Browsing All Posts filed under »disturbance«

Simplifying urban stream assessment

December 21, 2017

0

Urban streams experience high levels of stormwater runoff and channel erosion, and represent a significant challenge for ecological restoration.  Nevertheless, it’s generally agreed that urban stream restoration should aim to mimic the natural (pre-development) flow regime as closely as possible.  It’s been proposed that ecologically important aspects of flow can be used as a basis […]

Invasive waterplants: be prepared

December 21, 2017

0

Investigators from Europe, the USA and New Zealand recently authored a comprehensive review of methods for the management of invasive freshwater plants.   As well as describing options for mechanical, biological and chemical control, the review includes information on relevant biology, management costs, the effects of management on freshwater ecosystems, and the post-management restoration of native […]

Deforestation means defishation

December 21, 2017

0

The impacts of tropical deforestation on terrestrial biodiversity are well known but only a few studies have considered the impacts of deforestation on freshwater systems.  Such effects are likely to be significant, given the importance of riparian vegetation as a source of nutrients and the high abundances of fish in tropical floodplain forests.  In a […]

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

September 25, 2017

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

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 […]

Restoration and invertebrates: Reappraising stream condition indicators

September 25, 2017

Comments Off on Restoration and invertebrates: Reappraising stream condition indicators

In degraded rivers and stream systems, the replanting of riparian vegetation is a common restoration activity, partly because increases in shading, nutrient interception and litter fall are expected to provide food and habitat benefits for aquatic communities. Changed habitat conditions should be reflected in indices of stream condition, such as those based on macroinvertebrate richness. […]

Lateral thinking on riverbank erosion

September 25, 2017

Comments Off on Lateral thinking on riverbank erosion

Although bank erosion is often thought of as problem that has to be addressed through engineered stabilization, the lateral migration of meandering streams is a natural mechanism that redistributes channel sediment and maintains habitat diversity. New riparian zones are formed as sediment is deposited on the inside of bends and colonised by vegetation.  Meandering creates […]

Coarse, shallow and wooden… but useful nonetheless

June 19, 2017

Comments Off on Coarse, shallow and wooden… but useful nonetheless

Coarse woody debris (CWD) derived from shoreline trees provides an important, spatially complex habitat and a food source for lake-dwelling organisms. Here are some interesting facts about lake CWD, taken from a recent review paper: In the absence of the physical action of flowing water, CWD breaks down more slowly in lakes than in streams. […]