Understanding the Relationship Between Shrinking Cities and Land Prices:Spatial Pattern,Effectiveness,and Policy Implications

Urban shrinkage has emerged as a widespread phenomenon globally and has a significant impact on land,particularly in terms of land use and price.This study focuses on 2851 county-level cities in China in 2005–2018(excluding Hong Kong,Macao,Taiwan,and‘no data’areas in Qinhai-Tibet Plateau)as the fundamental units of analysis.By employing nighttime light(NTL)data to identify shrinking cities,the propensity score matching(PSM)model was used to quantitatively examine the impact of shrinking cities on land prices,and evaluate the magnitude of this influence.The findings demonstrate the following:1)there were 613 shrinking cities in China,with moderate shrinkage being the most prevalent and severe shrinkage being the least.2)Regional disparities are evident in the spatial distribution of shrinking cities,especially in areas with diverse terrain.3)The spatial pattern of land price exhibits a significant correlated to the economic and administrative levels.4)Shrinking cities significantly negatively impact on the overall land price(ATT=–0.1241,P<0.05).However,the extent of the effect varies significantly among different spatial regions.This study contributes novel insights into the investigation of land prices and shrinking cities,ultimately serving as a foundation for government efforts to promote the sustainable development of urban areas.

Exploring social-ecological system resilience in South China Karst:Quantification,interaction and policy implication

China’s Grain to Green Program(GTGP),which is one of the largest payments for ecosystem services(PES)in the world,has made significant ecological improvements to the environment.However,current understanding of its outcomes on the social-ecological system(SES)remains limited.Therefore,taking the South China Karst as an example,a SES resilience evaluation index system was constructed followed by an exploratory spatial analysis,root mean square error,and Self-Organizing Feature Map to clarify the spatiotemporal changes and relationship of SES resilience,achieve the zoning of SES resilience and provide restoration measures.The results showed an upward trend in social resilience from 2000 to 2020,especially its subsystem of social development.Regional ecological resilience was stable,owing to a slightly declined ecosystem services and increased landscape pattern.Spatially,nearly half of the counties exhibited a distribution mismatch in SES resilience.There was an obvious inverted U-shaped relationship of SES resilience,indicating a clear threshold effect,and the constraint relation-ship of SES resilience eased over time,demonstrating the effectiveness of the ecological restoration program.GTGP played a positive role in reducing regional SES trade-off,but this positive effect was limited,reflecting the limitations of overemphasizing the conversion from farmland to forest and grassland.Regional SES resilience can be divided into four clusters,which were the key optimization zone for social system,the SES resilience safety zone,the key restoration zone for SES resilience,and the key optimization zone for ecological system.Adaptive adjustments for the GTGP in these zones should be taken to achieve maximum SES benefits in the future.

Role of permafrost in resilience of social-ecological system and its spatio-temporal dynamics in the source regions of Yangtze and Yellow Rivers

Permafrost is one of the key components of terrestrial ecosystem in cold regions. In the context of climate change, few studies have investigated resilience of social ecological system(SER) from the perspective of permafrost that restricts the hydrothermal condition of alpine grassland ecosystem. In this paper, based on the structural dynamics, we developed the numerical model for the SER in the permafrost regions of the source of Yangtze and Yellow Rivers, analyzed the spatial-temporal characteristics and sensitivity of the SER, and estimated the effect of permafrost change on the SER. The results indicate that: 1) the SER has an increasing trend, especially after 1997, which is the joint effect of precipitation, temperature, NPP and ecological conservation projects; 2) the SER shows the spatial feature of high in southeast and low in northwest,which is consistent with the variation trends of high southeast and low northwest for the precipitation, temperature and NPP, and low southeast and high northwest for the altitude; 3) the high sensitive regions of SER to the permafrost change have gradually transited from the island distribution to zonal and planar distribution since 1980, moreover, the sensitive degree has gradually reduced; relatively, the sensitivity has high value in the north and south, and low value in the south and east; 4) the thickness of permafrost active layer shows a highly negative correlation with the SER. The contribution rate of permafrost change to the SER is-4.3%, that is, once the thickness of permafrost active layer increases 1 unit, the SER would decrease 0.04 units.

The coupling mechanism between the suitable space and rural settlements considering the effect of mountain hazards in the upper Minjiang River basin

Some settlements were located in unsuitable regions due to limited land resources in mountainous areas,some settlements were even even constructed in areas prone to geological hazards in Southwest China.Therefore,it was important to evaluate the spatial appropriateness of a region and determine the areas that were unsuitable for settlements,and then find out the settlements located in unsuitable regions.It will assist in decision making associated with the relocation of settlements.Furthermore,it will be the key to ensure the safety of inhabitants and promoting sustainable development in mountainous areas.This study explored the coupling mechanism between suitable space and rural settlements in the upper Minjiang River basin,which is an ecologically fragile area with high-frequency of natural hazards.Firstly,we identified relief degree of land surface(RDLS),elevation,and disaster risk as the limiting factors.Then,by determining the thresholds of these limiting factors,we recognized the suitable areas for inhabitation in the upper Minjiang River basin with GIS.Finally,using the distribution map of rural settlements and that of suitable space,the distribution of rural settlements located at unsuitable area was obtained by coupling relationship analysis.Consequently,an in-depth understanding of this relationship was achieved as follows:(1)The suitable space of the upper Minjiang River basin is 13.7 thousand km2,accounting for 54.9%of the total land space;(2)There were 196 settlements located in the unsuitable area,the total area of these settlements was 125.27 km2,and there were 68000 people in these settlements,accounting for 17.65%of the total population;(3)There were 65 settlements located near mountain hazard areas,accounting for 4.9%of the total.These findings suggest that it was necessary to carefully investigate settlements with risks and develop targeted relocation policies to help find the most effective way of using land safely and to good effect.The details are as follows:(1)Fully consider the safety of residents:For the 196 settlements distributed in the unsuitable region,the government should undertake a point-by-point survey and classify these settlements into different categories for relocation;(2)For the 65 settlements closely related with mountain hazards,professional geological prospecting teams should be organized to conduct a field survey at each point;(3)Besides considering the safety of residents during the relocation process,it is necessary to pay more attention to the cultural customs of inhabitants and livelihood sustainability.

Effects of the Land Use Change on Ecosystem Service Value Based on RS & GIS

Assessing the effect of land use change on ecosystem service value(ESV) can provide reference for sustainable land use and ecological environment protection. The land use information was extracted and analyzed based on Landsat TM images in Shuangliu County, Sichuan Province from 1992 to 2008, following remote sensing(RS) and GIS. The ESV of the land use change in study area was evaluated by adopting the service value method within Chinese terrestrial ecosystem. The results showed that:(1) the area of paddy field and forest land reduced in the 16 years, total area of construction land expanded fast on the basis of occupying paddy field and forest land.(2) The regional ESV increased by 4,508.859×104 RMB, but there is different change trend at different times, such as the ESV fell by 10.59% in 1992–2000, increased by 16.024% in 2000–2008.(3) The conversion from forest land and cultivated land to construction land caused a decline and negative flow in ESV, the total value was 2,197.233×104 RMB and 5,317.460×104 RMB.(4) All land use types showed that change of the ESV coefficient was less elastic, the relative sensitivity: forest land > cultivated land > water area. In terms of variability of ESV, water area change had greater influence on the change of ESV in the study area, and cultivated land and forest land had relatively smaller impact.

Spatiotemporal Characteristics of Rural Labor Migration in China: Evidence from the Migration Stability under New-type Urbanization

Although the factors affecting rural-to-urban migration have been discussed and analyzed in detail, few studies have examined the spatiotemporal dynamic characteristics of rural migrants’ employment and working-cities in the post-immigrate era, which is essential for the citizenization and social integration of new-type urbanization in China. This study uses survey data from rural migration laborers across the eastern, central, and western China to construct a comprehensive labor migration stability index, and compares the determinants of the migration stability of rural labor among cities and industries using Geodetector. The results are as follows: 1) Compared with the midwestern cities, eastern cities have attracted younger and more skilled rural labor, and industries with higher technical content have higher migration stability among rural laborers. 2) Rural laborers more often adapt to changes by changing employment instead of changing working-cities. 3) The individual experiences of rural laborers and urban characteristics have significant impacts on the stability of migration, and family and societal guanxi(Chinese interpersonal relationships) enhance migration stability. 4) A unified labor market and convenient transportation have somewhat slowed industrial transfers and labor backflow. This study enhances our understanding of the roles of industrial transfer and new-type urbanization in shaping the labor geography landscape and provides policy implications for the promotion of people-oriented urbanization.

Ecosystem Health: Assessment Framework, Spatial Evolution, and Regional Optimization in Southwest China

Regional ecological health,the core of comprehensive ecosystem assessments,is an important foundation for regional exploration,environmental conservation,and sustainable development.The mountainous areas in southwest China are backward in economy,but industrialization and urbanization have been rapid in recent years.This study assessed the ecosystem health of the Sichuan and Yunnan provinces in China using a pressure-state-response(PSR)model.Spatiotemporal patterns of regional ecosystem health were analyzed from 2000 to 2016,including overall characteristics as well as local characteristics.Ecosystem health in most regions was improved over time(Y=0.0058 X–11.0132,R2=0.95,P<0.001),and areas with poorer ecosystem health decreased from half to one-third of the total area.Analysis of the primacy ratio and the variation coefficient confirmed that the gap in health scores between regions has gradually expanded since 2007,but there are more high quality regions overall(Z of Moran’s index<1.96,P>0.05).Overall,the regional ecosystems to the east of the Hu line-an imaginary line dividing east and west China into roughly equivalent parts-were healthier than those to the west.The pressure and state scores of ecosystems were determined by physiographic condition,and the response scores by government policies and social concern.The spatiotemporal patterns of ecosystem health were dominated to a greater extent by natural than anthropogenic factors,which explains why the shift in the patterns aligned with the direction of the Hu line.Dividing regions into key management areas based on natural geographical conditions and socioeconomic development could contribute to the formulation of a reasonable ecological and environmental protection policy,guaranteeing ecosystem services in the long run.

Impacts of native vegetation on the hydraulic properties of the concentrated flows in bank gullies

To quantify the impacts of native vegetation on the spatial and temporal variations in hydraulic properties of bank gully concentrated flows,a series of in situ flume experiments in the bank gully were performed at the Yuanmou Gully Erosion and Collapse Experimental Station in the dry-hot valley region of the Jinsha River,Southwest China.This experiment involved upstream catchment areas withone-and two-year native grass(Heteropogon contortus)and bare land drained to bare gully headcuts,i.e.,Gullies 1,2 and 3.In Gully 4,Heteropogon contortus and Agave sisalana were planted in the upstream catchment area and gully bed,respectively.Among these experiments,the sediment concentration in runoff in Gully 3 was the highest and that in Gully 2 was the lowest,clearly indicating that the sediment concentration in runoff obviously decreased and the deposition of sediment obviously increased as the vegetation cover increased.The concentrated flows were turbulent in response to the flow discharge.The concentrated flows in the gully zones with native grass and bare land were sub-and supercritical,respectively.The flow rate and shear stress in Gully 3 upstream catchment area were highest among the four upstream catchment areas,while the flow rate and shear stress in the gully bed of Gully 4 were lowest among the four gully beds,indicating that native grass notably decreased the bank gully flow rate and shear stress.The Darcy–Weisbach friction factor(resistance f)and flow energy consumption in the gully bed of Gully 4 were notably higher than those in the other three gully beds,clearly indicating that native grass increased the bank gully surface resistance and flow energy consumption.The Reynolds number(Re),flow rate,shear stress,resistance f,and flow energy consumption in the gully beds and upstream areas increased over time,while the sediment concentration in runoff and Froude number(Fr)decreased.Overall,increasing vegetation cover in upstream catchment areas and downstream gully beds of the bank gully is essential for gully erosion mitigation.

Time-lagged and cumulative effects of drought and anthropogenic activities on China's vegetation greening from 1990 to 2018

Previous studies have confirmed the time-lagged and cumulative effects of drought and anthropogenic activities on vegetation growth,but these studies focus on the time-lagged effect of drought and are poorly known how vegetation productivity responds to anthropogenic activities.Here,based on the reconstructed Normalized Difference Vegetation Index,the Standardized Precipitation Evapotranspiration Index and land use degree comprehensive index,we diagnosed the spatiotemporal pattern of vegetation and drought,investigated time-lagged and cumulative effects of drought and anthropogenic activities over China through the month where the maximum correlation coefficient occurred.It revealed that the browning trend of 32.21%of vegetated lands was covered by overall greening,especially northwestern China.Drought intensified with a rate of 0.0014/year.in 66.41%and 54.57%of the vegetated lands had time-lagged and cumulative response to drought,with a shorter timescales of 1–4 months,indicating the higher sensitivity of vegetation growth to drought.There was a U-shaped relationship between moisture conditions and vegetation response time.49.9%of China’s vegetation showed time-lagged effects to anthropogenic activities,with a longer timescales of 6–10 years,demonstrating that anthropogenic activities triggered ecological changes but vegetation ecosystems cannot keep pace.The accumulated and time-lagged years declined with increased land use intensity.

^(137)Cs tracing of the spatial patterns in soil redistribution,organic carbon and total nitrogen in the southeastern Tibetan Plateau

The southeastern Tibetan Plateau,which profoundly affects East Asia by helping to maintain the stability of climate systems,biological diversity and clean water,is one of the regions most vulnerable to water erosion,wind erosion,tillage erosion,freeze-thaw erosion and overgrazing under global climate changes and intensive human activities.Spatial variations in soil erosion in terraced farmland(TL),sloping farmland(SL)and grassland(GL)were determined by the^(137)Cs tracing method and compared with spatial variations in soil organic carbon(SOC)and total nitrogen(total N).The^(137)Cs concentration in the GL was higher in the 0-0.03 m soil layer than in the other soil layers due to weak migration and diffusion under low precipitation and temperature conditions,while the^(137)Cs concentration in the soil layer of the SL was generally uniform in the 0-0.18 m soil layer due to tillage-induced mixing.Low^(137)Cs inventories appeared at the summit and toe slope positions in the SL due to soil loss by tillage erosion and water erosion,respectively,while the highest^(137)Cs inventories appeared at the middle slope posi-tions due to soil accumulation under relatively flat landform conditions.In the GL,the^(137)Cs data showed that higher soil erosion rates appeared at the summit due to freeze-thaw erosion and steep slope gradients and at the toe slope position due to wind erosion,gully erosion,freeze-thaw erosion and overgrazing.The^(137)Cs inventory generally increased from upper to lower slope positions within each terrace(except the lowest terrace).The^(137)Cs data along the terrace toposequence showed abrupt changes in soil erosion rates between the lower part of the upper terrace and the upper part of the immediate terrace over a short distance and net deposition on the lower and toe terraces.Hence,tillage erosion played an important role in the soil loss at the summit slope positions of each terrace,while water erosion dominantly transported soil from the upper terrace to the lower terrace and resulted in net soil deposition on the flat lower terrace.The SOC inventories showed similar spatial patterns to the^(137)Cs inventories in the SL,TL and GL,and significant correlations were found between the SOC and^(137)Cs inventories in these slope landscapes.The total N inventories showed similar spatial patterns to the inventories of,37Cs and SOC,and significant correlations were also found between the total N and^(137)Cs inventories in the SL,TL and GL Therefore,^(137)Cs can successfully be used for tracing soil,SOC and total N dynamics within slope landscapes in the southeastern Tibetan Plateau.

Evolution characteristics of the Atlantic Meridional Overturning Circulation and its thermodynamic and dynamic effects on surface air temperature in the Northern Hemisphere

Based on modern observations,historical proxy data,and climate model simulations,this paper provides a comprehensive overview of the past,present and future evolution characteristics of the Atlantic Meridional Overturning Circulation(AMOC),as well as its impact on the surface air temperature(SAT)at regional and hemispherical scales.The reconstruction results based on the proxy data indicate that the AMOC has weakened since the late 19th century and experienced overall weakening throughout the 20th century with low confidence.Direct observations show that the AMOC weakened during 2004–2016,but it is not possible to distinguish between its decadal variability and long-term trend.Climate models predict that if greenhouse gas emissions continue to increase,AMOC will weaken in the future,but there will not be a sudden collapse before 2100.For the thermodynamic effects of AMOC,the increased surface heat flux release and meridional heat transport(MHT)over the North Atlantic associated with the strong AMOC cause an increase in the hemispherical SAT.At the millennial scale,climate cooling(warming)periods correspond to a weakened(strengthened)AMOC.The enhanced MHT of a strong AMOC can affect Arctic warming and thus influence regional SAT anomalies and SAT extremes through mutual feedback between Arctic sea ice and AMOC.In terms of dynamic effects,a strong AMOC modulates the Rossby wave trains originating from the North Atlantic and spreading across mid-to-high latitudes in the Northern Hemisphere and causes an increase in the variabilities in the circulation anomalies over the Ural and Siberian regions.Ultimately,a strong AMOC significantly affects the frequencies of extreme cold and warm events in the mid-to-high latitude regions over Eurasia.In addition,AMOC can also influence regional and global SAT anomalies through its dynamic adjustment of planetary-scale circulation.Decadal variation in AMOC is closely related to the Atlantic Multidecadal Oscillation(AMO).During positive phases of AMO and AMOC,enhanced surface heat fluxes over the North Atlantic lead to abnormal warming in the Northern Hemisphere,while during negative phases,the reverse case occurs.Under high emission scenarios in the future,the possibility of AMOC collapse increases due to freshwater forcing.However,most advanced climate models underestimate the strength of the AMOC and its impact on the AMO and relevant climate change,which presents a major challenge for future understanding and prediction of the AMOC and its climate effects.

Amplification effect of intra-seasonal variability of soil moisture on heat extremes over Eurasia

Drying soil has been conducive to a high frequency of extreme high-temperature events over many regions worldwide in recent decades.However,changes in the intraseasonal variability of soil moisture can also influence the likelihood of extremely high temperatures.Although previous investigators have examined the association between extremely high temperatures and large-scale atmospheric circulation variability,the role of land-atmosphere coupling dominated by soil moisture variability in extremely high temperatures,particularly over the Eurasian continent,is not well understood.In this study,on the basis of the Land Surface,Snow,and Soil Moisture Model Intercomparison Project,we found that land-atmosphere feedback amplified the variability of soil moisture in most regions of Eurasia during summer from 1980 to 2014.This amplification of soil moisture variability is closely correlated with more intensive intraseasonal variability of surface air temperature and more frequent occurrences of extreme high-temperature events,particularly in Europe,Siberia,Northeast Asia,and the Indochina Peninsula.This correlation implies that increasing the intraseasonal variability of soil moisture results in a high likelihood of heat extremes during summer in most parts of Eurasia except Asian desert areas.On the intraseasonal timescale,the land-atmosphere coupling increases the variability of surface sensible heat flux and net long-wave radiation heating the atmosphere by intensifying the soil moisture variability,thus amplifying the variability of surface air temperature and enhancing the extreme high-temperature days.This finding demonstrates the importance of changes in intraseasonal soil moisture variability for the increasing likelihood of heat extremes in summer.

Iron loss of paddy soil in China and its environmental implications

Iron(Fe)is an important element for the terrestrial and marine ecosystems through its biogeochemical cycling on the Earth’s surface.China has a long rice cultivation history,with extensive rice distribution across many types of paddy soils.Paddy soils are the largest anthropogenic wetlands on earth with critical roles in ecosystem functions.The periodic artificial submergence and drainage during paddy soil evolution result in significant changes in soil moisture regime and redox conditions from the natural soils,which facilitate the increase of Fe solubility and mobilization.However,there is a lack of systematic assessment on the magnitude of the migration and loss amount of Fe from paddy soils.In order to quantify the Fe loss and assess the dynamic evolution of Fe in the soils after rice cultivation,seven paddy soil chronosequences derived from different landscapes(bog,plain,terrace)and parent materials(acidic,neutral,calcareous)with cultivation history from 0 to 2,000 yr were studied.Results showed that the rates and trajectories of Fe evolution showed distinct patterns among the studied seven paddy soil chronosequences.However,net losses of Fe from 1 m soil depth occurred at all studied paddy soil chronosequences regardless of the original landscapes and parent materials.Fe in the paddy soils derived from the calcareous lacustrine sediments in the bog area showed a slight accumulation during the initial stage(50 yr)of paddy cultivation,with a loss rate of0.026 kg m^(-2)yr^(-1) during the 50-to 500-yr time period.For the paddy soils developed on the calcareous marine sediments in the plain area,Fe evolution was dominated by the internal movement in soil profiles through coupled reducing-eluviation reactions in the surface horizons and oxidation-illuviation in the subsurface horizons within 1,000 yr of paddy cultivation,with an averaged net loss rate of 0.029 kg m^(-2)yr^(-1) during the 1,000-to 2,000-yr time period of rice cultivation.In contrast,Fe in the paddy soils derived from the acidic and neutral parent materials in the plain and terraced upland areas was rapidly lost during the initial stage of paddy cultivation,with a maximum loss rate of 1.106 kg m^(-2)yr^(-1),while the Fe loss rate decreased gradually with increasing paddy cultivation age.Soil pH,CaCO_(3),and organic matter contents of the original soils,the length of time of paddy cultivation,landscape types and positions,and changes in soil moisture regime and redox condition induced by artificial submergence and drainage were the main factors controlling the rates and trajectories of Fe loss during paddy soils evolution.The amount of Fe loss caused by rice cultivation at the national scale was estimated based on the data collected from this study and the literature.The Fe loss fluxes of paddy soils in China were about 46.4–195.7 Tg yr^(-1),and the amounts of Fe losses from paddy fields nationwide were about 5,121.5–9,412.2 Tg.Quantifying Fe loss from paddy fields is important to scientifically assess the impact of paddy cultivation on the Fe biogeochemical cycle.

Spatiotemporal evolution and driving factors of the rural settlements in the mountain-plain transitional zone

Identifying the spatiotemporal evolution characteristics of rural settlements and their driving factors is of great significance to layout optimization of rural settlements,intensive and economical use of rural land,and preparation of land space planning.Focusing on the mountain-plain transitional zone of Dujiangyan City,China,as the study area,this paper employs methods including landscape pattern index,kernel density estimation,average nearest neighbor index,and Geodetector to quantitatively analyze the spatiotemporal layout evolution characteristics of rural settlements and relevant driving factors in Dujiangyan City over the last decade.The four main findings are as follows.First,land use area of rural settlements and the quantity of patches in Dujiangyan exhibited synchronous changes during 2005-2015.Total class area(CA)increased from 6161.43 to 7265.43 hm^(2),then declined to 7043.01 hm^(2),and the number of patches(NP)increased from 16543 to 26018,and then declined to 25890.Second,the maximum kernel density estimation values in the east and southeast of Dujiangyan City increased remarkably from 48.34 to 74.69 per hm^(2) during 2005-2010.Third,the average nearest neighbor index of rural settlements continually decreased in the foregoing 10 years,indicating a higher concentration of rural settlements.Finally,production and living conditions are the main driving factors of dynamic change in land use in rural settlements,while the impact of socio-economic factors is relatively smaller.Among others,the p-value of road accessibility is 0.057,and the impact p-value of land slope is 0.035.

The Spatial Subject of China’s Urbanization:Development Patterns and Challenges of Urban Agglomerations

China’s urban agglomerations have gradually become new world economic centers and strategic regions under the initiatives of"The Belt and Road."Various researchers have long been interested in the issues encountered during the development of urban agglomerations.However,systematic research analyzing issues in the development of China’s urban agglomeration are relatively few.On the basis of a brief introduction to the concept of urban agglomeration and the status of current development in China,this paper analyzes current issues in China’s urban agglomerations from the perspectives of spatial attribution,function,resources,and environmental utilization as well as new patterns in urban agglomeration,which reaches the following conclusions:conficts exist between spatial identifcation and layouts in urban agglomerations;issues such as,unsound internally functioning systems,improper land utilization,and stressful resource and environmental pressures still prevail in certain urban agglomerations;in addition,the number and layouts of newly constructed areas in urban agglomerations are controversial because some new areas are eager to develop new cities but have neglected their transitions from and interactions with older districts,thus wasting resources unnecessarily.This paper also proposes certain suggestions regarding the problems mentioned above.In short,these fndings will elucidate a fresh perspective and ideas for researchers studying urban agglomeration and offer references related to policy making concerning China’s urban agglomerations in the future.

Identifying Neighborhood Effects on Geohazard Adaptation in Mountainous Rural Areas of China:A Spatial Econometric Model

In mountainous rural settlements facing the threat of geohazards,local adaptation is a self-organizing process influenced by individual and group behaviors.Encouraging a wide range of local populations to embrace geohazard adaptation strategies emerges as a potent means of mitigating disaster risks.The purpose of this study was to investigate whether neighbors influence individuals'adaptation decisions,as well as to unravel the mechanisms through which neighborhood effects exert their influence.We employed a spatial Durbin model and a series of robustness checks to confirm the results.The dataset used in this research came from a face-to-face survey involving 516 respondents residing in 32 rural settlements highly susceptible to geohazards.Our empirical results reveal that neighborhood effects are an important determinant of adaptation to geohazards.That is,a farmer's adaptation decision is influenced by the adaptation choices of his/her neighbors.Furthermore,when neighbors adopt adaptation strategies,the focal individuals may also want to adapt,both because they learn from their neighbors'choices(social learning)and because they tend to abide by the majority's choice(social norms).Incorporating neighborhood effects into geohazard adaptation studies offers a new perspective for promoting disaster risk reduction decision making.

Terrestrial Ecosystem Modeling with IBIS:Progress and Future Vision

Dynamic Global Vegetation Models(DGVM)are powerful tools for studying complicated ecosystem processes and global changes.This review article synthesizes the developments and applications of the Integrated Biosphere Simulator(IBIS),a DGVM,over the past two decades.IBIS has been used to evaluate carbon,nitrogen,and water cycling in terrestrial ecosystems,vegetation changes,land-atmosphere interactions,land-aquatic system integration,and climate change impacts.Here we summarize model development work since IBIS v2.5,covering hydrology(evapotranspiration,groundwater,lateral routing),vegetation dynamics(plant functional type,land cover change),plant physiology(phenology,photosynthesis,carbon allocation,growth),biogeochemistry(soil carbon and nitrogen processes,greenhouse gas emissions),impacts of natural disturbances(drought,insect damage,fire)and human induced land use changes,and computational improvements.We also summarize IBIS model applications around the world in evaluating ecosystem productivity,carbon and water budgets,water use efficiency,natural disturbance effects,and impacts of climate change and land use change on the carbon cycle.Based on this review,visions of future cross-scale,cross-landscape and cross-system model development and applications are discussed.

Ecological Protection and Livelihood Improvement in Ecologically Vulnerable Regions

1 Introduction With the rapid economic growth in recent decades,humans have used and consumed natural ecosystems more rapidly and extensively than in any comparable period of time in human history.Thus,ecological degradation has become increasingly significant around the world,especially in the ecologically vulnerable regions,,and it remains one of the most serious problems facing society,which disproportionately affects the world's poorest people.

山区过渡性地理空间识别及分类研究——基于人文自然耦合分异视角

The coupling of humans and nature differs in terms of distribution and intensity, thus producing a gradient of synthetic geographical environments. Within this variety of gradients, the transitional zone represents a complex space where dynamic processes and unstable conditions are observed. Based on the concepts of ecotone and transitional zone, we propose a conceptual framework for the transitional geospace of coupled human and natural systems and a quantitative identification method for the zone. Taking the Sichuan Basin as an example, this study defined the strength and direction of the coupling of the natural ecosystem and socioeconomic system and divided different types of transitional geospace. The transitional geospace of the strong coupling type accounted for approximately 16.7% of the study area. Nine of the ten counties with the largest proportion of the type were formerly nationally poor counties in the study area. In the strong coupling type, human and nature jointly explained a high proportion of the variance in transitional stability(e.g., in Shifang city, with an unexplained proportion of 1.7%). The discovery and characterization of the transitional geospace types is crucial for facilitating more effective land use planning and sustainable balance among the population, resources, and environment.