scholarly journals Impact of humic substances on Sphagnum denticulatum habitats

2014 ◽  
Vol 71 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Krzysztof Banaś
Keyword(s):  
Humic Substances ◽  
Calcium Concentration ◽  
Habitat Characteristics ◽  
Low Density ◽  
Sediment Characteristics ◽  
Acid Lakes ◽  
Water And Sediment ◽  
Frequent Species ◽  
Softwater Lakes ◽  
Nw Poland

In 10 softwater lakes of NW Poland (5 very acid and 5 slightly acid) three kinds of <em>Sphagnum denticulatum</em> Bridel [=<em>S. auriculatum</em> Schimper] habitats have been studied: oligohumic (&lt;2.0 mg C<sub>DHS</sub> dm<sup>-3</sup>) and α-mesohumic (2.0-4.0 mg C<sub>DHS</sub> dm<sup>-3</sup>) and β-mesohumic (4.1-8.0 mg C<sub>DHS</sub> dm<sup>-3</sup>). During habitats humification in very acid lakes some water and sediment characteristics, such as pH, conductivity, TDS, and calcium concentration are low and almost invariable, whereas variable are the colour and clearness of the water. In low-acidity lakes the values of habitat characteristics are higher and also nearly invariable. The optimum habitats for <em>S. denticulatum</em> are oligohumic (&lt;1.8 mg C<sub>DHS</sub> dm <sup>-3</sup>), very acid (pH 4.0-4.4) sites found at depths from 4 to 8 m, where the species forms large and close carpets. In slightly acid lakes it is rare, grows at depths below 5 m and forms populations of very low density. In mesohumic habitats in both kinds of lakes <em>S. denticulatum</em> is a frequent species, but its populations are very thin there.

Improved prediction of vegetation composition in NW European softwater lakes by combining location, water and sediment chemistry

2011 ◽  
Vol 74 (2) ◽  
pp. 351-360 ◽  
Author(s):  
Cristina Pulido ◽  
Kaj Sand-Jensen ◽  
Esther C. H. E. T. Lucassen ◽  
Jan G. M. Roelofs ◽  
Klaus P. Brodersen ◽  
...  
Keyword(s):  
Sediment Chemistry ◽  
Vegetation Composition ◽  
Water And Sediment ◽  
Softwater Lakes

scholarly journals ASSESSMENT OF WATER AND SEDIMENT CHARACTERISTICS OF THE NORTHERN DANUBE DELTA LAKES - MATIȚA, BABINA AND MERHEI, ROMANIA

2017 ◽  
Author(s):  
Irina Catianis ◽  
◽  
Dan Secrieru ◽  
Albert Scrieciu ◽  
Dumitru Grosu ◽  
...  
Keyword(s):  
Danube Delta ◽  
Sediment Characteristics ◽  
Water And Sediment

scholarly journals Spatial and temporal variation in macroparasite communities of three-spined stickleback

Parasitology ◽  
2016 ◽  
Vol 144 (4) ◽  
pp. 436-449 ◽  
Author(s):  
REBECCA E. YOUNG ◽  
ANDREW D. C. MACCOLL
Keyword(s):  
Calcium Concentration ◽  
Gasterosteus Aculeatus ◽  
Parasite Community ◽  
Field Studies ◽  
Habitat Characteristics ◽  
Spatial And Temporal Variation ◽  
Natural Systems ◽  
Parasite Communities ◽  
Average Temperature ◽  
Parasite Ecology

SummaryPatterns in parasite community structure are often observed in natural systems and an important question in parasite ecology is whether such patterns are repeatable across time and space. Field studies commonly look at spatial or temporal repeatability of patterns, but they are rarely investigated in conjunction. We use a large dataset on the macroparasites of the three-spined stickleback,Gasterosteus aculeatusL., collected from 14 locations on North Uist, Scotland over an 8-year period to investigate: (1) repeatability of patterns in parasite communities among populations and whether variation is consistent across years, (2) whether variation between years can be explained by climatic variation and progression of the season and (3) whether variation in habitat characteristics explain population differences. Differences in relative abundance and prevalence across populations were observed in a number of parasites investigated indicating a lack of consistency across years in numerous parasite community measures; however, differences between populations in the prevalence and abundance of some parasites were consistent throughout the study. Average temperature did not affect parasite community, and progression of the season was only significant for two of 13 community measures. Two of the six habitat characteristics investigated (pH and calcium concentration) significantly affected parasite presence.

180 Relationships Between Water and Sediment Characteristics and Benthic Green Macroalgal Abundance in Yaquina Bay, Oregon: 1999-2002

2003 ◽  
Vol 39 (s1) ◽  
pp. 62-62
Author(s):  
D. R. Young ◽  
R. J. Ozretich ◽  
D. T. Specht ◽  
J. O. Lamberson ◽  
R. S. Caldwell ◽  
...  
Keyword(s):  
Sediment Characteristics ◽  
Water And Sediment

Population structure of breeding Harlequin Ducks and the influence of predation risk

2006 ◽  
Vol 84 (6) ◽  
pp. 855-864 ◽  
Author(s):  
J.P. Heath ◽  
G.J. Robertson ◽  
W.A. Montevecchi
Keyword(s):  
Prey Availability ◽  
Management Strategies ◽  
High Density ◽  
Habitat Characteristics ◽  
Low Density ◽  
Avian Predators ◽  
Harlequin Ducks ◽  
Local Measurements ◽  
Demographic Processes ◽  
Regional Population

Landscape features can have an important influence on the characteristics of populations, often resulting in heterogeneity in demographic processes. Therefore, local measurements of population parameters may not reflect regional characteristics. We studied populations of Harlequin Ducks ( Histrionicus histrionicus L., 1758) breeding in 11 river canyons in northern Labrador in relation to biophysical habitat characteristics and abundance of avian predators. Density and stability of Harlequin Duck populations varied among river canyons and were positively related (mean of 4.7 survey years per river). Both density and stability were negatively related to densities of raptorial birds. Raptor density was related to availability of suitable cliff ledges for nesting. Comparison of rivers with stable, high-density Harlequin Duck populations and those with variable, low-density populations revealed no detectable differences in habitat or prey availability. In a high-density population, observed stability but positive projected growth suggested the system was at carrying capacity and a source of emigrants. In contrast, unstable, low-density populations approached local extinction in some years, while large increases in subsequent years were suggestive of immigration. These findings demonstrate that breeding aggregations in different river canyons could represent an important unit of demographic structure. The abundance of raptors appears to be an important factor influencing local characteristics of Harlequin Duck populations. We discuss the potential influence of local demographic differences on regional population dynamics and their importance for conservation management strategies for migratory species.

scholarly journals Probability Analysis and Control of River Runoff–sediment Characteristics based on Pair-Copula Functions: The Case of the Weihe River and Jinghe River

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 510 ◽  
Author(s):  
Qiying You ◽  
Hao Jiang ◽  
Yan Liu ◽  
Zhao Liu ◽  
Zilong Guan
Keyword(s):  
River Runoff ◽  
Copula Function ◽  
Distribution Functions ◽  
Sediment Characteristics ◽  
Copula Functions ◽  
Sediment Yields ◽  
Water And Sediment ◽  
Weihe River ◽  
Runoff Sediment ◽  
Sediment Resources

Analyzing the encounter frequency of high–low runoff and sediment yield is important for the appropriate dispatching of runoff–sediment resources, as well as river regulation. However, there have been no reports on the utilization of the pair-copula function in analyzing the runoff–sediment characteristics from a probabilistic perspective and conducting probability control on the runoff–sediment yields of different hydrologic stations. This paper builds marginal distribution functions on the basis of kernel distribution theory. In addition, this paper builds the joint distribution functions through pair-copula functions in order to analyze the encounter probability and the compensation characteristics of high–low runoff and sediment at different stations on the Weihe River in China, as well as the origins of runoff–sediment, to conduct probability control of river runoff–sediment resource allocation. The results show that, in different periods, the synchronous probability of high–low runoff of the Weihe River’s Xianyang and Huaxian Stations, and the Jinghe River’s Zhangjiashan Station differ, while that of high–low sediment at the three stations changes little—remaining at around 54%. Therefore, the sediment and runoff of the Weihe River apparently have different origins. In years of high and low runoff, if the runoffs of the Xianyang and Zhangjiashan Stations can be kept within a certain range, then the runoff of the Huaxian Station will be in a particular range, at a certain probability. Sediment at the Huaxian Station can be controlled, in a similar way. These results are of great significance for the water and sediment management department of the Weihe river, in order to reasonably allocate water and sediment resources.

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