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 […]

How the terrestrial landscape affects aquatic dispersal

June 19, 2017

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How does the surrounding terrestrial landscape affect the dispersal of pond-dwelling organisms? Although some studies suggest that small aquatic crustaceans can disperse efficiently across a range of intervening environments, other work has pointed to dispersal limitation, especially over large distances.  Czech researchers examined the passive dispersal of microcrustaceans (cladocerans, copepods, and ostracods) by comparing communities […]

How big is a food patch?

June 19, 2017

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Most studies of food patch choice by foraging animals have assumed that the patches in question are separate and well-defined. However, in many cases, predators feed in continuous habitats without obvious, discrete patches, and researchers are forced to choose an arbitrary spatial scale when calculating prey densities and interpreting the impacts of predators. An important […]

Dealing with river complexity

March 27, 2017

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Hydromorphology is a relatively new field that deals with the structure of hydrological systems and changes in their form over time. Many such changes are influenced by human-induced pressures. Realistic attempts to conceptualize hydromorphological forms and processes reflect the fact that rivers are complex multidimensional systems with longitudinal, lateral, vertical and temporal components, as well […]

How fish negotiate culverts

March 27, 2017

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While culverts are designed to facilitate the movement of water by allowing it to flow under roads or other obstructions, they can place physiological and/or behavioural restrictions on the movements of fish. Although several studies have considered the implications of culvert design for fish passage, surprisingly few have tried to identify the factors that influence […]

Herbivory is important in freshwater systems

March 27, 2017

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Until the 1990s it was believed that, in the main, freshwater and marine plants were connected to aquatic food webs only indirectly, through the breakdown of decaying vegetation by decomposers. However, over the last two decades there’s been a growing realisation that the activities of aquatic herbivores in consuming plants and channeling the derived nutrients […]

Stocking up on threatened amphibians

March 27, 2017

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Zoos have an important role to play in helping to conserve globally threatened species and building public awareness of biodiversity issues. Following massive declines in recent decades, amphibians are now one of the most vulnerable animal groups, with over 40% of all amphibian species classified as threatened. Despite this collapse, relatively few threatened amphibians are […]