The decline of Myriophyllum spicatum in a eutrophic Wisconsin lake

1980 ◽  
Vol 58 (5) ◽  
pp. 527-535 ◽  
Author(s):  
Stephen R. Carpenter
Keyword(s):  
Exotic Species ◽  
Myriophyllum Spicatum ◽  
Simple Wave ◽  
Wave Pattern ◽  
Single Factor ◽  
Submersed Macrophyte ◽  
Macrophyte Communities ◽  
Biomass Dynamics

The recent changes in the submersed macrophyte communities of Lake Wingra, Wisconsin, have been dominated by the dynamics of one exotic species. After a decade of abundance, Myriophyllum spicatum has undergone a sustained decline in the Madison lakes. A pattern of explosive growth followed by declining abundance may describe most M. spicatum invasions.No simple single-factor explanation can adequately account for the biomass dynamics of M. spicatum in Lake Wingra. The decline in M. spicatum biomass appears to be the result of a complex of synergistically interacting factors, perhaps including nutrients, epiphytes, competitors, and parasites or pathogens.Invasions of lake districts by M. spicatum are hypothesized to follow a wave pattern. When interlake distances are accounted for, departure from a simple wave is hypothesized to result from lags in infestation of lakes which are not susceptible to colonization by M. spicatum. Several testable hypotheses are suggested by this view of M. spicatum invasions.

scholarly journals The propagation of groups of waves in dispersive media, with application to waves on water produced by a travelling disturbance

1908 ◽  
Vol 81 (549) ◽  
pp. 398-430 ◽  
Keyword(s):  
Wave Train ◽  
Harmonic Wave ◽  
Simple Wave ◽  
Fourier Integral ◽  
Wave Pattern ◽  
Difficult Problem ◽  
Point Of View ◽  
Simple Groups ◽  
Dispersive Media ◽  
Single Element

The object of this paper is to illustrate the main features of wave propagation in dispersive media. In the case of surface waves on deep water it has been remarked that the earlier investigators considered the more difficult problem of the propagation of an arbitrary initial disturbance as expressed by a Fourier integral, ignoring the simpler theory developed subsequently by considering the propagation of a single element of their integrals, namely an unending train of simple harmonic waves. The point of view on which stress is laid here consists of a return to the Fourier integral, with the idea that the element of disturbance is not a simple harmonic wave-train, but a simple group, an aggregate of simple wave-trains clustering around a given central period. In many cases it is then possible to select from the integral die few simple groups that are important, and hence to isolate the chief regular features, if any, in the phenomena. In certain of the following sections well-known results appear; the aim has been to develop these from the present point of view, and so illustrate die dependence of the phenomena upon the character of the velocity function, In the other sections it is hoped that progress has been made in the theory if the propagation of an arbitrary initial group of waves, and also of the character of the wave pattern diverging from a point impulse travelling on die surface.

scholarly journals Synergy of High-Resolution Radar and Optical Images Satellite for Identification and Mapping of Wetland Macrophytes on the Danube Delta

2020 ◽  
Vol 12 (14) ◽  
pp. 2188 ◽  
Author(s):  
Simona Niculescu ◽  
Jean-Baptiste Boissonnat ◽  
Cédric Lardeux ◽  
Dar Roberts ◽  
Jenica Hanganu ◽  
...  
Keyword(s):  
Time Series ◽  
Aquatic Macrophytes ◽  
Aquatic Vegetation ◽  
Myriophyllum Spicatum ◽  
Danube Delta ◽  
Backscatter Coefficient ◽  
Macrophyte Communities ◽  
Optical Images ◽  
Detailed Classification ◽  
Floating Vegetation

In wetland environments, vegetation has an important role in ecological functioning. The main goal of this work was to identify an optimal combination of Sentinel-1 (S1), Sentinel-2 (S2), and Pleiades data using ground-reference data to accurately map wetland macrophytes in the Danube Delta. We tested several combinations of optical and Synthetic Aperture Radar (SAR) data rigorously at two levels. First, in order to reduce the confusion between reed (Phragmites australis (Cav.) Trin. ex Steud.) and other macrophyte communities, a time series analysis of S1 data was performed. The potential of S1 for detection of compact reed on plaur, compact reed on plaur/reed cut, open reed on plaur, pure reed, and reed on salinized soil was evaluated through time series of backscatter coefficient and coherence ratio images, calculated mainly according to the phenology of the reed. The analysis of backscattering coefficients allowed separation of reed classes that strongly overlapped. The coherence coefficient showed that C-band SAR repeat pass interferometric coherence for cut reed detection is feasible. In the second section, random forest (RF) classification was applied to the S2, Pleiades, and S1 data and in situ observations to discriminate and map reed against other aquatic macrophytes (submerged aquatic vegetation (SAV), emergent macrophytes, some floating broad-leaved and floating vegetation of delta lakes). In addition, different optical indices were included in the RF. A total of 67 classification models were made in several sensor combinations with two series of validation samples (with the reed and without reed) using both a simple and more detailed classification schema. The results showed that reed is completely discriminable compared to other macrophyte communities with all sensor combinations. In all combinations, the model-based producer’s accuracy (PA) and user’s accuracy (UA) for reed with both nomenclatures were over 90%. The diverse combinations of sensors were valuable for improving the overall classification accuracy of all of the communities of aquatic macrophytes except Myriophyllum spicatum L.

The submersed macrophyte communities of adirondack lakes (New York, U.S.A.) of varying degrees of acidity

1985 ◽  
Vol 21 (3) ◽  
pp. 219-235 ◽  
Author(s):  
Deborah A. Roberts ◽  
Robert Singer ◽  
Charles W. Boylen
Keyword(s):  
New York ◽  
Submersed Macrophyte ◽  
Macrophyte Communities ◽  
Adirondack Lakes

Light-dependent phosphate uptake of a submersed macrophyte Myriophyllum spicatum L.

2011 ◽  
Vol 94 (4) ◽  
pp. 151-157 ◽  
Author(s):  
Meng Zhang ◽  
Te Cao ◽  
Leyi Ni ◽  
Ping Xie ◽  
Guorong Zhu ◽  
...  
Keyword(s):  
Phosphate Uptake ◽  
Myriophyllum Spicatum ◽  
Submersed Macrophyte ◽  
Myriophyllum Spicatum L

scholarly journals Assessing watermilfoil invasion effects on native macrophyte communities in North American lakes using a novel approach for macrophyte sampling

2021 ◽  
pp. 1
Author(s):  
Shannon Smith ◽  
Frithjof C. Küpper ◽  
Clare Trinder ◽  
Vasilis Louca
Keyword(s):  
Invasive Species ◽  
Species Richness ◽  
Native Species ◽  
Community Dynamics ◽  
Myriophyllum Spicatum ◽  
Community Response ◽  
Freshwater Biodiversity ◽  
Macrophyte Communities ◽  
Novel Approach ◽  
Native Species Richness

Aquatic invasive species are among the greatest threats to freshwater biodiversity. The aim of this study was to understand the effects of two invasive watermilfoil species (Myriophyllum heterophyllum Michx. and Myriophyllum spicatum L.) on native macrophyte communities and to assess community response to a range of invasion intensities as well as examine the influence of canopy types. We hypothesized that some communities would be more sensitive to invasion, and that some canopy species would facilitate watermilfoil presence. We used a novel approach to give better representation of the 3D aspect of the community which involved employing a modified quadrat approach to sample at two Connecticut lakes. Results show that watermilfoil invasion has a significant negative effect on native species richness. Floating canopy does not vary with invasion intensity, but submerged canopy does. One species, (Utricularia purpurea Walter), was associated with high native species richness and rarely occurred with invasive species. The results identify potential species that are disproportionally threatened by invasive species, as well as identifying invasion indicator species. The examination of canopy effects is uncommon in aquatic invasion ecology, and this study suggests that this aspect may have significant effects on resilience to invasion and overall community dynamics.

Submersed macrophyte communities before and after an episodic ice jam in the St. Clair and Detroit rivers

1989 ◽  
Vol 67 (8) ◽  
pp. 2364-2370 ◽  
Author(s):  
S. J. Nichols ◽  
D. W. Schloesser ◽  
P. L. Hudson
Keyword(s):  
Ground Truth ◽  
Early Spring ◽  
Total Abundance ◽  
Ice Jam ◽  
Submersed Macrophyte ◽  
Macrophyte Communities ◽  
Before And After ◽  
Permanent Effect ◽  
Free Growth ◽  
Low Altitude

We conducted surveys in 1983 and 1984 of submersed macrophyte communities off six islands in the St. Clair and Detroit rivers using low altitude aerial photography and ground-truth collections. Sample collections in 1984 followed one of the coldest winters on record, during which ice up to 4 m thick developed in areas that were normally ice-free. Growth of many of the 20 taxa collected was delayed in the spring of 1984, as compared with the spring of 1983. By September 1984, however, total abundance of all taxa was equal to or greater than that in 1983. The location, size, and shape of plant beds in September 1984 were similar to those in 1983. We concluded that the unusual ice jam in early spring of 1984 had little, if any, permanent effect on submersed macrophytes in the St. Clair and Detroit rivers.

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