Holocene development of aquatic vegetation in shallow Lake Njargajavri, Finnish Lapland, with evidence of water-level fluctuations and drying

2005 ◽  
Vol 34 (2) ◽  
pp. 203-215 ◽  
Author(s):  
Minna Väliranta ◽  
Seija Kultti ◽  
Marjut Nyman ◽  
Kaarina Sarmaja-Korjonen
Keyword(s):  
Water Level ◽  
Shallow Lake ◽  
Aquatic Vegetation ◽  
Water Level Fluctuations ◽  
Finnish Lapland

scholarly journals How suitable are man-made water bodies as habitats for Odonata?

2020 ◽  
pp. 13 ◽  
Author(s):  
Marina Vilenica ◽  
Ivana Pozojević ◽  
Natalija Vučković ◽  
Zlatko Mihaljević
Keyword(s):  
Water Level ◽  
Aquatic Vegetation ◽  
Negative Impact ◽  
Sampling Site ◽  
Water Bodies ◽  
Habitat Modification ◽  
Water Level Fluctuations ◽  
Widespread Species ◽  
Rare And Endangered ◽  
Vegetation Water

Many studies have reported a negative impact of freshwater habitat modification on biota. Nevertheless, some man-made water bodies have proven to be valuable for biodiversity conservation as they can harbour many species. We investigated 36 man-made water bodies to determine their suitability as habitats for Odonata. Larvae were sampled in littoral, during the summer months of 2016 and 2017. At each sampling site, ten samples were collected using a benthos hand net. A total of 21 Odonata species was recorded. Odonata assemblages mainly consisted of common widespread species. Yet, at Vlačine Reservoir, located in the Dinaric Western Balkan ecoregion, we also recorded a rare and endangered Mediterranean species, Lindenia tetraphylla (Vander Linden, 1825). Aquatic and riparian vegetation, water level fluctuations and dissolved oxygen concentration had the highest influence on Odonata, showing that man-made water bodies with a well-developed riparian zone and aquatic vegetation, and with low daily and seasonal water level fluctuations, can provide suitable habitats for diverse Odonata species. Odonata are among the sensitive freshwater insects widely used as ecological indicators and umbrella species, therefore these results about their assemblages in heavily modified and man-made habitats could contribute to future conservation activities of freshwater biota and habitats.

The role of water-level fluctuations in shallow lake ecosystems – workshop conclusions

Hydrobiologia ◽  
2003 ◽  
Vol 506-509 (1-3) ◽  
pp. 23-27 ◽  
Author(s):  
Hugo Coops ◽  
Meryem Beklioglu ◽  
Thomas L. Crisman
Keyword(s):  
Water Level ◽  
Shallow Lake ◽  
Water Level Fluctuations ◽  
Lake Ecosystems

scholarly journals Influence of Hydrological Conditions on the Ecological State of Shallow Lake Vörtsjärv

Geografie ◽  
2004 ◽  
Vol 109 (2) ◽  
pp. 129-144
Author(s):  
Arvo Järvet
Keyword(s):  
Water Level ◽  
Shallow Lake ◽  
Water Body ◽  
Water Regime ◽  
Water Level Fluctuations ◽  
Ecological State ◽  
Fish Kills ◽  
Lake Võrtsjärv ◽  
Phosphorous Compounds ◽  
Area And Volume

Lake Vörtsjärv as a very shallow (mean depth 2.8 m) water-body and considerable water level fluctuations cause changes in both the surface area and volume of the lake. Due to the shallowness of the lake, low level periods are accompanied by several phenomena detrimental to its ecosystem, like cyanophyte blooms, overgrowing with macrophytes, resuspension of phosphorous compounds, restricted spawning places for pike and winter fish kills. In the years of low water level the perspectives to catch in established fishing sites using particular gear as well as access to harbours are hindered. Causal relations between the water regime and ecological state of the lake Vörtsjärv have been discussed in this paper.

Disturbance effects on aquatic vegetation in regulated and unregulated lakes in northern Minnesota

1991 ◽  
Vol 69 (7) ◽  
pp. 1542-1551 ◽  
Author(s):  
Douglas A. Wilcox ◽  
James E. Meeker
Keyword(s):  
Water Level ◽  
Growth Form ◽  
Aquatic Vegetation ◽  
Aquatic Macrophyte ◽  
Structural Diversity ◽  
Water Level Fluctuations ◽  
Vegetation Growth ◽  
Macrophyte Communities ◽  
Regulated Lakes ◽  
Diverse Plant

The effects of water-level regulation on aquatic macrophyte communities were investigated by comparing two regulated lakes in northern Minnesota with a nearby unregulated lake. Natural annual fluctuations of about 1.8 m were replaced with fluctuations of 1.1 m and 2.7 m in the regulated lakes, and the timing of water-level changes was also altered. Quadrats were sampled along transects that followed depth contours representing different plant habitats in the unregulated lake. Ordinations showed that the macrophyte communities at all sampled depths of the regulated lakes differed from those in the unregulated lake. The unregulated lake supported structurally diverse plant communities at all depths. In the lake with reduced fluctuations, only four taxa were present along transects that were never dewatered; all were erect aquatics that extended through the entire water column. In the lake with increased fluctuations, rosette and mat-forming species dominated transects where drawdown occurred in early winter and disturbance resulted from ice formation in the sediments. The natural hydrologic regime at the unregulated lake resulted in intermediate disturbance and high diversity. There was either too little or too much disturbance from water-level fluctuations in the regulated lakes, both resulting in reduced structural diversity. Key words: reservoirs, lake-level regulation, winter drawdown, aquatic vegetation, growth form, disturbance.

scholarly journals Long Term Aquatic Vegetation Dynamics in Longgan Lake Using Landsat Time Series and Their Responses to Water Level Fluctuation

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2178
Author(s):  
Wenxia Tan ◽  
Jindi Xing ◽  
Shao Yang ◽  
Gongliang Yu ◽  
Panpan Sun ◽  
...  
Keyword(s):  
Water Level ◽  
Water Depth ◽  
Vegetation Index ◽  
Aquatic Vegetation ◽  
Yangtze River Basin ◽  
Google Earth ◽  
Water Level Fluctuations ◽  
Quantitative Evidence ◽  
Longgan Lake

Aquatic vegetation in shallow freshwater lakes are severely degraded worldwide, even though they are essential for inland ecosystem services. Detailed information about the long term variability of aquatic plants can help investigate the potential driving mechanisms and help mitigate the degradation. In this paper, based on Google Earth Engine cloud-computing platform, we made use of a 33-year (1987–2019) retrospective archive of moderate resolution Landsat TM, ETM + and OLI satellite images to estimate the extent changes in aquatic vegetation in Longgan Lake from Middle Yangtze River Basin in China using the modified enhanced vegetation index, including emerged, floating-leaved and floating macrophytes. The analysis of the long term dynamics of aquatic vegetation showed that aquatic vegetation were mainly distributed in the western part of the lake, where lake bottom elevation ranged from 11 to 12 m, with average water depth of less than 1 m in spring. The vegetation area variation for the 33-year period were divided into six stages. In years with heavy precipitation, the vegetation area decreased sharply. In the following years, the area normally restored. Aquatic vegetation area had a significant negative correlation with the spring water level and summer water level. The results showed that aquatic vegetation was negatively affected when water depth exceeded 2.5 m in May and 5 m in summer. It is recommended that water depth remain close to 1 m in spring and close to 3 m in summer for aquatic vegetation growth. Our study provide quantitative evidence that water-level fluctuations drive vegetation changes in Longgan Lake, and present a basis for sustainable lake restoration and management.

scholarly journals Effects of Water Level Fluctuation on Waterbirds Distribution and Aquatic Vegetation Composition at Natural Wetland Reserve, Peninsular Malaysia

ISRN Ecology ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Muhammad Nawaz Rajpar ◽  
Mohamed Zakaria
Keyword(s):  
Water Level ◽  
Water Body ◽  
Aquatic Vegetation ◽  
Open Water ◽  
Peninsular Malaysia ◽  
Water Level Fluctuations ◽  
Sampling Point ◽  
Vegetation Composition ◽  
Natural Wetland ◽  
Open Water Body

The effects of water level fluctuations on waterbirds distribution and aquatic vegetation composition was determined using distance sampling point count method and direct visual observation at Paya Indah Natural Wetland Reserve, Peninsular Malaysia. A total of 2563 waterbird individual of 28 species and 8 families were detected in three habitats, that is, marsh swamp (68.59%), open water body (18.42%), and lotus swamp (12.99%). Porphyrio porphyrio was the most dominant species in marsh swamp (45.39%), and lotus swamp (23.42%), whereas Dendrocygna javanica (42.16%) was the most abundant in open water body. The highest water level for marsh swamp (2.313 m) and lotus swamp (2.249 m) was recorded in January, 2008 and for open water body (2.572 m) in January and April, 2008. In contrast, the lowest water level for marsh swamp (2.048 m) and lotus swamp (1.834 m) was determined in October, 2008 and for open water body (2.398 m) in January, 2009. Pearson test indicates weak linear correlationship between water level and waterbird abundance in lotus swamp habitat (r2=0.120,P>0.05) and in marsh swamp (r2=0.100,P>0.05) and negative linear correlationship (r2=−0.710,P>0.05) in open water body habitat. Canonical correspondence analysis indicated strong correlationship between waterbird abundance and vegetation (73.0%) in open water body, and weaker association (29.8%) in lotus swamp. The results of this study indicate that water level is a major factor that influences the relative abundance and distribution of ducks, swamphen, crakes, herons, jacanas, and moorhens directly and indirectly. In addition, it also effects on the dynamics of aquatic vegetation composition such as, emergent, submerged, and grasses in this wetland reserve.

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