State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, PR China; College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, 311300, PR China; Zhejiang Provincial Key Laboratory of Forest Aromatic Plants-based Healthcare Functions, Zhejiang A&F University, Hangzhou, 311300, PR China.
State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, PR China; College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, 311300, PR China.
J Environ Manage. 2024 Feb;351:119980. doi: 10.1016/j.jenvman.2023.119980. Epub 2024 Jan 4.
In the context of rapid global urbanization, the sustainable development of ecosystems should be considered. Accordingly, the Planetary Boundaries theory posits that reducing the amount of nitrogen and phosphorus pollutants entering bodies of water is necessary as excess levels may harm the aquatic environment and reduce in water quality. Thus, based on the long-term monitoring data of representative urban rivers in the Yangtze River Delta region, we evaluated the nitrogen and phosphorus pollution of water bodies in different urbanization stages and further quantified the effect of urban forests on water quality improvement. The results showed that, with the continuous progression of urbanization, the proportion of impervious surface area increased, along with the levels of nitrogen and phosphorus pollution in water bodies. The critical period of water quality deterioration in urban rivers occurred during the medium urbanization level when the proportion of impervious surface area reached 55-65 %, and the probability of an abrupt increase in total nitrogen (TN) and total phosphorus (TP) concentration exceeded 95 %. However, increasing the area of urban forests during this period reduced TN pollution by 36.64 % and TP pollution by 49.03 %. The results of this study support the expansion of urban forests during the medium urbanization stage to improve water quality. Furthermore, our results provide a reference and theoretical basis for urban forest construction as a key aspect of the sustainable development of the urban ecosystem in the Yangtze River Delta and similar regions around world.
在全球快速城市化的背景下，应该考虑生态系统的可持续发展。因此，行星边界理论认为，减少进入水体的氮和磷污染物的数量是必要的，因为过量的氮和磷可能会损害水生态环境，降低水质。因此，基于长三角地区具有代表性的城市河流的长期监测数据，我们评估了不同城市化阶段水体的氮磷污染状况，并进一步量化了城市森林对水质改善的影响。结果表明，随着城市化的不断推进，不透水面的比例增加，水体中的氮磷污染水平也随之增加。在城市化水平达到中等水平时，城市河流的水质恶化进入关键时期，此时不透水面的比例达到 55-65%，总氮（TN）和总磷（TP）浓度突然增加的概率超过 95%。然而，在这一时期增加城市森林的面积可以减少 36.64%的 TN 污染和 49.03%的 TP 污染。本研究的结果支持在中等城市化阶段扩大城市森林，以改善水质。此外，我们的研究结果为城市森林建设提供了参考和理论依据，城市森林建设是长三角地区乃至全球类似地区城市生态系统可持续发展的关键方面。
