Historically, lakes have been perceived as contributors to carbon dioxide emissions; however, recent research indicates they may function as carbon sinks. Research conducted by Uppsala University indicates that lake shorelines sequester more carbon than previously estimated, underscoring the necessity of including these littoral zones in assessments of the continental carbon balance. The littoral zones of lakes are typically bordered by aquatic plants, which are among the fastest-growing flora globally. They absorb significant quantities of carbon from the atmosphere, while substantial…
A spectacular phenomenon
This theme issue of Philosophical Transactions A (a Royal Society journal) deals with the phenomenon of ball lightning, a rarely seen and slow-moving luminous phenomenon usually associated with thunderstorms. A collection of previously unpublished sightings is presented, including close-up encounters describing the detailed internal structure of the balls. Many of these observations are from scientifically or technically trained people, probably doubling the n
Urban wildlife may not use green corridors.
Green corridors do little to aid wildlife, say UK ecologists. Their discovery that isolated wild ground contains just as many plant species as do patches linked by continuous greenery casts doubt on current conservation priorities.
“The proportion of organisms that use [wildlife corridors] is exceedingly small,” says botanist Mark Hill of the Centre for Ecology and Hydrology in Monks Wood. Only vertebrates seem to benefit, he says.
A solar slump may have chilled the Northern Hemisphere.
The flickering sun may cause rapid climate change, according to a new comparison of climate records. A 200-year cold snap 10, 300 years ago seems to have coincided with a passing slump in the sun’s activity 1 .
Svante Bjorck of Lund University in Sweden and colleagues looked at sediments in Lake Starvatn on the Faroe Islands and in the Norwegian Sea, the width of growth rings in ancient German pine trees
Residual heat from volcanic activity may be causing a river of ice to flow in Greenland, a new study indicates. Geologists have found that the region directly above a stream of relatively fast moving ice is thinner than a simple model of glacier change would predict. This observation, described in a report published today in the journal Science, may help researchers pin down the contribution ice sheets have made to sea level changes.
Glaciers are built up from layers of fused snow that spr
Researchers at Plant Research International in the Netherlands have achieved a breakthrough in the development of chrysanthemums with resistance to thrips, bringing the ecological cultivation of chrysanthemums a step closer. This is the conclusion of the thesis with which Seetharam Annadana, a Plant Research International guest member of staff from India, recently obtained his doctorate at Wageningen University. Annadana developed new techniques which make possible the genetic modification of two th
Most climate change research has focused on gradual changes, such as the processes by which emissions of greenhouse gases lead to warming of the planet.
But new evidence shows that periods of gradual change in Earth’s past were punctuated by episodes of abrupt change, including temperature changes of about 10 degrees Celsius, or 18 degrees Fahrenheit, in only a decade in some places.
Severe floods and droughts also marked periods of abrupt change.
A new report from the Nati
American Geophysical Society Meeting, San Francisco, December 2001
Pressure system secrets could help long range forecasts.
The rise in levels of greenhouse gases has halted an oscillation of air pressures over the Arctic, bringing warmer, wetter winters to Northern Europe, Siberia and Alaska. The shift could get worse with increasing CO2 emissions, delegates heard this week at the American Geophysical Union meeting in San Francisco, California.
The trend is unlikel
In 1998, Paul F. Hoffman and Daniel P. Schrag at Harvard University put forth a chilling description of earth’s climate some 650 million years ago. Their theory, dubbed snowball earth, held that between 750 million and 580 million years ago, ice repeatedly enveloped our planet, coating the seas from pole to pole and killing off early life almost completely. During the past few years, the idea has stirred up a great deal of debate. And new data published in the December issue of Geology only furt
Keeping parks pretty means tailoring the trees to their source of water.
Irrigation water recycled from sewage can damage many plant species, new research has found 1 . The results show that landscape architects should tailor their choice of plants to the type of water they will receive.
Dale Devitt of the University of Nevada at Reno and colleagues began studying the effects of different water sources on plants after reports that ’reuse’ water had damaged tr
The question of which forces control terrestrial ecosystems lies at the heart of a long-standing debate among ecologists. One theory, the so-called bottom-up theory, suggests that plant defense mechanisms exert control by limiting food availability for herbivores. Top-down theorists, however, suggest that predators limit the numbers of herbivores and hence their impact on the vegetation. Now new findings in the current issue of the journal Science that describe animal communities isolated for 15 year
Mount Vesuvius, the volcano most famous for blanketing the towns of Pompei and Herculaneum with lava and debris in 79 A.D., may be sitting atop a reservoir of magma that covers more than 400 square kilometers, a new study suggests. The finding, reported in the current issue of the journal Science by a group of Italian and French scientists, may lead to more accurate monitoring of the area surrounding the volcano.
Building on previous work that suggested the presence of a magma zone underne
New catalyst means greener paper is not pulp fiction.
Pollution from paper production could be cut, say US chemists, with a new way of refining wood pulp 1 . But the process must go through the mill before it can convert industry.
During paper production, gluey wood component lignin is stripped out to leave stringy cellulose. The harsh chemicals used create environmental pollutants, such as toxic and long-lasting chlorinated compounds.
A new chemical
Mosquitoes’ evolve rapidly in response to global warming.
Mosquitoes are holing up later as winters get warmer, US ecologists have shown. This is the first genetic adaptation to global warming to be identified. Less flexible animals could face extinction, they warn.
The North American mosquito Wyeomyia smithii uses shortening day length to judge when to bed down for the winter. Modern mozzies wait nine days more than their ancestors did in 1972, William Bradshaw and Christin
Water trapped for millions of years gives a glimpse of oceans’ turbulent past.
Drops of sea water entombed within salt crystals millions of years ago are giving researchers a glimpse of ancient oceans. The water, trapped during evaporation, reveals that the seas have seen large chemical changes during their history.
“The consensus had been that sea-water chemistry hadn’t changed that much over the past 600 million years,” says geochemist Juske Horita of Oak Ridge National La
Half a century of thinning ice leaves Greenland’s future looking wet.
There is new evidence that the Greenland ice pack is in retreat. The finding may be a foretaste of still more rapid melting, and in turn, rising sea levels.
The ice sheet over northwest Greenland has thinned by 10-15 cm a year over the past 40 years, two scientists calculate 1 . The trend indicates “a significant long-term thinning”, says one, Niels Reeh, of the Technical University of
With a weather monitoring network a new model could predict coastal floods in Bangladesh. A new model should help forecast the massive floods to which the northern coast of Bangladesh is prone 1 . In principle, the model can predict the heights and arrival times of the huge waves that cyclones cause, and so could improve the planning of sea defences. The effectiveness of the model will depend on the availability of accurate, timely and detailed meteorological data, ca