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With the advancement of global maritime transport, the carriage of foreign organisms by vessels is inciting ecological catastrophes such as red tides, posing a grave threat to China's marine environmental security. Clarifying the geographical distribution of invasive species and their relationship with climate change can provide scientific basis for their prevention and control. In this discourse, the study centers on the typical alien microalgae, Nitzschiella closterium. By integrating environmental variables and distribution data and employing an optimized Maxent model, we delve into its potential distribution in current and future ecological conditions in the coastal waters of China, as well as the response relationship to environmental variables. After model optimization, the results reveal that the Area Under the Curve (AUC) value of the training dataset for Nitzschiella closterium stands at 0.993, denoting a high degree of model accuracy and bestowing credibility upon the simulated outcomes. Currently, the high suitability area constitutes 0.74% of the total suitability area, with an area of 0.44×104 km², and is mainly distributed in the sea area corresponding to Jiangsu Province, Shanghai City, and Zhejiang Province. The most significant environmental factor affecting the geographical distribution of Nitzschiella closterium is the annual temperature variation range (bio24). In the context of future climate changes, there is an overall trend of substantial expansion in the high suitability area for Nitzschiella closterium, which is profoundly affected by climate change, suggesting that the future control will be more severe. This research comprehensively understands the response relationship of the invasive species Nitzschiella closterium to leading environmental variables and its potential geographical distribution in the context of climate change through macro prediction and proposes control countermeasures. It will provide a scientific basis for preventing and controlling Nitzschiella closterium invasions. [ABSTRACT FROM AUTHOR]

Water scarcity is a growing global concern, resulting from drastic climate and societal changes witnessed over the past few decades. Previous attention has predominantly focused on inadequate water quantity as the main cause of water scarcity, but pollution-induced water scarcity has been largely overlooked. Furthermore, there is a lack of understanding about the effectiveness of policy interventions in mitigating water scarcity and its social impact. To address these knowledge gaps, we developed an ecosystem service-based approach to measure quantity- and quality-related water scarcity by comparing supply of and demand for water provision and water purification services. We also developed several water and land management scenarios to examine their potential in alleviating water scarcity under different climate conditions and water quality requirements. Our case study in the Taihu Basin of southeastern China identified four types of water scarcity status across different sub-basins, including quantity-based, quality-based, quantity- and quality-based, and no water scarcity. The degradation of water quality in the Taihu Basin has exacerbated the scarcity of clean water supply. Water conservation measures effectively alleviated quantity-based water scarcity, while nitrogen reduction and grain for green (i.e., conversion of cropland into forest land) exhibited similar efficacy in alleviating quality-based water scarcity. Integrating these measures contributed to alleviating both quantity- and quality-based water scarcity. However, the effectiveness of these measures decreased under drier climate conditions and higher water quality requirements, highlighting the importance of climate and water quality in determining the magnitude, extent, and severity of water scarcity. The approaches and findings presented here provide new insights into the sustainable management of water resources in the Taihu Basin and other similar basins worldwide. • Quantity- and quality-related water scarcity were assessed using an ecosystem service-based approach. • Water scarcity was influenced by changes in climate, land use, and water quality requirement. • Water pollution exacerbated water scarcity in the Taihu Basin of China. • The impact of water scarcity on human populations was further enlarged due to spatial mismatches. • Improved water and land management strategies could potentially alleviate water scarcity. [ABSTRACT FROM AUTHOR]