Snowmelt runoff is a vital source of fresh water in cold regions. Accurate snowmelt runoff forecasting is crucial in supporting the integrated management of water resources in these regions. However, the performances of such forecasts are often very low as they involve many meteorological factors and complex physical processes. Aiming to improve the understanding of these influencing factors on snowmelt runoff forecast, this study investigated the time lag of various meteorological factors before identifying the key factor in snowmelt processes. The results show that solar radiation, followed by temperature, are the two critical influencing factors with time lags being 0 and 2 days, respectively. This study further quantifies the effect of the two factors in terms of their contribution rate using a set of empirical equations developed. Their contribution rates as to yearly snowmelt runoff are found to be 56% and 44%, respectively. A mid-long term snowmelt forecasting model is developed using machine learning techniques and the identified most critical influencing factor with the biggest contribution rate. It is shown that forecasting based on Supporting Vector Regression (SVR) method can meet the requirements of forecast standards.

The semiconductor industry typifies the international division of labor and exhibits significant structural differences in global trade in key product segments. The evolution of cross-border trade flows and dependency relationships, as well as trade organization patterns of manufactured products, equipment and materials for manufacturing, are investigated by constructing a global semiconductor trade relationship matrix and using the Gini coefficient and trade dependency index. It was found that: (1) the global semiconductor trade is highly spatially unbalanced, with materials and equipment trade in particular highly concentrated in a few countries on both the supply and demand sides; (2) China has replaced the US as the largest global semiconductor trade player and has shaped the regionalized system of manufactured goods and materials trade with East and Southeast Asian economies, but its equipment trade is highly dependent on Europe and the US; (3) the semiconductor production model has promoted the regionalization of the east and southeast Asia region in the trade of manufactured products and materials, and developed economies such as the US, the EU, Japan, and South Korea have maintained their monopolistic advantage in the trade of semiconductor equipment by building exclusive innovation networks and establishing trade barriers. The monopolistic nature of the semiconductor equipment trade and the regionalization of manufactured goods and materials have formed the characteristics of the global semiconductor trade and are likely to be further strengthened in future trade.

Driven by urbanization and industrialization, arable land in hilly and mountainous regions of China is gradually becoming marginalized, with the extent of arable land abandonment rapidly expanding from poor-quality sloping arable land to high-quality terraces. The abandonment of large-scale terraces will lead to a series of socio-economic and ecological effects. A national sample survey was used to investigate the extent and spatial distribution of terrace abandonment in China, and a total of 560 valid village questionnaires from 329 counties were collected in the mountainous areas of China. The main findings are as follows: (1) The phenomenon of terrace abandonment was widespread throughout the country, with 54% of the total surveyed villages exhibiting terrace abandonment, and the area of abandoned terraces accounting for 9.79% of the total. (2) The degree of terrace abandonment is high in the south and low in the north. The most serious region with abandonment was the hilly and mountainous areas in the south, especially in the middle and lower Yangtze River region. (3) The main driving factors of terrace abandonment were rural labor migration, agricultural mechanization level, irrigation conditions, and transportation conditions for cultivation. Targeted measures should be taken based on the specific conditions of each area to alleviate terrace abandonment. Measures such as improving terrace mechanization are universally applicable. Specifically, low-quality terraces can be withdrawn orderly, and for high-quality terraces, multiple measures are needed to consolidate agricultural production, such as adjusting the planting structure, strengthening agricultural infrastructure construction, and encouraging the transfer of land-use rights as well as large-scale operation.

How the dynamics in soil loss (SL) and sedimentation are affected by land use/cover change (LULCC) has long been one of the most important issues in watershed management worldwide, especially in fragile mountainous river basins. This study aimed to investigate the impact of LULCC on SL and sediment export (SE) in eastern regions of the Koshi River basin (KRB), Nepal, from 1990 to 2021. The Random Forest classifier in the Google Earth Engine platform was employed for land use/land cover (LULC) classification, and the Integrated Valuation Ecosystem Services and Trade-offs (InVEST) Sediment Delivery Ratio model was used for SL and SE modeling. The results showed that there was a pronounced increase in forest land (4.12%), grassland (2.35%), and shrubland (3.68%) at the expense of agricultural land (10.32%) in KRB over the last three decades. Thus, the mean SL and SE rates decreased by 48% and 60%, respectively, from 1990 to 2021. The conversion of farmland to vegetated lands has greatly contributed to the decrease in SL and SE rates. Furthermore, the rates of SL and SE showed considerable spatiotemporal variations under different LULC types, topographic factors (slope aspect and gradient), and sub-watersheds. The higher rates of SL and SE in the study area were observed mostly in slope gradient classes between 8° and 35° (accounting for 83%-91%) and sunny and semi-sunny slope aspects (SE, S, E, and SW) (accounting for 57%-65%). Although the general mean rate of SL presented a decreasing trend in the study area, the current mean SL rate (23.33 t ha^-1 yr^-1) in 2021 is still far beyond the tolerable SL rate of both the global (10 Mg ha^-1 yr^-1) and the Himalayan region (15 t ha^-1 yr^-1). Therefore, landscape restoration measures should be integrated with other watershed management strategies and upscaled to hotspot areas to regulate basin sediment flux and secure ecosystem service sustainability.

The agglomeration of the rural e-commerce industry represented by Taobao villages has reshaped the existing urban and rural spatial organization and proposed a new urbanization model. This study identified the spatiotemporal characteristics of Taobao villages in Quanzhou city and built panel regression models to examine the impact of these villages on urbanization level, which is measured via nighttime light (NTL). The results show that (1) while the number of Taobao villages in Quanzhou city has increased rapidly, it has also experienced sporadic growth and monocentric agglomeration, finally forming a polycentric agglomeration pattern; (2) Taobao villages display a significant near-city tendency, and the urbanization level of towns with Taobao villages is higher than that of towns without Taobao villages; (3) the panel regression model highlights that Taobao villages have a significant positive impact on urbanization level. Taobao villages near the city exhibit a greater effect; meanwhile, those that are far away from the city cannot improve their urbanization level unless they reach a considerable degree of agglomeration. Rural e-commerce will become an important direction for the transformation of urban fringe areas, which provides a certain reference for the development of new urbanization in China.

Rust belt cities are largely threatened by a waste of urban space at their core; however, in developing countries where land resources are widely used as instruments for macroeconomic stabilization, urban periphery is also at risk of being underutilized due to land hoarding. Such geographic differences entail new knowledge about how, where, and why underutilized lands are regenerated in the city. Furthermore, rapid urban growth imposes development disparity and mixed underutilization issues on cities in developing countries; therefore, how the geo-information obtained by the regeneration of different underutilized lands differs will be valuable for urban planners and policymakers to make prudent trade-offs. To fill these gaps, we conducted a sequential investigation into the regeneration of underutilized lands in a representative rust belt city - Changchun City in Northeast China, in an attempt to measure the regeneration pattern and analyze the underlying determinants using the Classification and Regression Trees analysis. The results indicated that, of all underutilized lands, increments of vacant lot and remnant cultivated land continued to plague the expanding urban periphery during 2016-2019. In a way, reduced underutilized lands alleviated land use conflicts at the city core. Nearly 23% of the underutilized areas had been regenerated, dominated by realty development, with most converted to residential lands, ecological lands and industrial lands. On the contrary, conversion to transportation lands and parking lots seemed to avoid the rapidly expanding sites. The regeneration rates in a certain area can be increased by a multitude of factors, including denser, simply structured land underutilization, abundant ecosystem services nearby and accessibility to public infrastructures. Site conditions such as residential density and accessibility may have fueled the regeneration associated with residential purposes, while regeneration of industrial development was closely associated with the underutilization density and parcel regularity. This research provides an empirical paradigm for delivering regeneration geo-information across different underutilized lands, particularly for rust belt cities that are caught between a shrinking core and speculative periphery.

As a new mode for Chinese overseas investment and a growth pole for industrialization and urbanization of the host countries, the overseas economic and trade cooperation zone (OETCZ) or overseas free economic zone (OFEZ) of China plays an important role under the Belt and Road Initiative. With the rising attention on OETCZ, studies regarding OETCZ have also increased. However, there is a lack of studies reviewing this topic’s progress, challenges and future directions. This paper employs a systematic review to examine the literature on the OETCZ along the Belt and Road, based on domestic and overseas studies. The results show that domestic studies account for a large proportion of the collected literature, compared to overseas studies. Interdisciplinary research focus includes inductive case studies from a classification perspective, deductive studies based on cultural and institutional perspectives, trade network and bilateral trade relations based on the perspectives of international trade and regional economy, spatial planning studies from urban planning perspective, and overseas comments and earlier studies on Japan’s and Singapore’s overseas parks from the geopolitical and international political perspectives. Despite diverse research contents and dramatic progress, limitations exist in current OETCZ-related studies, including a lack of exploration of the mechanism, questions and concerns from overseas scholars, sustainable development and other problems. Future studies should broaden and deepen research insights, including the “overseas free economic zones (OFEZ)” as a general designation to cover all other types of OETCZs, studies on the primary conditions of host countries, exploration of the theoretical issues behind China’s OETCZ, comparative study of OETCZs such as management structures, profit models, environmental standards and legal systems as well as popular issues questioned internationally.

Rapid urbanization has occurred in arid/semiarid China, threatening the sustainability of fragile dryland ecosystems; however, our knowledge of natural environmental constraints on multiscale urban lands in this region is still lacking. To solve this issue, this study retrieved 15-m multiscale urban lands. Results indicated that urban area increased by 68% during 2000-2018, and one-third of the increase was contributed by only three large cities. The coverage of impervious surface area (ISA) and vegetated area (VA) increased by 16.6% and 1.38%, respectively. Such land-cover change may be helpful in suppressing wind erosion and sand storms. We also found that the newly urban lands had relatively lower ISA and higher VA than the old urban lands, indicating an improved human settlement environment. Strong environmental constraints on urban expansion were identified, with cities in oasis urban environments (OUEs) that had water supply expanding 150% faster than cities in desert urban environments (DUEs). Urban development was also constrained by terrain, with 73% of the ISA expansion occurring in relatively flat areas. Overall, the aggregated pattern of urbanization and the increase in ISA and VA in the newly urbanized lands have improved water-use efficiency and ecological services and benefited desert ecosystem protection in arid/semiarid China.

The transition of human societies from high mobility to sedentary lifestyles had a profound impact on subsistence, technology, and the origin of civilization. Sedentism was influenced by various factors such as climate change, population growth, resource pressure, and technological innovation. The Tibetan Plateau, due to its alpine and hypoxic conditions, is an ideal region to study human adaptation to extreme environments. However, the prehistoric process of sedentism on the Tibetan Plateau is unclear and the chronological sequence and driving mechanism of sedentism on the Tibetan Plateau are still controversial. Previous studies have focused on the diffusion of agriculture from low to high elevation areas, with little attention given to the role of animal resources in sedentism. Seasonality analysis using animal remains is crucial in determining whether a site was occupied year-round. To establish the seasonal calendar of animal resource utilization, it is recommended to create a database of skeletal morphology, whole genome, and proteome of contemporary Tibetan Plateau fauna to aid in the identification of animal remains from archaeological sites. Thus, intricate web of human-animal-environment relationship and the role of animal resources in human sedentism on the Tibetan Plateau can then be evaluated.

Elucidating the distribution of the grazing pressure requires an understanding of the grazing activities. In this study, we analyzed the grazing behavior of yaks in Three-River- Source Region (TRSR) and identified the main factors influencing the distribution of grazing intensity (GI) using trajectory data and remote sensing datasets. Our results revealed that a semi-resident transhumance strategy is employed in this region. The average grazing time (GT) of four GPS collars over the year was 11.84 h/day (N6), 11.01 h/day (N11), 9.25 h/day (N18), and 11.61 h/day (N24). GT was generally higher in warm seasons (summer and autumn) than in cold seasons (spring and winter). The average daily moving speed was found to be closely related to the pasture size of different herders and the seasons. Geodetector analysis identified the distance to camp (DOC) as the most important single factor influencing the distribution of GI, explaining up to 52% of the GI variations. However, relying solely on this factor may not accurately depict the actual GI distribution. When pairwise factors interacted, the explanatory power of the model increased, ranging from 34.55% to 63.26%. Our study highlights the importance of considering multiple factors when predicting grazing intensity, as grazing activities tend to cluster near settlements, but other factors may also be influential.

Cropping systems worldwide have been affected by the current trend in global warming and the optimization of cropping systems is an important area of research in the transition of agricultural land. The Loess Plateau is a typical ecologically fragile region with the most serious soil erosion in China. We carried out a field experiment in Yan’an city on the Loess Plateau to explore the effect of sowing date on crop growth and yield. We then analyzed the feasibility of a double-cropping system by considering climatic adaptability, ecological suitability and economic viability. Our results showed that different sowing dates resulted in significant differences in crop growth and that appropriate early sowing can result in higher crop yields for early maturing varieties. We showed that double-cropping systems of sweet maize (Zea mays)-forage rape and feed maize-forage rape are feasible on the Loess Plateau. We discuss the implications for the efficient use of farmland, which is important in guiding agricultural supply-side reform and the development of modern agricultural management.

Exploring the coupling coordinated level of rural population-land-industry (PLI) and its underlying driving mechanism contributes to the scientific decision-making on rural sustainable development. This study assessed the coupling coordinated level of PLI based on an improved evaluation index system and then revealed the regional differentiation and driving mechanism in China’s rural areas in 2020. The results showed that the rural PLI coupling coordinated degree was 0.4694, and thus was in the stage of approximate incoordination. In addition, China’s rural PLI coupling coordinated degree formed a spatially heterogeneous pattern with high levels in the northeast, eastern and central regions, and the intragroup difference contributed more than 80% to the total difference. The rural PLI coupling coordinated level was influenced by the combined effects of rural kernel and peripheral systems, but the rural kernel system mostly determined the differentiation. In the future, rural areas should first exploit population quality improvement projects, land consolidation projects and industrial integration development strategies to promote benign mutual feedback of PLI. Second, driving factors should be comprehensively regulated by implementing a “one village, one product” strategy, breaking the urban-rural dual system, improving agricultural machinery subsidies policy, and promoting urban-rural integrated development.

The mass elevation effect (MEE) is a thermal effect, in which heating produced by long wave radiation on a mountain surface generates atmospheric uplift, which has a profound impact on the hydrothermal conditions and natural geographical processes in mountainous areas. Based on multi-source remote sensing data and field observations, a spatial downscaling inversion of temperature in the Tianshan Mountains in China was conducted, and the MEE was estimated and a spatio-temporal analysis was conducted. The GeoDetector model (GDM) and a geographically weighted regression (GWR) model were applied to explore the spatial and temporal heterogeneity of the study area. Four key results can be obtained. (1) The temperature pattern is complex and diverse, and the overall temperature presented a pattern of high in the south and east, but low in the north and west. There were clear zonal features of temperature that were negatively correlated with altitude, and the temperature difference between the internal and external areas of the mountains. (2) The warming effect of mountains was prominent, and the temperature at the same altitude increased in steps from west to east and north to south. Geomorphological units, such as large valleys and intermontane basins, weakened the latitudinal zonality and altitudinal dependence of temperature at the same altitude, with the warming effect of mountains in the southern Tianshan Mountains. (3) The dominant factors affecting the overall pattern of the MEE were topography and location, among which the difference between the internal and external areas of the mountains, and the absolute elevation played a prominent role. The interaction between factors had a greater influence on the spatial differentiation of mountain effects than single factors, and there was a strong interaction between terrain and climate, precipitation, the normalized difference vegetation index (NDVI), and other factors. (4) There was a spatial heterogeneity in the direction and intensity of the spatial variation of the MEE. Absolute elevation was significantly positively correlated with the change of MEE, while precipitation and the NDVI were dominated by negative feedback. In general, topography had the largest effect on the macroscopic control of MEE, and coupled with precipitation, the underlying surface, and other factors to form a unique mountain circulation system and climate characteristics, which in turn enhanced the spatial and temporal heterogeneity of the MEE. The results of this study will be useful in the further analysis of the causes of MEE and its ecological effects.

The Regional Comprehensive Economic Partnership (RCEP) was formally signed by the Association of Southeast Asian Nations (ASEAN) countries, along with China, Japan, South Korea, Australia, and New Zealand. This was a significant step towards regional integration in the Asia-Pacific region. Analysing the trade structure among member states is crucial in understanding the path to regional integration and policy implications of regional cooperation within the RCEP framework. Based on subdivided commodity data, this study reviews the evolution of merchandise trade in the RCEP region in the past two decades. It investigates the current trade structure of the RCEP, emphasising the relative importance of intra-regional versus extra-regional interdependence and the trade asymmetry of the regional members. The results of the study are as follows: First, the overall extent of regional trade integration in the RCEP region increased modestly from 2001 to 2018, indicating that the RCEP region was export-oriented and there was significant room for further expansion of regional trade. Second, most of the commodities traded in the RCEP region demonstrated much higher extra-regional interdependence than intra-regional in 2018, particularly labor-, capital-, and technology-intensive products such as television and radio apparatus. Third, the trade networks of the top five traded commodities were distinguished by large economic asymmetries, with China, Japan, and South Korea being the dominant regional powers. These findings have significant implications for understanding how to promote regional integration and cooperation. Besides expanding intra-regional trade, outward-oriented factors influenced by the regional powers—including consolidating the global advantages of manufacturing, stabilizing supply chains by including large resource countries, and attracting extra-regional investments—were also the main rationales for the conclusion of the RCEP.

Under the wave of globalization, some cities in China, especially the so-called “megacities” are entering or have already entered the stage of post-suburbanization. The study places Shanghai suburbs in the post-suburbanization landscape and takes Qingpu New Town as an example to systematically analyze the development and formation mechanism of post-suburbanization spaces. This study reveals the features of the post-suburbanization in China as follows. Firstly, In China, post-suburbanization is achieved based on industrialization as well as on the promotion of urbanization. Although urbanization has strengthened other functions of suburban spaces aside from living and production, the production attributes of suburbs remain stable. Secondly, post-suburbanization space with the new town as the development model is an important path for a new round of suburban space growth, it has expanded the space for capital accumulation in metropolitan areas, thus promoting the possibility of reorganizing economic activities within metropolitan areas. At the same time, it focuses on the integration of industries and cities, and the simultaneous development of urbanization and industrialization. In turn, this promotes the accumulation of capital centered on the urban environment and manufacturing production. Furthermore, China’s special institutional circumstance enables its government to organize various actors to form a growth alliance, which will act together in the production of post-suburbanization space.

In this paper, we firstly constructed a theoretical framework based on major function-oriented zones (MFOZs). Then taking the Loess Plateau (LP) as the study area, we revealed the spatio-temporal differences and influencing factors of carbon emission equity by using the carbon equity model, Theil index, and Geo-detector. The results showed that: (1) From 2000 to 2017, the carbon equity of the Loess Plateau showed a downward trend, but the ecological carbon equity remained above 2.3, which was significantly higher than the economic carbon equity. (2) The ecological carbon equity in the Loess Plateau increased from the core of urban agglomeration to the periphery. The spatial pattern of economic carbon equity changed from low in the northeast and high in the southwest to low in the north and high in the south. The ecological support coefficient and economic contribution coefficient of provincial capital cities and their surrounding districts remained low since 2000. (3) The equity of carbon emissions in each function-oriented zone in the Loess Plateau was compatible with its orientation. The ecological carbon equity of the key ecological functional zones (KEFZs) was significantly higher than that of the key development zones (KDZs) and the major agricultural production zones (MAPZs), while the economic carbon equity of the KDZs was significantly higher than that of the MAPZs and the KEFZs. (4) The formation and evolution of the spatial differentiation pattern of carbon equity in the Loess Plateau was the result of the long-term interaction effects of geographic location, social economy, science and technology level, and policy system. Among them, eco-environmental protection policy, government financial support, and geographical location are the key driving factors for the spatial pattern of ecological carbon equity. Geographical location, social economic level, and science and technology level are the key factors driving the spatial pattern of economic carbon equity. According to this study, to achieving carbon equity on the Loess Plateau region, what the key approaches are to fully implement the planning of MFOZs, design differentiated regional carbon compensation mechanisms, improve energy efficiency and ecological environment capacity, and build a collaborative regional carbon emission governance system. This research can not only provide an effective framework for analysing the carbon equity, but also offer policy implication for promoting carbon emission reduction and achieving high-quality development goals in the ecologically fragile areas.

Current ecosystem models used to simulate global terrestrial carbon balance generally suggest that terrestrial landscapes are stable and mature, but terrestrial net primary productivity (NPP) data estimated without accounting for disturbances in species composition, environment, structure, and ecological characteristics will reduce the accuracy of the global carbon budget. Therefore, the steady-state assumption and neglect of elevation-related changes in forest NPP is a concern. The Qilian Mountains are located in continental climate zone, and vegetation is highly sensitive to climate change. We quantified aboveground biomass (AGB) and aboveground net primary productivity (ANPP) sequences at three elevations using field-collected tree rings of Picea crassifolia in Qilian Mountains of Northwest China. The results showed that (1) There were significant differences between AGB and ANPP at the three elevations, and the growth rate of AGB was the highest at the low elevation (55.99 t ha^-1 10a^-1). (2) There are differences in the response relationship between the ANPP and climate factors at the three elevations, and drought stress is the main climate signal affecting the change of ANPP. (3) Under the future climate scenario, drought stress intensifies, and the predicted decline trend of ANPP at the three elevations from mid-century to the end of this century is -0.025 t ha^-1 10a^-1, respectively; -0.022 t ha^-1 10a^-1; At -0.246 t ha^-1 10a^-1, the level of forest productivity was significantly degraded. The results reveal the elevation gradient differences in forest productivity levels and provide key information for studying the carbon sink potential of boreal forests.

The number of urban vitality assessment studies is rising continuously, owing to the emergence of geographic data. The current literature focuses primarily on evaluation, rather than implementation, of urban vitality. Hence, a scoping review and research agenda are needed for urban vitality research to be more practical. This study aims to fill the research gap by exploring the content and methods of vitality assessment that can make urban vitality research more compatible with policy, planning, and design practice. We chose the neighborhood scale, which is the most practical initiative unit for vitality enhancement. We discovered that the gaps between the current research and practice primarily lie in the diversity of research subjects, the authenticity and comprehensiveness of vitality measurement, and the multi-domain of impact factor analysis. On this basis, we classified the following expandable aspects: (1) multi-type, multi-dimensional, multi-temporal, and implementation-adaptive vitality evaluation; (2) methods reflecting high-quality social interactions and the perceptions of vulnerable groups; (3) how design and urban management impacts vitality; and (4) the synergistic effects of multiple indicators on vitality. Overall, the research content and methodology presented in this paper can help neighborhood-scale vitality assessment to provide more meaningful insights for policy makers and practitioners.

Climate change is manifesting rapidly in the form of fires, droughts, floods, resource scarcity, and species loss, and remains a global risk. Owing to the disaster risk management, there is a need to determine the Dead Fuel Index (DFI) threshold of the fire occurrence area and analyze the spatio-temporal variation of DFI to apply prevention measures efficiently and facilitate sustainable fire risk management. This study used the MODIS Burned Area Monthly L3 (MCD64A1), Landsat Global Burned Area (BA) products, and MODIS Surface Reflectance 8-Day L3 (MOD09A1) data from 2001 to 2020 to calculate the values of the DFI in the study area before the occurrence of fire. The results showed that: (1) The inversion of the meadow steppe DFI values in the fire area was distributed in the range of 14-26, and the fire rate was the highest in the range of 20-22. The inversion of the typical steppe DFI values in the fire area was distributed in the range of 12-26, and the fire rate was the highest in the range of 16-22. (2) Areas with high fire DFI values included Khalkhgol, Matad, Erdenetsagaan, Bayandun, Gurvanzagal, Dashbalbar in Mongolia, and scattered areas of the Greater Khingan Mountains (forest edge meadow steppe area), East and West Ujumqin Banner, and Xin Barag Right Banner. The highest fire probability of fire occurred during October and April. (3) The DFI values were sensitive to changes in altitude. The results of this study may provide useful information on surface energy balance, grassland carbon storage, soil moisture, grassland health, land desertification, and grazing in the study area, especially for fire risk management.

Ecosystem services are the media and channels through which ecological elements, structures, functions, and products benefit human society. Regulating the utilization intensity and protection methods of society on the ecosystem according to the ecosystem service value (ESV) and its influencing mechanism is of great significance for achieving the sustainable development goals. This paper takes the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) as the research object and describes the spatiotemporal evolution characteristics of ESV in the GBA from 2000 to 2015. Panel quantile regression is also implemented to increase the understanding of the influencing mechanism of ESV. The main results are as follows: (1) From 2000 to 2015, the total ESV declined with a decreasing rate. The areas of decline were mainly distributed in the central part of the GBA and areas along the Pearl River Estuary. (2) Elasticity index, indicating response of ESV to land use change, reached its peak (1.08). The spatial distribution of elasticity index showed that land use changes brought about more intense ESV variations at the junction of cities. (3) In areas with different ESV levels, the influencing factors have different effects. Land use integrity can only promote ecosystem service capabilities in low-ESV areas. The positive effect of temperature on ecosystem service capacity increases with the increase of ESV, which reflects the self-reinforcement of the ecosystem. Moreover, the negative effect of economic density on ecosystem service capacity decreases with the increase of ESV, which reflects the self-protection of the ecosystem. The combination of such self-reinforcement and self-protection will lead to an ESV gap between the high- and low-ESV areas, and induce the “natural Matthew effect.”

Yield forecasting can give early warning of food risks and provide solid support for food security planning. Climate change and land use change have direct influence on regional yield and planting area of maize, but few studies have examined their synergistic impact on maize production. In this study, we propose an analysis framework based on the integration of system dynamic (SD), future land use simulation (FLUS) and a statistical crop model to predict future maize yield variation in response to climate change and land use change in a phaeozem region of central Jilin province, China. The results show that the cultivated land is likely to reduce by 862.84 km² from 2030 to 2050. Nevertheless, the total maize yield is expected to increase under all four RCP scenarios due to the promotion of per hectare maize yield. Among the scenarios, RCP4.5 is the most beneficial to maize production, with a doubled total yield in 2050. Notably, the yield gap between different counties will be further widened, which necessitates the differentiated policies of agricultural production and farmland protection, e.g., strengthening cultivated land protection and crop management in low-yield areas, and taking adaptation and mitigation measures to coordinate climate change and production.

The degradation of ecosystem structure and function on the Qinghai-Tibet Plateau is the result of a combination of natural and anthropogenic factors, with landscape change driven by global change and human activities being one of the major ecological challenges facing the region. This study analyzed the spatiotemporal characteristics of ecosystem services (ESs) and landscape patterns in eastern Qinghai province (EQHP) from 2000 to 2018 using multisource datasets and landscape indices. Three ecosystem service bundles (ESBs) were identified using the self-organizing map (SOM), and changes in ecosystem structure and function were analyzed through bundle-landscaped spatial combinations. The study also explored the interactions between ESs and natural and human factors using redundancy analysis (RDA). We revealed an increase in total ecosystem service in the EQHP from 1.59 in 2000 to 1.69 in 2018, with a significant change in landscape patterns driven by the conversion of unused land to grassland in the southwest. Forestland, grassland, and unused land were identified as important to the supply of ESs. In comparison to human activities, natural environmental factors were found to have a stronger impact on changes in ESs, with vegetation, meteorology, soil texture, and landscape composition being the main driving factors. However, the role of driving factors within different ESBs varied significantly. Exploring the response of ecosystem services to changes in landscape patterns can provide valuable insights for achieving sustainable ecological management and contribute to ecological restoration efforts.

Construction land is the leading carrier of human activities such as production and living. Evaluating the construction land suitability (CLS) on the Qinghai-Tibet Plateau (QTP) holds significant implications for harmonizing the relationship between ecological protection and human activity and promoting population and industry layout optimization. However, no relevant studies provide a complete CLS assessment of the QTP. In this study, we developed a model-based CLS evaluation framework coupling of pattern and process to calculate the global CLS on the QTP based on a previously developed CLS evaluation model. Then, using the land-use data of 1990, 2000, 2010, and 2020, we examined the adaptability of existing construction land (ECL) to the CLS assessment result through the adaptability index and vertical gradient index and further analyzed the limitations of maladaptive construction land. Finally, we calculated the potential area of reserve suitable construction land. This article includes four conclusions: (1) The highly suitable, suitable, moderately suitable, marginally suitable, and unsuitable CLS classes cover areas of 0.33×10⁴ km², 10.42×10⁴ km², 18.06× 10⁴ km², 24.12×10⁴ km², and 205.29×10⁴ km², respectively. Only approximately 11% of the study area on the QTP is suitable for large-scale permanent construction land, and approximately 79.50% of the area is unsuitable under current economic and technological conditions. (2) The ECL adaptability index is 85.16%, 85.93%, 85.18%, and 78.01% during 1990-2020, respectively, with an average adaptability index exceeding 80% on the QTP. The ECL distribution generally conforms to construction land suitable space characteristics but with a significant spatial difference. (3) From 1990 to 2020, the maladaptive ECL was dominated by rural settlement land, transport land, and special land, with a rapidly increasing proportion of urban and other construction land. The maladaptive ECL is constrained by both elevation and slope in the southern Qinghai Plateau, the Hengduan Mountains, and the Qilian Mountains. In contrast, elevation is significantly more limiting than slope in the northern Tibet Plateau, the Gangdis Mountains, and the Himalayan Mountains. (4) The potential area of reserve suitable construction land is 12.41×10⁴ km², accounting for 4.81% of the total land area of the QTP, and the per capita area is 9928 m². Regions of Qaidam Basin, Gonghe Basin, and Lhasa-Shannan Valley have the richest and most concentrated land resource of reserve suitable construction land. The research results provide spatial decision support for urban and rural settlement planning and ecological migration on the QTP.

Climate change and human activities have profoundly altered ecosystem services in the Yellow River Basin (YRB) since the Grain for Green project was implemented, but have not been accurately revealed on a year-by-year scale. This study combined the InVEST model to reveal the year-by-year changes in the water-related ecosystem services (WRESs) in YRB during 1990-2020, including water yield, soil conservation and water purification services. The trade-off/synergy of WRESs and impacts of land management measures on WRESs were assessed fully. The results showed that from 1990 to 2020, cropland and barren land were considerably converted to forest and grassland in YRB. WRESs were continuously improved as a result of increase of water yield and reductions of soil export and nitrogen export, at rates of +1.11 mm·yr^-1, -0.23 t·km^-2·yr^-1 and -1.01 kg·km^-2·yr^-1, respectively. We found that in YRB water purification service showed trade-off relationships with soil conservation and water yield services in recent decades, and water yield and soil conservation maintained a synergitic effect. Additionally, the revegetation measures showed a potential of enhancing soil conservation and water purification, but reducing water yield. This study provided a thorough understanding of WRESs dynamics and a valuable reference for the ecological restoration practices.

Under the framework of ecological civilisation, the formulation of territorial spatial planning (TSP) and improvement of spatial governance systems are of great practical significance. Since the founding of the People’s Republic of China, land-use planning (LUP) has experienced profound changes, and tremendous research efforts have been made in that field. However, systematic studies on LUP history are scarce. To bridge the existing gap, this study traced back to the emergence of LUP, described its practice stages, and analysed the evolution of its classification system and methods. Further, the three rounds of general LUP practice and the current TSP over the past 40 years of the reform and opening-up have been discussed. The evolution of LUP was found to be closely related to economic development and could be broadly divided into four stages. The development of land-use classification in China has been slow and can be divided into five stages according to the evolution of the land classification system and important historical events. The development of LUP methods can be divided into two stages, before and after 1978. Since the economic reform, China has successively conducted three rounds of general LUP under different institutional and policy backgrounds. Future development should aim to innovate the theories and methods of TSP with Chinese characteristics and promote the study of village planning and the construction of TSP systems to achieve rural revitalisation and ecological civilisation.

Karst depressions are common negative topographic landforms formed by the intense dissolution of soluble rocks and are widely developed in Guizhou province. In this work, an inventory of karst depressions in Guizhou was established, and a total of approximately 256,400 karst depressions were extracted and found to be spatially clustered based on multidistance spatial cluster analysis with Ripley's K function. The kernel density (KD) can transform the position data of the depressions into a smooth trend surface, and five different depression concentration areas were established based on the KD values. The results indicated that the karst depressions are clustered and developed in the south and west of Guizhou, while some areas in the southeast, east and north have poorly developed or no clustering. Additionally, the random forest (RF) model was used to rank the importance of factors affecting the distribution of karst depressions, and the results showed that the influence of lithology on the spatial distribution of karst depressions is absolutely dominant, followed by that of fault tectonics and hydrological conditions. The research results will contribute to the resource investigation of karst depressions and provide theoretical support for resource evaluation and sustainable utilization.

Spatial-temporal scales effects are general among human-nature interactions. However, the laws and mechanisms of the interaction between humans and the environment at different spatial-temporal scales remain to be identified. The Hexi Corridor in Northwest China is located in the eastern section of the Silk Road and is one of the world’s first long-distance cultural exchange centers. Here we present a comprehensive dataset of the Hexi Corridor, including changes in environments, population, wars, famines, settlements, and ancient oases from the Neolithic to the historic period. Results show that humans adapt to climate change on the millennium scale by choosing corresponding production methods. Environmental change, civilization evolution, and dynasty replacement interrelate on the decadal and centennial scales. Social crises are closely linked to extreme weather events on the interannual scale. On the basis of these results, we find similar time scale effects in the world’s major ancient civilizations. We do so by analyzing their processes of civilization evolution.

Effective soil particle size composition can more realistically reflect the particle size sorting process of erosion. To reveal the individual contributions of rainfall intensity and slope to splash erosion, and to distinguish the enrichment ratio of each size and the critical size in splash, loessial soil collected on the Loess Plateau in May 2019 was tested under different rainfall intensities (60, 84, 108, 132, 156 mm h^-1) and slopes (0°, 5°, 10°, 15°, 20°). The results demonstrated that 99% of splash mass was concentrated in 0-0.4 m. Rainfall intensity was the major factor for splash according to the raindrop generation mode by rainfall simulator nozzles. The contributions of rainfall intensity to splash erosion were 82.72% and 93.24%, respectively in upslope and downslope direction. The mass percentages of effective clay and effective silt were positively correlated with rainfall intensity, while the mass percentages of effective very fine sand and effective fine sand were negatively correlated with rainfall intensity. Opposite to effective very fine sand, the mass percentages of effective clay significantly decreased with increasing distance. Rainfall intensity had significant effects on enrichment ratios, positively for effective clay and effective silt and negatively for effective very fine sand and effective fine sand. The critical effective particle size in splash for loessial soil was 50 μm.

The leaf area index (LAI) shows a significant increasing trend from global to regional scales, which is known as greening. Greening will further enhance photosynthesis, but it is unclear whether the contribution of greening has exceeded the CO₂ fertilization effect and become the dominant factor in the gross primary productivity (GPP) variation. We took the Yangtze River Delta (YRD) of China, where cropland and natural vegetation are significantly greening, as an example. Based on the boreal ecosystem productivity simulator (BEPS) and Revised-EC-LUE models, the GPP in the YRD from 2001 to 2020 was simulated, and attribution analysis of the interannual variation in GPP was performed. In addition, the reliability of the GPP simulated by the dynamic global vegetation model (DGVM) in the area was further investigated. The research results showed that GPP in the YRD had three significant characteristics consistent with LAI: (1) GPP showed a significant increasing trend; (2) the multiyear mean and trend of natural vegetation GPP were higher than those of cropland GPP; and (3) cropland GPP showed double-high peak characteristics. The BEPS and Revised-EC-LUE models agreed that the effect of LAI variation (4.29 Tg C yr^-1 for BEPS and 2.73 Tg C yr^-1 for the Revised-EC-LUE model) determined the interannual variation in GPP, which was much higher than the CO₂ fertilization effect (2.29 Tg C yr^-1 for BEPS and 0.67 Tg C yr^-1 for the Revised-EC-LUE model). The GPP simulated by the 7 DGVMs showed a huge inconsistency with the GPP estimated by remote sensing models. The deviation of LAI simulated by DGVM might be a potential cause for this phenomenon. Our study highlights that in significant greening areas, LAI has dominated GPP variation, both spatially and temporally, and DGVM can correctly simulate GPP only if it accurately simulates LAI variation.

Megacities serve as global centers for economic, cultural, and high-tech industries. The structural features and population agglomerations are typical traits of urbanization, yet little is known about the morphological features and expansion patterns of megacities worldwide. Here we examined the spatiotemporal variations of urban land in megalopolises from 2000 to 2020 using the Urban Expansion Intensity Differentiation Index. The fractal features and expansion patterns of megacities were analyzed using the Area-Radius Multidimensional Scaling Model. Urban land use efficiency was then evaluated based on the linear relationship between urban land area and population. We found that Southeast Asia and China were the hotspots of urban expansion in megacities from 2000 to 2020, with urban land areas expanding by 3148.32 km² and 5996.26 km², respectively. The morphological features and expansion patterns of megacities exhibited a growing trend towards intensification and compactness, with the average radial dimension increasing from 1.54 to 1.56. The annual decrease in fractal dimensions indicated the integration of inner urban areas. North America and Europe megacities showed a low urban land use efficiency, with a ratio of urban land area to population ranging from 0.89 to 4.11 in 2020. Conversely, South Asia and Africa megacities exhibited a high urban land use efficiency, with the ratios between 0.23 and 0.87. Our results provide information for promoting efficient urban land utilization and sustainable cities. It is proposed to control the scale of urban expansion and to promote balanced development between inner and outer urban areas for achieving resilient and sustainable urban development.