The scales of variability of stream fish assemblages at tributary confluences

Czeglédi, István; Sály, Péter; Takács, Péter; Dolezsai, Anna; Nagy, S.; Erős, Tibor

doi:10.1007/s00027-015-0454-z

Cited by 55 publications

(19 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are other reasons why confluences are important for river biodiversity including: provision of nutrient or prey subsidies (Wipfli and Gregovitch, 2002;Fernandes et al, 2004;Wellard-Kelly, 2013); the presence of unique confluence-zone habitats (Nakamoto, 1994;Franks et al, 2002;Kreb and Budiono, 2005); the amplification of competition amongst species (Besemer et al, 2013); and bi-directional filtering that affects organism dispersal (e.g. Thornbrugh and Gido, 2010;Wilson and McTammany, 2014;Czeglédi et al, 2015). Confluences may therefore be biodiversity hotspots in river networks (Benda et al, 2004b), where added biological value partly reflects increased physical heterogeneity produced by tributary-forced aggradation.…”

Section: Tributary-driven Aggradation In River Networkmentioning

confidence: 99%

Tributary connectivity, confluence aggradation and network biodiversity

Rice

2017

Geomorphology

View full text Add to dashboard Cite

In fluvial networks, some confluences are associated with tributary-driven aggradation where coarse sediment is stored, downstream sediment connectivity is interrupted and substantial hydraulic and morphological heterogeneity is generated. To the extent that biological diversity is supported by physical diversity, it has been proposed that the distribution and frequency of tributary-driven aggradation is important for the magnitude and spatial structure of river biodiversity. Relevant ideas are formulated within the Link Discontinuity Concept and the Network Dynamics Hypothesis, but many of the issues raised by these conceptual models have not been systematically evaluated. This paper first tests an automated method for predicting the likelihood of tributary-driven aggradation in three large drainage networks in the Rocky Mountain foothills, Canada. The method correctly identified approximately 75% of significant tributary confluences and 97% of insignificant confluences. The method is then used to evaluate two hypotheses of the Network Dynamics Hypothesis: that linear-shaped basins are more likely to show a longitudinal, downstream decline in tributary-driven aggradation; and that larger and more compact basins contain more confluences with a high probability of impact. The use of a predictive model that included a measure of tributary basin sediment delivery, rather than symmetry ratio alone, mediated the outcomes somewhat, but as anticipated, the number of significant confluences increased with basin size and basin shape was a strong control of the number and distribution of significant confluences. Doubling basin area led to a 1.9-fold increase in the number of significant confluences and compact basins contained approximately twice as many significant confluences per unit channel length as linear basins. In compact basins, significant confluences were more widely distributed, whereas in linear basins they were concentrated in proximal reaches. Interesting outstanding issues include the possibility of using spatially-distributed sediment routing models to predict tributary-driven confluence aggradation and the need to gather ecological data sufficient to properly test for increases in local and network-scale biodiversity associated with significant confluences and their network-scale controls.

show abstract

Section: Tributary-driven Aggradation In River Networkmentioning

confidence: 99%

Tributary connectivity, confluence aggradation and network biodiversity

Rice

2017

Geomorphology

View full text Add to dashboard Cite

show abstract

“…It is well known, that stream fish assemblages are influenced by the position of the site along the upstream-downstream gradient (Osborne & Wiley 1992, Schlosser & Angermeier 1995, Thornbrugh & Gido 2009, Czeglédi et al 2015.…”

Section: Discussionmentioning

confidence: 99%

Do diel variations in stream fish assemblages depend on spatial positioning of the sampling sites and seasons?

Czeglédi

Sály

Takács

et al. 2016

Acta Zool Acad Sci H

View full text Add to dashboard Cite

The effect of diel period (i.e. day vs night) and its dependence on the spatial position of the sampling site were evaluated on the assessment of fish assemblage attributes in a wadeable lowland stream (Hajagos stream, Hungary). Species richness, composition and abundance data of two 150 m long reaches, one situated directly at the tributary mouth and one 6 km upstream were compared using three pass removal by electrofishing in three seasons (summer, autumn and spring) to test the effect of spatial position on day and night patterns. No differences in any assemblage level variables were found between day and night. Although fish assemblages showed large temporal variations, spatial position of the sampling site had the most influential effect on fish assemblage attributes compared with seasonal and/ or day night patterns. Consequently, the diel period had rather negligible effect in the studied stream. Daytime electrofishing data seems to be highly representative for the accurate assessment of fish assemblages in relatively small (less than 5 m wide) wadeable streams and maybe used reliably for any model of community organization (e.g. food web studies).

show abstract

“…4). In this regard, the primary scales of the study of fi sh metacommunities in stream systems are the network of reaches (10 -1 -10 0 km) and segments (10 1 -10 2 km), because their extent fi ts best to the movement patterns and population dynamics of most fi sh populations, and these are the units at which different fi sh communities form (Matthews 1986, 1998, Lasne et al 2007, Erős et al 2016. Spatio-temporal scaling is thus critical in separating within community patterns and processes from metacommunity dynamics.…”

Section: Back To Basics: Defining Fish Metacommunities In Stream Netwmentioning

confidence: 99%

“…They emphasized that predictions of the RCC for fish community changes along the longitudinal profile of streams and rivers might be improved by using very simple measures, such as the size and proximity of connected streams. In an elongated river basin, Czeglédi et al (2016) showed that spatial position of parallel tributaries along the river influenced community structure in the tributaries. Another example of dispersal effects comes from Perkin and Gido (2012) who proved that fragmentation of stream segments by road crossing caused significant changes in fish community structure.…”

Section: Patterns In Diversitymentioning

confidence: 99%

“…For example, the importance of dispersal limitation (which can be partly indicated by spatial factors in variance partitioning) increases with spatial distance among sites and spatial extent surveyed. Recent studies on stream fishes showed that the relative role of environmental and spatial factors is very context dependent and depends largely on stream network topology (Troia andGido 2013, Sály andErős 2016). For example, Sály and Erős (2015) proved that 1) the importance of variance fractions (environmental, spatial, and shared environmental and spatial) depended largely on sample size, and that 2) values of the estimated variance fractions had remarkable random fluctuation at a given sample size depending on the spatial configuration of the sites in the stream network.…”

Section: The Importance Of Niche and Dispersal Processes In Metacommumentioning

confidence: 99%

See 1 more Smart Citation

Scaling fish metacommunities in stream networks: synthesis and future research avenues

Erős

2017

Community Ecology

Self Cite

View full text Add to dashboard Cite

Abstract:The metacommunity perspective has substantially advanced our understanding of how local (within community) and dispersal (between community) processes influence the assembly of communities. The increased recognition of dispersal processes makes it necessary to re-evaluate former views on community organization in different ecological systems and for specific organisms. Stream systems have long been considered from a linear perspective, in which local community organization was examined along the longitudinal profile, from source to mouth. However, the hierarchically branching (i.e. dendritic) structure of stream networks also significantly affects both local and regional scale community organization, which has just only recently been fully recognized by ecologists. In this review, I examine how the shift from a strictly linear to a dendritic network perspective influenced the thinking about the organization of fish metacommunities in stream networks. I argue that while longitudinal patterns in the structure of fish communities are relatively well known, knowledge is still limited about how the structure of the stream network ultimately affects the spatial and temporal dynamics of metacommunities. I suggest that scaling metapopulation models up to the metacommunity level can be useful to further our understanding of the spatial structure of metacommunities. However, this requires the delineation of local communities and the quantification of the contribution of dispersal to local community dynamics. Exploring patterns in diversity, spatial distribution and temporal dynamics of metacommunities is not easily feasible in continuous stream habitats, where some parts of the habitat network are exceptionally hard to sample representatively. Combination of detailed field studies with modelling of dispersal is necessary for a better understanding of metacommunity dynamics in stream networks. Since most metacommunity level processes are likely to happen at the stream network level, further research on the effects of stream network structure is needed. Overall, separation of the effect of dispersal processes from local scale community dynamics may yield a more mechanistic understanding of the assembly of fish communities in stream networks, which may also enhance the effectiveness of restoration efforts.

show abstract

The scales of variability of stream fish assemblages at tributary confluences

Cited by 55 publications

References 31 publications

Tributary connectivity, confluence aggradation and network biodiversity

Tributary connectivity, confluence aggradation and network biodiversity

Do diel variations in stream fish assemblages depend on spatial positioning of the sampling sites and seasons?

Scaling fish metacommunities in stream networks: synthesis and future research avenues

Contact Info

Product

Resources

About