Carbon and nutrient subsidies to a lowland river following floodplain inundation

2016 ◽  
Vol 67 (9) ◽  
pp. 1302 ◽  
Author(s):  
Daryl L. Nielsen ◽  
Robert A. Cook ◽  
Nathan Ning ◽  
Ben Gawne ◽  
Rochelle Petrie
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
River Channel ◽  
Resource Subsidies ◽  
Lowland Rivers ◽  
Main River ◽  
Main River Channel ◽  
Eastern Australia ◽  
Floodplain Inundation ◽  
Nutrient Subsidies

Despite the perceived importance of floodplain inundation to the functioning of lowland rivers, there is limited understanding of the contribution that floodplains make to the main river channel during floods. In 2010, substantial flooding occurred throughout south-eastern Australia, which provided an opportunity to quantify the export of biological material and nutrients from a floodplain back in to the main river channel. We quantified the amounts of zooplankton, phytoplankton, dissolved organic carbon and nutrients within the main river channel of the River Murray immediately upstream of the Barmah–Millewa Forest, and at two sites immediately downstream of the forest during two flood events in July and October of 2010. Results demonstrated that although a smaller flood event in July did not contribute substantially to an increase in the measured parameters, a much larger flood in October contributed 0.4 tonnes (t) of phytoplankton; 7t of zooplankton and 300t of dissolved organic carbon. This suggests that small floods will provide minimal resource subsidies back into the main channel after the cessation of flooding. In comparison, larger floods that result in large volumes of floodplain water returning to the river will provide substantial subsidies of terrestrially derived resources.

scholarly journals Habitat factors differentiating the occurrence of Ostracoda (Crustacea) in the floodplain of a small lowland River Krąpiel (N-W Poland)

2020 ◽  
pp. 23
Author(s):  
Agnieszka Szlauer-Łukaszewska ◽  
Vladimir Pešić
Keyword(s):  
Abiotic Factors ◽  
River Channel ◽  
Water Bodies ◽  
Oxbow Lakes ◽  
Factors Associated ◽  
Main River ◽  
Main River Channel ◽  
Habitat Factors ◽  
Sediment Sorting ◽  
Physical And Chemical

We analysed the occurrence of ostracods in a small river, taking into account all the types of water bodies in the floodplain − these included helocrenes, oxbow lakes, and ponds, as well as the main river channel. The objective of the study was to investigate the variation in ostracod communities and identify those factors determining species distribution. The environmental factors considered were the type of water body, responsible for 17% of the variance, the physical and chemical water properties (29%), and the biotic and abiotic factors associated with the substrate type (23%). Among the factors associated with the substrate, sediment sorting, plant coverage and insolation were the most important. The ostracod fauna of the helocrenes differed from that of the other water bodies in the floodplain. In the water bodies of the Krąpiel valley and in the main river channel, 33 ostracod species were recorded, of which 26 were found in the main river channel. Refugia in the floodplain were the main source of the diversity and abundance of ostracods in the main river channel. The mean density in the main river channel was very low, at 330 indiv. m−2, while in the water bodies of the floodplain it was the greatest, reaching up to 5568 indiv. m−2.

Open water metabolism and dissolved organic carbon in response to environmental watering in a lowland river–floodplain complex

2016 ◽  
Vol 67 (9) ◽  
pp. 1346 ◽  
Author(s):  
Todd A. Wallace ◽  
Deborah Furst
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Food Webs ◽  
Ecosystem Respiration ◽  
Open Water ◽  
Relative Role ◽  
Eastern Australia ◽  
Return Flows ◽  
Receiving Waters ◽  
The Impact

The relative importance of autochthonous and allochthonous organic material in fuelling ecosystem metabolism is increasingly understood for some river systems. However, in south-eastern Australia, the majority of studies have been conducted during low flows when the supply of allochthonous carbon was limited. Consequently, the importance of episodic inputs of terrestrially derived material in supporting these food webs remains poorly understood. We assessed the influence of return flows from two different scales of environmental watering actions on dissolved organic carbon and open-water productivity in receiving waters adjacent to the watered area. For the wetland-scale event, gross primary productivity and ecosystem respiration increased in the receiving waters during the period of return flows. During the floodplain-scale watering, differences were observed among sites. Within the managed inundation zone, values for net ecosystem productivity switched from near zero during the baseline to strongly negative during the impact period, whereas values at the river sites were either near zero or positive. The results contribute to our understanding of the relative role of allochthonous material in supporting aquatic food webs in lowland rivers, and demonstrate potential for watering actions to have a positive influence on riverine productivity during periods of low water availability.

scholarly journals Coleoptera associated with macrophytes of the genus Salvinia in four oxbow lakes in two river basins in southeast Brazil

2015 ◽  
Vol 75 (4 suppl 1) ◽  
pp. 108-118 ◽  
Author(s):  
M. C. Paula-Bueno ◽  
A. A. Fonseca-Gessner
Keyword(s):  
River Basins ◽  
River Channel ◽  
The State ◽  
The Other ◽  
Oxbow Lakes ◽  
Aquatic Fauna ◽  
Southeast Brazil ◽  
Main River ◽  
Main River Channel ◽  
The Difference

Abstract Macrophytes in oxbow lakes represent an important substrate for the Coleoptera. Two oxbow lakes the Rio Paranapanema were studied and the other two Rio Mogi-Guaçu, in the State de São Paulo, Brasil. In this study, there is greater similarity between the communities of Coleoptera of lakes greater connectivity with the main river channel or the difference in the species of Salvinia collected in the lakes studied interferes Coleoptera fauna that uses as substrate. A total of 9,222 specimens of Coleoptera were collected and identified in 10 families and 40 genera. The analysis MDS for abundance of Coleoptera showed the grouping of the oxbow lakes the Paranapanema River and a distancing the oxbow lakes the Mogi-Guaçu. The PERMANOVA test did not reveal any difference in the fauna between the wet and dry periods. It was concluded that the connectivity between river and lake is not decisive for the richness and abundance of aquatic fauna of Coleoptera. Therefore, the richness and abundance of aquatic Coleoptera associated vary with the species of Salvinia used as substrate.

A Comparison of Species Richness and Traits of Riparian Plants between a Main River Channel and Its Tributaries

1994 ◽  
Vol 82 (2) ◽  
pp. 281 ◽  
Author(s):  
Christer Nilsson ◽  
Alf Ekblad ◽  
Mats Dynesius ◽  
Susanne Backe ◽  
Maria Gardfjell ◽  
...  
Keyword(s):  
Species Richness ◽  
River Channel ◽  
Riparian Plants ◽  
Main River ◽  
Main River Channel

scholarly journals Floodplain sediment from a 30-year-recurrence flood in 2005 of the Ping River in northern Thailand

2007 ◽  
Vol 4 (5) ◽  
pp. 3839-3868 ◽  
Author(s):  
S. H. Wood ◽  
A. D. Ziegler
Keyword(s):  
Fine Sand ◽  
Sediment Concentration ◽  
Main Channel ◽  
River Channel ◽  
Northern Thailand ◽  
Main River ◽  
Main River Channel ◽  
Clayey Silt ◽  
Secondary Objective ◽  
Sedimentation Processes

Abstract. This paper documents the nature of flood-producing storms and floodplain deposition associated with the 28 September–2 October 2005 30-year-recurrence flood on the Ping River in northern Thailand. The primary purpose of the study is to understand the extent that deposits from summer-monsoon floods can be identified in floodplain stratigraphy A secondary objective is to document the sedimentation processes/patterns associated with a large contemporary flood event on a medium-sized Asian river. Maximum sediment depths of 15 cm were found on the river levee, within 30 m of the main channel, and at 350 m thickness was 4 cm. Sediment depth generally decreased exponentially with distance away from the main channel. The extent of sediment deposition was about 1 km from the river channel. However, 72% of the sediment was deposited within an oval-shaped area 200–400 m from the main channel and centered on a tributary stream, through which sediment-laden water entered the floodplain, in addition to overtopping the levee of the main channel. Sediment concentration during the flood was estimated at 800–1500 mg L−1; and we believe the sediment was delivered by flows of well-mixed flood water occurring over a 1–2 day period. These data suggest that flood-deposited strata related to 30-year recurrence floods is only likely to be preserved in deposits located relatively close to the main river channel where fine sand and clayey coarse silt deposits have thicknesses of at least 5–10 cm. These relatively thick deposits would survive bioturbation, whereas more distal areas with thin clayey silt deposits would not.

scholarly journals Fish, tributaries of middle Rio Mogi Guaçu, upper Rio Paraná basin, São Paulo state, Southeastern Brazil

Check List ◽  
2009 ◽  
Vol 5 (3) ◽  
pp. 488 ◽  
Author(s):  
Alexandre K. de Oliveira ◽  
Fernando Apone ◽  
José Luís O. Birindelli ◽  
Odney R. Perez Júnior
Keyword(s):  
Sao Paulo ◽  
River Channel ◽  
Southeastern Brazil ◽  
São Paulo ◽  
Paulo State ◽  
Main River ◽  
Main River Channel ◽  
Paraná Basin ◽  
São Paulo State ◽  
Parana Basin

In this paper we compiled a fish list obtained from field collections performed between 1999 and 2005 in four tributaries of the Rio Mogi Guaçu, upper Rio Paraná basin, São Paulo State, Brazil. The collected fishes belong to six orders, 21 families, 60 genera and 82 species. The number of species represents 20 to 30% of the fish richness for the entire upper Rio Paraná basin according to recent estimates. A comparison to earlier published fish lists of the Rio Mogi Guaçu basin, chiefly from its main river channel, is also presented.

scholarly journals Seasonal abundance and breeding habitat occupancy of the Orinoco Goose (Neochen jubata) in western Brazilian Amazonia

2014 ◽  
Vol 24 (4) ◽  
pp. 518-529 ◽  
Author(s):  
WHALDENER ENDO ◽  
TORBJØRN HAUGAASEN ◽  
CARLOS A. PERES
Keyword(s):  
Sandy Beaches ◽  
Dry Season ◽  
River Channel ◽  
Habitat Associations ◽  
Breeding Habitat ◽  
Seasonal Abundance ◽  
Encounter Rate ◽  
Brazilian Amazonia ◽  
Main River ◽  
Main River Channel

SummaryThe Near-threatened Orinoco Goose Neochen jubata is a poorly known South American sheldgoose with a declining population and range distribution. In this study, we surveyed the Orinoco Goose population along the middle reaches of the Rio Juruá, western Brazilian Amazonia, and its first-order tributaries. We quantified the seasonal abundance of geese, pinpointed their approximate breeding season, and examined their habitat associations and the potential effects of human activities on their abundance. Hunting by local villagers was also monitored to assess the offtake rate of this species. Orinoco Goose occurrence in the region was highly seasonal and restricted to the dry season. We estimated a mean dry-season encounter rate of 7.18 ± 2.45 adult individuals per 4-km section along this river. Immature individuals were seen along the river margins from August to December. The species showed a strong preference for sandy beaches and was primarily restricted to the main river channel, with few individuals occurring along tributaries. The encounter rate of this species was also significantly related to fluvial distance from the municipal urban centre and to the level of protection from hunting. Hunting of Orinoco Goose was reported in 12 of the 26 villages monitored. The seasonal appearance of the Orinoco Goose in the region indicates that this is a migratory population. Our study indicates that strict protection of the river margins, and sandy beaches in particular, along the main river channel is likely to be positive for the conservation of this species along the Rio Juruá. However, further knowledge of migration routes is critical for effective protection of both breeding and non-breeding populations.

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