快速城市化与气候变化的共同胁迫使得高密度城市面临多重生态风险,包括城市热岛、洪涝灾害与空气污染等,这些生态问题不仅影响城市生态系统的稳定性,同时威胁人类福祉。因此,亟需对全球高密度城市的生态问题与应对策略开展研究。以Web o...快速城市化与气候变化的共同胁迫使得高密度城市面临多重生态风险,包括城市热岛、洪涝灾害与空气污染等,这些生态问题不仅影响城市生态系统的稳定性,同时威胁人类福祉。因此,亟需对全球高密度城市的生态问题与应对策略开展研究。以Web of Science和Scopus为文献检索数据源,通过系统性分析258篇文献揭示全球高密度城市生态问题的研究特征。首先,对全球高密度城市关键生态问题的数量分布与地理空间分布特征进行分析;其次,对三大生态问题的影响因素与尺度差异进行讨论,并提出城区与场地尺度下生态问题的应对策略;最后,研究表明城市三维形态、立体生态空间是未来生态问题的重点。研究结论表明:(1)亚洲地区对高密度城市生态问题关注度最高,城市热岛是全球高密度城市研究的热点问题;(2)景观格局特征与建成环境特征是城市热岛与洪涝的重要影响因素,生物物理特征与建成环境特征是空气污染的重要影响因素;(3)优化城市景观构成与空间配置可缓解高密度城市生态问题。研究结果为高密度城市开展生态研究与应对生态风险提供了重要启发。展开更多
Vegetation restoration(VR)is critical for enhancing the resilience of fragile ecosystems,yet its impact on landscape ecological risk(LER)remains uncertain.The VR project on the Loess Plateau in Shaanxi Province(LPSX)w...Vegetation restoration(VR)is critical for enhancing the resilience of fragile ecosystems,yet its impact on landscape ecological risk(LER)remains uncertain.The VR project on the Loess Plateau in Shaanxi Province(LPSX)was taken as a case study to address ecological and environmental challenges,including soil erosion and land degradation.This study used multi-source data,including land cover,fractional vegetation cover,and nighttime light.It employed landscape pattern analysis,spatio-temporal correlation analysis,and causality analysis to assess the impacts.This study found a generally positive relationship between VR and the mitigation of LER in LPSX,though spatial and temporal variations exist from 2000 to 2020.Localized VR significantly influenced 17.66%to 27.03%of the study area.Positive effects were mainly observed in sandy and gully-hilly regions,showing an upward fluctuating trend that peaked at 21.91%in 2010.After 2010,negative effects in the Fen-Wei Plain,Qinling Mountains,and Liupan Mountains outweighed the positive effects and continued to expand.Urbanization had a broader impact on LER distribution compared to VR.The findings indicate that future VR projects should focus on the spatial pattern of restoration and its associated eco-social effects to ensure sustainable development.展开更多
Heavy metal concentrations in surface water and sediments collected from Honghu Lake in Hubei Province, China were analyzed, and ecological risks were evaluated according to the sediment quality guidelines. The result...Heavy metal concentrations in surface water and sediments collected from Honghu Lake in Hubei Province, China were analyzed, and ecological risks were evaluated according to the sediment quality guidelines. The results showed that the average concentrations of heavy metals in surface water were ranked as： As 〉 Zn 〉 Cu 〉 Cr 〉 Pb 〉 Ni 〉 Cd 〉 Hg. In comparison with results reported in other rivers and the background values, The Honghu Lake was polluted by As, Cr, Pb, Cu and Ni. Most of metals might be mainly from fertilizers, industrial effluent and domestic wastewater around the lake. Heavy metals concentrations were relatively higher in the inlet area than in other areas. Negative correlations were observed between most heavy metals and pH, while a significant positive correlation was present between Zn, Cd and Pb. In the sediment core, Cu, Zn, Cr and Ni showed a decreasing trend while Cd present an increasing trend. The decrease of As, Cu, Zn, Cr and Ni in the 1990s might due to the flood event in 1998. The analysis of ecological risk assessment based on sediment quality guidelines suggested that heavy metals in most sediments from the Honghu Lake had moderate toxicity, with Cr being the highest priority pollutant.展开更多
文摘快速城市化与气候变化的共同胁迫使得高密度城市面临多重生态风险,包括城市热岛、洪涝灾害与空气污染等,这些生态问题不仅影响城市生态系统的稳定性,同时威胁人类福祉。因此,亟需对全球高密度城市的生态问题与应对策略开展研究。以Web of Science和Scopus为文献检索数据源,通过系统性分析258篇文献揭示全球高密度城市生态问题的研究特征。首先,对全球高密度城市关键生态问题的数量分布与地理空间分布特征进行分析;其次,对三大生态问题的影响因素与尺度差异进行讨论,并提出城区与场地尺度下生态问题的应对策略;最后,研究表明城市三维形态、立体生态空间是未来生态问题的重点。研究结论表明:(1)亚洲地区对高密度城市生态问题关注度最高,城市热岛是全球高密度城市研究的热点问题;(2)景观格局特征与建成环境特征是城市热岛与洪涝的重要影响因素,生物物理特征与建成环境特征是空气污染的重要影响因素;(3)优化城市景观构成与空间配置可缓解高密度城市生态问题。研究结果为高密度城市开展生态研究与应对生态风险提供了重要启发。
基金the National Social Science Foundation of China(Grant No.23AZD062).
文摘Vegetation restoration(VR)is critical for enhancing the resilience of fragile ecosystems,yet its impact on landscape ecological risk(LER)remains uncertain.The VR project on the Loess Plateau in Shaanxi Province(LPSX)was taken as a case study to address ecological and environmental challenges,including soil erosion and land degradation.This study used multi-source data,including land cover,fractional vegetation cover,and nighttime light.It employed landscape pattern analysis,spatio-temporal correlation analysis,and causality analysis to assess the impacts.This study found a generally positive relationship between VR and the mitigation of LER in LPSX,though spatial and temporal variations exist from 2000 to 2020.Localized VR significantly influenced 17.66%to 27.03%of the study area.Positive effects were mainly observed in sandy and gully-hilly regions,showing an upward fluctuating trend that peaked at 21.91%in 2010.After 2010,negative effects in the Fen-Wei Plain,Qinling Mountains,and Liupan Mountains outweighed the positive effects and continued to expand.Urbanization had a broader impact on LER distribution compared to VR.The findings indicate that future VR projects should focus on the spatial pattern of restoration and its associated eco-social effects to ensure sustainable development.
基金Acknowledgements This work was financially supported by the National Natural Science Foundation of China （Grant No. 41073070） and the Research Fund for the Doctoral Program of Higher Education, China （No. 20090145110004）. The authors are grateful to acknowledge the State Laboratory of Biogeology and Environmental Geology. The authors also would like to appreciate the reviewers for their suggestions.
文摘Heavy metal concentrations in surface water and sediments collected from Honghu Lake in Hubei Province, China were analyzed, and ecological risks were evaluated according to the sediment quality guidelines. The results showed that the average concentrations of heavy metals in surface water were ranked as： As 〉 Zn 〉 Cu 〉 Cr 〉 Pb 〉 Ni 〉 Cd 〉 Hg. In comparison with results reported in other rivers and the background values, The Honghu Lake was polluted by As, Cr, Pb, Cu and Ni. Most of metals might be mainly from fertilizers, industrial effluent and domestic wastewater around the lake. Heavy metals concentrations were relatively higher in the inlet area than in other areas. Negative correlations were observed between most heavy metals and pH, while a significant positive correlation was present between Zn, Cd and Pb. In the sediment core, Cu, Zn, Cr and Ni showed a decreasing trend while Cd present an increasing trend. The decrease of As, Cu, Zn, Cr and Ni in the 1990s might due to the flood event in 1998. The analysis of ecological risk assessment based on sediment quality guidelines suggested that heavy metals in most sediments from the Honghu Lake had moderate toxicity, with Cr being the highest priority pollutant.
