Figure - available from: Hydrobiologia
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Study regions with the position of 54 lakes in Czechia and 58 study lakes in Albania. Classification of sites: black/green/blue dots, molluscs were recorded; white dot, no mollusc recorded; cross, both no mollusc recorded and environmental variables not measured. Czechia: green dots, low trophic (mesotrophic/oligotrophic) lakes; black dots, high trophic (eutrophic/hypertrophic) lakes. Albania: blue dots, low trophic (oligotrophic) lakes; black dots, high trophic (mesotrophic/eutrophic) lakes (see Methods). The lake numbers correspond to the numbers in Table A.1 and A.2 in the Online Resource
Source publication
Species distribution and assemblage structuring are influenced by a combination of species dispersal mode and the dispersal routes used. Habitat connectivity is particularly important for passively dispersing taxa such as freshwater molluscs. In addition, current anthropogenic eutrophication affects the structure of assemblages by reducing native f...
Citations
... For example, excessive overgrowth and waterlogging of floodplain water bodies during a long absence of floods may be indicated by a high proportion of organisms that prefer such conditions, for example, rotifers of the genera Trichocerca and Monommata and cladoceran crustaceans Graptoleberis testudinaria (Fischer, 1851) and Dunhevedia crassa King, 1853. Loss of connection to the river, isolation of water bodies, and their drying out may be indicated by a decrease in species richness and homogenization of the structure of freshwater mollusk communities (Zheng et al., 2022;Šlachtová et al., 2023). ...
Обобщается информация об основных негативных факторах, влияющих на состояние пойменных водоемов, описываются самые распространенные последствия абиотических и биотических процессов, предлагаются возможные пути для сохранения пойменных водоемов. Приводятся свидетельства негативного влияния гидростроительства, обвалования пойм, спрямления русел, сельского хозяйства и других антропогенных воздействий. Особую роль играет изменение климата, которое приводит к снижению поемности, высыханию и зарастанию водоемов, их эвтрофированию. Предлагаются критерии для выбора корректных индикаторов, которые могут свидетельствовать о последствиях антропогенных и климатических изменений и о коллапсе таких экосистем. Рекомендовано при оценках состояния пойменных водоемов, рассматривать не отдельные водоемы, а их скопления, и использовать в качестве индикатора изменение β-разнообразия сообществ водных организмов. Дальнейшие природоохранные стратегии могут опираться на подходы Красной книги экосистем Международного союза охраны природы и природных ресурсов, что поможет привлечь внимание к проблеме. Ключевую роль для сохранения пойменных водоемов должны играть территориальные меры охраны, вплоть до разработки отдельной категории для малых водоемов в целом.
... For example, excessive overgrowth and waterlogging of floodplain water bodies during a long absence of floods may be indicated by a high proportion of organisms that prefer such conditions, for example, rotifers of the genera Trichocerca and Monommata and cladoceran crustaceans Graptoleberis testudinaria (Fischer, 1851) and Dunhevedia crassa King, 1853. Loss of connection to the river, isolation of water bodies, and their drying out may be indicated by a decrease in species richness and homogenization of the structure of freshwater mollusk communities (Zheng et al., 2022;Šlachtová et al., 2023). ...
This review summarizes information on the main negative factors affecting the state of floodplain water bodies ecosystems, describes the most common consequences for abiotic and biotic processes, and suggests possible ways to conserve these ecosystems. Evidence of the negative impact of hydraulic construction, embanking of floodplains, channelizing of rivers, agriculture, and other anthropogenic impacts is presented. A special role is played by climate change, which leads to a decrease in flood inundation, drying and overgrowing of water bodies, and their eutrophication. The authors suggest criteria to choose correct indicators that can testify not only to special stages of water body succession (e.g., vegetation) or its trophic status (zooplankton), but also to the long-term effects of anthropogenic and climatic changes. As a recommendation, it is proposed not to consider water bodies separately, but to assess the whole waterscapes and use the change in β-diversity as an indicator. Further conservation strategies can be based on the approaches of the Red List of Ecosystems of the International Union for Conservation of Nature and Natural Resources (IUCN), which will help to draw attention to the problem. The key role for the conservation of floodplain water bodies should be played by territorial protection measures, up to the development of a separate category for small water bodies.
Lake eutrophication has become a significant water environmental issue worldwide. In order to further explore the mechanism of hydrologic connectivity on lake eutrophication and effectively control it, this study selected Poyang Lake, Junshan Lake, Chi Lake, Taibo Lake, and Yao Lake with varying degrees of hydrological connectivity in the Poyang Lake region as research subjects. The study utilized the comprehensive Trophic Level Index (TLI) method to assess the eutrophication of lakes. It also examined the impact of hydrological connectivity on eutrophication evaluation indices and the eutrophication state on a spatiotemporal scale. The results showed that the change in the hydrological period has little effect on the eutrophication of lakes, whether they are connected or obstructed. Except for Yao Lake, which was in a moderately eutrophic state (60, 70], the other four lakes were in a mildly eutrophic state (50, 60], consistent with the Trophic State Index (TSI) evaluation results. The eutrophication evaluation indices of obstructed lakes were significantly different from those of river-connected lakes. The change in eutrophication evaluation index of obstructed lakes was more likely to be influenced by human factors, whereas that of rivers-connected lakes was closely associated with hydrological connectivity. At present, there is a risk of a cyanobacteria bloom outbreak in Poyang Lake and its surrounding lakes. Therefore, this study suggests that strict control of point and non-point source pollution in the lake region, along with the scientific and reasonable formulation of a cultivation model, will effectively prevent lake eutrophication and cyanobacteria bloom outbreaks. This study provides theoretical support for investigating the mechanisms of lake eutrophication.
The Dongjiang River Basin is an important water source for Guangdong Province, providing water for living, production and ecology for more than 40 million people. The three large reservoirs, Xinfengjiang Reservoir, Fengshuba Reservoir and Baipenzhu Reservoir, are the three largest reservoirs in the Dongjiang River Basin. The quality of the water environment in the three reservoirs plays an important role in ensuring the safety of drinking water and promoting the overall protection, systematic restoration and comprehensive management of the water ecosystem. 11 indicators, including water temperature, transparency, pH, DO, turbidity, conductivity, ammonia nitrogen, TN, TP, CODMn and chlorophyll a, were tested in October 2022 to study the water quality characteristics and trophic status of the three cascade reservoirs. The results of the single-factor evaluation of water quality showed that all three reservoirs reached the surface water class II level. TN is the primary pollutant in Fengshuba and Baipenzhu reservoirs. The concentration of Chla in Baekpongju Reservoir was 3.4 μg/L, with a mild risk of algal bloom. TLI (Σ) of the three cascade reservoirs were about 16.41~32.14.The results of the integrated nutrient status evaluation showed that Xinfengjiang Reservoir was in a depleted nutrient status, while Mapeshuba and Bailuanzhu Reservoirs were in a medium nutrient status. Factor analysis showed that 11 water quality factors can be classified into four categories. F1 represents the organic pollution. F2represents the phytoplankton biomass. F3 represents the concentration of nitrogen. F4 represents the suspended solids in water.
