Browsing All Posts filed under »flow«

How land plants control water plants

July 5, 2018

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While terrestrial ecosystems rely on rainfall infiltration for their water supply, streamside ecosystems rely on the accumulation of surface and subsurface runoff in the riparian zone and the channel network.  Rainfall that manages to percolate through the soil profile recharges aquifers, and these  sustain streamflow and riparian and aquatic ecosystems during dry periods.  Focussing on […]

How delayed is the flow-on effect?

July 5, 2018

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It’s generally accepted that river flows have a major influence on the structure of stream communities, but what’s the lag time from river discharge to community expression?  This question is particularly relevant for headwater streams that are vulnerable to seasonal drying or the over-extraction of groundwater, where changes in flow often lead to successional changes […]

Restoration and invertebrates: Build it and at least some of them will come

September 25, 2017

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It’s commonly assumed that the biodiversity of a disturbed ecosystem can be improved by restoring its original physical and chemical conditions. According to this “Field of Dreams” view (“build it and they will come”), ecosystem recovery occurs through the recolonization activities of lost species.  While a lot of river restoration is founded on Field of […]

Recognising uncertainty in hydro modelling

September 25, 2017

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Because climate warming is thought to be a major cause of long-term shifts in storm runoff and the frequency of extreme floods and droughts, reliable projections of future hydrological changes are essential for the informed management of water resources.  However, hydrological modelling involves dealing with a wide range of uncertainties, and so far these uncertainties […]

Erasing the boundaries

June 19, 2017

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The new discipline of ecohydraulics considers the effects of water movement in aquatic ecosystems and blends ideas and techniques from aquatic ecology and engineering hydraulics. A central challenge for ecohydraulics is to reconcile differences between hydraulic engineers and ecologists in terms of the spatial and/or temporal scale of the processes that they tend to deal […]

Planting vegetation to stop stream bank erosion: where’s the evidence?

June 19, 2017

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Increased rates of stream bank erosion and sediment movement in disturbed catchments have been attributed to changes in catchment hydrology caused by land clearing, channel modification, the trampling activities of livestock and the removal of riparian vegetation. Given that these effects are human-induced, it’s commonly assumed that they can also be reversed by human intervention, […]

Human impacts on ecological connectivity

June 19, 2017

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Ecological connectivity – the exchange of organisms between habitat patches or subpopulations – has an influence on many key processes, including population dynamics, nutrient flux, disease transmission, species invasions, food-web interactions, genetic isolation and the maintenance of biodiversity. A recent study reviewed ways in which graph theory has been used to investigate how human activities […]