scholarly journals Effects of Water Level Fluctuations on the Growth Characteristics and Community Succession of Submerged Macrophytes: A Case Study of Yilong Lake, China

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2900
Author(s):  
Fengbin Zhao ◽  
Xin Fang ◽  
Zeyu Zhao ◽  
Xiaoli Chai
Keyword(s):  
Community Structure ◽  
Water Level ◽  
Water Depth ◽  
Seed Bank ◽  
Submerged Macrophytes ◽  
Growth Characteristics ◽  
Community Succession ◽  
Submerged Plant ◽  
Submerged Plants ◽  
Emergent Plants

Water level fluctuation (WLF) has a significant effect on aquatic macrophytes, but few experimental studies have examined the effect of WLF on submerged community succession, especially from a large-scale perspective. In this study, field monitoring of WLF and submerged macrophytes was conducted in Yilong Lake (SE China) over two years, and the impacts of WLF on the growth characteristics and the community structure of submerged macrophytes were determined. The results show that the biomass of submerged macrophytes decreased significantly after the water level increased and submerged macrophytes could cope with the adverse environment by adjusting their growth posture, for example, increasing plant length and reducing branch number. However, different submerged plants have different regulatory abilities, which leads to a change in the community structure. Myriophyllum spicatum, Stuckenia pectinata, and Najas marina had better adaptation abilities to WLF than Najas minor and Utricularia vulgaris. Changes in water depth, dissolved oxygen, and transparency significantly contribute to the effect of WLF on submerged plant communities. Therefore, when determining the range of WLF, the above three critical factors and submerged plant species should be considered. WLF changed the spatial distribution of the aquatic plant community. When water levels rose, the density of the submerged macrophyte community in the original growth region reduced as the emergent plants migrated to shallower water, and the seed bank germination was aided by transparent water produced among emergent plants. This can be used as a pioneering measure to restore submerged plants in eutrophic lakes with low transparency. In addition, a suitable water depth created by WLF was conducive to activating the seed bank and improving the diversity of aquatic plants. Finally, a distribution map of aquatic plants in Yilong Lake is drawn.

scholarly journals Effects of Water Depth on the Growth of the Submerged Macrophytes Vallisneria natans and Hydrilla verticillata: Implications for Water Level Management

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2590
Author(s):  
Qisheng Li ◽  
Yanqing Han ◽  
Kunquan Chen ◽  
Xiaolong Huang ◽  
Kuanyi Li ◽  
...  
Keyword(s):  
Water Level ◽  
Water Depth ◽  
Deep Water ◽  
Submerged Macrophytes ◽  
Hydrilla Verticillata ◽  
Water Level Fluctuations ◽  
Total Biomass ◽  
Intermediate Water ◽  
Factors Affecting ◽  
Vallisneria Natans

Water level is one of the most important factors affecting the growth of submerged macrophytes in aquatic ecosystems. The rosette plant Vallisneria natans and the erect plant Hydrilla verticillata are two common submerged macrophytes in lakes of the middle and lower reaches of the Yangtze River, China. How water level fluctuations affect their growth and competition is still unknown. In this study, three water depths (50 cm, 150 cm, and 250 cm) were established to explore the responses in growth and competitive patterns of the two plant species to water depth under mixed planting conditions. The results show that, compared with shallow water conditions (50 cm), the growth of both submerged macrophytes was severely suppressed in deep water depth (250 cm), while only V. natans was inhibited under intermediate water depth (150 cm). Moreover, the ratio of biomass of V. natans to H. verticillata gradually increased with increasing water depth, indicating that deep water enhanced the competitive advantage of V. natans over H.verticillata. Morphological adaptation of the two submerged macrophytes to water depth was different. With increasing water depth, H. verticillata increased its height, at the cost of reduced plant numbers to adapt to poor light conditions. A similar strategy was also observed in V. natans, when water depth increased from 50 cm to 150 cm. However, both the plant height and number were reduced at deep water depth (250 cm). Our study suggests that water level reduction in lake restoration efforts could increase the total biomass of submerged macrophytes, but the domination of key plants, such as V. natans, may decrease.

scholarly journals Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0146528 ◽  
Author(s):  
Mo-Zhu Wang ◽  
Zheng-Yuan Liu ◽  
Fang-Li Luo ◽  
Guang-Chun Lei ◽  
Hong-Li Li
Keyword(s):  
Community Structure ◽  
Water Level ◽  
Submerged Macrophytes ◽  
Water Level Fluctuations

scholarly journals Effect of Hydrologic Alteration on the Community Succession of Macrophytes at Xiangyang Site, Hanjiang River, China

Scientifica ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Na Yang ◽  
Yehui Zhang ◽  
Kai Duan
Keyword(s):  
Water Level ◽  
Submerged Macrophytes ◽  
Influence Factors ◽  
Low Flow ◽  
Community Succession ◽  
Flow Process ◽  
Survey Results ◽  
Hanjiang River ◽  
Flow Components ◽  
Flow Attenuation

With the intensification of human activities over the past three decades in China, adverse effects on river ecosystem become more serious especially in the Hanjiang River. Xiangyang site is an important spawn ground for four domestic fishes in the downstream region of Hanjiang River. Based on the field survey results of macrophytes during 1997–2000 and 2013-2014, community succession of aquatic macrophytes at Xiangyang site was evaluated and discussed. Two-key ecologic-related hydrologic characteristics, flow regime and water level, were identified as the main influence factors. The EFC (environmental flow components) parameters were adopted to evaluate the alteration of flow regimes at Xiangyang site during 1941–2013. Evaluation results demonstrate a highly altered flow process after being regulated by reservoir. The flow patterns tend to be an attenuation process with no large floods occurring but a higher monthly low flow. Furthermore, the water level decreased and fluctuation reduced after the dam was built, which caused the decrease of biomass but favored the submerged macrophytes during 1995–2009. However, with the water level increasing after 2010 and gently fluctuating, due to uplift by the hydraulic projects downstream as well as the flow attenuation, the dominant position of submerged macrophytes will be weakened.

A Study of the Average Flow in Open Channel with Baffle Blocks Distributed Uniformly

10.29007/zx1w ◽  
2018 ◽  
Author(s):  
Dung Tien Tran ◽  
Anh Tuan Le ◽  
Hong Nhung Le ◽  
Viet Hung Ho
Keyword(s):  
Water Level ◽  
Water Depth ◽  
Open Channel ◽  
Block Size ◽  
Average Flow ◽  
Modelling Studies ◽  
Baffle Block

A study of average flow in open channel with baffle blocks distributed uniformly has been considered by using channel with varied slopes. In this article, experimental and modelling studies were introduced when the correlation between the water depth and baffle block size is significant. The objective of the work is to give the rudimentary relations between discharge and water level in the channels. When the water depth is large, the effect of bottom channel friction on the flow is relatively small. This paper also gives applications of the software ‘Telemac-2D’ to simulate the flow under different conditions.

scholarly journals Snail communities improve submerged macrophytes growth by graze epiphytic algae and phytoplankton in a mesocosm experiment

2021 ◽  
Author(s):  
Tian Lv ◽  
Xin Guan ◽  
Shufeng Fan ◽  
Chunhua Liu
Keyword(s):  
Native Plants ◽  
Submerged Macrophytes ◽  
Mesocosm Experiment ◽  
Snail Species ◽  
Complex Relationship ◽  
Elodea Nuttallii ◽  
Submerged Plant ◽  
Epiphytic Algae ◽  
Complex Architecture ◽  
The Relationship

The relationship between producers (e.g., macrophyte, phytoplankton and epiphytic algae) and snails plays an important role in maintaining the function and stability of the shallow ecosystems. A complex relationship exists among macrophytes, epiphytic algae, phytoplankton and snails. An outdoor mesocosm experiment with two-way factorials was carried out, three species submerged macrophytes (Hydrilla verticillate, Vallisneria natans or one exotic submerged plant Elodea nuttallii) and two grazing treatments (4 snail species present or absent) to elucidate those relationships. The results showed that the snail communities reducing the biomass of phytoplankton and epiphytic algae indirect then enhanced the growth of the submerged macrophytes. The macrophyte with complex architecture supported more snail and epiphytic algae, and snails preferred to feed on native plants. Competition drove snails change the grazing preferences to achieve coexistence, so that led to the assembling of snail communities towards the direction of highest resource utilization.

scholarly journals Impact of Water Level on Species Quantity and Composition Grown from the Soil Seed Bank of the Inland Salt Marsh: An Ex-Situ Experiment

Land ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 533
Author(s):  
Eva Čížková ◽  
Jana Navrátilová ◽  
Stanislav Martinát ◽  
Josef Navrátil ◽  
Ryan J. Frazier
Keyword(s):  
Salt Marsh ◽  
Linear Regression ◽  
Water Level ◽  
Seed Bank ◽  
Multidimensional Analysis ◽  
Ex Situ ◽  
Individual Species ◽  
Lotus Tenuis ◽  
Number Of Species ◽  
The Impact

The near elimination of inland salt marshes in Central Europe occurred throughout the 19th and 20th centuries, and the currently remaining marshes exist in a degraded condition. This work examines the impact of groundwater level on the growth of plants from a seed bank obtained from a degraded salt marsh in proximity to still existing one through an ex-situ experiment. An experimental tank was set up with the sample seed bank experiencing differing levels of water level. There were 1233 specimens of 44 taxa grown from the seed bank, of which 5 species were abundant, and 10 species are considered as halophytes. Only Lotus tenuis from halophytes was more abundant, and only five species of halophytes were represented by more than three individuals. The water level has a significant impact on the number of species (based on linear regression analysis) as well as species distribution among different water level treatments (a non-metric multidimensional analysis (nMDS) followed by linear regression). The results show a strong negative relationship between the average water level and the number of species. The water level did not affect the species composition of halophytes, but differences in individual species abundances were found among the halophytes. The species Bupleurum tenuissimum, Crypsis schoenoides, Melilotus dentatus, and Plantago maritima grew on the drier and non-inundated soils. Tripolium pannonicum, Spergularia maritima, and Lotus tenuis grew on both wet and dry soils. Trifolium fragiferum and Bolboschoenus maritimus were found in places with water stagnant at the soil level. Pulicaria dysenterica grew in inundated soil.

scholarly journals Assessing macroinvertebrate communities in relation to environmental variables: the case of Sambandou wetlands, Vhembe Biosphere Reserve

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Tatenda Dalu ◽  
Rivoningo Chauke
Keyword(s):  
Community Structure ◽  
Water Depth ◽  
Environmental Variables ◽  
Anthropogenic Activities ◽  
Biosphere Reserve ◽  
High Water ◽  
Macroinvertebrate Community ◽  
Macroinvertebrate Communities ◽  
Negative Effect ◽  
Macrophyte Cover

AbstractThe Vhembe Biosphere Reserve, South Africa, contains many wetlands that serve as wildlife habitats and provide vital ecosystem services. Some of the wetlands are continuously being degraded or destroyed by anthropogenic activities causing them to disappear at an alarming rate. Benthic macroinvertebrates are known as good water quality bioindicators and are used to assess aquatic ecosystem health. The current study investigated habitat quality using macroinvertebrate community structure and other biotic variables (i.e. phytoplankton, macrophytes) in relation to environmental variables in the Sambandou wetlands using canonical correspondence analysis (CCA). A total of fifteen macroinvertebrate families were identified over two seasons. The CCA highlighted seven variables, i.e. pH, phosphate concentration, temperature, ammonium, macrophyte cover, conductivity and water depth, which were significant in structuring macroinvertebrate community. Picophytoplankton and microphytoplankton concentrations decreased from winter to summer, whereas nanophytoplankton concentration increased from winter to summer. Thus, the dominance of small-sized phytoplankton indicated nutrient limitation and decreased productivity, whereas winter sites 2 and 3 were dominated by large-celled phytoplankton, highlighting increased productivity. Winter sites were mostly negatively associated with CCA axis 1 and were characterised by high temperature, phosphate and ammonium concentrations, macrophyte cover, pH and conductivity. Summer sites were positively associated with axis 1, being characterised by high water depth and pH levels. The results obtained highlighted that agricultural activities such as cattle grazing and crop farming and sand mining/poaching had a negative effect on macroinvertebrate community structure.

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