Many types of vegetation have more or less ground cover and recruitment of new individuals often occurs only in temporarily empty patches or gaps. Ever since Watt’s (1947) Presidential address to the BES, the Journal of Ecology has been publishing the results of investigations into the importance of processes in such gaps in the determination of community structure. Three recent papers from Norway, the UK and the USA (Vandvik 2004, Turnbull et al. 2004 and Ewanchuk and Bertness, 2004, respectively - all in volume 92, issue 1), report different approaches to addressing this issue.
Working in salt marches in New England, USA, Ewanchuk and Bertness show that the recolonisation of gaps generated by ice scour is slow and driven by competitive processes. Parts of these marshes consist of patches of sparse, but species-rich, vegetation dominated by non-grassy herbaceous plants (forbs). These areas were found to be inhospitable to plants which grew well nearby, suggesting physical limitation at the local scale, while the forbs were restricted to these patches by interspecific competition.
Vandvik showed that revegetation of gaps in subalpine grassland in Norway depended upon gap size and grassland age along a gradient of secondary succession. The degree to which individual species depended on gaps for regeneration changed as the disturbance regime altered during succession, with such gap phase processes being important for a majority (74%) of species in the system. Taking a more mechanistic and small-scale approach, Turnbull et al. also found that most species of annuals in a limestone grassland showed a preference for colonizing unvegetated patches. Through a series of exacting and careful measurements of individual plants and neighbourhood modeling they derived individual-level competition coefficients for seven annuals. Seed size was found to be a key trait determining both competitive and colonizing ability.
Becky Allen | alfa
Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
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