Can the sedimentological and morphological structure of rivers be used to predict characteristics of riparian seed banks?

O’Donnell, Jessica; Fryirs, Kirstie; Leishman, Michelle R.

doi:10.1016/j.geomorph.2015.05.030

Cited by 4 publications

(6 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Siebentritt, Ganf, and Walker () found that an enhanced flood led to an increase in flood‐dependent species of vegetation and a reduction in flood‐intolerant species, also noting that small floods may be useful in the maintenance of vegetation communities rather than as a trigger for germination. Having said this, there is also growing evidence to suggest that stimulating the riparian seedbank along degraded rivers also leads to an increase in the germination and establishment of exotic species (Greet, Cousens, & Webb, ; O'Donnell et al, , , ). Greet () cautions that seed banks of degraded wetlands may act as sources of exotic plant species, and Greet, Cousens, and Webb () found more exotic species in regulated rivers compared with unregulated rivers.…”

Section: Discussionmentioning

confidence: 99%

“…One of the key indicators that geomorphic river recovery is underway is the formation of benches, step‐like inset floodplain features that occur along channel banks and act to reduce channel capacity in overwidened macrochannels (Erskine & Livingstone, ; Thoms & Olley, ; Erskine, Chalmers, Keene, Cheetham, & Bush, ). Benches potentially hold more numerous and deeper seedbanks in comparison with bar or floodplain units (O'Donnell, Fryirs, & Leishman, ), and the reworking of surfaces during flows provides suitable substrate and disturbance (e.g., exposure to light or water) for germination of seeds from the seed bank (Goodson, Gurnell, Angold, & Morrissey, ; O'Donnell, Fryirs, & Leishman, ). Benches play roles in both the hydrological and ecological functioning of rivers, and environmental flow studies often recommend the inundation of benches (Vietz, Rutherfurd, & Stewardson, ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Simulating the effect of environmental flow duration on seedling emergence from riparian seed banks of the Upper Hunter River, New South Wales

Stone

Fryirs

Leishman

2018

River Research & Apps

Self Cite

View full text Add to dashboard Cite

Passive riparian revegetation techniques are important tools in river rehabilitation.However, the utility of the sediment seed bank as a passive riparian regeneration option is poorly understood. After modelling a range of flows for field-surveyed cross sections, a glasshouse seedling emergence experiment was undertaken to compare the effects of simulated flow duration on seedling emergence of desirable riparian species that occur on benches of the gravel-bedded Hunter River near Muswellbrook, New South Wales. The duration of inundation did have an effect (although not always significant) on seed germination for most species. The most successful simulated flood conditions differed among species, with the control treatment (no inundation) resulting in the most germination for only two of the 10 species examined. These findings suggest that although environmental flows for the sole purpose of stimulating the riparian seed bank in order to facilitate regeneration of desirable riparian species would be largely ineffective and complicated by differing inundation responses among species, seed bank stimulation using environmental flows could be a value-added benefit from flows allocated for other purposes. As such, consideration of flow duration is worthy of inclusion in environmental flow allocation planning.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simulating the effect of environmental flow duration on seedling emergence from riparian seed banks of the Upper Hunter River, New South Wales

Stone

Fryirs

Leishman

2018

River Research & Apps

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, the spatial variation in the percentage of soil moisture did not seem to have a detectable influence on the spatial distribution of viable microfaunal and aquatic plant propagule bank communities in our study. A number of studies have argued that soil moisture conditions may have an important influence on the long-term conservation of seed and egg banks, since not all seeds and eggs have the ability to tolerate desiccation for prolonged dry periods without undergoing a loss of viability (O'Donnell et al 2015;Jenkins and Boulton 2007).…”

Section: Propagule Bank Communities In Relation To Sediment Charactermentioning

confidence: 99%

“…The high flows can also aid in restoring sediment conditions (e.g. soil moisture content) to support the viability of dormant seeds and eggs (O'Donnell et al 2015;Jenkins and Boulton 2007), although the influence of such flows is likely to vary among floodplain locations with differing elevations and/or commenceto-flow (CTF) thresholds (Tronstad et al 2005;Capon and Brock 2006).…”

Section: Introductionmentioning

confidence: 99%

Spatial variability of aquatic plant and microfaunal seed and egg bank communities within a forested floodplain system of a temperate Australian river

et al. 2016

View full text Add to dashboard Cite

Aquatic plant and microfaunal propagule banks represent a major source of regenerative potential in riverfloodplain ecosystems. This study investigated the spatial patterns of microfaunal and aquatic plant propagule bank communities within a wetland complex on the forested floodplain of a temperate Australian river system that had recently been completely inundated and dried again. Microfaunal emergence and aquatic plant germination were examined at the wetland complex spatial scale by incubating sediment samples collected from ten sites, randomly distributed within a 30 km 2 area of floodplain. Spatial (northing, easting and elevation) and environmental variables [commence-to-flow (CTF), %clay, %silt and %moisture] were also examined at each site to assist in describing the spatial patterns of the propagule banks across the floodplain. It was predicted that the microfaunal and aquatic plant propagule bank communities would be homogeneously distributed at the wetland complex scale in response to the recent widespread flooding. In contrast to our prediction, microfaunal and plant propagule bank communities varied among most sites, with this variation best explained by location (northing) and elevation (which was related to site CTF). This suggests that microfaunal and plant propagule bank communities are heterogeneously distributed in forested floodplain systems, even following widespread flooding events.

show abstract

“…Hydrodynamic phenomena that develop both at the free surface and in the water column are crucial for seed deposition but are very difficult to estimate in real channels because they depend on several factors. Seeds also interact with channel microscale features, such as the density of the living or dead vegetation (Chambert & James, ; Defina & Peruzzo, ; O'Donnell, Fryirs, & Leishman, ), the channel morphology (Merritt & Wohl, ; Soomers et al, ), and the presence of hydraulic structures (Merritt & Wohl, ). Due to the high number of interacting factors, their variability along channels (Groves, Williams, Caley, Norris, & Caitcheon, ), and the inherent difficulties in assessing some of them for an entire channel, the models for predicting water‐dispersed kernels lack accuracy.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the long‐distance dispersal of Johnsongrass (Sorghum halepense) in a vegetated irrigation channel

Rudi

Bailly

Belaud

et al. 2018

River Research & Apps

View full text Add to dashboard Cite

Hydrochorous dispersal may play a major role in the propagation of weeds such as Sorghum halepense (Johnsongrass). However, the long-distance dispersal of this weed via agricultural intermittent channel networks, such as irrigation channels, has been poorly studied. In this study, we focused on a seed dispersal kernel obtained after an irrigation event in a vegetated channel. The main objectives of the study were to highlight the specificities of irrigation channels in relation to seed transport and investigate hydraulic factors and microscale channel features associated with the deposition of seeds along the channel. Our results showed that despite very different flow and morphological conditions compared with natural waterways, seeds of Johnsongrass were able to travel hundred meters at the scale of one irrigation event. This is likely due to the floating ability of more than 50% of the Johnsongrass seeds. A Regression Tree algorithm, which explained 72% of seed deposition variability, showed the importance of the channel features such as the width of the section and the hydraulic structures, sluice gates and culvert, to explain the patterns of seed deposition. A complex role of the emergent vegetation was highlighted. The results suggest that a threshold of vegetation density should be reached to enhance seed deposition. The results indicate that the spread of existing Johnsongrass populations could be limited by preserving existing hydraulic structures or maintaining areas where the density of terrestrial vegetation is sufficient to enhance seed retention downstream.

show abstract

Can the sedimentological and morphological structure of rivers be used to predict characteristics of riparian seed banks?

Cited by 4 publications

References 67 publications

Simulating the effect of environmental flow duration on seedling emergence from riparian seed banks of the Upper Hunter River, New South Wales

Simulating the effect of environmental flow duration on seedling emergence from riparian seed banks of the Upper Hunter River, New South Wales

Spatial variability of aquatic plant and microfaunal seed and egg bank communities within a forested floodplain system of a temperate Australian river

Characterization of the long‐distance dispersal of Johnsongrass (Sorghum halepense) in a vegetated irrigation channel

Contact Info

Product

Resources

About