to be making a great contribution in preserving soil conservation service in Hainan Island.We also found that,the soil conservation capacity differed widely across various ecosystems,with a descending order from shrubs,natural forests,to grasslands,rubber plantations,pulp forests,tropical plantations,paddy lands,dry lands,mangroves,and shelterbelts.Natural ecosystems were generally found to perform better than artificial ones in terms of conserving soil resource.Besides natural factors,economic development,population explosion and farmland expansion are important factors influencing soil conservation service.Indicators such as gross regional product per area,GDP of primary industry per area,population density and area ratio of farmland,showed a negative relationship with soil conservation capacity(P0.05),while area ratio of rubber plantation showed a positive relationship with soil erosion rate(P0.01).In conclusion:(1) the central mountainous area was so important for erosion control and ecological security maintenance in Hainan Island,that it should be protected carefully;(2) natural forests performed much better than rubber plantations and dry lands in soil conservation,although their economic benefits went the opposite way.Ignorance of ecological benefits ought to be prohibited and preservation of natural forests should be strictly and continuously implemented;(3) traditional agriculture should be transformed to intensive one,so as to increase both productivity and ecological benefits of farmlands;(4) the economic development and population explosion in Hainan Island might impair soil conservation service of ecosystems,as a result,tradeoffs should be made to realize sustainable development.

In order to understand the urban road sediment pollutants concentration levels and possible ecological environmental hazards,urban road sediment samples were monitored and analyzed from four different functional areas including the living areas,the educational areas,the traffic routes and the green parks in the city of Beijing.Total nitrogen(TN),total phosphorus(TP),heavy metals and organic matter(TOC) in the road sediments were tested in order to get the pollutant characteristics.The research results show that high levels of TN,TP,and TOC are found in all types of road sediments.TN concentration in the road sediments in the living areas,the educational areas,the traffic routes and the green parks are 0.1009、0.1440、0.1071、0.0974mg/kg,respectively,which is significantly the most highest in the educational areas.TP concentration in the four areas are 0.0695、0.0729、0.0665、0.0608mg/kg,respectively,which is the most highest in the educational areas but not reach a significant level.Concentrations of TOC in sediments in the traffic routes and educational areas are found significantly higher than that in the living areas and the green parks.And heavy in the traffic routes,educational areas and the living areas are found much higher than that in the green parks.Human activities and traffic vehicles may be the main dominent factors.Dissolved nitrogen is the main form of nitrogen in the four fonction areas,but phosphorus is mainly in particles,and this is most significant in sediments in the traffic routes.Dissolved heavy metal content is low overall,and only dissolved Cu accounts above 5 percent in the total ammount.This indicates heavy metals are mainly in particles.Road sediments or outside solid substances are the important source of surface runoff pollutants.The findings of the paper provide important reference for the urban surface pollution control.

Home range is an important concept in animal behavior and conservation biology research,playing a key role in the study of ecological processes such as habitat selection,animal social interactions,and population density.This paper summarizes the historical development and latest advances in home range modeling.We discuss a variety of issues that should be addressed when estimating home range including sampling design considerations,sample size requirements,effects of autocorrelation,and evaluation of estimators.We assess the advantages and disadvantages of 3 main home range estimation approaches and subsequently summarize the research progress and future directions of home range modeling.In addition,we provide some suggestions for future research.This paper serves as a key reference for the latest theoretical advances and applications of home range modeling.

In order to provide the references for appropriate construction and protection of urban green system and reliable prevention and control of tropic pollinosis,the seasonal dynamics of species and quantity of airborne pollens were investigated in Beijing urban area.With a Burkard volumetric trap,airborne pollens were sampled from December 31st 2010 to December 31st 2011.Through the whole year of 2011 the total quantity of pollens amounted to 136 858 grains,and the pollen dispersion period lasted 213 days from March 20 th to October 18 th,accounting for 58% of the year.Two peaks of pollen concentration in air were observed,which happened from March to April and from August to September.In the spring peak,the major airborne pollens were tree pollens such as Oleaceae,Populus and Salix pollens,accounting for as much as 30% of the total annual pollen amount.While in the autumnal period,weed pollens such as Artemisia,Chenopodiaceae and Amaranthaceae pollens made up the second peak of pollen air concentration,and the amount of pollens accounted for 50% of the annual total value.In summer,the blooming flowers were generally entomophilous while in winter the plants and the flowers seared,resulting in low values of airborne pollen concentration in these periods.The results also indicated that the airborne pollens caught in autumn were of high allergenicity,which caused a high incidence of tropic pollinosis in autumn,with a peak from August to September and 95% of the patients with obvious symptoms recorded in this period.The composition of airborne pollens changed considerably compared with the reported pattern in 1980s,which might be attributed to extensive construction of parks,roads and communities in the past 30 years.It was further suggested that the dispersion characters and air concentration of pollen were largely determined by local vegetation and climatic condition.The results and findings of this investigation can provide reliable data for protection and treatment of tropic pollinosis as well as the varieties choice of city plants.

Ecosystems provide human multiple types of ecosystem services in the aspects of natural resources and living environment,and all these services are crucial foundation of sustainable social and economic development.However,between the understanding of ecosystem services and practice of management,there exist great challenges which contain: quantifying ecosystem services,relationships among multiple services,multi-scale correlation of services,combination of ecosystem services and policy design.In response to these challenges,researches of ecosystem services management in recent years have focused on fields as follow: quantitative estimate of ecosystem services,relationship between ecosystem services and human well-being,trade-offs among multiple ecosystem services,conservation planning of ecosystem services and mechanisms of payments for ecosystem services.With the goal to promote ecosystem services management practices,we should: further strengthen the theoretical research about provision of ecosystem services,develop more methods to display results of services research,carry out more interdisciplinary studies with sociology,economics,demography,search for practicable and reasonable approach to incorporating ecosystem services into decision-making.

Ecosystem services are benefits humans derive from natural ecosystems,which include provisioning services,regulating services,supporting services and cultural services.However,ecosystem services are undergoing degradation with the population growth and economic development.Moreover the increase of ecosystem provisioning services usually is at the expense of the other services,especially the regulating services.One of the great challenges faced by the decision-makers was that how to tradeoff the multiple ecosystem services through the informed management.We map seven ecosystem services(agricultural production,biodiversity conservation,water conservation,soil retention,carbon sequestration,water provisioning and pollination) in Baiyangdian watershed and analyze their tradeoffs based on the scenario analysis by using InVEST models,which enable decision-makers to assess the tradeoffs associated with alternative choices and to identify areas where investment in natural capital can enhance human development and conservation in terrestrial,freshwater,and marine ecosystems.The results showed that the western and northern areas provided higher services in biodiversity conservation,carbon sequestration,soil retention and water conservation than other areas,while the eastern and southern area provided higher services in N/P retention and pollination in Baiyangdian watershed.Under sloping land conservation scenario,N/P retention services increase greatly,however agricultural production decreases and carbon sequestration service is lower than that under conservation scenario.Under conservation scenario,the services in water provisioning,N/P retention and carbon sequestration increase with no impact on agricultural production.Our research presents an initially analytical framework for integrating direct benefits and ecosystem regulating services in policy design.InVEST models provide an effective approaches to map and tradeoff ecosystem service bundle,and then provide informed management for decision-makers.

Plant diversity has important ecosystem function in forest ecosystem.Forest restoration approaches can impact plant diversity,especially the understory plant diversity.We studied the floristic characteristics,plant community structure and diversity of three forest restoration approaches in red soil region of southern China,which included introduced species slash pine(Pinus elliottii) plantations,native species Masson pine(Pinus massoniana) plantations and natural secondary forests.For each forest restoration approach,a total of 15 independent plots were surveyed.On each plot,three 10 m × 10 m subplots of area were surveyed for trees′ abundance,height and diameter at breast height.Within each tree subplot,one to two shrub quadrates(5 m × 5 m) and one to three herb quadrates(1 m × 1 m) were surveyed for plant species abundance.A total of 127 tree subplots,238 shrub subplots and 357 herb subplots were effectively surveyed for plant community structure.The results showed that:(1) 155 species(which belong to 160 genera and 86 families),137 species(which belong to 97 genera,59 families) and 226 species(which belong to 160 genera,86 families) were identified in slash pine plantations,Masson pine plantations and natural secondary forests,respectively.Dominant species in these 3 forest restoration approaches varied in tree,shrub and herb layers.Dominant species in Masson pine plantations were more similar to that of natural secondary forests compared with that of slash pine plantations.In tree layer,the dominant plant in slash pine plantations was only P.elliotti.Similarly,the dominant plant in Masson pine plantations was only P.massoniana.The dominant species in natural secondary forests belong to Fagaceae,Lauraceae and Theaceae.In shrub layer,the dominant plants were Verbenaceae,Gramineae,Hamamelidaceae,Theaceae and Euphorbiaceae for slash pine plantations;Hamamelidaceae,Verbenaceae,Theaceae,Fagaceae and Myrtaceae for Masson pine plantations;Fagaceae,Hamamelidaceae,Theaceae,Rosaceae,Rubiaceae and Myrtaceae for natural secondary forest.In herb layer,the dominant plants were Gramineae,Gleicheniaceae and Thelypteridaceae for slash pine plantations;Gleicheniaceae,Hamamelidaceae,and Dryopteridaceae for Masson pine plantations;Myrsinaceae,Gramineae,Dryopteridaceae,Cyperaceae and Rubiaceae for natural secondary forests;(2) natural secondary forests had more flora types(21 flora types) than Masson pine plantations(16 flora types) and slash pine plantations(18 flora types),and had higher ratio of temperate flora.Natural secondary forests had more unique flora types in comparison with Masson pine plantations and slash pine plantations;(3) forest restoration approach had significant effects on forest community diversity.In tree,shrub and herb layer,natural secondary forest had higher species richness and Shannon-Wiener diversity index than Masson pine plantations and slash pine plantations.There was no significant difference in these indexes between slash pine plantations and Masson pine plantations;(4) multivariate analysis showed that these three reforestation approaches differed significantly in their species composition.Moreover,compared with slash pine plantations,the community composition of Masson pine plantations was more similar to the natural secondary forests.In conclusion,natural restoration is an important forest restoration approach since it was better than artificial plantations of P.massoniana and P.elliottii,yet the native species of P.massoniana plantations were superior to the introduced species of P.elliottii plantations in maintaining plant community structure.

Ecosystem services are the goods and services provided by ecosystems to people.Ecosystem services are important basis of human existence and strongly related to human well-being,and the sustainable provision of multiple services is essential for the sustenance of human societies.There are a series of factors driving ecosystem services,one of which is the change of land use pattern,and it is drawing more and more attention of ecologists. Miyun reservoir,which is the only surface water source for domestic water in Beijing,plays the key role for the ecological security of the capital.Miyun reservoir watershed is a vital water source region of Beijing city,and it has many important ecosystem services.The water yield and water quality of reservoir strongly depend on Miyun reservoir watershed′s condition,therefore,the conservation and improvement of ecosystem services in Miyun reservoir watershed has vital significance for local and Beijing′s ecological security.However,how the land use change influenced ecosystem services during the past decades is not clear yet,which may block the comprehensive development of watershed. So we take Miyun reservoir watershed as example,analyze the change of land use and ecosystem services between 1990 and 2009.We set up a two-grade classify system of land use and interpreted the remote sensing images of 1990,2000 and 2009 respectively,and then apply Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST model),which is a space explicit model and based on land use,to map the ecosystem services,and analyze the influence of Land Use to ecosystem services during study period.The sub models we apply in this research contain "Water Yield","Sediment Retention" and "Water Purification",and before running these sub models,we verify them with observed data. The results of image interpretation show that farmland,forest and grassland are main type of land use of watershed,and these areas account for more than 95% of the whole watershed.There are sharp changes of land use during study period,and conversion of land use types distributed more widely after 2000.The general trend in study period is farmland and grassland decreased by 30%,48% respectively,when forest increased by 30%,and another change cannot be neglected is residential area expanded by more than 280% during the past 20 years. The changes of land use have affect on the pattern of ecosystem services and there are trade-offs among different ecosystem services in question.During the study period,the decreasing of farmland and increasing of forest and grassland improved the ability of sediment retention,and this service increased by 46% in the past 20 years.But forest expansion caused more evapotranspiration,which reduced water yield of watershed by 3% at the same time.Because the nutrient loading of residential area is much higher than other types of land use,the large-scale expansion of residential area decreased water purification service sharply after 2000 although the expansion of forest and decrease of farmland can improve this service to a certain degree,and this service declined by 55% in the past 20 years.With the expansion of forest,carbon sequestration service increased about 19%.So with the goal to get overall improvement of ecosystem services in watershed,we suggest that manages should strengthen the control of forest and residential areas. Understanding the relationship between land use and ecosystem services,the department of decision-making can control and reduce the trade-off between ecosystem services and achieve the sustainable development through appropriate land use plan.Although the approach and process of evaluation still need more improvement,our research can provide scientific foundation for decision-making in Miyun reservoir watershed.