Long-distance dispersal (LDD) of wind-borne organisms is central to quantifying risk for transgenic escape and gene flow, control of pests and invasions, persistence in fragmented landscapes and species co-existence; yet LDD remains notoriously difficult to define, measure and model. This difficulty has shaped the current paradigm that the frequency and spatial extent of LDD events are almost impossible to predict.
In the September issue of The American Naturalist, G. G. Katul (Duke University) and colleagues introduce a mechanistic analytical model for estimating dispersal kernels of seeds and their escape probability from the canopy, using simplifications to well-established turbulent transport theories. The model parameters--wind statistics, seed release height, and seed terminal velocity--are clearly interpretable and can easily be measured independently of dispersal data, as compared to the synthetic parameters of equivalent phenomenological analytical models that necessitate dispersal data for calibration.
A necessary condition for LDD, seed uplifting and escape from the canopy, along with other key attributes of the dispersal kernel, were reproduced well by the model. To meet the increasing demand for proper evaluation of ecological risk reduction by employing less subjective and more transparent methods, mathematical models should make their assumptions explicit and should realistically incorporate the key biological and physical processes underlying environmental changes.
Value from wastewater
16.08.2017 | Hochschule Landshut
Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
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