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
Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)
Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Computer scientists use wave packet theory to develop realistic, detailed water wave simulations in real time. Their results will be presented at this year’s SIGGRAPH conference.
Think about the last time you were at a lake, river, or the ocean. Remember the ripples of the water, the waves crashing against the rocks, the wake following...
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
29.06.2017 | Physics and Astronomy
29.06.2017 | Life Sciences
29.06.2017 | Health and Medicine