The effects of seasonal changes to in-stream vegetation cover on patterns of flow and accumulation of sediment

Cotton, Jacqueline A.; Wharton, Geraldene; Bass, J. A. B.; Heppell, Catherine M.; Wotton, Roger S.

doi:10.1016/j.geomorph.2006.01.010

Cited by 237 publications

(237 citation statements)

References 42 publications

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“…In the case of Stream 1, flow velocity decreased with an increase of macrophyte abundance, whereby the culmination of water depth and macrophyte abundance temporally overlapped with the minimum flow velocity. This fully corroborates the observations of other authors, suggesting that growth and die-back of aquatic macrophytes have an effect on the dynamics of flow, demonstrated primarily in decreasing flow velocity caused by the expansion of macrophytes [13,33,34]. There might thus be a positive feedback between aquatic plants and their environment: high density of hydrophytes hampers the flow and causes increasing water level, which in turn provides optimum conditions for the growth and survival of this macrophyte group.…”

Section: Effect Of Environmental Characteristics To Seasonal Dynamicssupporting

confidence: 91%

Seasonal dynamics of macrophyte abundance in two regulated streams

2009

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This study analysed seasonal dynamics of macrophyte abundance in two perennial lowland regulated streams (Stream 1 and 2) in the Danube basin (Slovakia). Assessments of macrophyte abundance and environmental characteristics were accomplished 7 times during the vegetation period in 2005 within a 100 m long section. Statistically significant differences in total abundance of macrophytes as well as an abundance of macrophyte groups (hydrophytes, amphiphytes, helophytes) and Potamogeton nodosus were detected among months within the vegetation period. Abundance fluctuations for individual macrophyte groups and species were moderate in Stream 1 and much stronger in Stream 2. Only amphiphytes showed bimodal temporal distribution in Stream 1, but the abundance of this group was low, reflecting more or less random occurrence of species in vegetation period. Multiple linear regression revealed that water depths and air temperature are the most significant environmental variables affecting the seasonal pattern of total as well as dominating group abundance in Stream 1 and 2, respectively. In all cases, abundances are significantly influenced by the abundance of the respective group in the preceding month. Culmination time differed between streams for all macrophyte groups except helophytes. Total abundance culminated 0.57 month later in the Stream 1 compared to Stream 2.

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Section: Effect Of Environmental Characteristics To Seasonal Dynamicssupporting

confidence: 91%

Seasonal dynamics of macrophyte abundance in two regulated streams

2009

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“…and Berula spp. can cover up to 80% of the main river channel in chalk streams in late summer (Cotton et al 2006), and, therefore, our survey of the Bagnor study reach in early summer when we measured dense vegetation covering . 50% of the riverbed was characteristic of these lowland chalk rivers.…”

Section: Discussionmentioning

confidence: 99%

“…and Berula spp. can cover up to 80% of the main river channel in late summer, with net primary production over 8 months reaching , 826 g (dry weight, dry wt) m 22 (Cotton et al 2006;Trimmer et al 2009b). Macroinvertebrate taxon richness also is high (e.g., 188 taxa reported at Bagnor, 37 of which were Trichoptera) and, recently, Tod and Schmid-Araya (2009) reported high rates of total annual secondary production in the gravel beds at Bagnor of 23 g (dry wt) m 22 yr 21 and even more within the macrophyte stands of 65 g (dry wt) m 22 yr 21 .…”

Section: Discussionmentioning

confidence: 99%

Potential carbon fixation via methane oxidation in well‐oxygenated river bed gravels

Trimmer

Maanoja

Hildrew

et al. 2009

Limnology & Oceanography

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Due to a combination of local methanogenesis and high background concentrations in the groundwater, water in the River Lambourn is 51 times supersaturated with methane (162 nmol CH 4 L 21 ). Pore-water concentrations of methane in the gravels of the riverbed were much lower throughout the year (71 nmol CH 4 L 21 ), suggesting significant methane oxidation. To investigate the potential for methane oxidation as a novel chemosynthetic source of carbon to the food web, we made simultaneous measurements, in laboratory chambers, of primary production, respiration, and methane oxidation associated with the gravels. Biomass-specific net primary production was up to 2.7 mmol O 2 mg 21 chlorophyll (Chl) h 21 and was similarly high for respiration (2.7 mmol O 2 mg 21 Chl h 21 ). We also found active methane (CH 4 ) oxidation with the rate increasing in proportion to concentration. At the maximum rate of 0.18 mmol CH 4 mg 21 Chl h 21 and a growth efficiency of 0.8, net carbon fixation via methane oxidation was equivalent to 6% of the carbon fixed via net photosynthetic primary production. However, production via methane oxidation could be proportionately much greater under the shade of the profuse instream or riparian vegetation, deep in the gravels, and especially during winter, when light is limiting (, 25 mmol quanta m 22 s 21 ).

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“…Fluvial geomorphologists and hydraulic engineers recognise the importance of in-stream and riparian ecological processes for understanding sediment fluxes, water flow and landforming processes at a variety of scales (e.g. Millar, 2000;Gottesfeld et al, 2004;Buttler and Malanson, 2005;Cotton et al, 2006;Johnson et al, in press). Equally, ecologists have long recognised the importance of open-channel hydraulics, sediment stability and the other processes that provide and maintain channel morphology, for understanding the distribution and behaviour of aquatic organisms (e.g.…”

Section: Introductionmentioning

confidence: 99%

Experimentation at the interface of fluvial geomorphology, stream ecology and hydraulic engineering and the development of an effective, interdisciplinary river science

Rice

Lancaster

Kemp

2009

Earth Surf Processes Landf

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One "2020 vision" for fluvial geomorphology is that it sits alongside stream ecology and hydraulic engineering as a key element of an integrated, interdisciplinary river science. A challenge to this vision is that scientists from these three communities may approach problems from different perspectives with different questions and have different methodological outlooks. Refining interdisciplinary methodology is important in this context, but raises a number of issues for geomorphologists, ecologists and engineers alike. In particular, we believe that it is important that there is greater dialogue about the nature of mutually-valued questions and the adoption of mutually-acceptable methods. As a contribution to this dialogue we examine the benefits and challenges of using physical experimentation in flume laboratories to ask interdisciplinary questions. Working in this arena presents the same challenges that experimental geomorphologists and engineers are familiar with (scaling up results, technical difficulties, realism) and some new ones including recognising the importance of biological processes, identifying hydraulically meaningful biological groups, accommodating the singular behaviour of individuals, understanding biological as well as physical stimuli, and the husbandry and welfare of live organisms. These issues are illustrated using two examples from flume experiments designed (1) to understand how the movement behaviours of aquatic insects through the near-bed flow field of gravelly river beds may allow them to survive flood events, and (2) how an understanding of the way in which fish behaviours and swimming capability are affected by flow conditions around artificial structures can lead to the design of effective fish passages. In each case, an interdisciplinary approach has been of substantial mutual benefit and led to greater insights than discipline-specific work would have produced. Looking forward to 2020, several key challenges for experimentalists working on the interface of fluvial geomorphology, stream ecology and hydraulic engineering are identified.3

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The effects of seasonal changes to in-stream vegetation cover on patterns of flow and accumulation of sediment

Cited by 237 publications

References 42 publications

Seasonal dynamics of macrophyte abundance in two regulated streams

Seasonal dynamics of macrophyte abundance in two regulated streams

Potential carbon fixation via methane oxidation in well‐oxygenated river bed gravels

Experimentation at the interface of fluvial geomorphology, stream ecology and hydraulic engineering and the development of an effective, interdisciplinary river science

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