Browsing All Posts filed under »microbial«

The net effect: caddis flies and streambed flow

March 26, 2022

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The beds of streams are dynamic interfaces where water, nutrients and living organisms move between surface and sub-surface environments, and streambed permeability has a significant influence on processes such as nitrogen cycling and organic matter decomposition.  Although the physics of streambed exchange are well understood, interactions between physical and biological processes have received relatively little […]

Water flow through the beds of streams

December 14, 2021

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The permeability of saturated sediments at the bottom of streams, where surface water and groundwater can mix, has a strong influence on the exchange of mass and energy across the sediment-water interface.  Streambed permeability depends mainly on sediment properties such as pore networks and the size and sorting of particles, and can vary greatly, even […]

Key wetland species deliver most ecosystem services

September 28, 2021

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There’s a lot of evidence that in ecosystems such as grasslands and forests, biodiversity is positively related to productivity and to the efficiency of nutrient recycling and decomposition.   On this basis it can be argued that the loss of biodiversity is likely to damage the delivery of ecosystem services.  However, in the case of wetlands, […]

Earthquakes and groundwater

September 28, 2021

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Studies have shown that earthquake activity can change the chemistry of nearby groundwater reserves – for example, strong increases in chlorides and sulphates in groundwater were recorded in the period before and after the Kobe earthquake of 1995.  Such changes can alter the communities of organisms living in the aquifer and lead to the extinction […]

Crustaceans control the flow of groundwater

December 16, 2020

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Aquifers are an essential source of water for human needs and groundwater is the world’s most extracted raw material.   The capacity of aquifers to store and transport water critically depends on their hydraulic properties, which also have a strong influence on communities of underground lifeforms, including microbes, micro- and macro-invertebrates and fish.  Evidence is now […]

Soils as a guide to wetland condition

March 31, 2020

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Because wetlands provide valuable ecosystem services but are vulnerable to human impacts, increasing efforts have been made to develop indicators of wetland condition.  Wetland ecosystems are normally described by reference to three core dimensions, namely hydrology, biological communities and soils, but the most poorly developed condition indices are those based on soils, which don’t feature […]

Valuable real estate: old timber is more attractive

December 17, 2019

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Woody debris that falls into lakes and streams from shoreline trees supports aquatic food webs by providing food, shelter and egg-laying surfaces for invertebrate animals and fish. Submerged woody material gradually decomposes under the influence of microbial action and burrowing animals, and the decay process softens the wood and creates pits and grooves on its […]

Life between the sand grains

September 22, 2019

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Meiofauna are among the smallest creatures in existence, being defined as animals 44-500 microns in size.  They live in bottom sediments, where sand grains are “home” and a few square centimetres are “regions”.  They are a diverse group and include members of a number of phyla.  Although they’re an important part of aquatic food chains, […]

Early warnings of algal blooms

June 28, 2019

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Algal blooms are becoming more frequent in surface waters and have the capacity to disrupt significant ecosystem services, such as the provision of safe drinking water, irrigation, fisheries and recreation.  If bloom outbreaks can be predicted, preventative action may be taken in good time.  With this possibility in  mind, ecologists sampled two small (<3 ha) […]

Chemical signatures for plankton species

June 28, 2019

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Planktonic crustaceans feed on a wide variety of phytoplankton and bacteria.  Dietary differences between zooplankton species are difficult to define because their food organisms are so small, and this limits our understanding of how zooplankton diversity affects species coexistence and ecosystem processes.  However, a promising solution to this problem is to describe dietary differences in […]