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As an emerging national strategic urban agglomeration in China, the changing trend of vegetation net primary productivity (NPP) and the impact of the urbanization level (UL) on carbon cycle functions in the Chengdu–Chongqing urban agglomeration (CUA) have received increasing attention. Previous studies have largely overlooked externalities and the heterogeneity of urbanization effects, and urbanization has also been analyzed in isolation (with focus being on land and population urbanization). In this study, the spatial evolution of NPP was evaluated from 2000 to 2020 at the township level (3859) using multivariate remote sensing data and a comprehensive index (UL) that included population urbanization, land urbanization, and economic urbanization. Bivariate spatial autocorrelation, spatial Durbin models, and geographically weighted regression models were used to analyze the spatial externalities of urbanization impacts and assess the global and local effects. The results show that the region’s mean NPP increased by 177.25 g*c/m2 (annual growth of 1.59%), exhibiting a distribution of “low in the middle and high in the periphery” and low-value clustering along major traffic arteries and rivers. Low-value-NPP areas were mainly located in urban centers, while the high-level areas were in the mountainous region (in the southwest and southeast) and significantly expanded over time. Negative correlation clusters were the main clustering types between the UL and NPP; the “High-Low” negative correlation clusters accelerated outward from the urban centers of Chengdu and Chongqing. Overall, urbanization had negative direct and spillover effects on NPP, exhibiting spatial non-stationarity of the negative driving effect within the urban agglomeration. The results indicate the need to strengthen regional ecological joint governance and adopt more place-based urbanization optimization strategies. This study offers new insights to help to reduce the constraining effects of urbanization on vegetation productivity and ecological functions from the perspectives of population agglomeration, land expansion, and industrial construction.

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Based on the multidisciplinary research perspectives of economics, politics, and international relations, this paper starts with the analysis of the main characteristics of sub-Saharan African countries, analyzes their economic development difficulties and new challenges in the post-epidemic era, discusses the necessity for sub-Saharan African countries to explore the path of autonomous development at the level of economic structural reform and development model, and proposes coping strategies. Sub-Saharan African countries should seize the opportunity to accelerate economic restructuring under the favorable situation of the formal launch of the African Continental Free Trade Area (AfCFTA); take measures to develop agriculture and food production, manufacturing, digital economy, and the AfCFTA construction; and actively cooperate with China and other emerging countries to enhance their capacity for independent development.

Sustainable utilization evaluation is the basis for ensuring the sustainable exploitation of fisheries’ resources. This paper explores the changes in the mean trophic level of African marine fish catches during a 70-year period based on the statistical data on marine fisheries’ catches in Africa from 1950–2019, provided by the FAO in, order to determine the sustainable utilization of Africa’s fishery resources. The results indicate that although the marine fishery resources of African coastal countries have great variability, their exploitation has roughly gone through the stages of under-exploitation, rapid exploitation, and over-exploitation. Currently, marine fisheries in North and Central Africa are characterized by sustainable exploitation, while East, West, and Southern Africa are in a state of overfishing. The study implicates that African countries should establish a real-time monitoring system for marine fishery resources as soon as possible in order to dynamically grasp the actual changes in fish community structure due to fishing activities, ensure transparency in management and decision making, enact marine regulations to restrict massive fishing by overseas fleets, issue fisheries licenses cautiously, adopt conservative resource conservation policies, and enforce actions to achieve sustainable fisheries development.