Changes in functional composition and diversity of waterbirds: The roles of water level and submerged macrophytes

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.

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Species-Specific Responses of Submerged Macrophytes to Simulated Extreme Precipitation: A Mesocosm Study

Water ◽

10.3390/w11061160 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1160 ◽

Cited By ~ 1

Author(s):

Yu Cao ◽

Yongwei Zhi ◽

Erik Jeppesen ◽

Wei Li

Keyword(s):

Water Level ◽

Extreme Precipitation ◽

Submerged Macrophytes ◽

Freshwater Ecosystems ◽

Maximum Height ◽

Sudden Increase ◽

Growth Forms ◽

High Coverage ◽

Macrophyte Community ◽

Species Specific

More frequent extreme climate events (e.g., extreme precipitation) are to be expected in the future, and such events may potentially have significant effects on freshwater ecosystems. In the present mesocosm study, the effects of simulated extreme precipitation on submerged macrophytes were evaluated for three different macrophyte community (MC) treatments (MC1, MC2 and MC3). MC1 consisted of only Vallisneria denseserrulata, while MC2 and MC3 included three and six species of various growth forms. Two treatments of extreme precipitation (EP) were simulated—an extreme treatment (E) simulating a sudden increase of water level from 75 cm to 150 cm within one day and a gradual treatment (G) simulating an increase to the same water level within 3 months, combined with two control treatments. Total macrophyte community biomass was resilient to the EP and MC treatments, while species-specific variations in responses, in terms of biomass, maximum height, and sexual reproduction, were found. For instance, E led to earlier flowering of Potamogeton lucens and production of more flowers, while it had adverse effects on the flowering of Ottelia alismoides. We conclude that freshwater ecosystems with high coverage of submerged macrophytes may be overall resilient to extreme precipitation under nutrient-limited conditions, especially communities with diverse growth forms.

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How water level management affects cladoceran assemblages in lakes lateral to a reservoir

Marine and Freshwater Research ◽

10.1071/mf14281 ◽

2016 ◽

Vol 67 (12) ◽

pp. 1853 ◽

Cited By ~ 3

Author(s):

José Roberto Debastiani-Júnior ◽

Marcos Gomes Nogueira

Keyword(s):

Steady State ◽

Water Level ◽

Submerged Macrophytes ◽

Tropical Reservoir ◽

Main River ◽

River Reservoir ◽

Continuous Application ◽

Water Level Management ◽

Loss Of Diversity ◽

The Right

This study analysed the effects of induced water level depletion for macrophyte control in a tropical reservoir on the cladoceran fauna of two differentially connected lateral lakes. One lake, Pedra Branca, is located in the right margin and has a narrow connection to the main river–reservoir channel as well as a higher proportion of submerged macrophytes. On the opposite margin is Lake Guaritá, which is shallower and has a wider connection. Samples were collected over 16 consecutive months, including periods before, during and after depletion. Both lakes showed closely related trends in depth, pH, DO, conductivity, chlorophyll, temperature, suspended matter, phosphorus, nitrogen, silicate and ammonium variation, although a wider amplitude in variation was observed in Pedra Branca. This lake also had higher cladoceran diversity and a predominance of Chydoridae, whereas Bosminidae prevailed in Guaritá. Depletion caused a reduction in richness and an increase of Bosminidae in both lakes, although this was more pronounced in Pedra Branca. The management moderately affected both lakes but continuous application of this procedure may lead to a shift in the system steady-state and a loss of diversity that could be difficult to reverse.

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High-Resolution Flow-Simulation in Typhoon 21, 2018: Massive Loss of Submerged Macrophytes in Lake Biwa

10.21203/rs.3.rs-134971/v1 ◽

2020 ◽

Author(s):

Satoshi Nakada ◽

Hiroki Haga ◽

Maho Iwaki ◽

Keisuke Hatano ◽

Kohji Mabuchi ◽

...

Keyword(s):

High Resolution ◽

Water Level ◽

Lake Biwa ◽

Submerged Macrophytes ◽

Circulation Model ◽

Climate Change Scenarios ◽

The South ◽

Fluid Force ◽

South Basin ◽

Massive Outflow

Abstract Global activities of typhoons and hurricanes are gradually changing, and these storms can drastically affect lake ecosystems through the recession of submerged macrophytes that regulate the water quality in lakes. Using an echosounder, we captured the short-term, massive loss of submerged macrophytes attributed to the abnormal fluctuation of the water level induced by the approach of a catastrophic super typhoon in the south basin of Lake Biwa, Japan. This paper investigates the physical processes responsible for the loss of vegetation using a high-resolution circulation model in Lake Biwa as a pilot study area. The circulation model was coupled with dynamical models of the fluid force and erosion acting on the vegetation. Our simulation successfully reproduced the water level fluctuation and high-speed current (torrent) generated by the typhoon gale. The simulated results demonstrate that the fluid force driven by the gale-induced torrent uprooted submerged macrophytes during the typhoon approach and that this fluid force (rather than erosion) caused the outflow of vegetation. As a result, this uprooting attributed to the fluid force induced the massive loss of submerged macrophytes in a large area of the south basin, which might have increased primary production and reduced the stock of fish such as bluegill in the lake. Our approach is practical for evaluating changes in lake environments attributed to the massive outflow of submerged macrophytes under various climate change scenarios. (227 words)

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Eutrophication, agriculture and water level control shift aquatic plant communities from floating-leaved to submerged macrophytes in Lake Chini, Malaysia

Biological Invasions ◽

10.1007/s10530-011-0137-1 ◽

2011 ◽

Vol 14 (5) ◽

pp. 1029-1044 ◽

Cited By ~ 15

Author(s):

Zati Sharip ◽

Shon S. Schooler ◽

Matthew R. Hipsey ◽

Richard J. Hobbs

Keyword(s):

Water Level ◽

Plant Communities ◽

Aquatic Plant ◽

Submerged Macrophytes ◽

Level Control

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

Water ◽

10.3390/w13202900 ◽

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.

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High-resolution flow simulation in Typhoon 21, 2018: massive loss of submerged macrophytes in Lake Biwa

Progress in Earth and Planetary Science ◽

10.1186/s40645-021-00440-9 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Nakada Satoshi ◽

Haga Hiroki ◽

Iwaki Maho ◽

Mabuchi Kohji ◽

Takamura Noriko

Keyword(s):

High Resolution ◽

Water Level ◽

High Speed ◽

Lake Biwa ◽

Submerged Macrophytes ◽

Circulation Model ◽

Climate Change Scenarios ◽

Fluid Force ◽

Southern Basin ◽

Massive Outflow

AbstractThe global activities of typhoons and hurricanes are gradually changing, and these storms can drastically affect lake ecosystems through the recession of submerged macrophytes that regulate the water quality in lakes. Using an echosounder, we captured the short-term, massive loss of submerged macrophytes attributed to the abnormal fluctuation of the water level induced by the approach of a catastrophic super typhoon in the southern basin of Lake Biwa, Japan. This paper investigates the physical processes responsible for the loss of vegetation using a high-resolution circulation model in Lake Biwa as a pilot study area. The circulation model was coupled with dynamical models of the fluid force and erosion acting on the vegetation. Our simulation successfully reproduced the water level fluctuation and high-speed current (torrent) generated by the typhoon gale. The simulated results demonstrated that the fluid force driven by the gale-induced torrent uprooted submerged macrophytes during the typhoon approach and that this fluid force (rather than erosion) caused the outflow of vegetation. As a result, this uprooting attributed to the fluid force induced the massive loss of submerged macrophytes in a large area of the southern basin, which might have increased primary production and reduced the stock of fish such as bluegill in the lake. Our model can estimate the reduction in the macrophyte height within the range of − 1.3 to − 0.4 m, suggesting that fluid forces greater than the time-averaged value (1.24 × 10−4 N) were available. Flow speeds of approximately 0.8 m/s might be the critical value that induces the fluid force acting on the uprooting of the submerged macrophytes. Our approach is practical for evaluating changes in lake environments attributed to the massive outflow of submerged macrophytes under various climate change scenarios.

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

PLoS ONE ◽

10.1371/journal.pone.0146528 ◽

2016 ◽

Vol 11 (1) ◽

pp. e0146528 ◽

Cited By ~ 12

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

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Water level thresholds of benthic macroinvertebrate richness, structure, and function of boreal lake stony littoral habitats

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f2011-094 ◽

2011 ◽

Vol 68 (10) ◽

pp. 1695-1704 ◽

Cited By ~ 15

Author(s):

Michael S. White ◽

Marguerite A. Xenopoulos ◽

Robert A. Metcalfe ◽

Keith M. Somers

Keyword(s):

Community Structure ◽

Water Level ◽

Macroinvertebrate Community ◽

Functional Mobility ◽

Water Level Fluctuations ◽

Benthic Macroinvertebrate ◽

Functional Composition ◽

Macroinvertebrate Communities ◽

Taxa Richness ◽

Littoral Habitats

We investigated the role of water level fluctuation on benthic macroinvertebrate communities of stony littoral habitats located in the Boreal Shield Ecozone. Using the reference condition approach (RCA), regression analysis, nonmetric multidimensional scaling (NMDS), and analysis of variance (ANOVA), we analyzed the benthic macroinvertebrate community structure of 20 natural lakes and 28 hydroelectric reservoirs to determine if they are structured by change in water level (amplitude). Along a gradient of amplitude intensity, we found that taxa richness decreases with increasing amplitude (r2 = 0.47–0.60). Littoral benthic macroinvertebrate community structure is significantly different in reservoirs that experience amplitudes > 2.0 m. Out of 28 reservoirs, 13 fell outside the 95.5% confidence ellipse determined by 20 reference lakes. Functional mobility group and functional feeding group composition are also altered with increasing amplitude (nonparametric ANOVA, P < 0.05). Further, a change in benthic macroinvertebrate functional composition occurs after a change in taxa richness. Interestingly, reservoirs that experienced amplitudes < 2.0 m had benthic macroinvertebrate communities whose structural and functional composition is similar to lakes experiencing natural water level fluctuations.

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