scholarly journals A critical review of the effect of water storage reservoirs on organic matter decomposition in rivers

2017 ◽  
Vol 25 (2) ◽  
pp. 193-198 ◽  
Author(s):  
John Gichimu Mbaka ◽  
Mercy Wanjiru Mwaniki

Organic matter decomposition is vital in sustaining river food webs. However, little is known about the effect of water storage reservoirs on organic matter decomposition in rivers. In this paper, we reviewed and analyzed 37 studies that investigated the effect of man-made reservoirs on organic matter decomposition in rivers. Most studies focused on decomposition of tree leaf litter (54.1%) and macrophytes litter (43.2%), while fewer studies evaluated decomposition of wood (2.7%). Based on qualitative analysis, the effect of small weirs on organic matter decomposition is local and the effect on most habitat variables is minimal. Mean effect sizes (Hedges’ g) for organic matter decomposition were −1.98 for small weirs, −1.31 for small reservoirs, and −0.66 for large reservoirs. This review demonstrates that, in general, reservoirs have a negative effect on litter decomposition. Litter decomposition, an important ecosystem process, is sensitive to impacts of reservoirs in different types of rivers.

1980 ◽  
Vol 58 (4) ◽  
pp. 416-421 ◽  
Author(s):  
John D. Aber ◽  
Jerry M. Melillo

The relative contribution of different types of litter to the maintenance of soil organic matter and nitrogen levels cannot be determined from standard litter bag disappearance studies. By coupling measurements of weight loss with nitrogen dynamics and presenting results in a new format, estimates of both state of decay and percentage of material eventually transferred to lower soil horizons can be obtained.


1994 ◽  
Vol 29 (2-3) ◽  
pp. 385-402
Author(s):  
K. Ya. Kondratyev ◽  
D.V. Pozdnyakov

Abstract Large scale limnological applications of active optical remote sensing techniques are described. An airborne Nd:YAG laser with frequency doubling and tripling facilities is used. Algorithms for inferring concentrations in phytoplankton chlorophyll (CHL) and dissolved organic matter (DOM) are developed for inland water bodies. Through the analysis of specific features of retrieved 2-D fields of CHL and DOM, it is possible to characterize the surficial manifestations of various fundamental thermohydrodynamic phenomena in lakes and water storage reservoirs, such as upwellings, cores, stream patterns, etc.


2001 ◽  
Vol 10 (6) ◽  
pp. 639-660 ◽  
Author(s):  
Jacques Gignoux ◽  
Joanna House ◽  
David Hall ◽  
Dominique Masse ◽  
Hassan B. Nacro ◽  
...  

2020 ◽  
Vol 100 (1) ◽  
pp. 11-25 ◽  
Author(s):  
Guoyong Yan ◽  
Xiongde Dong ◽  
Binbin Huang ◽  
Honglin Wang ◽  
Ziming Hong ◽  
...  

We conducted a field experiment with four levels of simulated nitrogen (N) deposition (0, 2.5, 5, and 7.5 g N m−2 yr−1, respectively) to investigate the response of litter decomposition of Pinus koraiensis (PK), Tilia amurensis (TA), and their mixture to N deposition during winter and growing seasons. Results showed that N addition significantly increased the mass loss of PK litter and significantly decreased the mass loss of TA litter throughout the 2 yr decomposition processes, which indicated that the different responses in the decomposition of different litters to N addition can be species specific, potentially attributed to different litter chemistry. The faster decomposition of PK litter with N addition occurred mainly in the winter, whereas the slower decomposition of TA litter with N addition occurred during the growing season. Moreover, N addition had a positive effect on the release of phosphorus, magnesium, and manganese for PK litter and had a negative effect on the release of carbon, iron, and lignin for TA litter. Decomposition and nutrient release from mixed litter with N addition showed a non-additive effect. The mass loss from litter in the first winter and over the entire study correlated positively with the initial concentration of cellulose, lignin, and certain nutrients in the litter, demonstrating the potential influence of different tissue chemistries.


Author(s):  
Frowin Fasold ◽  
Benjamin Noël ◽  
André Nicklas ◽  
Fabian Lukac ◽  
Stefanie Klatt

Throwing a ball is a primary skill in team-handball and can be directly influenced by the properties of different types of balls. Therefore, the use of different balls (i.e., methodic ball) recommended by the handball federations (e.g., IHF) and the education guidelines, are important in teaching throwing. Previous studies have shown that movement patterns and throwing velocity can be influenced by different ball types and sizes. However, the influence of these factors on throwing accuracy has not been investigated in detail yet. This study aims to replicate the findings of previous studies on increasing throwing velocity in children by comparing the use of a soft methodic ball with a size 0 handball. Furthermore, this study investigates the influence of these balls on throwing accuracy. In an experimental study, participants (10-years of age) threw a soft methodic ball and a size 0 ball at target areas in a handball goal. For all the throws, throwing velocity and accuracy were measured. Commensurate with previous research, throwing velocity was higher for the soft methodic ball compared to a size 0 ball. No difference was found in accuracy, although, it is worth mentioning that the participants were only experienced in throwing using the size 0 ball. Moreover, only one-third of the children favored throwing with a size 0 ball, which is what they are used to in training and competition. The results of our study, therefore, confirm that using soft methodic balls additionally, positively influences the throwing velocity and has no negative effect on the accuracy in throwing among young handball beginners.


2021 ◽  
pp. 108302
Author(s):  
Gerrit Angst ◽  
Jan Pokorný ◽  
Carsten W. Mueller ◽  
Isabel Prater ◽  
Sebastian Preusser ◽  
...  

2016 ◽  
Vol 25 (2) ◽  
pp. 213 ◽  
Author(s):  
Kajar Köster ◽  
Frank Berninger ◽  
Jussi Heinonsalo ◽  
Aki Lindén ◽  
Egle Köster ◽  
...  

In boreal forest ecosystems fire, fungi and bacteria, and their interactions, have a pronounced effect on soil carbon dynamics. In this study we measured enzymatic activities, litter decomposition rates, carbon stocks and fungal and microbial biomasses in a boreal subarctic coniferous forest on a four age classes of non-stand replacing fire chronosequence (2, 42, 60 and 152 years after the fire). The results show that microbial activity recovered slowly after fire and the decomposition of new litter was affected by the disturbance. The percent mass loss of Scots pine litter increased with time from the last fire. Slow litter decomposition during the first post-fire years accelerates soil organic matter accumulation that is essential for the recovery of soil biological activities. Fire reduced the enzymatic activity across all the enzyme types measured. Carbon-degrading, chitin-degrading and phosphorus-dissolving enzymes showed different responses with the time elapsed since the fire disturbance. Microbial and enzymatic activity took decades before recovering to the levels observed in old forest stands. Our study demonstrates that slower post-fire litter decomposition has a pronounced impact on the recovery of soil organic matter following forest fires in northern boreal coniferous forests.


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