Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, PR China.
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, PR China.
Environ Pollut. 2022 Mar 15;297:118762. doi: 10.1016/j.envpol.2021.118762. Epub 2021 Dec 28.
In recent years, the scale of shrimp ponds has rapidly increased adjacent to mangrove forests. Discharge of shrimp pond effluent has led to degradation of the surrounding environment and reduction of biodiversity in the estuary. But it remains poorly understood how shrimp pond effluent affects functional traits and functional diversity of mangroves. We sampled roots, stems and leaves of Kandelia obovata and other mangrove plants, as well as sediments and pore water from shrimp pond effluent polluted area (P) and clean area (control area, C) in Zhangjiang Estuary in southeast coast of China. Twenty plant functional traits and six functional diversity indices were analyzed to explore the effects of shrimp pond effluent on individual plants and mangrove communities. The results showed that the discharge of shrimp pond effluent significantly affected the nutrient content in soils and pore water, for example, sediment NH and NO concentration increased from 0.26 ± 0.06 to 0.77 ± 0.29 mg/g and from 0.05 ± 0.03 to 0.16 ± 0.05 mg/g, respectively, when comparing the C and P site. Furthermore, some mangrove plant functional traits such as plant height, diameter at breast height, canopy thickness and specific leaf area were significantly increased by the effluent discharge. Functional diversity in the polluted area reduced as a whole compared to the control area. In particular, ammonium and nitrate nitrogen input is the main reason to induce the changes of plant functional traits and functional diversity. Besides, the community structure changed from functional differentiation to functional convergence after shrimp pond effluent discharge. In addition, the long-term shrimp pond effluent discharge may lead to the ecological strategy shift of K. obovata, while different organs may adopt different ways of nutrient uptake and growth strategies in the face of effluent disturbance. In conclusion, pollution from shrimp pond does affect the functional traits of mangrove plants and functional diversity of mangrove community. These results provide strong evidence to assess the impact of effluent discharges on mangrove plants and provide theoretical basis for conservation and sustainable development of mangroves.
近年来，虾塘的规模在红树林附近迅速扩大。虾塘污水的排放导致了河口周边环境的退化和生物多样性的减少。但目前还不太清楚虾塘污水如何影响红树林的功能特性和功能多样性。我们采集了中国东南沿海漳江河口红树林植物海桑和其他红树林植物的根、茎、叶，以及虾塘污水污染区（P）和清洁区（对照区，C）的沉积物和孔隙水。分析了 20 种植物功能性状和 6 种功能多样性指数，以探讨虾塘污水对单个植物和红树林群落的影响。结果表明，虾塘污水的排放显著影响了土壤和孔隙水中的养分含量，例如，与对照区相比，沉积物中 NH和 NO浓度分别从 0.26±0.06mg/g 增加到 0.77±0.29mg/g 和从 0.05±0.03mg/g 增加到 0.16±0.05mg/g。此外，一些红树林植物功能性状，如株高、胸径、冠层厚度和比叶面积，也因污水排放而显著增加。受污染区的功能多样性与对照区相比整体降低。特别是，铵态氮和硝态氮的输入是引起植物功能性状和功能多样性变化的主要原因。此外，虾塘污水排放后，群落结构由功能分化向功能趋同转变。此外，长期的虾塘污水排放可能导致海桑的生态策略发生转变，而不同器官在面对污水干扰时可能会采取不同的养分吸收和生长策略。总之，虾塘污染确实会影响红树林植物的功能特性和红树林群落的功能多样性。这些结果为评估污水排放对红树林植物的影响提供了有力证据，为红树林的保护和可持续发展提供了理论依据。
