Seasonal variations of dominant phytoplankton in humic forest lakes

2007 ◽  
Vol 36 (2) ◽  
Author(s):  
Tomasz Joniak
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Column ◽  
Humic Substances ◽  
Community Composition ◽  
Seasonal Variations ◽  
Humic Lakes ◽  
Forest Lakes ◽  
Dissolved Humic Substances

Seasonal variations of dominant phytoplankton in humic forest lakesThis work presents the community composition, abundance and seasonal dominance of phytoplankton taxa in three hydrochemically different, mid-forest humic lakes. The largest number of taxa was observed in the oligohumic lake (76), with smaller numbers seen in the mesohumic (42) and polyhumic lakes (37), which were characterized by higher contents of dissolved humic substances carbon (DHSC). Along an increasing gradient of DHSC in a pool of dissolved organic carbon (DOC) the autotrophic algae were seen to disappear, being replaced by taxa with features of facultative heterotrophs and flagellated algae that are able to move in the water column.

Contributions of humic substances to the dissolved organic carbon pool in wetlands from different climates

Chemosphere ◽  
2012 ◽  
Vol 88 (10) ◽  
pp. 1265-1268 ◽  
Author(s):  
Akira Watanabe ◽  
Kunio Moroi ◽  
Hiromu Sato ◽  
Kiyoshi Tsutsuki ◽  
Nagamitsu Maie ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Humic Substances ◽  
Carbon Pool ◽  
Organic Carbon Pool ◽  
Different Climates

Spatial and seasonal variations of sulphate, dissolved organic carbon, and nutrients in deep pore waters of intertidal flat sediments

2008 ◽  
Vol 79 (2) ◽  
pp. 307-316 ◽  
Author(s):  
Melanie Beck ◽  
Olaf Dellwig ◽  
Gerd Liebezeit ◽  
Bernhard Schnetger ◽  
Hans-Jürgen Brumsack
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Seasonal Variations ◽  
Intertidal Flat ◽  
Pore Waters

scholarly journals Seasonal variations and sources of particulate and dissolved organic carbon in Lake Bosten, Xinjiang Province

2014 ◽  
Vol 26 (4) ◽  
pp. 552-558 ◽  
Author(s):  
WANG Xiujun ◽  
◽  
FANG Chuanling ◽  
YU Zhitong ◽  
WANG Jiaping ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Seasonal Variations

scholarly journals New possibility for characterization of dissociation behaviour of supramolecular electrolytes: results obtained for the International Humic Substances Society standard and reference samples by coulometry

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Martina Klučáková
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Humic Substances ◽  
Functional Groups ◽  
Dissociation Constants ◽  
Fulvic Acids ◽  
Molecular Organization ◽  
Humic And Fulvic Acids ◽  
Acid Base ◽  
Reference Samples

Abstract Background Humic substances can be considered as polyelectrolytes with supramolecular character and complicated behaviour in water environment. The fractions of humic substances dissolved in water are the most active ones and determinative for their functioning in nature, where the proton-binding and dissociation ability play a crucial role. The dissociation behaviour of humic and fulvic acids can be affected by different circumstances including their concentration which is directly connected with the molecular organization of humic particles in solution and the accessibility of their ionizable functional groups. This study is focused just on these active fractions and their dissociation behaviour in the dependence on their content in studied system. Results Standards and reference samples of International Humic Substances Society were used. Flow-through coulometry was used to determine the total content of acidic functional groups in fulvic solutions and humic leachates. The amount of dissociated acidic groups was determined on the basis of potentiometry. Several differences between the behaviour of humic and fulvic acids were found. While whole samples of fulvic acids including the weakest functional groups were analysed, only the active dissolved humic fractions containing stronger acidic functional groups were characterized. The fractions containing higher amounts of the weakest functional groups remained insoluble. The dissociation degree of fulvic acids decreased with their increasing content, but a maximum on its concentration dependence obtained for humic acids was observed. Conclusions Two different values of dissociation constants were determined for each sample. The first was determined on the basis of the extrapolation of infinite dilution, second was determined as their average value in the region of high concentrations in which it was constant. Obtained values characterize the functioning of dissolved humic substances from point of view of their dissociation ability. The results obtained by this approach can help to predict the acid–base behaviour of dissolved organic carbon in soil and generally in nature. The acid–base behaviour of dissolved organic carbon depends on its ratio to water. It behaves differently in soil which is dry and in soil which is wet or saturated by water.

scholarly journals Lack of Correlation between Turnover of Low-Molecular-Weight Dissolved Organic Carbon and Differences in Microbial Community Composition or Growth across a Soil pH Gradient

2011 ◽  
Vol 77 (8) ◽  
pp. 2791-2795 ◽  
Author(s):  
Johannes Rousk ◽  
Philip C. Brookes ◽  
Helen C. Glanville ◽  
David L. Jones
Keyword(s):  
Molecular Weight ◽  
Microbial Community ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Community Composition ◽  
Soil Ph ◽  
Predictive Power ◽  
Microbial Community Composition ◽  
Low Molecular Weight ◽  
Soil C

ABSTRACTWe studied how soil pH (pHs 4 to 8) influenced the mineralization of low-molecular-weight (LMW)-dissolved organic carbon (DOC) compounds, and how this compared with differences in microbial community structure. The mineralization of LMW-DOC compounds was not systematically connected to differences in soil pH, consistent with soil respiration. In contrast, the microbial community compositions differed dramatically. This suggests that microbial community composition data will be of limited use in improving the predictive power of soil C models.

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