Implications for faunal habitat related to altered macrophyte structure in regulated lakes in northern Minnesota

Wetlands ◽  
1992 ◽  
Vol 12 (3) ◽  
pp. 192-203 ◽  
Author(s):  
Douglas A. Wolcox ◽  
James E. Meeker
Keyword(s):  
Regulated Lakes ◽  
Macrophyte Structure

scholarly journals Upper thermal threshold of Lepidurus arcticus (Branchiopoda, Notostraca) in lakes on the southern outreach of its distribution range

2021 ◽  
Vol 41 ◽  
pp. 50-88
Author(s):  
Tore Qvenild ◽  
Eirik Fjeld ◽  
Arne Fjellheim ◽  
Johan Hammar ◽  
Trygve Hesthagen ◽  
...  
Keyword(s):  
Water Temperature ◽  
Fish Predation ◽  
High Arctic ◽  
Water Bodies ◽  
The Arctic ◽  
Thermal Threshold ◽  
Tadpole Shrimp ◽  
Area North ◽  
Regulated Lakes ◽  
Southern Island

The Arctic tadpole shrimp Lepidurus arcticus has a circumpolar distribution and the Scandes (Fennoscandian Mountains) marks its southernmost limit in Europe. Within this area, 391 natural and 88 regulated lakes with L. arcticus have been identified, of which 87% are above the treeline. The lakes hosting L. arcticus decrease in altitude from south to north, which results from its temperature preferences. The majority of the locations are at a lower lake air temperature than 11°C which is equivalent to a water temperature near 14°C. This is assumed to be near the upper thermal threshold for L. arcticus. In lakes that exceed this average summer water temperature (1 July – 15 September), sustainable populations seem to be rare. In warmer lakes, life cycle mismatches are assumed to explain the absence of L. arcticus, most likely by affecting the embryo and juvenile stages. The distribution appears to be dichotomous, with one large northern area north of 65°N and one separated southern “island”. Only two locations of L. arcticus are known for the area between latitudes 62.88 and 64.39°N. In this part of the Scandes, the lakes are likely too warm to host L. arcticus as most of them are situated below 700 m a.s.l. This may also be the case in the northernmost region, north of 70°N, where only 11 populations are recorded. Most of the lakes in this area typically occurs below 400 m a.s.l. L. arcticus populations are sensitive to fish predation, and dense fish populations may be another stressor limiting its distribution. In contrast to water bodies in the High Arctic where L. arcticus only exists in shallow, fishless ponds, in the Scandes they co-exist with fish in 97% of the findings. Global warming has already modified the environment of the Scandes, and populations of L. arcticus are at threat in many of the small and shallow water bodies at low altitudes.

scholarly journals Long- and Short-Term Changes of the Structure of Macrophytes in Lake Piaseczno in Relation to Land Use in the Łęczna-Włodawa Lakeland (Poland)

2013 ◽  
Vol 15 (2) ◽  
pp. 101-110
Author(s):  
Joana Sender ◽  
Weronika Maślanko
Keyword(s):  
Land Use ◽  
Aquatic Plants ◽  
Short Term ◽  
Main Interest ◽  
Central European ◽  
Macrophyte Communities ◽  
Long Term Changes ◽  
Very High ◽  
Macrophyte Structure

ABSTRACT The Łęczna-Włodawa Plain, known also as the Łęczna-Wlodawa Lakeland, lies within the territory of the largest subregion of the Polesie region, covering over 1,300 km2. The main interest of the Łęczna-Włodawa Lakeland is that it is the oldest in the Central European Lowlands group of about 68 lakes. Among such a large number of lakes there exist all trophic types. However, since the late 1950’s, enormous dynamics of change associated with the disappearance of oligo- and mesotrophic lakes and their transformation into eutrophic, even hypertrophic, lakes have been observed. One of the biocenotic elements of the lakes, which are indicators of these changes, is aquatic plants. The aim of this study was to determine the macrophyte structure of Piaseczno Lake and changes of land use in its surroundings. Piaseczno Lake still represents very high natural values. A reduction in the number of macrophyte communities, which occurred especially in 2008, was a consequence of the fast-growing recreation infrastructure. From 1976 until 2010 an area of recreation infrastructure in the studied area increased more than 3.5 times, and in the built-up area more than five times, as well as a doubling of the total length of the roads. Meanwhile the surface area of wetlands and peatbogs significantly decreased - more than 11 times. Long-term changes in the structure of the macrophyte communities show that the number of communities has varied in each year, probably as a consequence of changes in landuse. Analysis showed changes to the surfaces inhabited by macrophytes, which have decreased significantly over only four years, by more than 25%. However, the proportion of rush communities has increased.

Changes in Wetland Vegetation in Regulated Lakes in Northern Minnesota, USA Ten Years after a New Regulation Plan Was Implemented

Wetlands ◽  
2017 ◽  
Vol 38 (3) ◽  
pp. 437-449 ◽  
Author(s):  
James E. Meeker ◽  
Douglas A. Wilcox ◽  
Allan G. Harris
Keyword(s):  
Wetland Vegetation ◽  
Regulated Lakes

Macrophyte Structure and Growth of Bluegill (Lepomis macrochirus): Design of a Multilake Experiment

1998 ◽  
pp. 217-226 ◽  
Author(s):  
Stephen R. Carpenter ◽  
Mark Olson ◽  
Paul Cunningham ◽  
Sarig Gafny ◽  
Nathan Nibbelink ◽  
...  
Keyword(s):  
Lepomis Macrochirus ◽  
Macrophyte Structure

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.

Sign in / Sign up

Export Citation Format

Share Document