Since the 1970s, resource crisis, environmental pollution and ecological degradation have become prominent globally, and the limits to growth have always been an important theoretical and policy issue. The technological system of early warning and regulation based on carrying capacity evaluation has great potential in natural resource utilization, environmental management and ecosystem conservation. In this paper, the evolution of carrying capacity research and the concept of ecological carrying capacity are summarized, and the existing evaluation methods of ecological carrying capacity are classified into ecological footprint method, comprehensive index system method, ecosystem service analysis method and human appropriation of net primary productivity method. The current problems in ecological carrying capacity study were analyzed and the trend was outlooked. Combined with the special issue, the recent proceeding of ecological carrying capacity study in the Belt and Road Initiative (BRI) region was narrated, from the aspects of ecological carrying capacity evaluation method and application, the supply and consumption of ecosystem services, and the resources use and environment change. Some suggestions have been proposed to improve the accuracy and reliability of ecological carrying capacity evaluation: 1) the spatial heterogeneity and temporal dynamic change of ecological carrying capacity should be explored furtherly; 2) the interaction between ecological process and human activities should be simulated; 3) factors such as climate change, human activities and ecological products and ecological service flows should be integrated into the evaluation system of ecological carrying capacity.

Most countries along the route of the “Belt and Road” initiative are faced with a shortage of water resources. However, successful implementation of the initiative depends on water availability to support economic and social development. We designed a water resources carrying capacity evaluation index system, assigned grades and weights to each evaluation index and calculated a water resources carrying index for the 65 countries along the route. We used virtual water theory to analyze China's net virtual water import from key bulk agricultural products through international trade. For more than half of the countries along the route, their water resources will be unable to support the economic development that will be necessary for fulfilling the goals of the Initiative. As a country with insufficient water resources carrying capacity, China is a net virtual water importer in the virtual water trade. This virtual water trade can improve China's water resources support capacity, and ensure China's water and food security for the future.

In the context of global ecological overload, international trade has become one of the most important ways to make up for the ecological deficit. This study takes the “Belt and Road” Initiative as the study area to analyze the biocapacity and ecological footprint characteristics between China and other countries along the “Belt and Road” Initiative. Trade flow characteristics were explored from the perspective of biocapacity. The import and export of virtual land was used to assess the effect of trade on compensating for the resource gaps in crop and grazing land. The main results show that: 1) In 2005–2014, the majority of “Belt and Road” countries were experiencing increasing degrees of overload. In China, cropland takes up the largest proportion of biocapacity, while the ecological footprint is dominated by the carbon footprint. 2) The trade flow of agricultural and livestock products in the mainland of China shows a trend of increasing imports and decreasing exports, which increases dependence on specific regions. 3) In 2005–2014, China's trade in cereals and oil crops along the “Belt and Road” Initiative were generally net imports, and the share of cereals traded along the “Belt and Road” Initiative is increasing gradually, but that of oil crops decreased rapidly. 4) The import trade has alleviated ecological deficit, as the selected products compensated for 1.03 times of the cropland deficit and 0.65 times of the grazing land deficit in China. This study is helpful to understand the relationship between the land use and trade deeply, and provide decision-making references for reducing ecological deficits, optimizing land resource allocation, and promoting win–win cooperation among China and other countries in the “Belt and Road” Initiative.

Grassland ecosystems are one of the most important terrestrial ecosystems on the earth. Central Asia has the largest contiguous grazing area in the world and good conditions for the development of animal husbandry. However, in the past 30 years, the grassland ecosystem in Central Asia has experienced significant degradation, and the livestock industry has also experienced an overall decline to the point that livestock products are now dependent on imports. The ecological footprint method was used to analyze the change trend and characteristics of grassland ecological carrying capacity and ecological occupation in Central Asia. The grassland ecological capacity in Central Asia was found to be much higher than the global level, and great potential still remains for further development and utilization. The international trade of livestock products in Central Asian countries showed a deficit, and the net import of livestock products increased year by year. Net imports reached 9.5% in 1992–2016, and the dependence on foreign countries increased significantly, which is not conducive to the sustainable development of animal husbandry in Central Asia. In the future, the counties of Central Asia should optimize the aspects of policy, management and technology to improve the productivity of grassland animal husbandry, strengthen grassland ecological protection, and realize the coordinated and sustainable development of their grassland ecological economic systems.

Determining the carrying capacity of ecological resources is the key to finding contradictions between human activities and the environment, as well as the links between economic growth, environmental protection and social development. In recent years, the carrying capacity of the ecological environment has been extensively studied at home and abroad. Through extensive literature research and analysis, this paper discusses the current status and main problems of recent research on the carrying capacity of the ecological environment in China. For example, two of the main problems are that: 1) the concepts and connotations are not clear enough, and 2) the research content is not systematic enough. This is followed by a summary of the evaluation index system and main calculation methods. Finally, according to the research status and development trends at home and abroad, the possible direction for the development of this research field in the future is proposed.

Food safety is an important issue for the development of the national economy and society. Studying regional food supply and demand from the perspective of land resource carrying capacity can provide new references for regional resource sustainability. This study uses the data from farmer and herdsmen household questionnaires, statistical data, land use data, and other sources to construct a land resource carrying capacity (LCC) assessment framework, targeting the food supply and demand of residents in representative areas, specifically the typical grassland pastoral areas, sandy pastoral areas and agro-pastoral areas on the Xilin Gol grassland transects. The three food nutritional indicators of calories, protein and fat were selected for analyzing the balance of land resource carrying capacity. We found that: 1) Along the Xilin Gol grassland, the main local food supply showed a shift from meat and milk to grains, vegetables and fruits. 2) From north to south along the grassland transects, the calorie intake increased gradually, while the intake of protein and fat was highest in pastoral areas and lowest in agricultural areas. 3) The overall land resource carrying capacity of the Xilin Gol grassland transects was in a surplus state, but the land carrying capacity of typical grassland pastoral area was higher than the two other types of areas. This study provides an empirical reference for the sustainable development of regional food nutrition.

With great significance in ecosystem protection and sustainable development, the study of ecosystem service consumption (ESC) has become a hot topic in ecological research. Based on FAOSTAT data, in this study the patterns, composition and evolution of ESC and ecosystem service consumption patterns (ESCP) in the “Belt and Road” were revealed on the total and regional scales, taking consumed-biomass as a main indicator. Three main conclusions were reached. 1) The total ESC was mainly contributed from farmland ecosystems along the “Belt and Road” , followed by grassland ecosystems. The ESC indicators on the whole system scale fluctuated, but increased from year 2000 to year 2016. The total ESC increased from 12911.89 Tg yr^–1 to 16810.00 Tg yr^–1, and the annual per capita consumption of ecosystem services increased from 3.3228 million g p^–1 yr^–1 to 3.6392 million g p^–1 yr^–1. 2) The ESC, composition and evolution varied significantly among countries, zones and ecosystems. The annual per capita ESC was highest in Mongolia on the national scale, and highest in Central and Eastern Europe and lowest in Southeast Asia on zone scale, which represented the results from the joint effects of regional resource endowments, consumption habits, levels of productive forces, and other factors. 3) Higher farmland ESC was the dominant ESCP, which accounted for about 76.7% of the total area along the “Belt and Road”, followed by higher farmland + higher grassland ESC, which accounted for about 19.0% of the total area. The other consumption patterns (i.e., those of higher grassland ESC, higher forestland ESC or higher farmland + higher forest + higher grassland ESC) were found in only a few countries. The ESCP may be related to higher regional population density or the higher proportions of developing countries. Therefore, to realize sustainable social, economic and ecological development, and to improve people's well-being, countries along the “Belt and Road” should take advantage of their own resources in developing industries, actively expand trade, achieve mutual benefits and win-win situations, and adjust and optimize consumption patterns of ecosystem services. This study can provide data support for further research on the mechanism of ESCP formation this area.

In Nepal, nearly half of the total land is covered by forest, which holds a potentially important position in promoting rural livelihoods and in alleviating rural poverty. The rural landscape that encompasses an agrarian economy, a fragile ecology, and a complex and differentiated society is changing rapidly in Nepal today. Although poverty alleviation has been one of the top priorities for national development since 1976, poverty still remains widespread, persistent and it is also an acute problem in Nepal, where people are in a state of deprivation with regard to incomes, clothing, housing, healthcare, education, sanitary facilities and human rights. Thus, Nepal is considered as one of the poorest countries in South-Asia, with 25.2% people living below the poverty line. The objective of this study was to assess changes in poverty of forest users brought on by the community forestry program, in order to analyze the level of participation in community forestry management activities. For this study, Bajhang district was chosen as the study site, which is one of the poorest and most remote districts in the country of Nepal. Different Participatory Rural Appraisal methods such as face-to face interviews, focus group discussions and key informants' interviews including secondary data were used to gather information. The findings showed that the forest users' participation in meetings, discussion and other activities, like community forestry management or silvicultural operation related to community forestry, was high. The assessment found that 42.3%, 32.6% and 25.1% of respondents strongly agreed, agreed and were neutral, respectively, towards the idea that poverty reduction from community forests had occurred. The results showed almost all the respondents were depended upon agriculture and/or forest resources for their livelihoods. Different ecosystem services such as ethnomedicines, aesthetic value and ecotourism, control of soil erosion/land-slides, water recharge and soil fertility have increased due to the decomposition of leaf litter. This was apparent from the formulation of community forests. Poverty in rural areas of the country is still higher than in urban areas and the incidence of poverty is the highest in the Far western Province where this research was conducted, Therefore, the government, policy makers and other stakeholders should work hand-in-hand to effectively reduce the poverty that persists in Nepal.

The exponential increase of ecosystem utilization has instigated a serious conflict between ecosystem services and residents' needs. The Belt and Road Initiative has greatly influenced Laotian production and living, and the scientific assessment of the consumption of ecosystem services in Laos is important for exploring residents' influence on the ecosystem. Based on data for the Laotian consumption of agricultural products, fruits and livestock products during 1961–2013, normalized by either harvest index or feed conversion ratio, this study draws three main conclusions. 1) Ecosystem service consumption in Laos is centered on the consumption of farmland, forestry and grassland ecosystem services, which account for over 80%, over 10% and under 2%, showing downward, upward and constant trends, respectively. The consumption of these ecosystem services shows a trend of increasing first, then fluctuating, and finally increasing. 2) The consumption of ecosystem services in Laos was characterized by the mode of “dominance of consumption of the farmland ecosystem services” from 1961 to 2008, and the mode of “balanced development of consumption of farmland, forest and grassland ecosystem services” from 2008 to 2013, with a trend of transformation from the former into the latter. 3) The formation and change in the consumption mode of Laotian ecosystem services have been affected by both supply and trade. Laos developed agriculture mainly during the period from 1961 to 2008, forming the mode of “dominance of consumption of the farmland ecosystem services”. This development benefited from the enriched varieties of imports as well as the increased value of trade and import volume. However, the consumption of ecosystem services in Laos after 2008 changed from the mode of “dominance of consumption of the farmland ecosystem services” to one of “balanced development of consumption of farmland, forest and grassland ecosystem services”. This study provides an empirical reference for research on the consumption of ecosystem services.

The countries along the “Belt and Road” (B&R) should devote their efforts to top-level planning in the field of agriculture, so as to ensure the sustainable development of agriculture in the region. This will require a precise assessment of the sustainability of agriculture along the B&R. With a view to understanding the concept of sustainable agriculture along the B&R, combined with the interpretation of the agricultural objectives contained in the United Nation's Sustainable Development Goals (SDGs), this study uses statistical regression analysis and trend prediction to predict the social and economic development trends in terms of economic growth and urbanization in the countries along the B&R up until 2030, and the corresponding impacts on agricultural resources and the environment. The results show that the future prospects for agricultural resources and the environment along the B&R are not promising, and meeting the future food security needs of the region will be difficult. Only by adopting innovative policies and implementing strategic planning can the goals of sustainable agricultural development and food security by 2030 be achieved in this region. Therefore, countries along the B&R should formulate agricultural development strategies from three aspects: building an agricultural cooperation platform, setting up special funds, and innovating the agricultural cooperation mode, so as to achieve the sustainable development of agriculture in the region.

The duration of travel climate comfort degree is an important factor that influences the length of the tourism season and the development of a tourism destination. In this study, we used the monthly average meteorological data for the last 10 years from 46 weather stations in Heilongjiang Province (China) and Primorsky Krai (Russia) to calculate the temperature–humidity index (THI) and wind chill index (WCI) based on ArcGIS software interpolation technology. We obtained the climate comfort charts of the study area with a grid size a 1 km² grid size, and analyzed the spatial distribution of comfort for each month. The results show the following: 1) The THI and WCI of the cross-border region gradually decrease from south to north and from low altitude to high altitude. The annual comfortable climate period is longer when analyzed in terms of the WCI rather \than the THI. 2) The travel climate comfortable period of the study area shows significant regional difference and the length of the comfortable period in Heilongjiang Province is 4 to 5 months. Meanwhile, the period in Primorsky Krai decreases from south to north and the length of the comfortable period length in its southern region can reach 7 months. 3) The predominant length of the climate comfortable period in the cross-border area is 5 months per year, and it covers 46.6% of the total area, while areas that have a climate comfortable period of 2 months are the most limited, covering less than 0.3% of the area. The results provide a scientific basis for the utilization and development of a meteorological tourism resources and touring arrangements for tourists in the cross-border region between China and Russia.

Affected by climate change and policy factors, Kazakhstan is the country with the most severe ecological degradation and grassland conflicts in Central Asia. Therefore, studying the state of grassland carrying resources in Kazakhstan is particularly important for understanding the responses of grassland ecosystems to climate change and human activities. Based on Kazakhstan's remote sensing data and animal husbandry statistics, this study analyzes the patterns of changes in grassland ecosystems in Kazakhstan based on the supply and consumption of these ecosystems. The results show that: 1) From 2003 to 2017, the number of livestock raised in Kazakhstan showed a trend of sustained and steady growth. Due to freezing damage, the scale of livestock farming decreased in 2011, but a spatial difference in the livestock farming structure was not obvious. 2) The fluctuation of grassland supply in Kazakhstan has increased, while the consumption due to animal husbandry has also continued to increase, resulting in an increasing pressure on the grassland carrying capacity. 3) Between 2003 and 2017, the overall grassland carrying status of Kazakhstan have been abundant, but the grassland carrying pressure index has shown a steadily increasing trend, the grassland carrying pressure is growing, and it is mainly determined by grassland productivity. The greater pressure in lower Kyzylorda state, the southern Kazakhstan state of the cultivated land and the northern Kazakhstan state has gradually expanded to include the agro-pastoral zone and the semi-desert zone.

Mongolia is an important part of the Belt and Road Initiative “China-Mongolia-Russia Economic Corridor” and a region that has been severely affected by global climate change. Changes in grassland production have had a profound impact on the sustainable development of the region. Our study explored an optimal model for estimating grassland production in Mongolia and discovered its temporal and spatial distributions. Three estimation models were established using a statistical analysis method based on EVI, MSAVI, NDVI, and PsnNet from Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing data and measured data. A model evaluation and accuracy comparison showed that an exponential model based on MSAVI was the best simulation (model accuracy 78%). This was selected to estimate the grassland production in central and eastern Mongolia from 2006 to 2015. The results show that the grassland production in the study area had a significantly fluctuating trend for the decade study; a slight overall increasing trend was observed. For the first five years, the grassland production decreased slowly, whereas in the latter five years, significant fluctuations were observed. The grassland production (per unit yield) gradually increased from the southwest to northeast. In most provinces of the study area, the production was above 1000 kg ha^-1, with the largest production in Hentiy, at 3944.35 kg ha^-1. The grassland production (total yield) varied greatly among the provinces, with Kent showing the highest production, 2341.76×10⁴ t. Results also indicate that the trend in grassland production along the China-Mongolia railway was generally consistent with that of the six provinces studied.

This paper aims to explore the determinants of CO₂ emissions in Laos by accounting for the significant role played by foreign direct investment (FDI) in influencing CO₂ emissions during the period 1990–2017. We apply a Johansen co-integration testing approach to investigate the presence of co-integration, and the empirical findings underscore the presence of a long-run co-integration relationship between CO₂ emissions, FDI, per capita GDP, and industrial structure. We also employ an error-correcting model to examine the short-term dynamic effect of FDI on CO₂ emissions. The empirical results show that FDI has a significant short-term dynamic effect on changes in CO₂ emissions, indicating that the relationship between FDI and CO₂ emissions is an inverted U-shaped curve. This is a validation of the EKC. Changes of FDI, per capita GDP, and industrial structure increase CO₂ emissions. Based on the analysis results, this paper puts forward policy suggestions emphasizing the need for both Laotian policymakers and Chinese investors to improve eco-environmental quality.

Desertification research plays a key role in the survival and development of all mankind. The Normalized Comprehensive Hotspots Index (NCH) is a comprehensive index that reveals the spatial distribution of research hotspots in a given research field based on the number of relevant scientific papers. This study uses Web Crawler technology to retrieve the full text of all Chinese journal articles spanning the 1980s–2018 in the Chinese Academic Journal full-text database (CAJ) from CNKI. Based on the 253,055 articles on desertification that were retrieved, we have constructed a research hotspot extraction model for desertification in China by means of the NCH Index. This model can reveal the spatial distribution and dynamic changes of research hotspots for desertification in China. This analysis shows the following: 1) The spatial distribution of research hotspots on desertification in China can be effectively described by the NCH Index, although its application in other fields still needs to be verified and optimized. 2) According to the NCH Index, the research hotspots for desertification are mainly distributed in the Agro-Pastoral Ecotone and grassland in Inner Mongolia, the desertification areas of Qaidam Basin in the Western Alpine Zone and the Oasis-Desert Ecotone in Xinjiang (including the extension of the central Tarim Basin to the foothills of the Kunlun Mountains, the sporadic areas around the Tianshan Mountains and the former hilly belt of the southern foothills of the Altai Mountains). Among these three, the Agro-Pastoral Ecotone in the middle and eastern part of Inner Mongolia includes the most prominent hotspots in the study of desertification. 3) Since the 1980s, the research hotspots for desertification in China have shown a general downward trend, with a significant decline in 219 counties (10.37% of the study area). This trend is dominated by the projects carried out since 2002. The governance of desertification in the eastern part of the Inner Mongolia-Greater Khingan Range still needs to be strengthened. The distribution of desertification climate types reflects the distribution of desertification in a given region to some extent. The Normalized Comprehensive Hotspots Index provides a new approach for researchers in different fields to analyze research progress.