Large mammals helped create park-like Europe
Danish researchers have demonstrated that large grazers and browsers of the past – wild cattle, bison and even straight-tusked elephants – created a mosaic of varied landscapes consisting of closed and semi-closed forests and parkland in prehistoric Europe. Their study appears in the current Proceedings of the National Academy of Sciences.
They found that beetles associated with the dung of large animals were much more common in Europe 110,000 to 132,000 years ago than in later prehistoric times.
“Large animals in high numbers were an integral part of nature in prehistoric times. ... The proportion and number of the wild large animals declined after the appearance of modern man. As a result of this, the countryside developed into predominantly dense forest that was first cleared when humans began to use the land for agriculture,” said Jens-Christian Svenning of Denmark’s Aarhus University.
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“An important way to create more self-managing ecosystems with a high level of biodiversity is to make room for large herbivores in the European landscape. They would create and maintain a varied vegetation in temperate ecosystems, and thereby ensure the basis for a high level of biodiversity,” senior scientist Rasmus Ejrnæs said. au.dk
Bright lights, better space veggies
Exposing leafy vegetables grown during spaceflight to a few bright pulses of light daily could increase the amount of eye-protecting nutrients produced by the plants, according to a study by researchers at the University of Colorado at Boulder.
One of the concerns for astronauts during future extended spaceflights will be the onslaught of eye-damaging radiation they’ll be exposed to. But astronauts should be able to mitigate that by eating plants that contain carotenoids, especially zeaxanthin, which is known to promote eye health.
Zeaxanthin could be ingested as a supplement, but there is evidence that human bodies are better at absorbing carotenoids from whole foods, such as green leafy vegetables.
Using Arabidopsis – also called rockcress, a flowering plant related to cabbage and mustard – the team demonstrated that a few pulses of bright light on a daily basis spurred the plants to begin making zeaxanthin in preparation for an expected excess of sunlight. colorado.edu/news
More ice-free days in Arctic
The ice-free season across the Arctic is getting longer by five days per decade, according to new research. New analysis of satellite data shows the Arctic Ocean absorbing ever more of the sun’s energy in summer, leading to an ever later appearance of sea ice in the autumn. In some regions, autumn freeze-up is occurring up to 11 days per decade later than it used to.
The research, published in a forthcoming issue of the journal Geophysical Research Letters, has implications for tracking climate change, as well as having practical applications for shipping and the resource industry in the arctic regions.
“The extent of sea ice in the Arctic has been declining for the last four decades,” said Julienne Stroeve, a member of the research team and a climatologist and professor of polar observation at Britain’s University College London, “and the timing of when melt begins and ends has a large impact on the amount if ice lost each summer. With the Arctic region becoming more accessible for long periods of time, there is a growing need for improved prediction of when the ice retreats and reforms in winter.” ucl.ac.uk